WO2009154191A1 - Semiconductor light emitting element, electrode and manufacturing method for the element, and lamp - Google Patents

Semiconductor light emitting element, electrode and manufacturing method for the element, and lamp Download PDF

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Publication number
WO2009154191A1
WO2009154191A1 PCT/JP2009/060926 JP2009060926W WO2009154191A1 WO 2009154191 A1 WO2009154191 A1 WO 2009154191A1 JP 2009060926 W JP2009060926 W JP 2009060926W WO 2009154191 A1 WO2009154191 A1 WO 2009154191A1
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Prior art keywords
layer
electrode
bonding
light emitting
semiconductor light
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PCT/JP2009/060926
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French (fr)
Japanese (ja)
Inventor
大介 平岩
健彦 岡部
玲美 大庭
宗隆 渡邉
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昭和電工株式会社
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Priority claimed from JP2008199802A external-priority patent/JP5178383B2/en
Priority claimed from JP2008228133A external-priority patent/JP2010062425A/en
Priority claimed from JP2009133177A external-priority patent/JP5515431B2/en
Application filed by 昭和電工株式会社 filed Critical 昭和電工株式会社
Priority to CN200980131958.1A priority Critical patent/CN102124574B/en
Priority to US12/999,530 priority patent/US8569735B2/en
Publication of WO2009154191A1 publication Critical patent/WO2009154191A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/36—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the electrodes
    • H01L33/40—Materials therefor
    • H01L33/405—Reflective materials
    • H—ELECTRICITY
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    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42—Wire connectors; Manufacturing methods related thereto
    • H01L2224/44—Structure, shape, material or disposition of the wire connectors prior to the connecting process
    • H01L2224/45—Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
    • H01L2224/45001—Core members of the connector
    • H01L2224/45099—Material
    • H01L2224/451—Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof
    • H01L2224/45138—Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof the principal constituent melting at a temperature of greater than or equal to 950°C and less than 1550°C
    • H01L2224/45144—Gold (Au) as principal constituent
    • H—ELECTRICITY
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    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42—Wire connectors; Manufacturing methods related thereto
    • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/4805—Shape
    • H01L2224/4809—Loop shape
    • H01L2224/48091—Arched
    • H—ELECTRICITY
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    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42—Wire connectors; Manufacturing methods related thereto
    • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/481—Disposition
    • H01L2224/48151—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/48221—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/48245—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being metallic
    • H01L2224/48247—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being metallic connecting the wire to a bond pad of the item
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42—Wire connectors; Manufacturing methods related thereto
    • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/481—Disposition
    • H01L2224/48151—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/48221—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/48245—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being metallic
    • H01L2224/48257—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being metallic connecting the wire to a die pad of the item
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42—Wire connectors; Manufacturing methods related thereto
    • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/49—Structure, shape, material or disposition of the wire connectors after the connecting process of a plurality of wire connectors
    • H01L2224/491—Disposition
    • H01L2224/49105—Connecting at different heights
    • H01L2224/49107—Connecting at different heights on the semiconductor or solid-state body
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    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/73—Means for bonding being of different types provided for in two or more of groups H01L2224/10, H01L2224/18, H01L2224/26, H01L2224/34, H01L2224/42, H01L2224/50, H01L2224/63, H01L2224/71
    • H01L2224/732—Location after the connecting process
    • H01L2224/73251—Location after the connecting process on different surfaces
    • H01L2224/73265—Layer and wire connectors
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    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/15—Details of package parts other than the semiconductor or other solid state devices to be connected
    • H01L2924/181—Encapsulation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2933/00—Details relating to devices covered by the group H01L33/00 but not provided for in its subgroups
    • H01L2933/0008—Processes
    • H01L2933/0016—Processes relating to electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
    • H01L33/26—Materials of the light emitting region
    • H01L33/30—Materials of the light emitting region containing only elements of group III and group V of the periodic system
    • H01L33/32—Materials of the light emitting region containing only elements of group III and group V of the periodic system containing nitrogen
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/36—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the electrodes
    • H01L33/38—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the electrodes with a particular shape

Definitions

  • the present invention relates to a semiconductor light emitting device, an electrode thereof, a manufacturing method thereof, and a lamp, and more particularly to a semiconductor light emitting device including an electrode having improved bonding properties and corrosion resistance, an electrode thereof, a manufacturing method thereof, and a lamp.
  • the present application was filed on June 16, 2008, Japanese Patent Application No. 2008-157248 filed in Japan, August 1, 2008, Japanese Patent Application No. 2008-199802 filed in Japan, September 5, 2008 Priority is claimed based on Japanese Patent Application No. 2008-228133 filed in Japan and Japanese Patent Application No. 2009-133177 filed in Japan on June 2, 2009, the contents of which are incorporated herein by reference.
  • GaN-based compound semiconductors have attracted attention as semiconductor materials for short wavelength light emitting devices.
  • GaN-based compound semiconductors include sapphire single crystals, various oxides and III-V compounds as substrates, and metalorganic vapor phase chemical reaction method (MOCVD method) and molecular beam epitaxy method (MBE method). It is formed by thin film forming means such as.
  • a thin film made of a GaN compound semiconductor has a characteristic that current diffusion in the in-plane direction of the thin film is small. Furthermore, the p-type GaN-based compound semiconductor has a characteristic that the resistivity is higher than that of the n-type GaN-based compound semiconductor. For this reason, there is almost no spread of current in the in-plane direction of the p-type semiconductor layer simply by stacking a p-type electrode made of metal on the surface of the p-type semiconductor layer.
  • a laminated semiconductor layer having an LED structure including an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer is formed, and a p-type semiconductor layer is formed on the uppermost p-type semiconductor layer.
  • the electrode is formed, only the portion of the light emitting layer located immediately below the p-type electrode emits light. For this reason, in order to take out the light emitted immediately below the p-type electrode to the outside of the semiconductor light emitting device, it is necessary to make the p-type electrode transparent so that the p-type electrode can transmit the emitted light. is there.
  • Patent Document 1 discloses a method using a metal thin film of about several tens of nanometers. Ni and Au are stacked on a p-type semiconductor layer of several tens of nanometers each as a p-type electrode, and then in an oxygen atmosphere. It has been proposed to perform alloying treatment by heating to simultaneously promote the reduction in resistance of the p-type semiconductor layer and to form a p-type electrode having translucency and ohmic properties.
  • a translucent electrode made of a metal oxide such as ITO or an ohmic electrode made of a metal thin film of about several tens of nm has a problem that it is difficult to use the electrode itself as a bonding pad electrode because the strength of the electrode itself is low. was there.
  • a p-type electrode such as a translucent electrode made of a metal oxide such as ITO or an ohmic electrode made of a metal thin film of about several tens of nm.
  • a pad electrode is arranged.
  • this bonding pad electrode is a metal material having a certain thickness, it has no translucency and blocks light emitted through the translucent p-type electrode. There is a problem that it cannot be taken out.
  • Patent Document 2 discloses a method of laminating a bonding pad electrode made of a reflective film such as Ag or Al on a p-type electrode.
  • a metal oxide such as ITO is used as the p-type electrode and a reflective film such as Ag or Al is used as the bonding pad electrode, bonding is attempted when bonding wires or the like are bonded to the bonding pad electrode.
  • the bonding pad electrode could not withstand the tensile stress during wire bonding, and the pad electrode would peel off. In some cases, the bonding pad electrode is peeled off from the translucent electrode, thereby reducing the yield in manufacturing a lamp using the bonding pad electrode. Further, the conventional semiconductor light emitting device has insufficient corrosion resistance and has been required to improve the corrosion resistance.
  • the present invention has been made in view of the above circumstances, and a semiconductor light emitting device including an electrode having excellent bonding properties and corrosion resistance, a manufacturing method thereof, and a lamp that is excellent in corrosion resistance and can be manufactured with high yield using the same.
  • the purpose is to provide.
  • the present invention employs the following configuration. That is, (1) A substrate, a laminated semiconductor layer including a light emitting layer formed on the substrate, one electrode formed on an upper surface of the laminated semiconductor layer, and a portion of the laminated semiconductor layer being cut away The other electrode formed on the exposed surface of the semiconductor layer, wherein at least one of the one electrode or the other electrode covers the bonding layer and the bonding layer.
  • the bonding pad electrode is formed such that the maximum thickness of the bonding pad electrode is larger than the maximum thickness of the bonding layer, and the bonding pad electrode includes one or more layers.
  • a semiconductor light emitting element characterized in that an inclined surface is formed on the outer periphery of the pad electrode so that the film thickness gradually decreases toward the outer periphery.
  • the bonding layer is selected from the group consisting of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh, Ir, and Ni.
  • the semiconductor light-emitting device according to (1) comprising a thin film having a maximum thickness in the range of 10 to 1000 mm.
  • the bonding pad electrode is made of a bonding layer made of Au, Al, or an alloy containing any of these metals, and the bonding layer is a thin film having a maximum thickness in the range of 50 nm to 2000 nm.
  • the bonding pad electrode includes a metal reflection layer formed so as to cover the bonding layer and a bonding layer formed so as to cover the metal reflection layer, and the metal reflection layer includes Ag, Al. , Ru, Rh, Pd, Os, Ir, Pt, Ti, or an alloy containing any of these metals, and having a maximum thickness in the range of 20 nm to 3000 nm
  • the semiconductor light emitting device according to any one of (1) to (3).
  • a translucent electrode is formed between the one electrode and the upper surface of the stacked semiconductor layer or between the other electrode and the exposed surface of the semiconductor layer, and the translucent electrode is In , Zn, Al, Ga, Ti, Bi, Mg, W, Ce, Sn, a light-transmitting material selected from the group consisting of any one of zinc sulfide and chromium sulfide
  • the semiconductor light-emitting device according to any one of (1) to (4), wherein the semiconductor light-emitting device is made of a conductive material.
  • the stacked semiconductor layer is formed by stacking an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer in this order from the substrate side, and the light-emitting layer has a multiple quantum well structure (1)
  • the semiconductor light emitting device according to any one of to (5).
  • the semiconductor light emitting element according to any one of (1) to (7), a first frame in which the semiconductor light emitting element is disposed and wire-bonded to one electrode of the semiconductor light emitting element, and the semiconductor A lamp comprising: a second frame wire-bonded to the other electrode of the light-emitting element; and a mold formed surrounding the semiconductor light-emitting element.
  • a substrate, a laminated semiconductor layer including a light emitting layer formed on the substrate, one electrode formed on an upper surface of the laminated semiconductor layer, and a part of the laminated semiconductor layer are cut away
  • the bonding layer is selected from the group consisting of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh, Ir, and Ni.
  • the bonding pad electrode is made of a bonding layer made of Au, Al, or an alloy containing any of these metals, and the bonding layer is a thin film having a maximum thickness in the range of 50 nm to 2000 nm.
  • the bonding pad electrode includes a metal reflection layer formed so as to cover the bonding layer and a bonding layer formed so as to cover the metal reflection layer, and the metal reflection layer includes Ag, Al. , Ru, Rh, Pd, Os, Ir, Pt, Ti, or an alloy containing any of these metals, and having a maximum thickness in the range of 20 nm to 3000 nm (9)
  • the electrode for a semiconductor light-emitting device according to any one of (9) to (11).
  • a translucent electrode is formed between the one electrode and the upper surface of the stacked semiconductor layer or between the other electrode and the exposed surface of the semiconductor layer, and the translucent electrode is In , Zn, Al, Ga, Ti, Bi, Mg, W, Ce, Sn, a light-transmitting material selected from the group consisting of any one of zinc sulfide and chromium sulfide (9)
  • a bonding layer is formed on the upper surface of the stacked semiconductor layer or the exposed surface of the semiconductor layer, and then covers the bonding layer
  • a semiconductor light emitting device comprising a step of forming a bonding pad electrode having a maximum thickness compared to the maximum thickness of the bonding layer to form one electrode or the other electrode. The method of production.
  • a metal reflective layer having a maximum thickness compared to the maximum thickness of the bonding layer is formed so as to cover the bonding layer; Thereafter, a bonding layer having a maximum thickness compared to the maximum thickness of the metal reflection layer is formed so as to cover the metal reflection layer, thereby forming one electrode or the other electrode.
  • the method includes a step of forming a protective film on the upper surface of the translucent electrode and the upper surface of the laminated semiconductor layer or on the exposed surface of the semiconductor layer before the mask forming step (14).
  • a substrate, a laminated semiconductor layer including a light emitting layer formed on the substrate, one electrode formed on an upper surface of the laminated semiconductor layer, and a part of the laminated semiconductor layer are cut away.
  • a semiconductor light emitting element comprising:
  • the bonding layer is selected from the group consisting of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh, Ir, and Ni.
  • the bonding pad electrode includes a metal reflection layer formed so as to cover the bonding layer and a bonding layer formed so as to cover the metal reflection layer, and the metal reflection layer includes Ag, Al.
  • the translucent electrode is a conductive oxide, zinc sulfide, or chromium sulfide containing any one of In, Zn, Al, Ga, Ti, Bi, Mg, W, Ce, Sn, and Ni.
  • an edge protection film is formed which covers an outer edge of the bonding pad electrode and exposes a part of the bonding pad electrode.
  • a transparent protective film is formed so as to cover a region where the bonding recess is not formed on the upper surface of the translucent electrode, and the outer edge portion of the bonding layer and the outer edge portion of the bonding pad electrode are The semiconductor light-emitting device according to any one of (19) to (24), which is disposed on a transparent protective film.
  • the stacked semiconductor layer is formed by stacking an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer in this order from the substrate side, and the light-emitting layer has a multiple quantum well structure (19)
  • a substrate, a laminated semiconductor layer including a light emitting layer formed on the substrate, one electrode formed on an upper surface of the laminated semiconductor layer, and a part of the laminated semiconductor layer are cut away.
  • a method of manufacturing a semiconductor light emitting device comprising the other electrode formed on the exposed surface of the semiconductor layer, wherein the step of manufacturing at least one of the one electrode or the other electrode comprises a translucent electrode Forming a mask having an opening having an inner wall shape whose cross-sectional area gradually increases toward the bottom surface on the upper surface of the translucent electrode, and the transparent electrode exposed from the opening.
  • a substrate, a laminated semiconductor layer including a light emitting layer formed on the substrate, one electrode formed on an upper surface of the laminated semiconductor layer, and a part of the laminated semiconductor layer are cut away.
  • a semiconductor light emitting device comprising the other electrode formed on the exposed surface of the semiconductor layer, wherein either one or both of the one electrode and the other electrode is the upper surface of the stacked semiconductor layer or the semiconductor layer
  • a semiconductor light emitting device comprising: an ohmic bonding layer formed on an exposed surface; a bonding layer formed on the ohmic bonding layer; and a bonding pad electrode formed so as to cover the bonding layer.
  • the bonding layer is selected from the group consisting of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh, Ir, and Ni.
  • the bonding pad electrode includes a metal reflection layer formed so as to cover the bonding layer and a bonding layer formed so as to cover the metal reflection layer, and the metal reflection layer includes Ag, Al. , Ru, Rh, Pd, Os, Ir, Pt, Ti, or an alloy containing any one of these metals.
  • the ohmic junction layer is any one of a conductive oxide, zinc sulfide, or chromium sulfide containing any one of In, Zn, Al, Ga, Ti, Bi, Mg, W, Ce, Sn, and Ni.
  • the laminated semiconductor layer is formed by laminating an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer in this order from the substrate side, and the light emitting layer has a multiple quantum well structure (32)
  • the semiconductor light-emitting device according to any one of to (37).
  • the semiconductor light emitting element according to any one of (32) to (38), a first frame in which the semiconductor light emitting element is disposed and wire-bonded to one electrode of the semiconductor light emitting element,
  • a lamp comprising: a second frame wire-bonded to the other electrode of the semiconductor light emitting element; and a mold formed surrounding the semiconductor light emitting element.
  • a semiconductor light emitting device including an electrode with improved bondability and corrosion resistance, a manufacturing method thereof, and a lamp.
  • one electrode includes a bonding layer and a bonding pad electrode formed so as to cover the bonding layer, and the maximum thickness of the bonding pad electrode is thicker than the maximum thickness of the bonding layer.
  • the inclined surface is formed of one or two or more layers and the outer peripheral side of the bonding layer and the bonding pad electrode is gradually thinned, the external air or moisture bonding layer is formed. Can be prevented, the corrosion resistance of the bonding layer can be improved, and the lifetime of the semiconductor light emitting device can be extended.
  • the bonding layer is made of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh, Ir, and Ni. Since it is composed of at least one element selected from the group consisting of a thin film having a maximum thickness in the range of 10 to 1000 mm, the bonding between the translucent electrode and the bonding pad electrode is improved. Further, an electrode that does not peel off due to tensile stress during bonding of the bonding wires can be obtained.
  • the semiconductor light emitting device of the present invention is composed of a bonding layer made of Au, Al, or an alloy containing any of these metals, and the maximum thickness of the bonding layer is a thin film having a range of 50 nm to 2000 nm, a bonding pad By improving the bondability of wire bonding to the electrode, it is possible to obtain an electrode that does not peel off due to tensile stress during bonding wire bonding.
  • the semiconductor light emitting device of the present invention comprises a metal reflective layer in which the bonding pad electrode is formed so as to cover the bonding layer, and a bonding layer formed so as to cover the metal reflective layer, and the metal reflective layer 117 is made of Ag. , Al, Ru, Rh, Pd, Os, Ir, Pt, Ti, or an alloy containing any of these metals, and a maximum thickness of 20 nm to 3000 nm. Therefore, it is possible to improve the bondability and corrosion resistance of the electrodes and improve the light emission characteristics of the semiconductor light emitting device.
  • the electrode for a semiconductor light emitting device of the present invention comprises a bonding layer and a bonding pad electrode formed so as to cover the bonding layer, at least one of the one electrode and the other electrode, and the maximum thickness of the bonding pad electrode. However, it is formed thicker than the maximum thickness of the bonding layer, and is composed of one or more layers, and the film thickness gradually decreases toward the outer peripheral side at the outer peripheral portion of the bonding layer and the bonding pad electrode, respectively. Since it is the structure in which the inclined surface is formed, it can be set as the electrode which improved bondability and corrosion resistance.
  • the electrode for a semiconductor light emitting device of the present invention can be used for applications other than the light emitting device.
  • the electrode forming step forms an inversely tapered mask on the upper surface of the laminated semiconductor layer, then forms a bonding layer on the upper surface of the laminated semiconductor layer, and then covers the bonding layer In this way, the bonding pad electrode having a maximum thickness compared to the maximum thickness of the bonding layer is formed, and one electrode is formed.
  • the outer peripheral side of the bonding layer and the bonding pad electrode is gradually thinner on the outer peripheral side.
  • the semiconductor light-emitting device of the present invention includes a translucent electrode in which at least one of one electrode or the other electrode has a bonding recess on an upper surface, a bonding layer formed so as to cover the bonding recess, and the bonding And a bonding pad electrode formed so as to cover the layer and having an inclined surface with a gradually decreasing thickness toward the outside at the outer peripheral portion.
  • the bonding pad electrode having the inclined surface whose thickness is gradually reduced toward the outside is formed so as to cover the bonding layer.
  • the contact area between the outer peripheral portion and the lower surface of the outer peripheral portion of the bonding pad electrode is sufficiently ensured, and excellent bondability is obtained, and between the outer peripheral portion of the bonding pad electrode and the lower surface thereof, Air and moisture can be effectively prevented from entering the bonding layer from the outside, and excellent corrosion resistance can be obtained.
  • the lamp of the present invention includes the semiconductor light emitting device of the present invention provided with electrodes having excellent bonding properties and corrosion resistance, it can be manufactured with a high yield and has excellent corrosion resistance.
  • the step of manufacturing at least one of one electrode or the other electrode includes a step of forming a translucent electrode, and an upper surface of the translucent electrode.
  • the method includes a step of forming a bonding pad electrode having an inclined surface that gradually becomes thinner on the outer peripheral portion and a step of removing the mask, the half of the present invention including an electrode having excellent bonding properties and corrosion resistance is provided.
  • the body light-emitting element can be easily manufactured.
  • either one or both of one electrode and the other electrode is formed on the upper surface of the laminated semiconductor layer or the exposed surface of the semiconductor layer, and on the ohmic junction layer. Since the bonding layer formed and a bonding pad electrode formed so as to cover the bonding layer, one or both of the one electrode and the other electrode are formed on the ohmic bonding layer. The bonding layer and the bonding pad electrode formed so as to cover the bonding layer provide a sufficiently high bonding force between the ohmic bonding layer and the bonding pad electrode, and thus have excellent bonding properties. An electrode is provided.
  • the lamp of the present invention includes the semiconductor light emitting device of the present invention having one electrode having excellent bonding properties and the other electrode, the tensile force when bonding a bonding wire to the bonding pad electrode is obtained. It is possible to prevent the bonding pad electrode from being peeled off from the translucent electrode due to the stress, and it is possible to manufacture with high yield.
  • both the step of manufacturing the one electrode and the step of manufacturing the other electrode are performed in an ohmic contact on the upper surface of the stacked semiconductor layer or the exposed surface of the semiconductor layer.
  • the pad forming step and the heat treatment step in the step of manufacturing the one electrode and the step of manufacturing the other electrode are performed simultaneously, And the other electrode are formed at the same time, and can be manufactured efficiently and easily as compared with the case where one electrode and the other electrode are formed separately.
  • FIG. 14 is a view showing an example of the semiconductor light emitting device of the present invention, and is a schematic sectional view of the semiconductor light emitting device.
  • FIG. 15 is a schematic plan view of the semiconductor light emitting device shown in FIG. 16 is an enlarged schematic cross-sectional view of a laminated semiconductor layer constituting the semiconductor light emitting device shown in FIG.
  • FIG. 17 is an enlarged schematic cross-sectional view of a p-type electrode constituting the semiconductor light emitting device shown in FIG. FIG.
  • FIG. 18 is an example of a process diagram for explaining a process of manufacturing the p-type electrode, and is an enlarged cross-sectional view showing only a part of a region where the p-type electrode is manufactured.
  • FIG. 19 is an example of a process diagram for explaining the manufacturing process of the mask shown in FIG. 18B, and is an enlarged cross-sectional view showing only a region where one p-type electrode is formed.
  • FIG. 20 is a diagram showing another example of the semiconductor light emitting device of the present invention, and is a schematic cross-sectional view of the semiconductor light emitting device.
  • FIG. 21 is a view showing another example of the semiconductor light emitting device of the present invention, and is an enlarged schematic cross-sectional view of a p-type electrode constituting the semiconductor light emitting device.
  • FIG. 22 is a view showing another example of the semiconductor light emitting device of the present invention, and is a schematic sectional view of the semiconductor light emitting device.
  • FIG. 23 is a process diagram for describing a process of manufacturing a p-type electrode, and is an enlarged cross-sectional view illustrating only a part of a region where the p-type electrode is manufactured. It is a cross-sectional schematic diagram which shows an example of the lamp
  • FIG. 26 is a diagram showing an example of the semiconductor light emitting device of the present invention, and is a schematic sectional view of the semiconductor light emitting device.
  • 27 is a schematic plan view of the semiconductor light emitting device shown in FIG.
  • FIG. 28 is an enlarged schematic cross-sectional view of a laminated semiconductor layer constituting the semiconductor light emitting device shown in FIG. 29A and 29B are diagrams for explaining the electrodes constituting the semiconductor light emitting device shown in FIG. 26.
  • FIG. 29A is an enlarged schematic cross-sectional view of a p-type electrode
  • FIG. 29B is an n-type. It is an expanded section schematic diagram of an electrode.
  • FIG. 30 is a process diagram for explaining a process of manufacturing the p-type electrode, and is an enlarged cross-sectional view showing only a part of a region where the p-type electrode 111 is manufactured.
  • FIG. 31 is a process diagram for explaining a manufacturing process of a mask formed when manufacturing an n-type electrode and a p-type electrode, and is an enlarged sectional view showing only a region where one p-type electrode is formed. It is.
  • FIG. 32 is a process diagram for explaining a process of manufacturing the n-type electrode, and is an enlarged cross-sectional view showing only a part of a region where the n-type electrode is manufactured.
  • FIG. 30 is a process diagram for explaining a process of manufacturing the p-type electrode, and is an enlarged cross-sectional view showing only a part of a region where the n-type electrode is manufactured.
  • FIG. 33 is a schematic diagram for explaining a process of manufacturing the n-type electrode 108 and the p-type electrode 111.
  • FIG. 34 is a diagram showing another example of the semiconductor light emitting device of the present invention, and is a schematic cross-sectional view of the semiconductor light emitting device.
  • FIG. 35 is a diagram showing another example of the semiconductor light emitting device of the present invention, and is a schematic cross-sectional view of the semiconductor light emitting device.
  • FIG. 36 is a process diagram for explaining a process of manufacturing the n-type electrode 128 and the p-type electrode 111b, and is an enlarged cross-sectional view showing only a part of a region where the p-type electrode 111b is manufactured. It is.
  • FIG. 37 is a schematic sectional view showing an example of the lamp of the present invention.
  • FIG. 1 is a schematic cross-sectional view of the semiconductor light emitting device according to an embodiment of the present invention
  • FIG. 3 is a schematic diagram
  • FIG. 3 is a schematic cross-sectional view of a laminated semiconductor layer constituting the semiconductor light-emitting device
  • FIG. 4 is an enlarged schematic cross-sectional view of a p-type electrode constituting the semiconductor light-emitting device shown in FIG.
  • a semiconductor light emitting device 1 As shown in FIG. 1, in a semiconductor light emitting device 1 according to an embodiment of the present invention, a laminated semiconductor layer 20 including a buffer layer 102, a base layer 103, and a light emitting layer 105 is sequentially laminated on a substrate 101.
  • a translucent electrode 109 is stacked on the upper surface 106 c of the semiconductor layer 20, and one (one conductivity type) electrode 111 is formed on a part of the upper surface 109 c of the translucent electrode 109.
  • the other (other conductivity type) electrode 108 is formed on the semiconductor layer exposed surface 104c formed by cutting out part of the semiconductor layer, and is schematically configured.
  • the stacked semiconductor layer 20 is configured by stacking an n-type semiconductor layer 104, a light emitting layer 105, and a p-type semiconductor layer 106 in this order from the substrate 101 side. A portion of the upper surface 109 c of the translucent electrode 109 where the one conductive type electrode 111 is not formed is covered with the protective film 10.
  • One conductive type electrode 111 is formed by laminating a bonding layer 110 and a bonding pad electrode 120 including a metal reflection layer 117 and a bonding layer 119. In the following description, one electrode 111 is a p-type electrode and the other electrode 108 is an n-type electrode.
  • the semiconductor light emitting device 1 applies a voltage between a p-type electrode (one conduction type electrode) 111 and an n-type electrode (another conduction type electrode) 108 to pass a current.
  • the face-up mount is configured so that light emission can be obtained from the light-emitting layer 105 and taken out from the side on which the bonding pad electrode 120 (reflective bonding pad electrode) having a function of reflecting light from the light-emitting layer 105 is formed.
  • Type light emitting element is configured so that light emission can be obtained from the light-emitting layer 105 and taken out from the side on which the bonding pad electrode 120 (reflective bonding pad electrode) having a function of reflecting light from the light-emitting layer 105 is formed.
  • a part of light emitted from the light emitting layer 105 is transmitted through the translucent electrode 109 and the bonding layer 110, reflected by the bonding pad electrode 120 at the interface between the bonding layer 110 and the bonding pad electrode 120, and again, the laminated semiconductor layer 20. Introduced inside. Then, the light reintroduced into the laminated semiconductor layer 20 is further transmitted and reflected, and then extracted outside the semiconductor light emitting element 1 from a location other than the bonding pad electrode 120 formation region.
  • the substrate 101 of the semiconductor light-emitting element 1 according to the embodiment of the present invention is not particularly limited as long as a group III nitride semiconductor crystal is epitaxially grown on the surface, and various substrates can be selected and used.
  • various substrates can be selected and used.
  • a substrate made of lanthanum strontium oxide aluminum tantalum, strontium titanium oxide, titanium oxide, hafnium, tungsten, molybdenum, or the like can be used.
  • the buffer layer 102 is preferably formed on the c-plane of sapphire.
  • an oxide substrate or a metal substrate that is known to cause chemical modification by contact with ammonia at a high temperature can be used, and the buffer layer 102 can be formed without using ammonia.
  • the buffer layer 102 In the method using ammonia, when the base layer 103 is formed to form the n-type semiconductor layer 104 described later, the buffer layer 102 also functions as a coat layer. These methods are effective in preventing chemical alteration of the substrate 101.
  • the buffer layer 102 is formed by a sputtering method, the temperature of the substrate 101 can be kept low. Therefore, even when the substrate 101 made of a material that decomposes at a high temperature is used, the substrate 101 is damaged. Each layer can be formed on the substrate without giving.
  • the stacked semiconductor layer 20 of the semiconductor light emitting device 1 is a layer made of, for example, a group III nitride semiconductor. As shown in FIG. The light emitting layer 105 and the p-type semiconductor layer 106 are stacked in this order. Further, as shown in FIG. 3, each of the n-type semiconductor layer 104, the light emitting layer 105, and the p-type semiconductor layer 106 may be composed of a plurality of semiconductor layers. Furthermore, the laminated semiconductor layer 20 may be further referred to as including the base layer 103 and the buffer layer 102.
  • the stacked semiconductor layer 20 can be formed with a good crystallinity when formed by the MOCVD method, but by optimizing the conditions also by the sputtering method, a semiconductor layer having a crystallinity superior to that of the MOCVD method can be formed. .
  • description will be made sequentially.
  • Buffer layer (intermediate layer) 102 is preferably made of polycrystalline Al x Ga 1-x N (0 ⁇ x ⁇ 1), the single crystal Al x Ga 1-x N of (0 ⁇ x ⁇ 1) Those are more preferred.
  • the buffer layer 102 can be formed by MOCVD as described above, but may be formed by sputtering. When the buffer layer 102 is formed by sputtering, the temperature of the substrate 101 can be kept low when the buffer layer 102 is formed. Therefore, even when the substrate 101 made of a material having a property of decomposing at high temperature is used, Each layer can be formed on the substrate 101 without damaging the substrate 101, which is preferable.
  • the buffer layer 102 can be, for example, made of polycrystalline Al x Ga 1-x N (0 ⁇ x ⁇ 1) and having a thickness of 0.01 to 0.5 ⁇ m.
  • the buffer layer 102 may not sufficiently obtain an effect of reducing the difference in lattice constant between the substrate 101 and the base layer 103.
  • the thickness of the buffer layer 102 exceeds 0.5 ⁇ m, although the function as the buffer layer 102 is not changed, the film formation processing time of the buffer layer 102 becomes long, and the productivity may be reduced. There is.
  • the buffer layer 102 has a function of relaxing the difference in lattice constant between the substrate 101 and the base layer 103 and facilitating formation of a C-axis oriented single crystal layer on the (0001) C plane of the substrate 101. Therefore, when the single crystal base layer 103 is stacked over the buffer layer 102, the base layer 103 with higher crystallinity can be stacked. In the present invention, it is preferable to perform the buffer layer forming step, but it may not be performed.
  • the buffer layer 102 may have a hexagonal crystal structure made of a group III nitride semiconductor. Further, the group III nitride semiconductor crystals forming the buffer layer 102 may have a single crystal structure, and those having a single crystal structure are preferably used. By controlling the growth conditions, the group III nitride semiconductor crystal grows not only in the upward direction but also in the in-plane direction to form a single crystal structure. Therefore, by controlling the film formation conditions of the buffer layer 102, the buffer layer 102 made of a crystal of a group III nitride semiconductor having a single crystal structure can be obtained.
  • the buffer function of the buffer layer 102 is effective, so that the group III nitride semiconductor formed thereon has a good orientation. It becomes a crystalline film having the property and crystallinity.
  • the group III nitride semiconductor crystal forming the buffer layer 102 can be formed into a columnar crystal (polycrystal) having a texture based on a hexagonal column by controlling the film forming conditions.
  • the columnar crystal formed of the texture here is a crystal that is separated by forming a grain boundary between adjacent crystal grains, and is itself a columnar shape as a longitudinal sectional shape.
  • the film thickness of the underlayer 103 is preferably 0.1 ⁇ m or more, more preferably 0.5 ⁇ m or more, and most preferably 1 ⁇ m or more.
  • An Al x Ga 1-x N layer with good crystallinity is more easily obtained when the thickness is increased.
  • the base layer 103 is preferably not doped with impurities. However, when p-type or n-type conductivity is required, acceptor impurities or donor impurities can be added.
  • the n-type semiconductor layer 104 is preferably composed of an n-contact layer 104a and an n-clad layer 104b.
  • the n contact layer 104a can also serve as the n clad layer 104b.
  • the above-described base layer may be included in the n-type semiconductor layer 104.
  • the n contact layer 104a is a layer for providing an n-type electrode.
  • the n contact layer 104a is preferably composed of an Al x Ga 1-x N layer (0 ⁇ x ⁇ 1, preferably 0 ⁇ x ⁇ 0.5, more preferably 0 ⁇ x ⁇ 0.1). .
  • n-type impurity is doped into the n-contact layer 104a, an n-type impurity 1 ⁇ 10 17 ⁇ 1 ⁇ 10 20 / cm 3, preferably 1 ⁇ 10 18 ⁇ 1 ⁇ 10 19 / cm If it contains in the density
  • an n-type impurity For example, Si, Ge, Sn, etc. are mentioned, Preferably Si and Ge are mentioned.
  • the thickness of the n contact layer 104a is preferably 0.5 to 5 ⁇ m, and more preferably set to a range of 1 to 3 ⁇ m. When the film thickness of the n-contact layer 104a is in the above range, the semiconductor crystallinity is maintained well.
  • n-clad layer 104b is preferably provided between the n-contact layer 104a and the light-emitting layer 105.
  • the n-clad layer 104b is a layer that injects carriers into the light emitting layer 105 and confines carriers.
  • the n-clad layer 104b can be formed of AlGaN, GaN, GaInN, or the like. Alternatively, a heterojunction of these structures or a superlattice structure in which a plurality of layers are stacked may be used. Needless to say, when the n-cladding layer 104b is formed of GaInN, it is desirable to make it larger than the band gap of GaInN of the light emitting layer 105.
  • the film thickness of the n-clad layer 104b is not particularly limited, but is preferably 0.005 to 0.5 ⁇ m, and more preferably 0.005 to 0.1 ⁇ m.
  • the n-type doping concentration of the n-clad layer 104b is preferably 1 ⁇ 10 17 to 1 ⁇ 10 20 / cm 3 , more preferably 1 ⁇ 10 18 to 1 ⁇ 10 19 / cm 3 . A doping concentration within this range is preferable in terms of maintaining good crystallinity and reducing the operating voltage of the device.
  • n-cladding layer 104b is a layer including a superlattice structure, a detailed illustration is omitted, but an n-side first layer made of a group III nitride semiconductor having a thickness of 100 angstroms or less and A structure in which an n-side second layer made of a group III nitride semiconductor having a composition different from that of the n-side first layer and having a thickness of 100 angstroms or less is stacked may be included.
  • the n-clad layer 104b may include a structure in which n-side first layers and n-side second layers are alternately and repeatedly stacked. Preferably, either the n-side first layer or the n-side second layer is in contact with the active layer (light-emitting layer 105).
  • the n-side first layer and the n-side second layer as described above are, for example, AlGaN-based Al (which may be simply referred to as AlGaN), GaInN-based (which may be simply described as GaInN) including In,
  • the composition may be GaN.
  • the n-side first layer and the n-side second layer are composed of an alternating GaInN / GaN structure, an AlGaN / GaN alternating structure, an GaInN / AlGaN alternating structure, and a GaInN / GaInN alternating structure having a different composition (“ The description of “differing composition” means that each elemental composition ratio is different, and the same applies hereinafter), and may be an AlGaN / AlGaN alternating structure having a different composition.
  • the n-side first layer and the n-side second layer are preferably GaInN / GaInN having different GaInN / GaN structures or different compositions.
  • the superlattice layers of the n-side first layer and the n-side second layer are each preferably 60 angstroms or less, more preferably 40 angstroms or less, and each in the range of 10 angstroms to 40 angstroms. Most preferred. If the thicknesses of the n-side first layer and the n-side second layer forming the superlattice layer are more than 100 angstroms, crystal defects are likely to occur, which is not preferable.
  • the n-side first layer and the n-side second layer may each have a doped structure, or a combination of a doped structure and an undoped structure.
  • the impurity to be doped conventionally known impurities can be applied to the material composition without any limitation.
  • the n-side superlattice multilayer film as described above may be manufactured while doping is appropriately turned on and off even if the composition represented by GaInN, AlGaN, and GaN is the same.
  • a light emitting layer 105 As the light emitting layer 105 stacked on the n-type semiconductor layer 104, there is a light emitting layer 105 having a single quantum well structure or a multiple quantum well structure.
  • a well layer 105b having a quantum well structure as shown in FIG. 3 a group III nitride semiconductor layer made of Ga 1-y In y N (0 ⁇ y ⁇ 0.4) is usually used.
  • the film thickness of the well layer 105b can be set to a film thickness that can provide a quantum effect, for example, 1 to 10 nm, and preferably 2 to 6 nm in terms of light emission output.
  • the Ga 1-y In y N is used as the well layer 105b, and Al z Ga 1-z N (0 ⁇ z ⁇ 0) having a larger band gap energy than the well layer 105b. .3) is defined as a barrier layer 105a.
  • the well layer 105b and the barrier layer 105a may or may not be doped with impurities by design.
  • the p-type semiconductor layer 106 is generally composed of a p-clad layer 106a and a p-contact layer 106b.
  • the p contact layer 106b can also serve as the p clad layer 106a.
  • the p-cladding layer 106a is a layer for confining carriers in the light emitting layer 105 and injecting carriers.
  • the p-cladding layer 106a is not particularly limited as long as it has a composition larger than the band gap energy of the light-emitting layer 105 and can confine carriers in the light-emitting layer 105, but is preferably Al x Ga 1-x N (0 ⁇ x ⁇ 0.4).
  • the thickness of the p-clad layer 106a is not particularly limited, but is preferably 1 to 400 nm, more preferably 5 to 100 nm.
  • the p-type doping concentration of the p-clad layer 106a is preferably 1 ⁇ 10 18 to 1 ⁇ 10 21 / cm 3 , more preferably 1 ⁇ 10 19 to 1 ⁇ 10 20 / cm 3 .
  • the p-clad layer 106a may have a superlattice structure in which a plurality of layers are stacked.
  • the p-cladding layer 106a is a layer including a superlattice structure
  • a detailed illustration is omitted, but a p-side first layer made of a group III nitride semiconductor having a thickness of 100 angstroms or less and A structure in which a p-side second layer made of a group III nitride semiconductor having a composition different from that of the p-side first layer and having a film thickness of 100 angstroms or less is stacked may be included. Further, it may include a structure in which p-side first layers and p-side second layers are alternately and repeatedly stacked.
  • the p-side first layer and the p-side second layer as described above may have different compositions, for example, any composition of AlGaN, GaInN, or GaN, or an GaInN / GaN alternating structure, AlGaN.
  • An alternating structure of / GaN or an alternating structure of GaInN / AlGaN may be used.
  • the p-side first layer and the p-side second layer preferably have an AlGaN / AlGaN or AlGaN / GaN alternating structure.
  • the superlattice layers of the p-side first layer and the p-side second layer are each preferably 60 angstroms or less, more preferably 40 angstroms or less, and each in the range of 10 angstroms to 40 angstroms. Is most preferred. If the thickness of the p-side first layer and the p-side second layer forming the superlattice layer exceeds 100 angstroms, it becomes a layer containing many crystal defects and the like, which is not preferable.
  • the p-side first layer and the p-side second layer may each have a doped structure, or a combination of a doped structure and an undoped structure.
  • the impurity to be doped conventionally known impurities can be applied to the material composition without any limitation.
  • Mg is suitable as an impurity.
  • the p-side superlattice multilayer film as described above may be manufactured while doping is appropriately turned on and off even if the composition represented by GaInN, AlGaN, and GaN is the same.
  • the p contact layer 106b is a layer for providing a positive electrode.
  • the p contact layer 106b is preferably Al x Ga 1-x N (0 ⁇ x ⁇ 0.4).
  • Al composition is in the above range, it is preferable in terms of maintaining good crystallinity and good ohmic contact with the p ohmic electrode.
  • a p-type impurity (dopant) is contained at a concentration of 1 ⁇ 10 18 to 1 ⁇ 10 21 / cm 3 , preferably 5 ⁇ 10 19 to 5 ⁇ 10 20 / cm 3 , good ohmic contact can be obtained. It is preferable in terms of maintenance, prevention of crack generation, and good crystallinity.
  • the thickness of the p contact layer 106b is not particularly limited, but is preferably 0.01 to 0.5 ⁇ m, more preferably 0.05 to 0.2 ⁇ m. When the film thickness of the p-contact layer 106b is within this range, it is preferable in terms of light emission output.
  • an n-type electrode 108 is formed on the exposed surface 104 c of the n-type semiconductor layer 104.
  • the light emitting layer 105 and a part of the p-semiconductor layer 106 are cut and removed by means such as etching to expose the n-contact layer of the n-type semiconductor layer 104,
  • An n-type electrode 108 is formed on the exposed surface 104c.
  • the n-type electrode 108 has a circular shape when seen in a plan view, but is not limited to such a shape, and may have an arbitrary shape such as a polygonal shape. Further, the n-type electrode 108 also serves as a bonding pad, and can be connected to a bonding wire.
  • various known compositions and structures can be provided by conventional means well known in this technical field.
  • the n-type electrode 108 is also formed with a bonding layer having an inclined surface that gradually decreases in thickness toward the outer peripheral side, and a bonding pad electrode is formed so as to cover this. It may be formed. At this time, a permeable electrode or a protective film may be formed. Thereby, it is possible to prevent external air or moisture from entering the bonding layer of the n-type electrode 108, improve the corrosion resistance of the bonding layer, and extend the lifetime of the semiconductor light emitting device.
  • a translucent electrode 109 is stacked on the p-type semiconductor layer 106.
  • the translucent electrode 109 is formed on the upper surface 106c of the p-type semiconductor layer 106, part of which has been removed by means such as etching to form the n-type electrode 108.
  • it is formed so as to cover almost the entire surface, it is not limited to such a shape, and it may be formed in a lattice shape or a tree shape with a gap.
  • the structure of the translucent electrode 109 can be used without any limitation, including a conventionally known structure.
  • the translucent electrode 109 preferably has a small contact resistance with the p-type semiconductor layer 106.
  • the light-transmitting electrode 109 is preferably excellent in light transmittance. Furthermore, in order to diffuse current uniformly over the entire surface of the p-type semiconductor layer 106, the translucent electrode 109 preferably has excellent conductivity.
  • the constituent material of the translucent electrode 109 is a conductive oxide, sulfide, including any one of In, Zn, Al, Ga, Ti, Bi, Mg, W, Ce, Sn, and Ni.
  • a translucent conductive material selected from the group consisting of either zinc or chromium sulfide is preferred.
  • the translucent electrode 109 can be formed. Further, after forming the translucent electrode 109, thermal annealing may be performed for the purpose of alloying or transparency, but it may not be performed.
  • a crystallized structure may be used, and in particular, a translucent electrode (for example, ITO or IZO) containing an In 2 O 3 crystal having a hexagonal crystal structure or a bixbite structure is used. It can be preferably used.
  • a translucent electrode for example, ITO or IZO
  • ITO or IZO In 2 O 3 crystal having a hexagonal crystal structure
  • IZO containing In 2 O 3 crystal having a hexagonal crystal structure it can be processed into a specific shape using an amorphous IZO film having excellent etching properties, and then heat treatment is performed. By transferring from an amorphous state to a structure including the crystal by, for example, an electrode having a light-transmitting property better than that of an amorphous IZO film.
  • the ZnO concentration in IZO is preferably 1 to 20% by mass, and more preferably 5 to 15% by mass. 10% by mass is particularly preferable.
  • the film thickness of the IZO film is preferably in the range of 35 nm to 10000 nm (10 ⁇ m) at which low specific resistance and high light transmittance can be obtained. Furthermore, from the viewpoint of production cost, the thickness of the IZO film is preferably 1000 nm (1 ⁇ m) or less.
  • the patterning of the IZO film is preferably performed before the heat treatment process described later.
  • the amorphous IZO film becomes a crystallized IZO film, which makes etching difficult compared to the amorphous IZO film.
  • the IZO film before heat treatment is in an amorphous state, it can be easily and accurately etched using a known etching solution (ITO-07N etching solution (manufactured by Kanto Chemical Co., Inc.)).
  • the amorphous IZO film may be etched using a dry etching apparatus. At this time, Cl 2 , SiCl 4 , BCl 3, or the like can be used as an etching gas.
  • IZO film in an amorphous state for example, and was heat-treated in 500 ° C. ⁇ 1000 ° C., comprising an IZO film and that includes In 2 O 3 crystal having a hexagonal crystal structure for controlling the condition, an In 2 O 3 crystal bixbyite structure
  • An IZO film can be formed. Since an IZO film containing an In 2 O 3 crystal having a hexagonal crystal structure is difficult to etch as described above, it is preferable to perform a heat treatment after the above-described etching treatment.
  • Heat treatment of the IZO film is preferably performed in an atmosphere containing no O 2, as the atmosphere containing no O 2, N, such as 2 atmosphere or an inert gas atmosphere, or such as N 2 inert gas and H 2 A mixed gas atmosphere or the like can be given, and it is desirable to use an N 2 atmosphere or a mixed gas atmosphere of N 2 and H 2 .
  • N such as 2 atmosphere or an inert gas atmosphere, or such as N 2 inert gas and H 2
  • N 2 atmosphere or an inert gas atmosphere such as N 2 inert gas and H 2
  • a mixed gas atmosphere or the like can be given, and it is desirable to use an N 2 atmosphere or a mixed gas atmosphere of N 2 and H 2 .
  • N such as 2 atmosphere or an inert gas atmosphere, or such as N 2 inert gas and H 2
  • a mixed gas atmosphere or the like can be given, and it is desirable to use an N 2 atmosphere or a mixed gas atmosphere of N 2 and H 2 .
  • the IZO film is crystallized into a
  • the IZO film When heat treatment is performed at a temperature lower than 500 ° C., the IZO film may not be sufficiently crystallized, and the light transmittance of the IZO film may not be sufficiently high. When heat treatment is performed at a temperature exceeding 1000 ° C., the IZO film is crystallized, but the light transmittance of the IZO film may not be sufficiently high. Further, when heat treatment is performed at a temperature exceeding 1000 ° C., the semiconductor layer under the IZO film may be deteriorated.
  • the crystal structure in the IZO film differs depending on the film formation conditions, heat treatment conditions, and the like.
  • the translucent electrode in terms of adhesiveness with the adhesive layer, is not limited to a material, but a crystalline material is preferable, and in particular, in the case of crystalline IZO, bixbite crystal. It may be IZO including an In 2 O 3 crystal having a structure, or IZO including an In 2 O 3 crystal having a hexagonal structure. In particular, IZO containing In 2 O 3 crystal having a hexagonal structure is preferable.
  • an IZO film crystallized by heat treatment has a better adhesion to the bonding layer 110 and the p-type semiconductor layer 106 than an amorphous IZO film, and thus is very effective in the embodiment of the present invention. It is.
  • ⁇ P-type electrode> 4 is an enlarged cross-sectional view of the p-type electrode 111 of the semiconductor light emitting device 1 according to the embodiment of the present invention shown in FIG.
  • the p-type electrode (one conductivity type electrode) 111 includes a translucent electrode 109, a bonding layer 110, and a bonding pad electrode 120, and is formed on the p-type semiconductor layer 106 and schematically. It is configured. Upper surface 109c of the transparent electrode 109 is covered by a protective film 10 made of SiO 2, a portion of the protective film 10 is being opened openings 10d formed, the upper surface of the transparent electrode 109 through the opening 10d Part of 109c is exposed.
  • the bonding layer 110 covers the upper surface 109c of the translucent electrode 109 exposed from the opening 10d with a substantially uniform film thickness, and the film thickness is increased on the outer peripheral side of the opening 10d. It is formed so as to cover the end portion 10c. In addition, an inclined surface 110c is formed on the outer peripheral portion 110d of the bonding layer 110 that covers the end portion 10c of the protective film 10 so that the film thickness gradually decreases toward the outer peripheral side.
  • the bonding pad electrode 120 includes a metal reflection layer 117 and a bonding layer 119 that are formed to be thicker than the maximum thickness of the bonding layer 110.
  • an inclined surface 119c is formed on the outer peripheral portion 120d of the bonding pad electrode 120 so that the film thickness gradually decreases toward the outer peripheral side.
  • An inclined surface 117c is formed on the outer peripheral portion of the metal reflective layer 117 so that the film thickness gradually decreases toward the outer peripheral side.
  • the metal reflective layer 117 is formed so as to cover the bonding layer 110.
  • the metal reflection layer 117 is formed so as to completely cover the leading edge of the inclined surface 110c of the bonding layer 110, that is, the boundary that forms the contour line when the bonding layer 110 is viewed in plan. .
  • the metal reflective layer 117 is formed so as to cover the bonding layer 110 and further extend to the outer peripheral side of the bonding layer 110, so any portion of the bonding layer 110 can be any metal reflective layer 117. It is possible to prevent exposure from below.
  • an inclined surface 119c is formed on the outer peripheral portion of the bonding layer 119 so that the film thickness gradually decreases toward the outer peripheral side.
  • the bonding layer 119 is formed so as to cover the metal reflective layer 117.
  • the bonding layer 119 is formed so as to completely cover the tip of the tip of the inclined surface 117c of the metal reflection layer 117, that is, the boundary that forms the contour line when the metal reflection layer 117 is viewed in plan. Yes. That is, since the bonding layer 119 is formed so as to cover the metal reflection layer 117 and project to the outer peripheral side of the metal reflection layer 117 when seen in a plan view, any portion of the metal reflection layer 117 can be bonded to the bonding layer. It is possible to prevent exposure from below 119.
  • the bonding layer 110 is formed with the inclined surface 110c that gradually decreases in thickness toward the outer peripheral side at the outer peripheral portion, and double-shielded from the outside by the metal reflective layer 117 and the bonding layer 119. Therefore, air or moisture outside the semiconductor light-emitting element 1 does not pass to the bonding layer 110 unless it passes through the bonding surface between the protective film 10 and the bonding layer 119 and the bonding surface between the protective film 10 and the metal reflective layer 117. The possibility that external air or moisture cannot enter the bonding layer 110 can be greatly reduced. As a result, the bonding layer 110 is not easily decomposed, and by improving the corrosion resistance of the bonding layer 110, the element lifetime of the semiconductor light emitting element can be extended.
  • the exposed upper surface 109c of the translucent electrode 109 is preferably a fresh surface from which impurities and defects are removed by wet etching. Thereby, the adhesiveness between the upper surface 109c of the translucent electrode 109 and the bonding layer 110 can be improved.
  • the bonding layer 110 shown in FIG. 1 is laminated between the translucent electrode 109 and the bonding pad electrode 120 in order to increase the bonding strength of the bonding pad electrode 120 to the translucent electrode 109.
  • the bonding layer 110 preferably has a light-transmitting property so that the light from the light-emitting layer 105 that is transmitted through the light-transmitting electrode 109 and irradiated onto the bonding pad electrode 120 is transmitted without loss.
  • the bonding layer 110 is at least selected from the group consisting of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh, Ir, and Ni. What consists of a kind of element is preferable. Thereby, joint strength and translucency can be exhibited simultaneously.
  • the bonding layer 110 is more preferably made of at least one element selected from the group consisting of Cr, Ti, W, Mo, Zr, Hf, Co, Rh, Ir, and Ni, and more preferably Cr, Ti, W, Mo. It is more preferable to use at least one element selected from the group consisting of Rh, Co, and Ni. In particular, by using a metal such as Cr, Ti, Mo, Ni, and Co, the bonding strength of the bonding pad electrode 120 to the translucent electrode 109 can be significantly increased.
  • the bonding layer 110 is preferably a thin film having a maximum thickness in the range of 10 to 400 mm. Thereby, the light from the light emitting layer 105 can be effectively transmitted without being blocked. In addition, when the maximum thickness is less than 10 mm, the strength of the bonding layer 110 is lowered, which is not preferable because the bonding strength of the bonding pad electrode 120 to the translucent electrode 109 is lowered.
  • the bonding pad electrode 120 is formed of a laminated body in which a metal reflective layer 117 and a bonding layer 119 are laminated in order from the translucent electrode 109 side.
  • the bonding pad electrode 120 may have a single-layer structure composed of only the metal reflective layer 117, and a barrier layer that enhances the strength of the entire bonding pad electrode 120 is inserted between the metal reflective layer 117 and the bonding layer 119. And it is good also as a three-layer structure.
  • the metal reflective layer 117 shown in FIG. 1 is preferably composed of a metal having high reflectance, and platinum group metals such as Ru, Rh, Pd, Os, Ir, and Pt, Al, Ag, Ti, and a small amount of these metals. It is more preferable to use an alloy including one kind. Thereby, the light from the light emitting layer 105 can be reflected effectively.
  • Al, Ag, Pt, and an alloy containing at least one of these metals are generally used as electrode materials, and are excellent in terms of easy availability and handling.
  • the metal reflective layer 117 is formed of a metal having a high reflectance, it is desirable that the maximum thickness is 20 to 3000 nm.
  • the metal reflection layer 117 is too thin, a sufficient reflection effect cannot be obtained. If it is too thick, there is no particular advantage, and only a long process time and material waste are caused. More desirably, the thickness is 50 to 1000 nm, and most desirably 100 to 500 nm.
  • the metal reflective layer 117 is in close contact with the bonding layer 110 in that the light from the light emitting layer 105 can be efficiently reflected and the bonding strength of the bonding pad electrode 120 can be increased. For this reason, in order for the bonding pad electrode 120 to obtain sufficient strength, the metal reflective layer 117 needs to be firmly bonded to the translucent electrode 109 through the bonding layer 110. At a minimum, a strength that does not cause peeling in the step of connecting the gold wire to the bonding pad by a general method is preferable. In particular, Rh, Pd, Ir, Pt, and an alloy containing at least one of these metals are preferably used as the metal reflective layer 117 in view of light reflectivity.
  • the reflectance of the bonding pad electrode 120 varies greatly depending on the constituent material of the metal reflective layer 117, but is preferably 60% or more. Further, it is preferably 80% or more, and more preferably 90% or more. The reflectance can be measured relatively easily with a spectrophotometer or the like. However, since the bonding pad electrode 120 itself has a small area, it is difficult to measure the reflectance. Therefore, a “dummy substrate” having a large area, for example, a glass substrate, is placed in the chamber when forming the bonding pad electrode, and at the same time, the same bonding pad electrode is formed on the dummy substrate and measured. it can.
  • the bonding pad electrode 120 can be made of only the above-described highly reflective metal. That is, the bonding pad electrode 120 may be composed only of the metal reflective layer 117. However, various types of structures using various materials are known as the bonding pad electrode 120, and even if the above-described metal reflective layer is newly provided on the semiconductor layer side (translucent electrode side) of these known ones. Alternatively, the lowermost layer on the semiconductor layer side of these known ones may be replaced with the above-described metal reflection layer.
  • the bonding layer 119 shown in FIG. 1 is preferably made of Au, Al, or an alloy containing at least one of these metals. Since Au and Al are metals that have good adhesion to gold balls that are often used as bonding balls, the use of Au, Al, or an alloy containing at least one of these metals improves adhesion to bonding wires. It can be excellent. Of these, Au is particularly desirable.
  • the maximum thickness of the bonding layer 119 is preferably in the range of 50 nm to 2000 nm, and more preferably 100 nm to 1500 nm. If it is too thin, the adhesion to the bonding ball will be poor, and if it is too thick, no particular advantage will be produced, and only the cost will increase.
  • the light directed toward the bonding pad electrode 120 is reflected by the metal reflective layer 117 on the lowermost surface (translucent electrode side surface) of the bonding pad electrode 120, and part of the light is scattered and travels in the lateral direction or the oblique direction.
  • the portion proceeds directly below the bonding pad electrode 120.
  • the light that is scattered and travels in the lateral direction or the oblique direction is extracted from the side surface of the semiconductor light emitting element 1 to the outside.
  • the light traveling in the direction immediately below the bonding pad electrode 120 is further scattered and reflected by the lower surface of the semiconductor light emitting device 1 and is externally transmitted through the side surface and the translucent electrode 109 (the portion where the bonding pad electrode does not exist). Is taken out.
  • the bonding pad electrode 120 can be formed anywhere as long as it is on the translucent electrode 109. For example, it may be formed at a position farthest from the n-type electrode 108 or may be formed at the center of the semiconductor light emitting device 1. However, if it is formed too close to the n-type electrode 108, a short circuit between the wires and between the balls occurs during bonding, which is not preferable. Further, the electrode area of the bonding pad electrode 120 is as large as possible, but the bonding operation is easy, but it prevents the light emission from being taken out. For example, covering an area that exceeds half the area of the chip surface hinders the extraction of light emission, and the output is significantly reduced.
  • the bonding work becomes difficult and the yield of the product is lowered.
  • it is preferably slightly larger than the diameter of the bonding ball, and generally has a circular shape with a diameter of 100 ⁇ m.
  • the same metal element may be incorporated, or a combination of different metal elements may be used.
  • the bonding pad electrode 120 may have a three-layer structure by inserting a barrier layer between the metal reflection layer 117 and the bonding layer 119.
  • the barrier layer has a role of enhancing the strength of the bonding pad electrode 120 as a whole, and is formed on the metal reflective layer of the bonding pad electrode 120, for example. For this reason, it is necessary to use a relatively strong metal material or to sufficiently increase the film thickness. Desirable materials are Ti, Cr or Al. Among these, Ti is desirable in terms of material strength.
  • the metal reflective layer 117 may also serve as the barrier layer.
  • a thick metal material having good reflectivity and mechanically strong it is not necessary to form a barrier layer.
  • the barrier layer is not always necessary.
  • the maximum thickness of the barrier layer is preferably 20 to 3000 nm. If the barrier layer is too thin, a sufficient strength strengthening effect cannot be obtained, and if it is too thick, no particular advantage is produced and only an increase in cost is caused. More desirably, the thickness is 50 to 1000 nm, and most desirably 100 to 500 nm.
  • FIG. 14 is a schematic cross-sectional view of the semiconductor light emitting device according to the embodiment of the present invention.
  • FIG. 16 is a schematic cross-sectional view of a laminated semiconductor layer constituting the semiconductor light-emitting element
  • FIG. 17 is an enlarged schematic cross-sectional view of a p-type electrode constituting the semiconductor light-emitting element shown in FIG. As shown in FIG.
  • the semiconductor light emitting device 1 includes a substrate 101, a laminated semiconductor layer 20 formed on the substrate 101, and a p-type electrode 111 ( One electrode) and an n-type electrode 108 (the other electrode) formed on the semiconductor layer exposed surface 104c formed by cutting out a part of the laminated semiconductor layer 20.
  • the laminated semiconductor layer 20 is obtained by laminating an n-type semiconductor layer 104, a light emitting layer 105, and a p-type semiconductor layer 106 in this order from the substrate 101 side.
  • the semiconductor light emitting device 1 of the present embodiment light emission is obtained from the light emitting layer 105 by applying a voltage between the p-type electrode 111 and the n-type electrode 108 and passing the current.
  • the semiconductor light emitting device 1 of the present embodiment is a face-up mount type light emitting device that extracts light from the side where the p-type electrode 111 is formed.
  • the semiconductor light emitting device of the seventh embodiment basically has a feature that the configuration in which the electrodes are installed on the upper surface of the laminated semiconductor layer 20 is different from that of the semiconductor light emitting device of the first embodiment. That is, in Embodiment 7, at least one of one electrode or the other electrode has a translucent electrode having a bonding recess on an upper surface, a bonding layer formed so as to cover the bonding recess, and the bonding There is provided a structure of a semiconductor light emitting device, comprising a bonding pad electrode formed so as to cover a layer and having an inclined surface formed on an outer peripheral portion with a gradually decreasing thickness toward the outside.
  • the configuration of the substrate constituting the semiconductor light emitting device and the laminated semiconductor layer having the light emitting layer can be basically configured in the same range as in the first embodiment.
  • a detailed description will be given to describe different features from the configuration of the semiconductor light emitting device of the first embodiment.
  • the p-type electrode 111 includes a translucent electrode 109, a bonding layer 110, and a bonding pad electrode 120.
  • a bonding recess 109 a is provided on the upper surface 109 c of the translucent electrode 109.
  • a transparent protective film 10 a is formed so as to cover the translucent electrode 109 in a region where the bonding recess 109 a is not formed on the upper surface 109 c of the translucent electrode 109.
  • the region where the bonding recess 109a is formed is an opening 10d in which a part of the transparent protective film 10a is opened.
  • a bonding layer 110 is formed on the bonding recess 109a exposed from the opening 10d so as to cover the bonding recess 109a, and a bonding pad electrode 120 is formed on the bonding layer 110 so as to cover the bonding layer 110.
  • the outer edge part of the joining layer 110 and the outer edge part of the bonding pad electrode 120 are arrange
  • the bonding pad electrode 120 includes an inclined surface 119c on the outer peripheral portion 120d whose thickness gradually decreases toward the outside.
  • the outer edge portion of the bonding pad electrode 120 is covered with the edge protection film 10b.
  • the translucent electrode 109 is provided on the upper surface 106c of the p-type semiconductor layer 106. As shown in FIG. 17, the upper surface 109c has a bonding recess 109a.
  • the depth of the bonding recess 109 a of the translucent electrode 109 is not particularly limited, but is preferably about 1/10 of the thickness of the translucent electrode 109.
  • the planar shape of the bonding recess 109a may be any shape such as a circular shape or a polygonal shape, and is not particularly limited. It is preferable that
  • the translucent electrode 109 is formed so as to cover almost the entire upper surface 106c of the p-type semiconductor layer 106 in plan view, but is limited to such a shape. Instead, it may be formed in a lattice shape or a tree shape with a gap. Further, the bonding recess 109 a of the translucent electrode 109 may be formed anywhere on the translucent electrode 109. For example, it may be formed at a position farthest from the n-type electrode 108 or may be formed at the center of the semiconductor light emitting device 1.
  • the bonding layer 110 is laminated between the translucent electrode 109 and the bonding pad electrode 120 in order to increase the bonding strength of the bonding pad electrode 120 to the translucent electrode 109. As shown in FIG. 17, the bonding layer 110 is continuously formed so as to cover the bonding recess 109a and the end portion 10c of the transparent protective film 10a. In the present embodiment, since the bonding layer 110 is embedded in the bonding recess 109a of the translucent electrode 109 and the opening 10d of the transparent protective film 10a, the translucent electrode 109 is formed. And a high bonding force between the bonding layer 110 can be obtained.
  • the thickness of the bonding layer 110 is substantially uniform on the inner wall surface of the bonding recess 109a of the translucent electrode 109 and on the inner wall surface of the opening 10d of the transparent protective film 10a. Then, outside the opening 10d, the thickness of the bonding layer 110 gradually decreases toward the outside, and an inclined surface 110c is formed on the outer peripheral portion 110d of the bonding layer 110.
  • the bonding layer 110 preferably has translucency.
  • the bonding layer 110 has a light-transmitting property
  • light from the light-emitting layer 105 irradiated to the bonding pad electrode 120 can be transmitted without loss.
  • part of light emitted from the light-emitting layer 105 is transmitted through the light-transmitting electrode 109 and the bonding layer 110 to be bonded to the bonding layer 110 and the bonding pad.
  • the light is reflected by the bonding pad electrode 120 (in this embodiment, the metal reflection layer 117) at the interface with the electrode 120.
  • the light reflected by the bonding pad electrode 120 is again introduced into the laminated semiconductor layer 20, and after repeated transmission and reflection, the light is reflected to the outside of the semiconductor light emitting device 1 from a location other than the formation region of the bonding pad electrode 120. It is taken out. Therefore, when the bonding layer 110 has a light transmitting property, light from the light emitting layer 105 can be efficiently extracted outside the semiconductor light emitting element 1.
  • the bonding layer 110 is at least selected from the group consisting of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh, Ir, and Ni. What consists of a kind of element is preferable. When the bonding layer 110 is made of the above-described material, the bonding strength of the bonding pad electrode 120 to the translucent electrode 109 can be improved and the translucency can be exhibited.
  • the bonding layer 110 is more preferably composed of at least one element selected from the group consisting of Cr, Ti, W, Mo, Zr, Hf, Co, Rh, Ir, and Ni.
  • the bonding pad electrode 120 to the translucent electrode 109 is made of at least one element selected from the group consisting of W, Mo, Rh, Co, and Ni.
  • a metal such as Cr, Ti, Mo, Ni, or Co as the material of the bonding layer 110, the bonding strength of the bonding pad electrode 120 to the translucent electrode 109 can be significantly increased.
  • the translucent electrode 109 is made of a metal oxide such as IZO or ITO and the bonding pad electrode 120 is made of Ag, Al, or the like,
  • Cr it is particularly preferable to use Cr that can provide excellent bondability to Ag and Al.
  • the bonding layer 110 is preferably a thin film having a maximum thickness in the range of 10 to 400 mm.
  • the maximum thickness of the bonding layer 110 is less than 10 mm, the strength of the bonding layer 110 is decreased, and thus the bonding strength of the bonding pad electrode 120 to the translucent electrode 109 is not preferable.
  • the bonding pad electrode 120 is formed of a laminated body in which a metal reflective layer 117 and a bonding layer 119 are laminated in order from the translucent electrode 109 side.
  • the bonding pad electrode 120 may have a single layer structure including only the bonding layer 119 or a single layer structure including only the metal reflection layer 117, and a barrier layer may be provided between the metal reflection layer 117 and the bonding layer 119. It may be inserted into a three-layer structure.
  • the metal elements constituting the bonding layer 110, the metal reflection layer 117, the bonding layer 119, and the barrier layer may contain the same metal element, or may be a combination of different metal elements.
  • the reflectance of the bonding pad electrode 120 varies greatly depending on the material constituting the metal reflective layer 117, but the reflectance is preferably 60% or more, more preferably 80% or more, It is even better if the reflectance is 90% or more.
  • the reflectance can be measured relatively easily with a spectrophotometer or the like.
  • the bonding pad electrode 120 itself has a small area, it is difficult to measure the reflectance. Therefore, for example, a “dummy substrate” made of a transparent glass and having a large area is placed in a chamber for forming the bonding pad electrode, and at the same time, the same bonding pad electrode is formed on the dummy substrate. It can be measured using a method such as measuring the reflectance of the bonding pad electrode formed thereon.
  • the bonding pad electrode 120 has a larger area because the bonding operation can be easily performed.
  • the larger the bonding pad electrode 120 is the more light extraction is hindered.
  • the bonding pad electrode 120 hinders light extraction, and thus the output is significantly reduced.
  • the area of the bonding pad electrode 120 is preferably a size that is slightly larger than the diameter of the bonding ball.
  • the upper surface has a diameter of about 100 ⁇ m, and the transparent protective film 10a side. It is preferably a substantially cylindrical shape having a diameter that increases as it approaches.
  • the metal reflective layer 117 is formed so as to cover the bonding layer 110. Further, an inclined surface 117c is formed on the outer peripheral portion of the metal reflective layer 117 so that the film thickness gradually decreases toward the outside. Therefore, the metal reflective layer 117 is formed so as to completely cover the most distal portion of the inclined surface 110c of the bonding layer 110 on the transparent protective film 10a side, that is, the boundary portion that forms the contour line when the bonding layer 110 is viewed in plan view. Has been. In other words, the metal reflection layer 117 is formed so as to cover the bonding layer 110 when viewed in plan and further protrude to the outside of the bonding layer 110, and any part of the bonding layer 110 is below the metal reflection layer 117. Is not exposed from.
  • the metal reflective layer 117 shown in FIG. 14 is made of a highly reflective metal, such as a platinum group metal such as Ru, Rh, Pd, Os, Ir, and Pt, Al, Ag, Ti, and at least one of these metals. It is preferable to be comprised with the alloy containing 1 type.
  • a platinum group metal such as Ru, Rh, Pd, Os, Ir, and Pt
  • Al, Ag, Ti and at least one of these metals. It is preferable to be comprised with the alloy containing 1 type.
  • the metal reflective layer 117 made of the above material the light from the light emitting layer 105 can be effectively reflected.
  • Al, Ag, Pt, and alloys containing at least one of these metals are excellent in terms of easy availability and handling.
  • Rh, Pd, Ir, Pt and an alloy containing at least one of these metals are preferably used as the metal reflective layer 117 from the viewpoint of light reflectivity.
  • the metal reflective layer 117 is preferably formed so that the maximum film thickness is larger than that of the bonding layer 110. By making the metal reflective layer 117 thicker than the bonding layer 110, the metal reflecting layer 117 covers the bonding layer 110 more reliably and completely. Further, it is desirable that the metal reflective layer 117 has a maximum thickness of 20 to 3000 nm. If the thickness of the metal reflective layer 117 is thinner than the above range, the reflection effect may not be obtained sufficiently. In addition, when the thickness of the metal reflection layer 117 is thicker than the above range, there is no particular advantage, and only a long process time and material waste are caused. The thickness of the metal reflective layer 117 is more desirably 50 to 1000 nm, and most desirably 100 to 500 nm.
  • the bonding layer 119 is formed so as to cover the metal reflective layer 117.
  • an inclined surface 119c is formed on the outer peripheral portion of the bonding layer 119 (that is, the outer peripheral portion 120d of the bonding pad electrode 120) so that the film thickness gradually decreases toward the outside. Accordingly, the bonding layer 119 completely covers the most distal portion of the inclined surface 117c of the metal reflective layer 117 on the transparent protective film 10a side, that is, the boundary forming the contour line when the metal reflective layer 117 is viewed in plan view. Is formed.
  • the bonding layer 119 is formed so as to cover the metal reflective layer 117 when seen in a plan view and further to the outside of the metal reflective layer 117, and any portion of the metal reflective layer 117 is formed on the bonding layer 119. It is not exposed from the bottom.
  • the bonding layer 119 shown in FIG. 14 is preferably made of Au, Al, or an alloy containing at least one of these metals. Since Au and Al are metals with good adhesion to gold balls that are often used as bonding balls, by using Au, Al or an alloy containing at least one of these metals as the bonding layer 119, It can be set as the bonding layer 119 excellent in adhesiveness with a bonding wire. Of these, Au is particularly desirable.
  • the maximum thickness of the bonding layer 119 is preferably formed to be thicker than that of the bonding layer 110 and the metal reflective layer 117. By making the bonding layer 119 thicker than the bonding layer 110 and the metal reflection layer 117, the metal reflection layer 117 is more reliably and completely covered by the bonding layer 119.
  • the maximum thickness of the bonding layer 119 is preferably in the range of 50 nm to 2000 nm, and more preferably 100 nm to 1500 nm. If the maximum thickness of the bonding layer 119 is too thin, adhesion to the bonding ball may be insufficient. Further, even if the maximum thickness of the bonding layer 119 is made larger than the above range, there is no particular advantage and only the cost is increased.
  • the barrier layer is disposed between the metal reflective layer 117 and the bonding layer 119 and enhances the strength of the entire bonding pad electrode 120.
  • the barrier layer is made of a relatively strong metal material, or has a sufficiently thick film thickness.
  • As the material for the barrier layer Ti, Cr, Al, or the like can be used, but it is desirable to use Ti having excellent strength.
  • the maximum thickness of the barrier layer is preferably 20 to 3000 nm. If the thickness of the barrier layer is too thin, sufficient strength strengthening effects may not be obtained. In addition, if the thickness of the barrier layer is too thick, there is no particular advantage and only an increase in cost is caused.
  • the thickness of the barrier layer is more preferably 50 to 1000 nm, and most preferably 100 to 500 nm.
  • the metal reflective layer 117 when the metal reflective layer 117 is mechanically strong, it is not necessary to form a barrier layer.
  • the metal reflective layer 117 is made of Al or Pt, the barrier layer is not always necessary.
  • the transparent protective film 10a protects the translucent electrode 109 and the bonding layer 110. As shown in FIGS. 14 and 15, the transparent protective film 10 a is formed so as to cover a region where the bonding recess 109 a is not formed on the upper surface 109 c of the translucent electrode 109, and the bonding recess 109 a is formed. The area that is present is the opening 10d. In the present embodiment, as shown in FIG. 17, the bonding layer 110 is formed in contact with the inner wall surface of the opening 10d, and the outer edge portion of the bonding layer 110 is disposed on the transparent protective film 10a.
  • the transparent protective film 10a prevents contact of air or moisture in the portion of the bonding layer 110 that is in contact with the transparent protective film 10a.
  • the outer edges of the metal reflection layer 117 and the bonding layer 119 constituting the bonding pad electrode 120 are disposed in contact with the transparent protective film 10a.
  • the film 10a and the bonding pad electrode 120 surround the entire outer surface of the bonding layer 110 that is not in contact with the translucent electrode 109, and the contact between the bonding layer 110 and air or moisture is effectively prevented.
  • the transparent protective film 10a is preferably made of a material that is transparent and has excellent adhesion to each of the translucent electrode 109, the bonding layer 110, and the bonding pad electrode 120.
  • the transparent protective film 10a is made of SiO 2. It is preferable that The thickness of the transparent protective film 10a is preferably 20 to 500 nm, and more preferably 50 to 300 nm. If the thickness of the transparent protective film 10a is less than the above range, the effect of protecting the translucent electrode 109 and the bonding layer 110 may not be sufficiently obtained. On the other hand, when the thickness of the transparent protective film 10a exceeds the above range, the transparency may be deteriorated and the light extraction property may be hindered.
  • the thickness of the transparent protective film 10a exceeds the above range, the depth obtained by combining the depth of the opening 10d and the depth of the bonding recess 109a becomes deep, and the adhesion between the inner wall surface of the opening 10d and the bonding layer 110 is increased. May cause trouble.
  • the edge protective film 10b prevents contact between the bonding layer 110 and air or moisture, and prevents the bonding pad electrode 120 from peeling from the semiconductor light emitting element 1, thereby improving the bonding force of the bonding pad electrode 120. is there.
  • the edge protective film 10 b has a substantially donut shape that exposes the central portion of the bonding pad electrode 120 when viewed in plan.
  • the edge protective film 10b extends over a portion that becomes a joint between the outer edge (contour line) of the bonding pad electrode 120 and the transparent protective film 10a when viewed in plan. It is arranged and covers the outer edge portion of the bonding pad electrode 120. Therefore, in the present embodiment, as shown in FIG. 17, the outer edge portion of the bonding pad electrode 120 is sandwiched between the transparent protective film 10a and the edge protective film 10b.
  • the effect of providing the edge protective film 10b increases as the area of the edge protective film 10b increases with the boundary between the bonding pad electrode 120 and the transparent protective film 10a as the center.
  • the edge protection film 10b when the area of the edge protection film 10b is increased, the area of the bonding pad electrode 120 exposed from the edge protection film 10b is reduced, which may hinder the workability of the bonding work, or the edge protection film 10b.
  • the transparency of the region where the bonding pad electrode 120 is not formed may be lowered, and the light extraction property may be hindered. Therefore, it is preferable that the edge protection film 10b completely covers the boundary between the bonding pad electrode 120 and the transparent protection film 10a and completely exposes the top of the bonding pad electrode 120.
  • the edge protection film 10b preferably has a width of 5 to 10 ⁇ m with the boundary portion between the bonding pad electrode 120 and the edge protection film 10b as the center.
  • the edge protective film 10b is preferably made of a material that is transparent and has excellent adhesion to the transparent protective film 10a and the bonding pad electrode 120, and is formed of the same material as the transparent protective film 10a. More preferred. Specifically, it is possible to those made of transparent protective film 10a and the edge protection film 10b of SiO 2. When the edge protective film 10b and the transparent protective film 10a are formed of the same material, the adhesion between the edge protective film 10b and the transparent protective film 10a becomes very good. The effect by providing can be further improved.
  • Embodiment 12 26 to 29 are diagrams showing an example of the semiconductor light emitting device of the present invention.
  • FIG. 26 is a schematic sectional view of the semiconductor light emitting device
  • FIG. 27 is a schematic plan view of the semiconductor light emitting device shown in FIG.
  • FIG. 28 is an enlarged schematic sectional view of a laminated semiconductor layer constituting the semiconductor light emitting device shown in FIG.
  • FIG. 29 is a diagram for explaining the electrodes constituting the semiconductor light emitting device shown in FIG. 26.
  • FIG. 29A is an enlarged schematic cross-sectional view of a p-type electrode
  • FIG. It is an expanded sectional schematic diagram of an n-type electrode. As shown in FIG.
  • the semiconductor light emitting device 1 of the present embodiment includes a substrate 101, a laminated semiconductor layer 20 formed on the substrate 101, and a p-type electrode 111 (on the upper surface 106c of the laminated semiconductor layer 20).
  • a p-type electrode 111 on the upper surface 106c of the laminated semiconductor layer 20.
  • the laminated semiconductor layer 20 is formed by laminating an n-type semiconductor layer 104, a light emitting layer 105, and a p-type semiconductor layer 106 in this order from the substrate 101 side.
  • the semiconductor light emitting device 1 of this embodiment light emission is obtained from the light emitting layer 105 by applying a voltage between the p-type electrode 111 and the n-type electrode 108 and passing a current.
  • the semiconductor light emitting device 1 of the present embodiment is a face-up mount type light emitting device that extracts light from the side where the p-type electrode 111 is formed.
  • the semiconductor light emitting device of the twelfth embodiment is basically different from the semiconductor light emitting device of the first embodiment in that the configuration in which the electrodes are installed on the upper surface of the laminated semiconductor layer 20 is different. That is, in Embodiment 12, either one or both of the one electrode and the other electrode are in contact with the upper surface of the stacked semiconductor layer or the exposed surface of the semiconductor layer, and the ohmic contact layer is formed.
  • a structure of a semiconductor light emitting element comprising: a bonding layer formed on the bonding layer; and a bonding pad electrode formed so as to cover the bonding layer.
  • the configuration of the substrate constituting the semiconductor light emitting device and the laminated semiconductor layer having the light emitting layer is basically configured in the same range as the first embodiment and the seventh embodiment. Can do. In the following, a detailed description will be given in order to describe features different from the configurations of the semiconductor light emitting devices of the first embodiment and the seventh embodiment.
  • the p-type electrode 111 includes a translucent electrode 109, an ohmic bonding layer 9, a bonding layer 110, and a bonding pad electrode 120.
  • the translucent electrode 109 is provided with a hole 109a in which the upper surface 106c of the laminated semiconductor layer 20 is exposed on the bottom surface 109b.
  • a protective film 10a is formed so as to cover the translucent electrode 109 in a region where the hole 109a is not formed in the upper surface 109c of the translucent electrode 109. Has been.
  • the region where the hole 109a is formed is an opening 10d in which a part of the protective film 10a is opened.
  • An ohmic junction layer 9 is formed on the upper surface 106c of the laminated semiconductor layer 20 exposed from the opening 10d (the bottom surface 109b of the hole 109a), and is ohmically joined to the upper surface 106c of the laminated semiconductor layer 20. Yes. Further, as shown in FIG. 29A, a bonding layer 110 is formed on the ohmic bonding layer 9 so as to cover the ohmic bonding layer 9, and bonding is performed on the bonding layer 110 so as to cover the bonding layer 110. A pad electrode 120 is formed.
  • the n-type electrode 108 is formed on the exposed surface 104c of the n-type semiconductor layer 104 as shown in FIG.
  • the exposed surface 104c of the n-type semiconductor layer 104 is formed by cutting away a part of the light emitting layer 105 and the p semiconductor layer 106 by means such as etching.
  • a protective film 10 a having an opening 10 d is formed on the exposed surface 104 c of the n-type semiconductor layer 104.
  • An ohmic junction layer 9 is formed on the exposed surface 104 c of the n-type semiconductor layer 104 exposed from the opening 10 d and is in ohmic contact with the n-type semiconductor layer 104.
  • a bonding layer 110 is formed on the ohmic bonding layer 9 so as to cover the ohmic bonding layer 9, and bonding is performed on the bonding layer 110 so as to cover the bonding layer 110.
  • a pad electrode 120 is formed. Therefore, the n-type electrode 108 is the same as the p-type electrode 111 except that the translucent electrode 109 is not provided.
  • the outer edge portion of the electrode 120 (the metal reflection layer 117 and the bonding layer 119) is disposed on the protective film 10a.
  • the bonding pad electrode 120 includes an inclined surface 119c on the outer peripheral portion 120d that gradually decreases in thickness toward the outside.
  • the outer edge portion of the bonding pad electrode 120 is covered with the edge protection film 10b.
  • the translucent electrode 109 is provided on the upper surface 106c of the p-type semiconductor layer 106, as shown in FIG. 26, and the upper surface 106c of the laminated semiconductor layer 20 is exposed on the bottom surface 109b, as shown in FIG.
  • the hole 109a is formed.
  • the planar shape of the hole 109a of the translucent electrode 109 can be any shape such as a circular shape or a polygonal shape, and is not particularly limited. However, in order to facilitate the bonding operation, as shown in FIG. Moreover, it is preferable that it is circular.
  • the hole 109a of the translucent electrode 109 may be formed anywhere on the upper surface 106c of the p-type semiconductor layer 106, and corresponds to the position where the ohmic junction layer 9, the junction layer 110, and the bonding pad electrode 120 are formed. Provided. For example, it may be formed at a position farthest from the n-type electrode 108 or may be formed at the center of the semiconductor light emitting device 1. However, if it is formed too close to the n-type electrode 108, a short circuit between the wires and between the balls occurs when the wire is bonded to the bonding pad electrode 120 formed on the hole 109a. . Further, as shown in FIGS.
  • the translucent electrode 109 is formed so as to cover almost the entire upper surface 106c of the p-type semiconductor layer 106 in plan view.
  • the present invention is not limited to this, and it may be formed in a lattice shape or a tree shape with a gap.
  • the translucent electrode 109 has a small contact resistance with the p-type semiconductor layer 106, the ohmic junction layer 9, and the junction layer 110. Furthermore, the translucent electrode 109 is preferably excellent in light transmissivity in order to efficiently extract light from the light emitting layer 105 to the side where the p-type electrode 111 is formed. Furthermore, the translucent electrode 109 preferably has excellent conductivity in order to diffuse current uniformly over the entire surface of the p-type semiconductor layer 106.
  • a conductive oxide containing any one of In, Zn, Al, Ga, Ti, Bi, Mg, W, Ce, Sn, and Ni it is preferable to use a light-transmitting conductive material selected from the group consisting of any one of zinc sulfide and chromium sulfide.
  • the conductive oxide examples include ITO (indium tin oxide (In 2 O 3 —SnO 2 )), IZO (indium zinc oxide (In 2 O 3 —ZnO)), and AZO (aluminum zinc oxide (ZnO—Al 2 O 3 )), GZO (gallium zinc oxide (ZnO—Ga 2 O 3 )), fluorine-doped tin oxide, titanium oxide, or the like is preferably used.
  • Translucent electrode 109 if made of a crystallized IZO, may be a IZO containing an In 2 O 3 crystal having a bixbyite crystal structure, including In 2 O 3 crystal having a hexagonal crystal structure It may be IZO. In particular, IZO containing In 2 O 3 crystal having a hexagonal structure is preferable.
  • a crystallized IZO film is very preferable because it has better adhesion to the p-type semiconductor layer 106 than an amorphous IZO film.
  • the ZnO concentration in IZO is preferably 1 to 20% by mass, and more preferably 5 to 15% by mass. 10% by mass is particularly preferable.
  • the film thickness of the IZO film is preferably in the range of 35 nm to 10000 nm (10 ⁇ m) at which low specific resistance and high light transmittance can be obtained. Furthermore, from the viewpoint of production cost, the thickness of the IZO film is preferably 1000 nm (1 ⁇ m) or less.
  • the ohmic junction layer 9 constituting the p-type electrode 111 is provided on the upper surface 106 c of the laminated semiconductor layer 20 and is in ohmic contact with the p-type semiconductor layer 106.
  • the ohmic junction layer 9 constituting the n-type electrode 108 is provided on the exposed surface 104c of the n-type semiconductor layer 104, and is in ohmic contact with the n-type semiconductor layer 104. ing. Further, as shown in FIG.
  • the ohmic junction layer 9 constituting the p-type electrode 111 is formed on the upper surface 106c of the laminated semiconductor layer 20, the hole 109a of the translucent electrode 109, and the opening of the protective film 10a. It is formed continuously so as to cover the end portion 10c of the portion 10d.
  • the ohmic junction layer 9 constituting the n-type electrode 108 covers the exposed surface 104c of the n-type semiconductor layer 104 and the end 10c of the opening 10d of the protective film 10a. Are formed continuously.
  • the thickness of the ohmic bonding layer 9 is substantially uniform in the opening 10d of the protective film 10a and on the inner wall surface of the opening 10d. The thickness of the ohmic junction layer 9 is gradually reduced toward the outside outside the opening 10d, and an inclined surface is formed on the outer peripheral portion of the ohmic junction layer 9.
  • the ohmic junction layer 9 preferably has a low contact resistance with the p-type semiconductor layer 106, the n-type semiconductor layer 104, or the junction layer 110.
  • the ohmic junction layer 9 is preferably excellent in light transmittance in order to efficiently extract light from the light emitting layer 105 to the side where the p-type electrode 111 is formed. From the above, as the material constituting the ohmic junction layer 9, the same material as that constituting the translucent electrode 109 can be preferably used.
  • a crystallized structure for the ohmic bonding layer 9 in terms of adhesiveness to the bonding layer 110 and translucency.
  • a translucent electrode for example, ITO, IZO, etc.
  • the ohmic junction layer 9 may be an IZO containing an In 2 O 3 crystal having a bixbite crystal structure, or a hexagonal crystal structure, similar to the translucent electrode 109.
  • IZO containing In 2 O 3 crystal of N may be used.
  • IZO containing In 2 O 3 crystal having a hexagonal structure is preferable.
  • a crystallized IZO film is very preferable because it has better adhesion to the bonding layer 110 and the p-type semiconductor layer 106 than an amorphous IZO film.
  • the thickness of the ohmic bonding layer 9 is preferably in the range of 2 nm to 300 nm, preferably in the range of 50 nm to 250 nm, in which sufficient strength is obtained that is difficult to break and low resistivity and high light transmittance can be obtained. It is more preferable.
  • the bonding layer 110 is laminated between the ohmic bonding layer 9 and the bonding pad electrode 120 in order to increase the bonding strength of the bonding pad electrode 120 to the ohmic bonding layer 9.
  • the bonding layer 110 constituting the p-type electrode 111 is continuously formed in a concave shape so as to cover the ohmic bonding layer 9 and the end 10c of the opening 10d of the protective film 10a. Is formed. As a result, a high bonding force between the ohmic bonding layer 9 and the protective film 10a and the bonding layer 110 can be obtained. Also, as shown in FIG.
  • the bonding layer 110 constituting the n-type electrode 108 is continuous in a concave shape so as to cover the ohmic bonding layer 9 and the end 10c of the opening 10d of the protective film 10a. Is formed. As a result, a high bonding force between the ohmic bonding layer 9 and the protective film 10a and the bonding layer 110 can be obtained.
  • the thickness of the bonding layer 110 is substantially uniform in the opening 10d of the protective film 10a and on the inner wall surface of the opening 10d. Then, outside the opening 10d, the thickness of the bonding layer 110 gradually decreases toward the outside, and an inclined surface 110c is formed on the outer peripheral portion 110d of the bonding layer 110.
  • the bonding layer 110 preferably has a light-transmitting property.
  • the bonding layer 110 has a light-transmitting property
  • the light from the light emitting layer 105 irradiated to the bonding pad electrode 120 in the p-type electrode 111 can be transmitted without loss. More specifically, when the bonding layer 110 has a light-transmitting property, part of light emitted from the light-emitting layer 105 is transmitted through the ohmic bonding layer 9 and the bonding layer 110 constituting the p-type electrode 111, and The light is reflected by the bonding pad electrode 120 (in this embodiment, the metal reflection layer 117) at the interface between the bonding layer 110 and the bonding pad electrode 120.
  • the light reflected by the bonding pad electrode 120 of the p-type electrode 111 is again introduced into the laminated semiconductor layer 20, and after repeating transmission and reflection, the light other than the region where the bonding pad electrode 120 of the p-type electrode 111 is formed Are taken out of the semiconductor light-emitting element 1 from Therefore, when the bonding layer 110 constituting the p-type electrode 111 has a light transmitting property, the light from the light emitting layer 105 can be extracted to the outside of the semiconductor light emitting device 1 more efficiently.
  • the bonding layer 110 is at least selected from the group consisting of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh, Ir, and Ni. It is preferable that it consists of a kind of element. When the bonding layer 110 is made of the above-described material, the bonding strength of the bonding pad electrode 120 to the ohmic bonding layer 9 can be improved, and at the same time, the translucency can be exhibited.
  • the bonding layer 110 is more preferably composed of at least one element selected from the group consisting of Cr, Ti, W, Mo, Zr, Hf, Co, Rh, Ir, and Ni.
  • the bonding pad electrode 120 to the ohmic bonding layer 9 can be significantly increased.
  • the ohmic bonding layer 9 is made of a metal oxide such as IZO or ITO and the bonding pad electrode 120 is made of Ag, Al, or the like, In particular, it is particularly preferable to use Cr that can provide excellent bondability to Ag and Al.
  • the bonding layer 110 is preferably a thin film having a maximum thickness in the range of 10 to 400 mm.
  • the maximum thickness of the bonding layer 110 is lowered, which is not preferable because the bonding strength of the bonding pad electrode 120 to the ohmic bonding layer 9 is lowered.
  • the bonding pad electrode 120 is formed of a stacked body in which a metal reflective layer 117 and a bonding layer 119 are stacked in this order from the translucent electrode 109 side.
  • the bonding pad electrode 120 may have a single layer structure including only the bonding layer 119 or a single layer structure including only the metal reflection layer 117, and a barrier layer may be provided between the metal reflection layer 117 and the bonding layer 119. It may be inserted into a three-layer structure.
  • the metal elements constituting the bonding layer 110, the metal reflection layer 117, the bonding layer 119, and the barrier layer may contain the same metal element, or may be a combination of different metal elements.
  • the reflectance of the bonding pad electrode 120 varies greatly depending on the material constituting the metal reflective layer 117, but the reflectance is preferably 60% or more, more preferably 80% or more, It is even better if the reflectance is 90% or more.
  • the reflectance can be measured relatively easily with a spectrophotometer or the like.
  • the bonding pad electrode 120 itself has a small area, it is difficult to measure the reflectance. Therefore, for example, a “dummy substrate” made of a transparent glass and having a large area is placed in a chamber for forming the bonding pad electrode, and at the same time, the same bonding pad electrode is formed on the dummy substrate. It can be measured using a method such as measuring the reflectance of the bonding pad electrode formed thereon.
  • the area of the bonding pad electrode 120 that constitutes the p-type electrode 111 and the n-type electrode 108 is preferably a size that is slightly larger than the diameter of the bonding ball. It is preferably about 100 ⁇ m, and has a substantially cylindrical shape with a diameter increasing as it approaches the protective film 10a side.
  • the metal reflective layer 117 is formed so as to cover the bonding layer 110.
  • an inclined surface 117c is formed so that the film thickness gradually decreases toward the outside. Therefore, the metal reflective layer 117 is formed so as to completely cover the most distal portion of the inclined surface 110c of the bonding layer 110 on the protective film 10a side, that is, the boundary that forms the contour line when the bonding layer 110 is viewed in plan. ing.
  • the metal reflection layer 117 is formed so as to cover the bonding layer 110 when viewed in plan and further protrude to the outside of the bonding layer 110, and any part of the bonding layer 110 is below the metal reflection layer 117. Is not exposed from.
  • the metal reflection layer 117 is made of a metal having a high reflectance, and is an alloy containing platinum group metals such as Ru, Rh, Pd, Os, Ir, and Pt, Al, Ag, Ti, and at least one of these metals. It is preferable that it is comprised.
  • the metal reflective layer 117 made of the above material the light from the light emitting layer 105 can be effectively reflected by the p-type electrode 111.
  • Al, Ag, Pt, and alloys containing at least one of these metals are excellent in terms of easy availability and handling.
  • Rh, Pd, Ir, Pt and an alloy containing at least one of these metals are preferably used as the metal reflective layer 117 from the viewpoint of light reflectivity.
  • the metal reflective layer 117 is preferably formed so that the maximum film thickness is larger than that of the bonding layer 110. By making the metal reflective layer 117 thicker than the bonding layer 110, the metal reflecting layer 117 covers the bonding layer 110 more reliably and completely. Further, it is desirable that the metal reflective layer 117 has a maximum thickness of 20 to 3000 nm. If the thickness of the metal reflective layer 117 is thinner than the above range, the reflection effect may not be obtained sufficiently. In addition, when the thickness of the metal reflection layer 117 is thicker than the above range, there is no particular advantage, and only a long process time and material waste are caused. The thickness of the metal reflective layer 117 is more desirably 50 to 1000 nm, and most desirably 100 to 500 nm.
  • the bonding layer 119 is formed so as to cover the metal reflective layer 117.
  • an inclined surface 119c is formed on the outer peripheral portion of the bonding layer 119 (that is, the outer peripheral portion 120d of the bonding pad electrode 120) so that the film thickness gradually decreases toward the outside. Therefore, the bonding layer 119 is formed so as to completely cover the most distal portion of the inclined surface 117c of the metal reflection layer 117 on the protective film 10a side, that is, the boundary portion that forms the contour line when the metal reflection layer 117 is viewed in plan view. Has been.
  • the bonding layer 119 is formed so as to cover the metal reflective layer 117 when seen in a plan view and further to the outside of the metal reflective layer 117, and any portion of the metal reflective layer 117 is formed on the bonding layer 119. It is not exposed from the bottom.
  • the bonding layer 119 shown in FIG. 26 is preferably made of Au, Al, or an alloy containing at least one of these metals. Since Au and Al are metals with good adhesion to gold balls that are often used as bonding balls, by using Au, Al or an alloy containing at least one of these metals as the bonding layer 119, It can be set as the bonding layer 119 excellent in adhesiveness with a bonding wire. Of these, Au is particularly desirable.
  • the maximum thickness of the bonding layer 119 is preferably formed to be thicker than that of the bonding layer 110 and the metal reflective layer 117. By making the bonding layer 119 thicker than the bonding layer 110 and the metal reflection layer 117, the bonding layer 119 covers the bonding layer 110 and the metal reflection layer 117 more reliably and completely by the bonding layer 119. It will be a thing.
  • the maximum thickness of the bonding layer 119 is preferably in the range of 50 nm to 2000 nm, and more preferably 100 nm to 1500 nm. If the maximum thickness of the bonding layer 119 is too thin, adhesion to the bonding ball may be insufficient. Further, even if the maximum thickness of the bonding layer 119 is made larger than the above range, there is no particular advantage and only the cost is increased.
  • the barrier layer is disposed between the metal reflective layer 117 and the bonding layer 119 and enhances the strength of the entire bonding pad electrode 120.
  • the barrier layer is made of a relatively strong metal material, or has a sufficiently thick film thickness.
  • As the material for the barrier layer Ti, Cr, Al, or the like can be used, but it is desirable to use Ti having excellent strength.
  • the maximum thickness of the barrier layer is preferably 20 to 3000 nm. If the thickness of the barrier layer is too thin, sufficient strength strengthening effects may not be obtained. In addition, if the thickness of the barrier layer is too thick, there is no particular advantage and only an increase in cost is caused.
  • the thickness of the barrier layer is more preferably 50 to 1000 nm, and most preferably 100 to 500 nm.
  • the metal reflective layer 117 when the metal reflective layer 117 is mechanically strong, it is not necessary to form a barrier layer.
  • the metal reflective layer 117 is made of Al or Pt, the barrier layer is not always necessary.
  • the protective film 10 a protects the translucent electrode 109 and the bonding layer 110. As shown in FIGS. 26 and 27, the protective film 10 a is formed so as to cover a region where the hole 109 a is not formed on the upper surface 109 c of the translucent electrode 109 and the exposed surface 104 c of the n-type semiconductor layer 104. The region where the ohmic junction layer 9 of the p-type electrode 111 is formed (the region where the hole 109a is formed) and the region where the ohmic junction layer 9 of the n-type electrode 108 is formed serve as the opening 10d. Yes.
  • the ohmic junction layer 9 is formed in contact with the inner wall surface of the opening 10d, and the outer edge portion of the ohmic junction layer 9 is formed.
  • the protective film 10a is disposed in contact with the protective film 10a, and the protective film 10a prevents contact of air or moisture in a portion of the ohmic bonding layer 9 that is in contact with the protective film 10a.
  • FIGS. 29A and 29B the ohmic junction layer 9 is formed in contact with the inner wall surface of the opening 10d, and the outer edge portion of the ohmic junction layer 9 is formed.
  • the protective film 10a is disposed in contact with the protective film 10a, and the protective film 10a prevents contact of air or moisture in a portion of the ohmic bonding layer 9 that is in contact with the protective film 10a.
  • the outer edge portion of the bonding layer 110, the metal reflective layer 117 constituting the bonding pad electrode 120, and the outer edge portion of the bonding layer 119 are The protective film 10a is disposed in contact with the protective film 10a, and the protective film 10a and the bonding pad electrode 120 surround the entire outer surface of the bonding layer 110 that is not in contact with the ohmic bonding layer 9, and the bonding layer 110 and air or moisture. Is effectively prevented. Further, as shown in FIG. 26, the protective film 10a is continuously formed on the side surface formed by cutting out part of the light emitting layer 105 and the p semiconductor layer 106 and the side surface of the translucent electrode 109. Has been.
  • the protective film 10a is made of a material that is transparent and has excellent adhesion to the n-type semiconductor layer 104, the translucent electrode 109, the ohmic bonding layer 9, the bonding layer 110, and the bonding pad electrode 120. More specifically, it is preferably made of SiO 2 .
  • the thickness of the protective film 10a is preferably 20 to 500 nm, and more preferably 50 to 300 nm. If the thickness of the protective film 10a is less than the above range, the effect of protecting the translucent electrode 109, the n-type semiconductor layer 104, the ohmic bonding layer 9, and the bonding layer 110 may not be sufficiently obtained.
  • the thickness of the protective film 10a exceeds the above range, the transparency may be lowered, and the light extraction property may be hindered. Moreover, when the thickness of the protective film 10a exceeds the above range, the depth of the opening 10d becomes deep, and there is a risk that the adhesion between the inner wall surface of the opening 10d and the ohmic bonding layer 9 may be hindered.
  • the edge protective film 10b prevents contact between the bonding layer 110 and air or moisture, and prevents the bonding pad electrode 120 from peeling from the semiconductor light emitting element 1, thereby improving the bonding force of the bonding pad electrode 120. is there. As shown in FIGS. 26 and 27, the edge protection film 10b is formed over the entire region excluding the region where the central portion of the bonding pad electrode 120 is exposed when viewed in plan. Further, as shown in FIGS. 27, 29 (a), and 29 (b), the edge protective film 10b has an outer edge (contour line) of the bonding pad electrode 120 and the protective film 10a when viewed in plan. Are arranged across the seam of the bonding pad electrode 120 and cover the outer edge of the bonding pad electrode 120.
  • the outer edge portion of the bonding pad electrode 120 is sandwiched between the protective film 10a and the edge protective film 10b. Yes. Further, as shown in FIG. 26, the edge protection film 10 b protects the side surface formed by cutting out part of the light emitting layer 105 and the p semiconductor layer 106 and the side surface of the translucent electrode 109. It is formed continuously through the film 10a.
  • the effect of providing the edge protective film 10b increases as the area of the edge protective film 10b increases with the boundary between the bonding pad electrode 120 and the protective film 10a as the center.
  • the edge protection film 10b when the area of the edge protection film 10b is increased, the area of the bonding pad electrode 120 exposed from the edge protection film 10b is reduced, which may hinder the workability of the bonding work, or the edge protection film 10b.
  • the transparency of the region where the bonding pad electrode 120 is not formed may be lowered, and the light extraction property may be hindered. Therefore, it is preferable that the edge protective film 10b completely covers the boundary between the bonding pad electrode 120 and the protective film 10a and exposes the top of the bonding pad electrode 120.
  • the edge protection film 10b preferably has a width of 2 ⁇ m or more with the boundary portion between the bonding pad electrode 120 and the edge protection film 10b as the center.
  • the edge protective film 10b is preferably made of a material that is transparent and has excellent adhesion to the protective film 10a and the bonding pad electrode 120, and more preferably formed of the same material as the protective film 10a.
  • the protective film 10a and the edge protection film 10b may be those composed of SiO 2.
  • the edge protection film 10b and the protection film 10a are formed of the same material, the adhesion between the edge protection film 10b and the protection film 10a becomes very good, so the edge protection film 10b is provided. The effect by this can be further improved.
  • a method for manufacturing a semiconductor light-emitting device includes a step of forming a laminated semiconductor layer including a light-emitting layer on a substrate, and forming a semiconductor layer exposed surface by cutting out part of the laminated semiconductor layer. And an electrode forming step of forming one (one conductivity type) electrode and the other (other conductivity type) electrode on the upper surface of the laminated semiconductor layer and the exposed surface of the semiconductor layer.
  • the step of forming the laminated semiconductor layer including the light emitting layer includes a buffer layer forming step, a base layer forming step, an n-type semiconductor layer forming step, a light emitting layer forming step, and a p-type semiconductor layer forming step. Further, an n-type electrode is formed in the n-type electrode forming step. Further, in the p-type electrode forming step, the p-type electrode is formed using the mask forming step and the bonding electrode forming step. In the first embodiment, the translucent electrode forming step is performed in the p-type electrode forming step after the p-type semiconductor layer forming step.
  • a substrate 101 such as a sapphire substrate is prepared and pre-processed.
  • the pretreatment can be performed by, for example, a method in which the substrate 101 is disposed in a chamber of a sputtering apparatus and sputtering is performed before the buffer layer 102 is formed.
  • a pretreatment for cleaning the upper surface may be performed by exposing the substrate 101 to Ar or N 2 plasma in the chamber. By causing plasma such as Ar gas or N 2 gas to act on the substrate 101, organic substances and oxides attached to the upper surface of the substrate 101 can be removed.
  • the buffer layer 102 is stacked on the upper surface of the substrate 101 by sputtering.
  • the ratio of the nitrogen flow rate to the flow rate of the nitrogen source material and the inert gas in the chamber is 50% to 100%, preferably 75%. It is desirable to do so.
  • the buffer layer 102 having columnar crystals (polycrystal) is formed by sputtering, the ratio of the nitrogen flow rate to the nitrogen source flow rate in the chamber to the flow rate of the inert gas is preferably 1% to 50% for the nitrogen source. It is desirable to be 25%.
  • the buffer layer 102 can be formed not only by the sputtering method described above but also by the MOCVD method.
  • a single crystal base layer 103 is formed on the upper surface of the substrate 101 on which the buffer layer 102 is formed.
  • the base layer 103 is desirably formed by sputtering or sputtering.
  • the apparatus can have a simple configuration as compared with the MOCVD method, the MBE method, or the like.
  • a reactive sputtering method in which a group V material such as nitrogen is circulated in the reactor.
  • the underlayer 103 is formed by sputtering, it is possible to use a group III nitride semiconductor as a target material as a raw material and perform sputtering by plasma of an inert gas such as Ar gas.
  • the group III metal alone and the mixture thereof used as the target material in can be highly purified as compared with the group III nitride semiconductor. For this reason, in the reactive sputtering method, the crystallinity of the underlying layer 103 to be formed can be further improved.
  • the temperature of the substrate 101 when the base layer 103 is formed is preferably 800 ° C. or higher, more preferably 900 ° C. or higher, and 1000 ° C. or higher. Most preferably. This is because by increasing the temperature of the substrate 101 when forming the base layer 103, atom migration easily occurs and dislocation looping easily proceeds.
  • the temperature of the substrate 101 when the base layer 103 is formed needs to be lower than the temperature at which the crystal is decomposed, and is preferably less than 1200 ° C. If the temperature of the substrate 101 when forming the base layer 103 is within the above temperature range, the base layer 103 with good crystallinity can be obtained.
  • the n-type semiconductor layer 104 is formed by stacking the n-contact layer 104a and the n-cladding layer 104b.
  • the n contact layer 104a and the n clad layer 104b may be formed by sputtering or MOCVD.
  • the light emitting layer 105 can be formed by either sputtering or MOCVD, but MOCVD is particularly preferable.
  • the barrier layers 105a and the well layers 105b are alternately and repeatedly stacked, and the barrier layers 105a may be stacked in the order in which the barrier layers 105a are disposed on the n-type semiconductor layer 104 side and the p-type semiconductor layer 106 side. .
  • the p-type semiconductor layer 106 may be formed by either sputtering or MOCVD.
  • the p-cladding layer 106a and the p-contact layer 106b may be sequentially stacked.
  • Patterning is performed by a known photolithography technique, and a part of the laminated semiconductor layer 20 in a predetermined region is etched to expose a part of the n contact layer 104a.
  • the n-type electrode 108 is formed on the exposed surface 104c of the n-contact layer 104a by sputtering or the like.
  • the p-type electrode forming step includes a translucent electrode forming step and an electrode forming step.
  • ⁇ Translucent electrode forming step> The n-type electrode is covered with a mask, and the light-transmitting electrode 109 is formed on the p-type semiconductor layer 106 left without being removed by etching using a known method such as sputtering.
  • a part of the laminated semiconductor layer 20 in a predetermined region is etched to form the n contact layer 104a.
  • the n-type electrode 108 may be formed.
  • FIG. 5 is a process cross-sectional view illustrating an electrode forming process.
  • the metal reflection layer is formed so as to cover the bonding layer, and further the bonding layer is formed so as to cover the metal reflection layer, and the bonding layer, the metal reflection layer, and the bonding layer
  • the side surface is inclined so that the outer peripheral side is thinner than the center side.
  • FIG. 5B the portion of the resist 21 corresponding to the portion where the bonding pad electrode is to be formed is removed, thereby forming a cured portion (reverse taper type mask) made of a reverse taper type crosslinked polymer. 23 is formed.
  • a method of forming the inverse tapered mask 23 there are known methods such as a method using an n-type photoresist or a method using an image inversion type photoresist. In the first embodiment, an image inversion type photoresist is used. A method will be described.
  • FIG. 6 is a cross-sectional process diagram for explaining the reverse taper mask forming process shown in FIG.
  • the mask formation step includes: a resist coating step of forming a resist portion by applying an insoluble resist on the translucent electrode; and a soluble portion formed by exposure by masking and exposing a part of the resist portion.
  • a partial exposure step for forming an insoluble portion left unexposed a curing step in which the soluble portion becomes a cured portion by heating, and a resist portion is fully exposed to form the insoluble portion as a soluble portion.
  • ⁇ Resist application process> First, an insoluble resist is applied on the protective film 10 on the translucent electrode 109 and dried to form a resist portion 21.
  • the image reversal type photoresist for example, AZ5200NJ (product name: manufactured by AZ Electronic Materials Co., Ltd.) is used.
  • ⁇ Partial exposure process> Next, when viewed in cross section, as shown in FIG. 6A, a mask 25 is disposed on the upper surface of the resist portion 21 so as to cover the position where the electrode is formed, and from the mask 25 side to the substrate 1 side.
  • the resist portion 21 in the portion irradiated with light is photoreacted to form a soluble resist portion (soluble portion) 22. Since this photoreaction proceeds according to the intensity of light, the photoreaction progresses quickly on the light irradiation surface side, and the photoreaction progresses slowly on the translucent electrode 109 side. Therefore, the side surface of the soluble resist portion (soluble portion) 22 is directed toward the portion (position where the electrode is formed) covered with the mask 25 as shown in FIG. It forms so that it may become reverse taper shape (reverse inclination shape) which retreated inside, so that it goes below.
  • the masked portion of the resist portion 21 remains as an insoluble resist portion (insoluble portion) 21 and has a tapered shape (inclined shape) that recedes inward as the side faces upward when viewed in cross section. It is formed.
  • the soluble resist portion 22 is cross-linked by a thermal reaction as shown in FIG. It is set as the hardening part 23 which consists of.
  • the hardening part 23 which consists of.
  • FIG. 6C without using a mask, light is irradiated to the surface side of the insoluble resist portion (insoluble portion) 21 and the hardened portion 23 made of a crosslinked polymer, so that FIG.
  • the insoluble resist part (insoluble part) 21 that has not been converted into the soluble resist 22 in a) is photoreacted to form a soluble resist part (soluble part) 22.
  • RIE reactive ion etching
  • RIE reactive ion etching
  • the exposed upper surface 109c of the translucent electrode 109 is preferably wet etched. Accordingly, the upper surface 109c can be a fresh surface from which impurities and defects are removed, and adhesion with the bonding layer 110 bonded to the upper surface 109c can be improved.
  • the bonding layer 110 is formed on the upper surface 109c of the translucent electrode 109 and the cured portion (reverse taper type mask) 23 made of a crosslinked polymer by sputtering.
  • the bonding layer 110 can be formed with high coverage regardless of the sputtering material.
  • the bonding layer 110 is formed substantially uniformly over the entire upper surface 109 c of the translucent electrode 109 and is formed so as to partially cover the end portion 10 c of the protective film 10.
  • a metal reflection layer 117 is formed.
  • the metal reflective layer 117 can be formed with high coverage regardless of the sputtering material.
  • the metal reflective layer 117 is formed so as to completely cover the bonding layer 110 by forming the metal reflective layer 117 so as to be thicker than the bonding layer 110.
  • a bonding layer 119 is formed.
  • the bonding layer 119 can be formed with high coverage regardless of the sputtering material.
  • the bonding layer 119 is formed so as to be much thicker than the bonding layer 110 and the metal reflective layer 117, so that the metal reflective layer 117 is completely covered as shown in FIG. Is done.
  • the cured portion (reverse taper type mask) 23 made of a crosslinked polymer is peeled off by immersing in a resist stripping solution. Thereby, as shown in FIG. 5E, the p-type electrode 111 having the bonding pad electrode 120 composed of the metal reflection layer 117 and the bonding layer 119 is formed.
  • the film thickness is reduced in the portion that is shaded from the sputtering direction of the reverse tapered mask 23. Accordingly, layers having different inclination angles can be formed. Thereby, the inclined surfaces 110c, 117c, and 119c can be formed on the outer peripheral portions of the bonding layer 110 and the bonding pad electrode 120 so that the film thickness gradually decreases toward the outer peripheral side.
  • pretreatment for cleaning the surface of the light-transmitting electrode 109 in a region where the bonding layer 110 is formed may be performed.
  • a cleaning method there are a dry process that is exposed to plasma or the like and a wet process that is brought into contact with a chemical solution. The dry process is desirable from the viewpoint of simplicity of the process. In this way, the semiconductor light emitting device 1 shown in FIGS. 1 to 3 is manufactured.
  • one electrode 111 includes a bonding layer 110 and a bonding pad electrode 120 formed so as to cover the bonding layer 110, and the maximum thickness of the bonding pad electrode 120 is It is formed thicker than the maximum thickness of the bonding layer 110, and is composed of one or more layers.
  • the outer layer 110d and 120d of the bonding layer 110 and the bonding pad electrode 120 are gradually increased in thickness toward the outer periphery. Since the thin inclined surfaces 110c, 117c, and 119c are formed, it is possible to prevent external air or moisture from entering the bonding layer 110, improve the corrosion resistance of the bonding layer 110, and emit semiconductor light. The device life can be extended.
  • the bonding layer 110 has Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Since it is composed of at least one element selected from the group consisting of Rh, Ir and Ni and is a thin film having a maximum thickness in the range of 10 to 1000 mm, the translucent electrode 109 and the bonding pad electrode 120 Thus, an electrode that does not peel off due to tensile stress during bonding of the bonding wires can be obtained.
  • a semiconductor light-emitting device 1 is a thin film having a bonding layer made of Au, Al, or an alloy containing any of these metals, and a maximum thickness of the bonding layer in a range of 50 nm to 2000 nm. Since it is a structure, it can be set as the electrode which improves the bondability of the wire bonding to the bonding pad electrode 120, and does not peel even by the tensile stress at the time of bonding wire bonding.
  • the bonding pad electrode 120 includes a metal reflective layer 117 formed so as to cover the bonding layer 110, and a bonding layer 120 formed so as to cover the metal reflective layer 117.
  • the metal reflective layer 117 is made of Ag, Al, Ru, Rh, Pd, Os, Ir, Pt, Ti or an alloy containing any of these metals, and has a maximum thickness of 20 nm. Since the thin film has a thickness in the range of 3000 nm or less, the bonding property and corrosion resistance of the electrodes can be improved, and the light emission characteristics of the semiconductor light emitting element can be improved.
  • a translucent electrode 109 is formed between one conductive electrode 111 and the upper surface 106c of the laminated semiconductor layer 20, and the translucent electrode 109 is A conductive oxide containing any one of In, Zn, Al, Ga, Ti, Bi, Mg, W, Ce, Sn, and Ni, a transparent material selected from the group consisting of any one of zinc sulfide and chromium sulfide. Since the structure is made of a light conductive material, the bonding property and corrosion resistance of the electrodes can be improved, and the light emission characteristics of the semiconductor light emitting element can be improved.
  • the laminated semiconductor layer 20 is formed by laminating the n-type semiconductor layer 104, the light-emitting layer 105, and the p-type semiconductor layer 106 in this order from the substrate 101 side. Since the structure has a multi-quantum well structure, it is possible to improve the bondability and corrosion resistance of the electrodes and improve the light emission characteristics of the semiconductor light emitting device.
  • the laminated semiconductor layer 20 is mainly composed of a gallium nitride-based semiconductor, the bonding property and corrosion resistance of the electrodes are improved, and the light emitting characteristics of the semiconductor light emitting device are improved. Can be improved.
  • the electrode for the semiconductor light emitting device 1 includes a bonding pad electrode 120 formed so that at least one of the one electrode 111 and the other electrode 108 covers the bonding layer 110 and the bonding layer 110.
  • the bonding pad electrode 120 has a maximum thickness that is larger than the maximum thickness of the bonding layer 110, and is composed of one or more layers.
  • the outer peripheral portion 110d of the bonding layer 110 and the bonding pad electrode 120 Since the inclined surfaces 110c, 117c, and 119c are formed in 120d so that the film thickness gradually decreases toward the outer peripheral side, it is possible to obtain an electrode with improved bondability and corrosion resistance.
  • the bonding layer 110 has Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, and W. , Re, Rh, Ir, Ni, and at least one element selected from the group consisting of a thin film having a maximum thickness in the range of 10 mm to 1000 mm, so that the electrode has improved bondability and corrosion resistance It can be.
  • the bonding pad electrode 120 is made of a bonding layer 119 made of Au, Al, or an alloy containing any of these metals, and the bonding layer 119 has a maximum thickness. Since it is a structure which is a thin film of the range of 50 nm or more and 2000 nm or less, it can be set as the electrode which improved the bondability and corrosion resistance with a gold wire.
  • the bonding pad electrode 120 is formed so as to cover the bonding layer 110, and the bonding is formed so as to cover the metal reflecting layer 117.
  • the metal reflective layer 117 is made of Ag, Al, Ru, Rh, Pd, Os, Ir, Pt, Ti or an alloy containing any of these metals, and the maximum Since the thin film has a thickness in the range of 20 nm to 3000 nm, an electrode with improved light extraction efficiency can be obtained.
  • the electrode for the semiconductor light emitting device 1 is a translucent electrode between one electrode 111 and the upper surface 106c of the laminated semiconductor layer 20 or between the other electrode 108 and the semiconductor layer exposed surface 104c.
  • 109 is a conductive oxide containing any one of In, Zn, Al, Ga, Ti, Bi, Mg, W, Ce, Sn, Ni, zinc sulfide, Since it is the structure comprised from the translucent electroconductive material chosen from the group which consists of either 1 type among chromium sulfide, it can be set as the electrode which improved bondability and corrosion resistance.
  • the electrode forming step forms the inverse tapered mask 23 on the upper surface 106 c of the stacked semiconductor layer 20, and then the bonding layer 110 on the upper surface 106 c of the stacked semiconductor layer 20.
  • the bonding pad electrode 120 having a maximum thickness compared to the maximum thickness of the bonding layer 110 is formed so as to cover the bonding layer 110, and the one electrode 111 is formed.
  • Inclined surfaces 110c, 117c, and 119c can be formed on the outer peripheral portions 110d and 120d of the 110 and the bonding pad electrode 120 so that the outer peripheral side gradually becomes thinner, thereby preventing external air or moisture from entering the bonding layer 110. Therefore, the corrosion resistance of the bonding layer 110 can be improved, and the lifetime of the semiconductor light emitting device can be extended.
  • the method for manufacturing a semiconductor light emitting device includes a step of forming the translucent electrode 109 on the upper surface 106c of the stacked semiconductor layer 20 or the exposed surface 104c of the semiconductor layer before the electrode forming step, Electrode bondability and corrosion resistance can be improved, and the light emission characteristics of the semiconductor light emitting device can be improved.
  • the electrode forming step forms the inverse tapered mask 23 and the bonding layer 110 and then covers the bonding layer 110 so as to cover the bonding layer 110.
  • a metal reflective layer 117 having a maximum thickness is formed, and then a bonding layer 120 having a maximum thickness compared to the maximum thickness of the metal reflective layer 117 is formed so as to cover the metal reflective layer 117, and one electrode 111 is formed. Therefore, the inclined surfaces 110c, 117c, and 119c can be formed on the outer peripheral portions 110d and 120d of the bonding layer 110 and the bonding pad electrode 120 so that the outer peripheral sides become gradually thinner. Intrusion into the bonding layer 110 can be prevented, the corrosion resistance of the bonding layer 110 is improved, and the lifetime of the semiconductor light emitting device is extended. It is possible.
  • the formation of the bonding layer 110, the metal reflection layer 117, and the bonding layer 119 in the bonding electrode forming step is performed by the sputtering method, In a portion shaded from the sputtering direction, layers having different inclination angles can be formed according to the film thickness. Thereby, the inclined surfaces 110c, 117c, and 119c can be formed on the outer peripheral portions 110d and 120d of the bonding layer 110 and the bonding pad electrode 120 so that the outer peripheral sides become gradually thinner. Can be prevented, the corrosion resistance of the bonding layer 110 can be improved, and the lifetime of the semiconductor light emitting device can be extended.
  • the method of manufacturing a semiconductor light emitting device includes a step of forming the protective film 10 on the upper surface 109c of the translucent electrode 109 before the mask forming step, The top surface can be protected.
  • FIG. 7 is a schematic cross-sectional view showing another example of the semiconductor light emitting device according to the embodiment of the present invention.
  • another bonding layer 130 is formed on the exposed surface 104 c opened in the protective film 10 formed on the n-type semiconductor layer 104.
  • the configuration is the same as that of the first embodiment except that the n-type electrode 108 is formed so as to cover another bonding layer 130.
  • the same members as those in the first embodiment are denoted by the same reference numerals.
  • An inclined surface 130c is formed on the outer peripheral portion 130d of the bonding layer 130 so that the film thickness gradually decreases toward the outer peripheral side.
  • the maximum thickness of the n-type electrode 108 that also serves as a bonding pad electrode is formed to be thicker than the maximum thickness of the bonding layer 130 and is formed of one layer.
  • An inclined surface 108c is formed on the outer peripheral portion 108d of the n-type electrode 108 serving also as a bonding pad electrode so that the film thickness gradually decreases toward the outer peripheral side.
  • the n-type electrode bonding layer 130 may be formed between the n-type electrode 108 and the n-type semiconductor layer 104.
  • the bonding layer 130 is preferably made of the same material as that of the bonding layer 110 of the p-type electrode 111, and the maximum thickness is preferably in the same range and in the range of 10 to 1000 mm. Thereby, the bonding strength of the n-type electrode 108 to the n-type semiconductor layer 104 can be significantly increased.
  • a layer made of the above-described translucent conductive material Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W
  • a laminated structure with a metal film made of at least one element selected from the group consisting of Re, Rh, Ir, and Ni may be adopted.
  • a layer made of a light-transmitting conductive material and a metal film such as Cr may be sequentially stacked on the n-type semiconductor layer 104.
  • the bonding layer 130 it is more preferable to use an electrode having the same configuration as the bonding pad electrode 120 as the n-type electrode 108. That is, when the bonding pad electrode 120 has a two-layer structure of the metal reflection layer 117 and the bonding layer 119, the n-type electrode 108 is any one of Ag, Al, Pt group elements or any of these metals.
  • a laminated structure including at least a metal reflective layer made of an alloy containing and a bonding layer is preferable.
  • the bonding layer 130 is formed between the n-type electrode 108 and the n-type semiconductor layer 104, the light-transmitting electrode 109 of the p-type electrode 111 is formed, and then the bonding layer 110 of the p-type electrode 111 is formed.
  • the bonding layer 130 for the n-type electrode 108 is formed simultaneously with the formation, and then the n-type electrode 108 may be formed simultaneously with the formation of the bonding pad electrode 120 of the p-type electrode 111.
  • the n-type electrode 108 may have a three-layer structure including a stacked body in which a metal reflective layer, a barrier layer, and a bonding layer are sequentially stacked from the n-type semiconductor layer 104 side.
  • the n-type electrode 108 may have a single-layer structure including only a bonding layer that also serves as a metal reflection layer.
  • the other electrode 108 includes a bonding layer 130 and a bonding pad electrode 108 that also serves as the other electrode formed so as to cover the bonding layer 130.
  • the maximum thickness is formed thicker than the maximum thickness of the bonding layer 110, and is formed of one layer.
  • the film thickness gradually increases toward the outer peripheral side of the bonding layer 130 and the outer peripheral portions 130d and 108d of the bonding pad electrode 108, respectively. Since the thin inclined surfaces 130c and 108c are formed, it is possible to prevent external air or moisture from entering the bonding layer 130, improve the corrosion resistance of the bonding layer 130, and improve the lifetime of the semiconductor light emitting device. Can be lengthened.
  • FIG. 8 is a schematic cross-sectional view showing still another example of the semiconductor light emitting device according to the embodiment of the present invention, and is an enlarged cross-sectional view of a p-type electrode.
  • the semiconductor light emitting device according to the embodiment of the present invention is omitted in the drawing, but the protective film is not formed on the translucent electrode 109 of the p-type electrode 112. It is set as the same structure.
  • the same members as those in the first embodiment are denoted by the same reference numerals.
  • the metal reflective layer 117 is formed so as to cover the bonding layer 110
  • the bonding layer 119 is formed so as to cover the metal reflective layer 117.
  • the outer peripheral portions 110d and 120d of the bonding layer 110, the metal reflection layer 117, and the bonding layer 119 are inclined surfaces 110c, 117c, and 119c formed so that the film thickness gradually decreases toward the outer peripheral side.
  • External air or moisture can enter the bonding layer 110 unless it passes through the bonding surface between the translucent electrode 109 and the bonding layer 119 and the bonding surface between the translucent electrode 109 and the metal reflective layer 117. Therefore, it is difficult for external air or moisture to enter the bonding layer 110. Thereby, the bonding layer 110 is not easily decomposed, and the element lifetime of the semiconductor light emitting element can be extended.
  • the semiconductor light emitting device 1 includes a metal reflection layer 117 formed so that the bonding pad electrode 120 covers the bonding layer 110, and a bonding layer 119 formed so as to cover the metal reflection layer 117.
  • the outer peripheral portions 110d and 120d of the bonding layer 110, the metal reflective layer 117, and the bonding layer 119 are inclined surfaces 110c, 117c, and 119c formed so that the film thickness gradually decreases toward the outer peripheral side, respectively.
  • FIG. 9 is a schematic cross-sectional view showing an example of a lamp according to an embodiment of the present invention.
  • the lamp 3 according to the embodiment of the present invention is a shell type, and the semiconductor light emitting element 1 according to the embodiment of the present invention is used.
  • the lamp 3 according to the embodiment of the present invention is, for example, a combination of the semiconductor light emitting element 1 and a phosphor, and can have a configuration well known to those skilled in the art by means known to those skilled in the art. Further, it is known that the emission color can be changed by combining the semiconductor light emitting element 1 and the phosphor, but such a technique is adopted without any limitation in the lamp which is an embodiment of the present invention. It is possible.
  • the bonding pad electrode 120 of the p-type electrode 111 of the semiconductor light emitting device 1 is bonded to the frame 31 by the wire 33, and the n-type electrode 108 (bonding pad) of the semiconductor light emitting device 1 is connected by the wire 34 to the other side.
  • the frame 32 is joined and mounted. Further, the periphery of the semiconductor light emitting element 1 is sealed with a mold 35 made of a transparent resin.
  • a lamp 3 according to an embodiment of the present invention includes a semiconductor light-emitting element 1 described above, and a bonding pad on which the semiconductor light-emitting element 1 is disposed and one conductive type electrode (p-type electrode) 111 is disposed.
  • the first frame 31 is wire-bonded to the electrode 120
  • the second frame 32 is wire-bonded to another conductive electrode (n-type electrode) 108 of the semiconductor light emitting device 1, and the semiconductor light emitting device 1 is formed.
  • the mold 35 is provided with an excellent light emitting characteristic, can prevent external air or moisture from entering the bonding layer 110, improves the corrosion resistance of the bonding layer 110, and emits semiconductor light. It is possible to obtain a lamp having a long element life.
  • the lamp 3 according to the embodiment of the present invention can be used for any purposes such as a general-purpose shell type, a side view type for portable backlight use, and a top view type used for a display.
  • FIG. 10 is a schematic cross-sectional view showing still another example of the semiconductor light emitting device according to the embodiment of the present invention, and is an enlarged cross-sectional view of a p-type electrode.
  • the semiconductor light emitting device according to the embodiment of the present invention completely covers the outer periphery of the p-type electrode 111, that is, the boundary that forms the contour line when the p-type electrode 111 is viewed in plan.
  • the structure is the same as that of the first embodiment except that another protective film 11 is formed so as to cover it.
  • the same members as those in the first embodiment are denoted by the same reference numerals.
  • the p-type electrode 111 includes a translucent electrode 109, a bonding layer 110, and a bonding pad electrode 120, and is schematically formed by being formed on the p-type semiconductor layer 106.
  • Upper surface 109c of the transparent electrode 109 is covered by a protective film 10 made of SiO 2, a portion of the protective film 10 is being opened openings 10d formed, the upper surface of the transparent electrode 109 through the opening 10d Part of 109c is exposed.
  • the bonding layer 110 covers the upper surface 109c of the translucent electrode 109 exposed from the opening 10d with a substantially uniform film thickness, and the film thickness is increased on the outer peripheral side of the opening 10d. It is formed so as to cover the end portion 10c.
  • an inclined surface 110c is formed on the outer peripheral portion 110d of the bonding layer 110 that covers the end portion 10c of the protective film 10 so that the film thickness gradually decreases toward the outer peripheral side.
  • the bonding pad electrode 120 includes a metal reflection layer 117 and a bonding layer 119 that are formed to be thicker than the maximum thickness of the bonding layer 110.
  • an inclined surface 119c is formed on the outer peripheral portion 120d of the bonding pad electrode 120 so that the film thickness gradually decreases toward the outer peripheral side.
  • An inclined surface 117c is formed on the outer peripheral portion of the metal reflective layer 117 so that the film thickness gradually decreases toward the outer peripheral side.
  • the metal reflective layer 117 is formed so as to cover the bonding layer 110.
  • the metal reflection layer 117 is formed so as to completely cover the leading edge of the inclined surface 110c of the bonding layer 110, that is, the boundary that forms the contour line when the bonding layer 110 is viewed in plan. . That is, when viewed in plan, the metal reflective layer 117 is formed so as to cover the bonding layer 110 and further extend to the outer peripheral side of the bonding layer 110, so any portion of the bonding layer 110 can be any metal reflective layer 117. It is possible to prevent exposure from below.
  • an inclined surface 119c is formed on the outer peripheral portion of the bonding layer 119 so that the film thickness gradually decreases toward the outer peripheral side.
  • the bonding layer 119 is formed so as to cover the metal reflective layer 117.
  • the bonding layer 119 is formed so as to completely cover the tip of the tip of the inclined surface 117c of the metal reflection layer 117, that is, the boundary that forms the contour line when the metal reflection layer 117 is viewed in plan. Yes. That is, since the bonding layer 119 is formed so as to cover the metal reflection layer 117 and project to the outer peripheral side of the metal reflection layer 117 when seen in a plan view, any portion of the metal reflection layer 117 can be bonded to the bonding layer. It is possible to prevent exposure from below 119.
  • Another protective film 11 is formed so as to cover a boundary portion that forms a contour line when the bonding pad electrode 120 p-type electrode 111 is viewed in plan. That is, another protective film 11 is laminated on the protective film 10, and the end portion 11c rides on the inclined surface 119c so as to completely cover the inclined surface (tapered surface) 119c of the bonding layer 119.
  • the layer 119 is formed so as to partially cover the upper surface 119d. Since the boundary between the bonding layer 119 and the protective film 10 is covered with another protective film 11, moisture can be prevented from entering from the boundary between the bonding layer 119 and the protective film 10. It is not easy to get into. Therefore, the bonding layer 110 is not easily decomposed, and the element lifetime of the semiconductor light emitting element can be extended.
  • the other protective film 11 only needs to be formed so as to completely cover the boundary that forms the contour line when the bonding pad electrode 120 is viewed in plan, and almost covers the p-type electrode 111 and contacts. You may form so that the exposure area
  • the material of the other protective film 11 may be any material that can protect the bonding layer 110 from external air or moisture.
  • another protective film 11 can be formed with high adhesion, and the other protective film 11 can be prevented from being easily peeled off.
  • the p-type electrode 111 can be firmly fixed.
  • the material of the protective film 11 it is preferable to use the same material as that of the protective film 10.
  • the material of the protective film 10 it is preferable to use SiO 2 as the material of the protective film 11.
  • FIG. 11 is a schematic cross-sectional view showing still another example of the semiconductor light emitting device according to the embodiment of the present invention, and is an enlarged cross-sectional view of a p-type electrode.
  • another protective film 11 is formed so as to completely cover the boundary that forms the outline when the bonding pad electrode 120 is viewed in plan.
  • the configuration is the same as that of the third embodiment.
  • the same members as those in the third embodiment are denoted by the same reference numerals.
  • the p-type electrode 112 includes a translucent electrode 109, a bonding layer 110, and a bonding pad electrode 120, and is formed on the p-type semiconductor layer 106 and schematically configured.
  • the bonding layer 110 formed at a position and size corresponding to the p-type electrode 112 covers the upper surface 109c of the translucent electrode 109 with a substantially uniform film thickness, and the outer peripheral portion 110d of the bonding layer 110 has an outer peripheral side.
  • An inclined surface 110c is formed so that the film thickness gradually decreases toward the surface.
  • the bonding pad electrode 120 includes a metal reflection layer 117 and a bonding layer 119 that are formed to be thicker than the maximum thickness of the bonding layer 110.
  • an inclined surface 119c is formed on the outer peripheral portion 120d of the bonding pad electrode 120 so that the film thickness gradually decreases toward the outer peripheral side.
  • An inclined surface 117c is formed on the outer peripheral portion of the metal reflective layer 117 so that the film thickness gradually decreases toward the outer peripheral side.
  • the metal reflective layer 117 is formed so as to cover the bonding layer 110. In other words, the metal reflection layer 117 is formed so as to completely cover the leading edge of the inclined surface 110c of the bonding layer 110, that is, the boundary that forms the contour line when the bonding layer 110 is viewed in plan. .
  • the metal reflective layer 117 is formed so as to cover the bonding layer 110 and further extend to the outer peripheral side of the bonding layer 110, so any portion of the bonding layer 110 can be any metal reflective layer 117. It is possible to prevent exposure from below.
  • an inclined surface 119c is formed on the outer peripheral portion of the bonding layer 119 so that the film thickness gradually decreases toward the outer peripheral side.
  • the bonding layer 119 is formed so as to cover the metal reflective layer 117.
  • the bonding layer 119 is formed so as to completely cover the tip of the tip of the inclined surface 117c of the metal reflection layer 117, that is, the boundary that forms the contour line when the metal reflection layer 117 is viewed in plan. Yes. That is, since the bonding layer 119 is formed so as to cover the metal reflection layer 117 and project to the outer peripheral side of the metal reflection layer 117 when seen in a plan view, any portion of the metal reflection layer 117 can be bonded to the bonding layer. It is possible to prevent exposure from below 119.
  • the boundary part that forms the contour line when the bonding layer 119 is viewed in plan is the boundary part that forms the contour line when the p-type electrode 111 is viewed in plan.
  • Another protective film 11 is formed so as to cover a boundary portion that forms a contour line when the bonding pad electrode 120 is viewed in plan. That is, another protective film 11 is laminated on the translucent electrode 109, and the end portion 11c rides on the inclined surface 119c so as to completely cover the inclined surface (tapered surface) 119c of the bonding layer 119, Further, it is formed so as to cover a part of the upper surface 119d of the bonding layer 119. Since the boundary between the bonding layer 119 and the translucent electrode 109 is covered with another protective film 11, moisture can be prevented from entering from the boundary between the bonding layer 119 and the translucent electrode 109. It is not easy to penetrate into the bonding layer 110.
  • the other protective film 11 only needs to be formed so as to completely cover the boundary that forms the contour line when the bonding pad electrode 120 is viewed in plan, and almost covers the p-type electrode 112 and contacts. You may form so that the exposure area
  • the material of the other protective film 11 may be any material that can protect the bonding layer 110 from external air or moisture.
  • another protective film 11 can be formed with high adhesion, and the other protective film 11 can be prevented from being easily peeled off.
  • the p-type electrode 112 can be firmly fixed.
  • the manufacturing method of the semiconductor light emitting device of Embodiment 7 is the manufacturing method of the semiconductor light emitting device 1 shown in FIG.
  • the laminated semiconductor layer 20 is formed on the substrate 101.
  • the stacked semiconductor layer 20 is formed by the MOCVD method, a layer having good crystallinity can be obtained.
  • the sputtering method a layer having crystallinity superior to the MOCVD method can be obtained.
  • the “layered semiconductor layer formation” including the buffer layer forming step, the base layer forming step, the n-type semiconductor layer forming step, the light-emitting layer forming step, and the p-type semiconductor layer forming step is referred to as the semiconductor light-emitting device of the first embodiment. It is performed according to the manufacturing method. Then, after forming the stacked semiconductor layer 20 in this manner, the n-type electrode 108 and the p-type electrode 111 are formed.
  • ⁇ N-type electrode formation process First, patterning is performed by a known photolithography technique, and a part of the laminated semiconductor layer 20 in a predetermined region is etched to expose a part of the n contact layer 104a. Next, the n-type electrode 108 is formed on the exposed surface 104c of the n contact layer 104a by sputtering or the like.
  • FIG. 18 is a process diagram for explaining a process of manufacturing the p-type electrode, and is an enlarged cross-sectional view showing only a part of a region where the p-type electrode 111 is manufactured.
  • the translucent electrode 109 is formed on the p-type semiconductor layer 106.
  • the translucent electrode 109 is formed by forming a mask that covers a region other than the region where the translucent electrode 109 is formed, such as the exposed surface 104c of the n contact layer 104a where the n-type electrode 108 is formed, and then forming a p-type semiconductor layer. It is formed on the film 106 using a known method such as a sputtering method, and then formed by a method of removing the mask. Note that the translucent electrode 109 may be formed after the n-type electrode 108 is formed, but may be formed before the etching of the stacked semiconductor layer 20 for forming the n-type electrode 108.
  • a transparent protective film 10a is formed on the upper surface 109c of the translucent electrode 109, and a resist 21 is applied on the transparent protective film 10a and dried.
  • the cross-sectional area of the upper surface 109c of the transparent electrode 109 on which the transparent protective film 10a is formed gradually increases toward the bottom surface.
  • a reverse-tapered mask 23 shown in FIG. 18 (b) having an opening 23a having an inner wall shape that becomes wider is formed. Examples of the method for forming the inverse taper type mask 23 include a method using an n-type photoresist and a method using an image inversion type photoresist.
  • FIG. 19 is a process diagram for explaining the manufacturing process of the mask shown in FIG. 18B, and is an enlarged sectional view showing only a region where one p-type electrode 111 is formed.
  • an insoluble resist that is an image reversal type photoresist is used as the resist 21.
  • the image reversal type photoresist for example, AZ5200NJ (product name: manufactured by AZ Electronic Materials Co., Ltd.) is used.
  • a mask 25 is disposed so as to cover a predetermined position above the resist 21, and from the mask 25 side to the resist 21 side as shown by an arrow in FIG. Is irradiated with light of a predetermined intensity and wavelength. As a result, the portion of the resist 21 irradiated with light is photoreacted to form a soluble portion 22.
  • the fusible portion 22 is formed to have a reverse taper shape (reverse inclination shape) that recedes inward as the side faces downward when viewed in cross section.
  • the resist 21 in the portion covered with the mask 25 is left as an insoluble resist (insoluble portion) 21 so as to have a tapered shape (inclined shape) that recedes inward as the side faces upward when viewed in cross section. Formed.
  • the fusible part 22 is thermally reacted to form a cured part (mask) made of a crosslinked polymer. 23.
  • the surface side of the insoluble resist 21 and the cured portion (mask) 23 made of the crosslinked polymer is irradiated with light of a predetermined intensity and wavelength without using a mask.
  • the insoluble resist 21 that has not been converted into the soluble portion 22 by the photoreaction described with reference to FIG.
  • a mask 23 made of a cross-linked polymer having an inversely tapered shape (inversely inclined shape) having a portion 23a is obtained.
  • the transparent protective film 10a exposed from the opening 23a of the mask 23 shown in FIG. 18B is removed by RIE (reactive ion etching) from a direction perpendicular to the upper surface 109c of the translucent electrode 109.
  • RIE reactive ion etching
  • FIG. 18C an opening 10d is formed, and the upper surface 109c of the translucent electrode 109 is exposed from the opening 10d. Since RIE (Reactive Ion Etching) is an etching method with high straightness and less wraparound, the transparent protective film 10a in the region that is a shadow of the mask 23 when viewed from the etching direction (upward in FIG. 18)
  • the end portion 10c of the transparent protective film 10a remains as shown in FIG. 18C without being removed by etching.
  • the translucent electrode 109 exposed from the opening 23a of the mask 23 is etched to form a bonding recess 109a in the upper surface 109c of the translucent electrode 109.
  • the bonding recess 109 a By forming the bonding recess 109 a, the inner surface of the bonding recess 109 a that appears from the translucent electrode 109 has better adhesion to the bonding layer 110 than the upper surface 109 c of the translucent electrode 109.
  • the translucent electrode 109 to be etched here is, for example, an amorphous IZO film, the bonding recess 109a having a specific shape can be easily formed with excellent etching properties.
  • the amorphous IZO film can be easily and accurately etched using a known etching solution (for example, ITO-07N etching solution (manufactured by Kanto Chemical Co., Inc.)).
  • a known etching solution for example, ITO-07N etching solution (manufactured by Kanto Chemical Co., Inc.)
  • the amorphous IZO film may be etched using a dry etching apparatus.
  • Cl 2 , SiCl 4 , BCl 3, or the like can be used as an etching gas at this time.
  • the IZO film in an amorphous state by performing the heat treatment, the IZO film and containing an In 2 O 3 crystal having a hexagonal structure, it is preferable that the IZO film containing an In 2 O 3 crystal having a bixbyite structure.
  • the light-transmitting electrode 109 having better adhesion to the bonding layer 110 and light-transmitting property than the amorphous IZO film can be obtained.
  • an IZO film containing an In 2 O 3 crystal having a hexagonal crystal structure is difficult to etch, it is preferable to perform heat treatment after the above-described etching treatment.
  • the crystal structure in the IZO film differs depending on the film formation conditions, heat treatment conditions, and the like.
  • Heat treatment for crystallizing the IZO film is preferably performed in an atmosphere containing no O 2, as the atmosphere containing no O 2, or an inert gas atmosphere such as N 2 atmosphere, or an inert, such as N 2
  • N 2 atmosphere an inert gas atmosphere of gas and H 2
  • N 2 atmosphere or a mixed gas atmosphere of N 2 and H 2 is desirable.
  • the IZO film is crystallized into a film containing In 2 O 3 crystals having a hexagonal structure, and IZO It is possible to effectively reduce the sheet resistance of the membrane.
  • the heat treatment temperature for crystallizing the IZO film is preferably 500 ° C. to 1000 ° C.
  • the IZO film may not be sufficiently crystallized, and the light transmittance of the IZO film may not be sufficiently high.
  • the IZO film is crystallized, but the light transmittance of the IZO film may not be sufficiently high.
  • the semiconductor layer under the IZO film may be deteriorated.
  • the bonding layer 110 is formed by sputtering to cover the bonding recess 109a of the translucent electrode 109.
  • the coverage of the bonding layer 110 can be increased by using a sputtering method in which the sputtering conditions are controlled.
  • the bonding layer 110 includes the entire surface of the bonding recess 109a of the translucent electrode 109, the entire surface of the inner wall surface of the opening 10d of the transparent protective film 10a, and a part of the end 10c of the transparent protective film 10a.
  • An inclined surface 110c is formed on the outer peripheral portion 110d of the bonding layer 110 so as to cover and gradually decrease in thickness toward the outside.
  • a pretreatment may be performed to clean the surface of the bonding recess 109a of the translucent electrode 109 on which the bonding layer 110 is formed.
  • the cleaning method include a dry process method exposed to plasma and the like, and a wet process method in contact with a chemical solution, but it is desirable to use a dry process method from the viewpoint of simplicity of the process.
  • a metal reflection layer 117 is formed by sputtering.
  • the coverage of the metal reflective layer 117 can be increased, and the bonding layer 110 is covered and directed outward.
  • a metal reflection layer 117 having an inclined surface 117c whose thickness is gradually reduced at the outer peripheral portion is formed.
  • a bonding layer 119 is formed by sputtering.
  • the coverage of the bonding layer 119 can be increased, and the shape of the outer peripheral portion is formed along the shape of the inner wall of the opening 23a of the mask 23.
  • a bonding layer 119 (bonding pad electrode 120) is formed that covers the layer 117 and has an inclined surface 119c that gradually decreases in thickness toward the outside at the outer peripheral portion 120d.
  • the mask 23 made of a crosslinked polymer is peeled off by being immersed in a resist stripping solution.
  • a bonding pad electrode 120 composed of the metal reflection layer 117 and the bonding layer 119 is formed.
  • a mask 23 having an opening 23a having an inner wall shape whose cross-sectional area gradually increases toward the bottom surface is formed, and the bonding layer 110, the metal reflective layer 117, and the bonding layer 119 have high coverage. Since it is formed by the sputtering method, a layer having a different inclination angle is formed in the shadowed area of the mask 23 when viewed from the sputtering direction according to the thickness of each layer constituting the bonding layer 110, the metal reflection layer 117, and the bonding layer 119. Is done. As a result, inclined surfaces 110c, 117c, and 119c are formed on the outer peripheral portions of the bonding layer 110, the metal reflective layer 117, and the bonding layer 119, respectively, with the thickness gradually decreasing toward the outside.
  • the bonding pad electrode 120 when viewed in plan, it has a substantially donut shape that exposes the central portion of the bonding pad electrode 120, and is transparent to the outer edge portion (contour line) of the bonding pad electrode 120.
  • An edge protective film 10b that covers the outer edge of the bonding pad electrode 120 is formed across a portion that becomes a joint with the protective film 10a.
  • the bonding pad electrode 120 since the bonding pad electrode 120 has an inclined surface 119c whose thickness is gradually decreased toward the outside, formed on the outer peripheral portion 120d, the edge protection film 10b is formed on the bonding pad electrode 120.
  • the inclined surface 119c is easily formed with a uniform thickness.
  • edge protection film 10b This prevents a portion where the edge protection film 10b is not formed on a portion that becomes a joint between the outer edge (contour line) of the bonding pad electrode 120 and the transparent protection film 10a, and the outer edge of the bonding pad electrode 120 is prevented.
  • the edge protective film 10b straddling the portion that becomes the joint between the portion (contour line) and the transparent protective film 10a can be formed by easily adhering to the uniform film thickness. In this way, the semiconductor light emitting element 1 including the p-type electrode 111 shown in FIGS. 14 to 16 is formed.
  • the p-type electrode 111 includes the translucent electrode 109 having the bonding recess 109a on the upper surface 109c, the bonding layer 110 formed so as to cover the bonding recess 109a, and the bonding layer 110.
  • the bonding pad electrode 120 is formed on the outer peripheral portion 120d and has an inclined surface 119c that gradually decreases in thickness toward the outer side. A sufficiently high bonding force with the bonding pad electrode 120 is obtained, and the bonding property of the p-type electrode 111 is excellent.
  • the bonding pad electrode 120 having the inclined surface 119c whose thickness is gradually decreased toward the outside on the outer peripheral portion 120d is formed so as to cover the bonding layer 110. Therefore, intrusion of air and moisture from the outside to the bonding layer 110 can be effectively prevented, and excellent corrosion resistance can be obtained.
  • the effect of the semiconductor light emitting device 1 of the present embodiment will be described by taking, for example, a semiconductor light emitting device including a p-type electrode shown in FIG.
  • a semiconductor light emitting device including a p-type electrode shown in FIG. 25 only the p-type electrode provided in the semiconductor light emitting element is shown, and the substrate and the laminated semiconductor layer are not shown.
  • the edge protection film 10b is not formed, and the bonding recess 109a is not formed on the upper surface 109c of the translucent electrode 109.
  • the side surfaces of the bonding layer 210, the metal reflective layer 217 constituting the bonding pad electrode 220, and the bonding layer 219 are formed substantially perpendicular to the upper surface 109c of the translucent electrode 109.
  • the bonding layer 210 In the p-type electrode 201 shown in FIG. 25, external air or moisture easily enters from between the transparent protective film 10a and the metal reflective layer 217 and reaches the bonding layer 210. When air or moisture reaches the bonding layer 210, the bonding layer 210 deteriorates, causing a problem that the element lifetime of the semiconductor light emitting element is shortened.
  • the bonding layer 210 is made of Cr, Cr is easily oxidized or hydroxylated by air or moisture that reaches the bonding layer 210, and the bonding layer 210 is decomposed and lost. Become prominent. Further, since the oxidation or hydroxylation reaction of Cr is accelerated by applying a bias to the semiconductor light emitting device including the p-type electrode 201 shown in FIG. 25, the bonding layer 210 may be easily decomposed and lost. was there.
  • the bonding pad electrode is formed so as to cover the bonding layer 110, and the inclined surface 119c is formed on the outer peripheral portion 120d so that the film thickness gradually decreases toward the outside. Since 120 is provided, no part of the bonding layer 110 is exposed from below the bonding pad electrode 120. Therefore, according to the semiconductor light emitting device 1 of the present embodiment, air or moisture outside the semiconductor light emitting device 1 can be effectively prevented from entering the bonding layer 110, and the bonding layer 110 is made of Cr. Even so, excellent corrosion resistance and excellent bondability between the translucent electrode 109 and the bonding pad electrode 120 by the bonding layer 110 can be obtained.
  • the bonding layer 110 is formed of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh.
  • the thin film is made of at least one element selected from the group consisting of Ir, Ni, and has a maximum thickness in the range of 10 to 400 mm, the bonding property between the translucent electrode 109 and the bonding pad electrode 120 Can be further improved.
  • the transparent protective film 10a is formed so as to cover the region where the bonding recess 109a is not formed on the upper surface 109c of the translucent electrode 109, and the outer edge of the bonding layer 110 is formed. And the outer edge of the bonding pad electrode 120 are disposed on the transparent protective film 10a, so that even better corrosion resistance and bondability can be obtained.
  • the bonding pad electrode 120 is composed of the metal reflective layer 117 and the bonding layer 119, and no part of the bonding layer 110 is exposed from under the metal reflective layer 117. In addition, any part of the metal reflection layer 117 is not exposed from below the bonding layer 119, and the bonding layer 110 is double covered with the metal reflection layer 117 and the bonding layer 119. Furthermore, in the semiconductor light emitting device 1 of the present embodiment, the outer edge portion of the bonding pad electrode 120 is disposed on the transparent protective film 10a.
  • the semiconductor light emitting device 1 of the present embodiment does not pass through the joint surface between the transparent protective film 10a and the bonding layer 119 and the joint surface between the transparent protective film 10a and the metal reflective layer 117. 1 outside air or moisture cannot enter the bonding layer 110. Therefore, it is possible to more effectively prevent air or moisture outside the semiconductor light emitting element 1 from entering the bonding layer 110.
  • the edge protection film 10b that covers the outer edge of the bonding pad electrode 120 and exposes a part on the bonding pad electrode 120 is formed, so that it is further excellent. Corrosion resistance and bondability are obtained.
  • the step of manufacturing the p-type electrode 111 includes the step of forming the translucent electrode 109 and the step of forming the translucent electrode 109 on which the transparent protective film 10a is formed.
  • the step of forming the bonding recess 109a by etching the upper surface 109c of the translucent electrode 109 exposed from the opening 23a and the bonding recess 109a are covered.
  • Forming the bonding layer 110 the bonding layer 110 is formed in contact with the inner surface of the bonding recess 109 a that emerges from the translucent electrode 109 by forming the bonding recess 109 a.
  • the p-type electrode 111 having excellent adhesion to the bonding layer 110 can be obtained as compared with the case where the bonding layer 110 is formed on the upper surface 109 c of the translucent electrode 109.
  • FIG. 20 is a view showing another example of the semiconductor light emitting device of the present invention, and is a schematic cross-sectional view of the semiconductor light emitting device.
  • the semiconductor light emitting device 2 of the present embodiment shown in FIG. 20 is different from the semiconductor light emitting device 1 shown in FIG. 14 only in the n-type electrode 108, and other than the n-type electrode 108, the semiconductor light emitting device 1 shown in FIG. The same is said. Therefore, the same members as those of the seventh embodiment are denoted by the same reference numerals, and description thereof is omitted.
  • the same electrode as the p-type electrode 111 is used as the n-type electrode 108 except that the bonding pad electrode 120 has a single-layer structure composed of only the bonding layer 119. Is formed. Therefore, the n-type electrode 108 constituting the semiconductor light emitting element 2 of the present embodiment can be formed in the same manner as the p-type electrode 111 except that the metal reflective layer 117 is not formed.
  • the bonding property of the p-type electrode 111 is excellent as in the semiconductor light emitting device 1 shown in FIG.
  • the n-type electrode 108 has a translucent electrode 109 having a bonding recess 109a on the upper surface 109c and a bonding layer formed so as to cover the bonding recess 109a.
  • 110 and the bonding pad electrode 120 formed so as to cover the bonding layer 110 and formed with an inclined surface 119c whose thickness gradually decreases toward the outside on the outer peripheral portion 120d. A sufficiently high bonding force between the translucent electrode 109 and the bonding pad electrode 120 is obtained, and the bonding property of the n-type electrode 108 is excellent.
  • the bonding pad electrode 120 constituting the p-type electrode 111 and the n-type electrode 108 has an inclined surface 119c whose thickness is gradually reduced toward the outer periphery. Since the portion 120d is formed so as to cover the bonding layer 110, air and moisture can be effectively prevented from entering the bonding layer 110 from the outside, and excellent corrosion resistance is obtained. It will be.
  • the process of manufacturing the p-type electrode 111 and the n-type electrode 108 includes the process of forming the translucent electrode 109 and the transparent film on which the transparent protective film 10a is formed.
  • the bonding pad electrode 120 is formed which covers the bonding layer 110 and has an inclined surface 119c whose thickness is gradually reduced toward the outside at the outer peripheral portion 120d.
  • FIG. 21 is a view showing another example of the semiconductor light emitting device of the present invention, and is an enlarged schematic cross-sectional view of a p-type electrode constituting the semiconductor light emitting device.
  • the semiconductor light emitting device of this embodiment shown in FIG. 21 is different from the semiconductor light emitting device 1 shown in FIG. 14 only in that the transparent protective film 10a and the edge protective film 10b are not formed.
  • 14 is the same as the semiconductor light emitting device 1 shown in FIG. Therefore, the same members as those of the seventh embodiment are denoted by the same reference numerals, and description thereof is omitted.
  • the p-type electrode 112 constituting the semiconductor light emitting device of this embodiment can be formed in the same manner as the p-type electrode 111 shown in FIG. 14 except that the transparent protective film 10a and the edge protective film 10b are not formed.
  • the p-type electrode 112 has the translucent electrode 109 having the bonding recess 109a on the upper surface 109c.
  • a bonding layer 110 formed so as to cover the bonding recess 109a, and an inclined surface 119c formed so as to cover the bonding layer 110 and gradually decreasing in thickness toward the outside on the outer peripheral portion 120d. Since the pad electrode 120 is provided, a sufficiently high bonding force between the translucent electrode 109 and the bonding pad electrode 120 is obtained by the bonding layer 110, and the bonding property of the p-type electrode 112 is excellent.
  • the bonding pad electrode 120 having the inclined surface 119c whose thickness gradually decreases toward the outer side at the outer peripheral portion 120d is formed so as to cover the bonding layer 110. Intrusion of air and moisture from the outside to the bonding layer 110 can be effectively prevented, and excellent corrosion resistance can be obtained.
  • FIG. 22 is a view showing another example of the semiconductor light emitting device of the present invention, and is a schematic sectional view of the semiconductor light emitting device.
  • the semiconductor light emitting device 1a of the present embodiment shown in FIG. 22 is different from the semiconductor light emitting device 1 shown in FIG. 14 in that the transparent protective film 10a is not formed and the center of the bonding pad electrode 120 is viewed in plan view.
  • the upper surface protective film 10 is provided on the entire upper surface 109c of the translucent electrode 109 excluding the region where the portion is exposed. The rest is the same as the semiconductor light emitting device 1 shown in FIG.
  • the upper surface protective film 10 can have the same thickness made of the same material as the transparent protective film 10a in the semiconductor light emitting device 1 shown in FIG.
  • FIG. 23 is a process diagram for explaining a process of manufacturing the p-type electrode, and is an enlarged cross-sectional view showing only a part of a region where the p-type electrode 111a is manufactured.
  • a light-transmitting electrode is formed on the p-type semiconductor layer 106 in the same manner as the semiconductor light emitting device 1 shown in FIG. 109 is formed.
  • a resist 21 is applied on the transparent protective film 10a and dried, and the upper surface 109c of the translucent electrode 109 is formed in the same manner as the semiconductor light emitting device 1 shown in FIG. Then, a reverse taper type mask 23 shown in FIG. 23 (b) having an opening 23a having an inner wall shape whose cross-sectional area gradually increases toward the bottom surface is formed.
  • the transparent electrode 109 exposed from the opening 23a of the mask 23 shown in FIG. 23B is etched in the same manner as the semiconductor light emitting device 1 shown in FIG. As described above, the bonding recess 109 a is formed on the upper surface 109 c of the translucent electrode 109.
  • the bonding layer 110, the metal reflection layer 117, and the bonding layer 119 are formed in the same manner as the semiconductor light emitting device 1 shown in FIG. Thereafter, the mask 23 is peeled in the same manner as the semiconductor light emitting device 1 shown in FIG. As a result, as shown in FIG. 23E, a bonding pad electrode 120 composed of the metal reflective layer 117 and the bonding layer 119 is formed. Also in the present embodiment, similar to the semiconductor light emitting device 1 shown in FIG. 14, the inclined surface 110 c whose film thickness gradually decreases toward the outside on the outer peripheral portions of the bonding layer 110, the metal reflection layer 117, and the bonding layer 119, respectively. 117c and 119c are formed.
  • the upper surface protective film 10 is formed on the entire upper surface 109c of the translucent electrode 109 excluding a region exposing the central portion of the bonding pad electrode 120 when viewed in plan using a conventionally known method. .
  • the semiconductor light emitting element 1a including the p-type electrode 111a shown in FIG. 22 is formed.
  • the bonding property and the corrosion resistance are obtained.
  • the upper surface protective film 10 is provided on the entire upper surface 109c of the translucent electrode 109 excluding the region where the central portion of the bonding pad electrode 120 is exposed in plan view. Therefore, further excellent corrosion resistance and bondability can be obtained.
  • FIG. 24 is a schematic sectional view showing an example of the lamp of the present invention.
  • the lamp 3 of the present embodiment is a shell type, and is mounted with the semiconductor light emitting device 1 of the present invention shown in FIG. 14 as a semiconductor light emitting device.
  • the lamp 3 is, for example, a combination of the semiconductor light emitting element 1 and a phosphor, and can be configured as known to those skilled in the art by means known to those skilled in the art.
  • the emission color can be changed by combining the semiconductor light emitting element 1 and the phosphor, but such a technique can be adopted without any limitation in the lamp of this embodiment. It is.
  • the lamp 3 includes a frame 31 bonded to the bonding pad electrode 120 of the p-type electrode 111 of the semiconductor light-emitting element 1 with a wire 33 and an n-type electrode 108 ( The other frame 32 joined to the bonding pad) by a wire 34 and a mold 35 made of a transparent resin formed so as to surround the periphery of the semiconductor light emitting element 1.
  • the lamp 3 of the present embodiment uses the semiconductor light-emitting element 1 of the present invention shown in FIG. 14 provided with the p-type electrode 111 having excellent bonding properties and corrosion resistance as the semiconductor light-emitting element, the p-type electrode is used. 112 is excellent in bondability, can be manufactured with high yield, and has excellent corrosion resistance.
  • the lamp 3 of the present embodiment can be used for any purposes such as a general-use bullet type, a side view type for a portable backlight, and a top view type used for a display.
  • the lamp 3 manufactured from the semiconductor light emitting device of the present invention has the excellent effects as described above, a backlight, a mobile phone, a display, various panels, a computer, a game incorporating the lamp manufactured by this technology.
  • Electronic devices such as machines and lighting, and mechanical devices such as automobiles incorporating the electronic devices can give high reliability in use as products.
  • a battery-driven device such as a backlight, a cellular phone, a display, a game machine, and lighting, a product including a light-emitting element with excellent corrosion resistance and high reliability can be provided, which is preferable.
  • the manufacturing method of the semiconductor light emitting device of the twelfth embodiment is a manufacturing method of the semiconductor light emitting device 1 shown in FIG.
  • the laminated semiconductor layer 20 is formed on the substrate 101.
  • the stacked semiconductor layer 20 is formed by the MOCVD method, a layer having good crystallinity can be obtained.
  • the sputtering method a layer having crystallinity superior to the MOCVD method can be obtained.
  • the “layered semiconductor layer formation” including the buffer layer forming step, the base layer forming step, the n-type semiconductor layer forming step, the light-emitting layer forming step, and the p-type semiconductor layer forming step is referred to as the semiconductor light-emitting device of the first embodiment. It is performed according to the manufacturing method. Then, after forming the stacked semiconductor layer 20 in this manner, the n-type electrode 108 and the p-type electrode 111 are formed.
  • the ohmic junction layer 9, the junction layer 110, and the bonding pad electrode 120 are formed in the steps of manufacturing the n-type electrode 108 and the p-type electrode 111.
  • a manufacturing method will be described in which heat treatment is performed at the same time and heat treatment for improving the adhesion between the ohmic bonding layer 9 and the bonding layer 110 is performed simultaneously.
  • FIG. 33 is a schematic diagram for explaining a process of manufacturing the n-type electrode 108 and the p-type electrode 111.
  • FIG. 30 is a process diagram for explaining a process of manufacturing the p-type electrode, and is an enlarged cross-sectional view showing only a part of a region where the p-type electrode 111 is manufactured.
  • FIG. 31 is a process diagram for explaining a manufacturing process of a mask formed when manufacturing the n-type electrode 108 and the p-type electrode 111, and shows only a region where one p-type electrode 111 is formed. It is the expanded sectional view shown.
  • FIG. 32 is a process diagram for explaining a process of manufacturing the n-type electrode, and is an enlarged cross-sectional view showing only a part of a region where the n-type electrode is manufactured.
  • the laminated semiconductor layer 20 shown in FIG. 33A is patterned by a known photolithography technique, and a part of the laminated semiconductor layer 20 in a predetermined region is etched to expose a part of the n contact layer 104a.
  • a translucent electrode 109 is formed on the p-type semiconductor layer 106 of the stacked semiconductor layer 20.
  • the translucent electrode 109 is formed by forming a mask that covers a region other than the region where the translucent electrode 109 is formed, such as the exposed surface 104c of the n contact layer 104a, which is a region where the n-type electrode 108 is formed, and then p-type.
  • the translucent electrode 109 may be formed after the etching of the laminated semiconductor layer 20 for forming the n-type electrode 108, but before the etching of the laminated semiconductor layer 20 for forming the n-type electrode 108. You may form in.
  • the protective film 10a is formed on the upper surface 109c of the translucent electrode 109 shown in FIG. 30A, and at the same time, the protective film 10a is formed on the exposed surface 104c of the n-type semiconductor layer 104 shown in FIG. To do.
  • the protective film 10a is removed by RIE (reactive ion etching) from a direction perpendicular to the upper surface 109c of the translucent electrode 109 and the exposed surface 104c of the n-type semiconductor layer 104, and FIG. And as shown to Fig.32 (a), the opening part 10d is formed and the upper surface 109c of the translucent electrode 109 and the exposed surface 104c of the n-type semiconductor layer 104 are exposed from the opening part 10d.
  • RIE Reactive Ion Etching
  • a hole 109a is formed in the translucent electrode 109 as shown in FIGS. 30 (a) and 33 (a). Form.
  • the inner wall 109d of the hole 109a that emerges from the translucent electrode 109 is superior in adhesion to the ohmic bonding layer 9 compared to the upper surface 109c of the translucent electrode 109.
  • the translucent electrode 109 etched here is, for example, an amorphous IZO film, the hole 109a having a specific shape can be easily formed with excellent etching properties.
  • the amorphous IZO film can be easily and accurately etched using a known etching solution (for example, ITO-07N etching solution (manufactured by Kanto Chemical Co., Inc.)).
  • a known etching solution for example, ITO-07N etching solution (manufactured by Kanto Chemical Co., Inc.)
  • the amorphous IZO film may be etched using a dry etching apparatus.
  • Cl 2 , SiCl 4 , BCl 3, or the like can be used as an etching gas at this time.
  • the translucent electrode 109 is, for example, an amorphous IZO film
  • the amorphous IZO film is converted into an IZO film containing a hexagonal In 2 O 3 crystal, a bixbyite, or the like. It is preferable to form an IZO film including an In 2 O 3 crystal having a structure.
  • a light-transmitting electrode 109 having better adhesion and light-transmitting properties to the ohmic bonding layer 9 and the bonding layer 110 than an amorphous IZO film is obtained.
  • the crystal structure in the IZO film differs depending on the film formation conditions, heat treatment conditions, and the like.
  • Heat treatment for crystallizing the IZO film is preferably performed in an atmosphere containing no O 2, as the atmosphere containing no O 2, or an inert gas atmosphere such as N 2 atmosphere, or an inert, such as N 2
  • N 2 atmosphere an inert gas atmosphere of gas and H 2
  • N 2 atmosphere or a mixed gas atmosphere of N 2 and H 2 is desirable.
  • the IZO film is crystallized into a film containing In 2 O 3 crystals having a hexagonal structure, and IZO It is possible to effectively reduce the sheet resistance of the membrane.
  • the heat treatment temperature for crystallizing the IZO film is preferably 250 ° C. to 1000 ° C., more preferably 500 ° C. to 700 ° C.
  • the IZO film may not be sufficiently crystallized, and the light transmittance of the IZO film may not be sufficiently high.
  • the IZO film is crystallized, but the light transmittance of the IZO film may not be sufficiently high.
  • the semiconductor layer under the IZO film may be deteriorated.
  • the heat treatment for crystallizing the IZO film constituting the translucent electrode 109 may be performed immediately after the hole 109a is formed in the translucent electrode 109, but the bonding layer is formed on the ohmic bonding layer 9. This may be done after forming 110.
  • the heat treatment for crystallizing the IZO film constituting the light-transmitting electrode 109 after the bonding layer 110 is formed the heat treatment for crystallizing the IZO film, the ohmic bonding layer 9, the bonding layer 110, Since the heat treatment for improving the adhesiveness can be performed at the same time, the number of heat treatments can be reduced, and the manufacturing process can be simplified, which is preferable.
  • a resist is applied onto the protective film 10a and dried, and the resist corresponding to the part where the bonding pad electrode 120 is formed is removed, thereby removing the transparent film on which the protective film 10a shown in FIG.
  • a reverse taper type mask 23 having a portion 23a is formed (see FIG. 33C). As shown in FIGS. 30B and 33C, the opening 23a of the mask 23 formed on the translucent electrode 109 is a position where the hole 109a of the translucent electrode 109 is exposed. To form.
  • an insoluble resist which is an image reversal type photoresist is used as the resist 21 shown in FIG. 31A.
  • the image reversal type photoresist for example, AZ5200NJ (product name: manufactured by AZ Electronic Materials Co., Ltd.) is used.
  • the mask 25 is disposed so as to cover a predetermined position above the resist 21, and from the mask 25 side to the resist 21 side as shown by an arrow in FIG. Is irradiated with light of a predetermined intensity and wavelength. As a result, the portion of the resist 21 irradiated with light is photoreacted to form a soluble portion 22.
  • the fusible portion 22 is formed to have a reverse taper shape (reverse inclination shape) that recedes inward as the side faces downward when viewed in cross section.
  • the resist 21 in the portion covered with the mask 25 is left as an insoluble resist (insoluble portion) 21 so as to have a tapered shape (inclined shape) that recedes inward as the side faces upward when viewed in cross section. Formed.
  • the soluble part 22 is thermally reacted to form a cured part (mask) made of a crosslinked polymer. 23.
  • a heating device such as a hot plate or an oven
  • the soluble part 22 is thermally reacted to form a cured part (mask) made of a crosslinked polymer. 23.
  • light of a predetermined intensity and wavelength is irradiated on the surface side of the hardened portion (mask) 23 made of the insoluble resist 21 and the crosslinked polymer without using a mask.
  • the insoluble resist 21 that has not been converted to the soluble portion 22 by the photoreaction described with reference to FIG.
  • a predetermined developer to dissolve and remove the soluble portion 22 shown in FIG. 31 (c)
  • the opening recedes inward as the side faces downward.
  • the bonding layer 110 is formed by sputtering to cover the ohmic bonding layer 9 and the end 10c of the opening 10d of the protective film 10a. To do. At this time, the coverage of the bonding layer 110 can be increased by using a sputtering method in which the sputtering conditions are controlled. Thus, the bonding layer 110 is formed so as to cover the entire surface of the ohmic bonding layer 9 and a part of the end portion 10c of the protective film 10a, and the film thickness is formed on the outer peripheral portion 110d of the bonding layer 110 toward the outside. As a result, an inclined surface 110c is formed which becomes gradually thinner.
  • a pretreatment may be performed to clean the surface of the ohmic bonding layer 9 where the bonding layer 110 is formed or the end 10c of the opening 10d of the protective film 10a.
  • the cleaning method include a dry process method exposed to plasma and the like, and a wet process method in contact with a chemical solution, but it is desirable to use a dry process method from the viewpoint of simplicity of the process.
  • a metal reflection layer 117 is formed by sputtering.
  • a sputtering method in which the sputtering conditions are controlled is used.
  • the coverage of the metal reflective layer 117 can be enhanced, and the metal reflective layer 117 is formed that covers the bonding layer 110 and has an inclined surface 117c that gradually decreases in thickness toward the outer periphery. .
  • a bonding layer 119 is formed by sputtering.
  • a sputtering method with controlled sputtering conditions is used.
  • the coverage of the bonding layer 119 can be increased, the outer peripheral shape is formed along the inner wall shape of the opening 23a of the mask 23, the metal reflective layer 117 is covered, and the film thickness is directed outward.
  • a bonding layer 119 (bonding pad electrode 120) having an inclined surface 119c that gradually becomes thinner at the outer peripheral portion 120d is formed (see FIG. 33D).
  • the mask 23 made of a crosslinked polymer is peeled off by being immersed in a resist stripping solution.
  • a bonding pad electrode 120 including the metal reflective layer 117 and the bonding layer 119 is formed.
  • a mask 23 having an opening 23a having an inner wall shape whose cross-sectional area gradually increases toward the bottom surface is formed, and the bonding layer 110, the metal reflective layer 117, and the bonding layer 119 have high coverage. Since it is formed by the sputtering method, a layer having a different inclination angle is formed in the shadowed area of the mask 23 when viewed from the sputtering direction according to the thickness of each layer constituting the bonding layer 110, the metal reflection layer 117, and the bonding layer 119. Is done. As a result, inclined surfaces 110c, 117c, and 119c are formed on the outer peripheral portions of the bonding layer 110, the metal reflective layer 117, and the bonding layer 119, respectively, with the thickness gradually decreasing toward the outside.
  • Heat treatment process Thereafter, heat treatment is performed at a temperature of 80 ° C. to 700 ° C. in order to improve the adhesion between the ohmic bonding layer 9 and the bonding layer 110.
  • the heat treatment here can be performed in the same manner as the heat treatment for crystallizing the translucent electrode 109 made of an amorphous IZO film. Therefore, for example, in the case where the ohmic junction layer 9 is an amorphous IZO film, the heat treatment here causes the amorphous IZO film to include an IZO film containing a hexagonal In 2 O 3 crystal or a bixbite structure InZO.
  • the IZO film contains 2 O 3 crystals.
  • edge protective film 10b that covers the outer edge of the bonding pad electrode 120 is formed across a portion that becomes a joint with the film 10a (see FIG. 33D). In the present embodiment, the edge protective film 10b is formed over the entire region excluding the region where the central portion of the bonding pad electrode 120 is exposed when viewed in plan.
  • the edge protection film 10b is formed as the bonding pad.
  • the inclined surface 119c of the electrode 120 is easily formed with a uniform thickness. This prevents the formation of a portion where the edge protection film 10b is not formed on the joint portion between the outer edge portion (contour line) of the bonding pad electrode 120 and the protection film 10a.
  • the edge protective film 10b straddling the portion that becomes the joint between the portion (contour line) and the protective film 10a can be formed in a uniform film thickness by being easily adhered. In this way, the semiconductor light emitting device 1 including the n-type electrode 108 and the p-type electrode 111 shown in FIG. 26 is formed.
  • the n-type electrode 108 and the p-type electrode 111 are connected to the ohmic junction layer 9 formed on the upper surface 106c of the stacked semiconductor layer 20 or the exposed surface 104c of the n contact layer 104a, and the ohmic contact layer 9 is formed.
  • a bonding layer 110 formed on the bonding layer 9 and a bonding pad electrode 120 formed so as to cover the bonding layer 110 are provided.
  • Both the n-type electrode 108 and the p-type electrode 111 are connected to the bonding layer 110.
  • the bonding pad electrode 120 provide a sufficiently high bonding force between the ohmic bonding layer 9 and the bonding pad electrode 120. Therefore, the n-type electrode 108 and the p-type electrode 111 having excellent bonding properties are obtained. It will be prepared.
  • the bonding pad electrode 120 having the inclined surface 119c whose thickness is gradually reduced toward the outside on the outer peripheral portion 120d is formed so as to cover the bonding layer 110. Therefore, any part of the bonding layer 110 is not exposed from below the bonding pad electrode 120. Therefore, according to the semiconductor light emitting device 1 of the present embodiment, air or moisture outside the semiconductor light emitting device 1 can be effectively prevented from entering the bonding layer 110, and excellent corrosion resistance can be obtained and the bonding layer 110 can be obtained.
  • the laminated semiconductor layer 20 and the translucent electrode 109 and the excellent bonding property between the bonding pad electrode 120 can be obtained.
  • protection is performed so as to cover a region excluding the region where the ohmic junction layer 9 of the p-type electrode 111 is formed and the region where the ohmic junction layer 9 of the n-type electrode 108 is formed. Since the film 10a is formed and the outer edge portion of the bonding layer 110 and the outer edge portion of the bonding pad electrode 120 are disposed on the protective film 10a, much more excellent corrosion resistance and bondability can be obtained.
  • the bonding pad electrode 120 is composed of the metal reflective layer 117 and the bonding layer 119, and no part of the bonding layer 110 is exposed from under the metal reflective layer 117. In addition, any part of the metal reflection layer 117 is not exposed from below the bonding layer 119, and the bonding layer 110 is double covered with the metal reflection layer 117 and the bonding layer 119. Furthermore, in the semiconductor light emitting device 1 of the present embodiment, the outer edge portion of the bonding pad electrode 120 is disposed on the protective film 10a.
  • the semiconductor light emitting device 1 of the semiconductor light emitting device 1 has to pass through the joint surface between the protective film 10a and the bonding layer 119 and the joint surface between the protective film 10a and the metal reflective layer 117. External air or moisture cannot enter the bonding layer 110. Therefore, in the present embodiment, air or moisture outside the semiconductor light emitting element 1 can be effectively prevented from entering the bonding layer 110, and the deterioration of the bonding property and corrosion resistance due to the deterioration of the bonding layer 110 is effective. Can be prevented.
  • the edge protection film 10b that covers the outer edge of the bonding pad electrode 120 and exposes a part on the bonding pad electrode 120 is formed, so that it is further excellent. Corrosion resistance and bondability are obtained.
  • the bonding pad electrode 120 having the inclined surface 119c whose thickness is gradually reduced toward the outside on the outer peripheral portion 120d is formed so as to cover the bonding layer 110. Therefore, the contact area between the outer peripheral portion 120d of the bonding pad electrode 120 and the lower surface of the outer peripheral portion 120d of the bonding pad electrode 120 (the protective film 10a in this embodiment) is sufficiently secured, and excellent bonding is achieved. In addition, it is possible to effectively prevent air and moisture from entering the bonding layer 110 from the outside through the gap between the outer peripheral portion 120d of the bonding pad electrode 120 and the lower surface thereof, which is even better. Corrosion resistance is obtained.
  • the n-type electrode 108 and the p-type electrode 111 are the same except that the translucent electrode 109 is not provided on the n-type electrode 108.
  • the n-type electrode 108 and the p-type electrode 111 can be formed at the same time, and the productivity can be easily manufactured.
  • the n-type electrode is formed of a metal such as Ti / Au from the exposed surface on the exposed surface 104c of the n contact layer 104a, the n-type electrode And the p-type electrode 111 are not formed simultaneously.
  • the n-type electrode 108 and the p-type electrode 111 cover and cover the n-type electrode 108 except that the translucent electrode 109 is not provided. If the bonding pad electrodes are the same, the manufacturing conditions for both the n-type electrode 108 and the p-type electrode 111 can be easily optimized. Therefore, in the semiconductor light emitting device 1 of the present embodiment, the n-type electrode excellent in the adhesion between the ohmic junction layer 9 and the junction layer 110 is obtained by optimizing the manufacturing conditions of the n-type electrode 108 and the p-type electrode 111. 108 and the p-type electrode 111 may be provided.
  • both of the process of manufacturing the n-type electrode 108 and the process of manufacturing the p-type electrode 111 improve the adhesion between the ohmic junction layer 9 and the junction layer 110. Since the heat treatment is performed at a temperature of 250 ° C. to 700 ° C., the bonding layer 110 having excellent adhesion with the ohmic bonding layer 9 is obtained, and the bonding between the ohmic bonding layer 9 and the bonding pad electrode 120 is excellent. A semiconductor light emitting device 1 can be obtained.
  • both the step of manufacturing the n-type electrode 108 and the step of manufacturing the p-type electrode 111 are performed on the upper surface 106c of the stacked semiconductor layer 20 or the n-contact layer 104a.
  • Forming the ohmic bonding layer 9 on the exposed surface 104c, forming the bonding layer 110 on the ohmic bonding layer 9, forming the bonding pad electrode 120 so as to cover the bonding layer 110, and ohmic bonding layer In order to improve the adhesion between the adhesive layer 9 and the bonding layer 110, a process of performing a heat treatment at a temperature of 250 ° C. to 700 ° C. is provided.
  • a process of manufacturing the n-type electrode 108 and a process of manufacturing the p-type electrode 111 can be the same. Material used for the fine p-type electrode 111 can be easily manufactured as compared with the case where all different.
  • the pad forming step and the heat treatment step are simultaneously performed in the step of manufacturing the n-type electrode 108 and the step of manufacturing the p-type electrode 111. Compared with the case where the process is performed separately, it can be manufactured easily and efficiently, and the productivity is excellent.
  • the ohmic junction layer 9, the junction layer 110, the bonding pad electrode 120, and the p-type electrode constituting the n-type electrode 108 are used for easy and efficient production.
  • the ohmic junction layer 9, the junction layer 110, and the bonding pad electrode 120 that form the layer 111 are described as an example, but the ohmic junction layer 9, the junction layer 110, and the bonding pad electrode 120 are used as the n-type electrode 108.
  • the p-type electrode 111 may be formed separately, or only a part of the ohmic junction layer 9, the junction layer 110, and the bonding pad electrode 120 constituting the n-type electrode 108 and the p-type electrode 111 is formed. You may form separately.
  • the inner wall 109d of the hole 109a that emerges from the translucent electrode 109 by forming the hole 109a is superior in adhesion to the ohmic bonding layer 9 compared to the upper surface 109c of the translucent electrode 109.
  • the p-type electrode 111 having excellent adhesion of the ohmic junction layer 9 can be obtained as compared with the case where the ohmic junction layer 9 is formed on the upper surface 109c of the translucent electrode 109. .
  • FIG. 34 is a diagram showing another example of the semiconductor light emitting device of the present invention, and is a schematic cross-sectional view of the semiconductor light emitting device.
  • the semiconductor light emitting device 1a of the present embodiment shown in FIG. 34 is different from the semiconductor light emitting device 1 shown in FIG. 26 only in that the protective film 10a and the edge protective film 10b are not formed. This is the same as the semiconductor light emitting device 1 shown in FIG. Therefore, the same members as those of the twelfth embodiment are denoted by the same reference numerals, and description thereof is omitted. Further, the semiconductor light emitting device 1a of the present embodiment can be formed in the same manner as the semiconductor light emitting device 1 shown in FIG. 26 except that the protective film 10a and the edge protective film 10b are not formed.
  • the n-type electrode 118 and the p-type electrode 111a are formed on the upper surface 106c of the laminated semiconductor layer 20 or the exposed surface 104c of the n-contact layer 104a.
  • the bonding layer 110 formed on the ohmic bonding layer 9, and the bonding pad electrode 120 formed so as to cover the bonding layer 110, both the n-type electrode 118 and the p-type electrode 111 a are provided.
  • a sufficiently high bonding force between the ohmic bonding layer 9 and the bonding pad electrode 120 can be obtained by the bonding layer 110 and the bonding pad electrode 120.
  • both the step of manufacturing the n-type electrode 118 and the step of manufacturing the p-type electrode 111a are performed by the ohmic junction layer 9 and the junction layer 110. Since the step of performing a heat treatment at 250 ° C. to 700 ° C. for improving the adhesion of the substrate is obtained, the bonding layer 110 having excellent adhesion to the ohmic bonding layer 9 is obtained, and the ohmic bonding layer 9 and the bonding pad electrode 120 are bonded to each other. A semiconductor light emitting device 1a having excellent bonding properties is obtained.
  • the semiconductor light emitting device 1a of the present embodiment shown in FIG. 34 similarly to the semiconductor light emitting device 1 shown in FIG. 26, except that the translucent electrode 109 is not provided on the n type electrode 118, the n type is also provided. Since the electrode 118 and the p-type electrode 111a are the same, the n-type electrode 118 and the p-type electrode 111a can be formed at the same time, and the productivity can be easily and efficiently manufactured. Also in the semiconductor light emitting device 1a of this embodiment shown in FIG. 34, both the n-type electrode 118 and the p-type electrode 111a can be manufactured under optimum conditions.
  • FIG. 35 is a diagram showing another example of the semiconductor light emitting device of the present invention, and is a schematic cross-sectional view of the semiconductor light emitting device.
  • the semiconductor light emitting device 1b of the present embodiment shown in FIG. 35 is different from the semiconductor light emitting device 1 shown in FIG. 26 in that the protective film 10a is not formed and the center portion of the bonding pad electrode 120 is viewed in plan view.
  • the upper surface protective film 10 is provided on the entire upper surface 109c of the translucent electrode 109 and the entire exposed surface 104c of the n contact layer 104a except for the exposed region. The rest is the same as the semiconductor light emitting device 1 shown in FIG.
  • the upper surface protective film 10 can have the same thickness made of the same material as the protective film 10a in the semiconductor light emitting device 1 shown in FIG.
  • FIG. 36 is a process diagram for explaining a process of manufacturing the n-type electrode 128 and the p-type electrode 111b, and is an enlarged cross-sectional view showing only a part of a region where the p-type electrode 111b is manufactured. It is. Note that the step of forming the n-type electrode 128 is the same as the step of forming the p-type electrode 111b except that the step of providing the translucent electrode 109 is not performed. The illustration of the area where the product is manufactured is omitted.
  • n-contact layer 104a of the laminated semiconductor layer 20 is exposed in the same manner as in the semiconductor light emitting device 1 shown in FIG. 26, and p of the laminated semiconductor layer 20 is obtained in the same manner as in the semiconductor light emitting device 1 shown in FIG.
  • a translucent electrode 109 is formed on the type semiconductor layer 106.
  • the translucent electrode 109 formed here is an amorphous IZO film
  • the amorphous IZO film can be crystallized by performing heat treatment in the same manner as the semiconductor light emitting element 1 shown in FIG. preferable.
  • the resist 21 is applied on the exposed surface 104c of the n-contact layer 104a, and the resist 21 is dried, and the semiconductor light emitting device 1 shown in FIG.
  • the upper surface 109c of the translucent electrode 109 and the n-contact layer 104a are exposed as shown in FIG.
  • an inversely tapered mask 23 having an opening 23a having an inner wall shape whose cross-sectional area gradually increases toward the bottom surface is formed. 36B, the opening 23a of the mask 23 formed on the translucent electrode 109 is formed at a position where the hole 109a of the translucent electrode 109 is exposed.
  • the bonding layer 110, the metal reflective layer 117, and the bonding layer 119 are sequentially formed in the same manner as the semiconductor light emitting device 1 shown in FIG. Thereafter, the mask 23 is removed in the same manner as the semiconductor light emitting device 1 shown in FIG. As a result, as shown in FIG. 36E, a bonding pad electrode 120 composed of the metal reflective layer 117 and the bonding layer 119 is formed. Also in the present embodiment, similar to the semiconductor light emitting device 1 shown in FIG. 26, the inclined surface 110 c that gradually decreases in thickness toward the outside on the outer peripheral portions of the bonding layer 110, the metal reflection layer 117, and the bonding layer 119, respectively. 117c and 119c are formed.
  • Heat treatment process Next, in the same manner as in the semiconductor light emitting device 1 shown in FIG. 26, heat treatment for improving the adhesion between the ohmic junction layer 9 and the junction layer 110 is performed.
  • a top protective film 10 is formed on the entire upper surface.
  • the semiconductor light emitting element 1b including the n-type electrode 128 and the p-type electrode 111b shown in FIG. 35 is formed.
  • the n-type electrode 128 and the p-type electrode 111b are formed on the upper surface 106c of the laminated semiconductor layer 20 or the exposed surface 104c of the n-contact layer 104a.
  • the bonding layer 110 formed on the ohmic bonding layer 9, and the bonding pad electrode 120 formed so as to cover the bonding layer 110, both the n-type electrode 128 and the p-type electrode 111 b are provided.
  • a sufficiently high bonding force between the ohmic bonding layer 9 and the bonding pad electrode 120 can be obtained by the bonding layer 110 and the bonding pad electrode 120.
  • both the process of manufacturing the n-type electrode 128 and the process of manufacturing the p-type electrode 111b are performed by the ohmic junction layer 9 and the junction layer 110. Since the step of performing a heat treatment at 250 ° C. to 700 ° C. for improving the adhesion of the substrate is obtained, the bonding layer 110 having excellent adhesion to the ohmic bonding layer 9 is obtained, and the ohmic bonding layer 9 and the bonding pad electrode 120 are bonded to each other. A semiconductor light emitting device 1b having excellent bonding properties is obtained.
  • the semiconductor light emitting device 1b of the present embodiment similarly to the semiconductor light emitting device 1 shown in FIG. 26, except that the n-type electrode 128 is not provided with the translucent electrode 109, the n-type electrode 128 and p Since the mold electrode 111b is the same, the n-type electrode 128 and the p-type electrode 111b can be formed at the same time, and the productivity that can be easily and efficiently manufactured is excellent. Also in the semiconductor light emitting device 1b of this embodiment shown in FIG. 35, both the n-type electrode 128 and the p-type electrode 111b can be manufactured under optimum conditions.
  • FIG. 37 is a schematic sectional view showing an example of the lamp of the present invention.
  • the lamp 3 of the present embodiment is a shell type, and is mounted with the semiconductor light emitting device 1 of the present invention shown in FIG. 26 as a semiconductor light emitting device.
  • the lamp 3 is, for example, a combination of the semiconductor light emitting element 1 and a phosphor, and can be configured as known to those skilled in the art by means known to those skilled in the art.
  • the emission color can be changed by combining the semiconductor light emitting element 1 and the phosphor, but such a technique can be adopted without any limitation in the lamp of this embodiment. It is.
  • the lamp 3 includes a frame 31 bonded to the bonding pad electrode 120 of the p-type electrode 111 of the semiconductor light emitting element 1 with a wire 33, and an n-type electrode 108 of the semiconductor light emitting element 1.
  • the other frame 32 joined to the bonding pad electrode 120 with a wire 34 and a mold 35 made of a transparent resin formed so as to surround the periphery of the semiconductor light emitting element 1 are provided.
  • the lamp 3 according to the present embodiment includes the semiconductor light emitting device of the present invention including the n-type electrode 108 and the p-type electrode 111 having excellent bonding properties and corrosion resistance as the semiconductor light emitting device. It is excellent in that it can be manufactured with good yield.
  • the lamp 3 of the present embodiment can be used for any purposes such as a general-use bullet type, a side view type for a portable backlight, and a top view type used for a display.
  • the lamp 3 manufactured from the semiconductor light emitting device of the present invention has the excellent effects as described above, a backlight, a mobile phone, a display, various panels, a computer, a game incorporating the lamp manufactured by this technology.
  • Electronic devices such as machines and lighting, and mechanical devices such as automobiles incorporating the electronic devices can give high reliability in use as products.
  • a battery-driven device such as a backlight, a cellular phone, a display, a game machine, and lighting, a product including a light-emitting element with excellent corrosion resistance and high reliability can be provided, which is preferable.
  • the present invention will be specifically described based on examples. However, the present invention is not limited only to these examples.
  • Example 1 ⁇ Fabrication of semiconductor light emitting device>
  • a semiconductor light emitting device made of a gallium nitride compound semiconductor (hereinafter, the semiconductor light emitting device of Example 1) was manufactured as follows. First, an underlayer made of undoped GaN having a thickness of 8 ⁇ m was formed on a substrate made of sapphire via a buffer layer made of AlN.
  • a Si-doped n-type GaN contact layer having a thickness of 2 ⁇ m and an n-type In 0.1 Ga 0.9 N cladding layer having a thickness of 250 nm a Si-doped GaN barrier layer having a thickness of 16 nm and a thickness of 2 A .5 nm In 0.2 Ga 0.8 N well layer was stacked five times, and finally a light emitting layer having a multiple quantum well structure in which a barrier layer was provided was formed.
  • a Mg-doped p-type Al 0.07 Ga 0.93 N cladding layer having a thickness of 10 nm and an Mg-doped p-type GaN contact layer having a thickness of 150 nm were sequentially formed.
  • the gallium nitride-based compound semiconductor layer was stacked by MOCVD under normal conditions well known in the technical field.
  • a protective film made of SiO 2 was formed. Further, an inversely tapered mask was formed according to the mask forming process shown in the first embodiment. As the resist, AZ5200NJ (product name: manufactured by AZ Electronic Materials Co., Ltd.) was used. In the state equipped with the reverse taper type mask, the protective film made of SiO 2 is etched to expose a part of the upper surface of the translucent electrode and the n-type contact layer. A bonding layer was formed.
  • n-side electrode also has the same electrode stack structure as the p-side electrode.
  • the reflectance of the bonding pad electrode produced in this example was 70% in the wavelength region of 460 nm. This value was measured with a spectrophotometer using a glass dummy substrate placed in the same chamber when the bonding pad electrode was formed. In addition, a bonding test was performed on 100,000 chips (number of bonding failures), but there was no pad peeling.
  • the chip was subjected to a high temperature and high humidity test according to a conventional method.
  • a test method a chip is placed in a high-temperature and high-humidity device (Isuzu Seisakusho, ⁇ -SERIES), and a light emission test of 100 chips each in an environment of a temperature of 85 ° C. and a relative humidity of 85 RH% (amount of power applied to the chip). 5 mA, 2000 hours), the number of defects was 0.
  • Example 1 The semiconductor light emitting device of Example 1 was submerged in water in a water tank with a current application value of 20 mA, a forward voltage of 3.0 V, and a light emission output of 19.5 mW. After being kept for 10 minutes in that state, it was pulled up from the water and the luminescence characteristics were measured again. The light emission characteristics were almost the same as before submerging in water.
  • Example 2 to 20 Semiconductor light emitting devices of Examples 2 to 20 were manufactured in the same manner as Example 1 except that the p-type electrode was formed with the material and thickness shown in Table 1. Evaluation was performed in the same manner as in Example 1, and the evaluation results shown in Table 2 were obtained.
  • FIG. 12 is an enlarged cross-sectional view showing a p-type electrode of the semiconductor light emitting device of Comparative Example 1.
  • the p-type electrode 201 of this semiconductor light emitting element is composed of a translucent electrode 109 made of ITO, a bonding layer 210 made of Cr, and a bonding pad electrode 220.
  • the upper surface 109c of the translucent electrode 109 is covered with the protective film 10 made of SiO 2, and the bonding layer 210 is uniform on the upper surface 109c of the translucent electrode 109 exposed by opening a part of the protective film 10. It is formed with a thickness.
  • a metallic reflective layer 217 made of Al is formed on the bonding layer 210, and a barrier layer made of Ti and a bonding layer 219 made of Au are formed on the metallic reflective layer 217 in this order.
  • the side surfaces of the bonding layer 210, the metal reflection layer 217, the barrier layer (not shown), and the bonding layer 219 are formed substantially perpendicular to the upper surface 109 c of the translucent electrode 109.
  • the semiconductor light emitting device of Comparative Example 1 was formed as follows. First, in the same manner as in Example 1, a gallium nitride-based compound semiconductor layer was laminated by MOCVD under normal conditions well known in the technical field. Next, a translucent electrode 109 made of ITO having a thickness of 200 nm was formed on the p-type GaN contact layer. Next, as shown in FIG. 13A, after forming the protective film 10 made of SiO 2 on the upper surface 109c of the translucent electrode 109, a resist is applied and dried on the protective film 10 to form the resist portion 21. Formed. Next, as shown in FIG.
  • the resist portion 21 corresponding to the portion where the bonding pad electrode is formed is exposed to form a soluble resist by using a normal photolithography method.
  • the resist part 21 having an end surface perpendicular to the upper surface of the protective film 10 was formed by removing with a predetermined developer.
  • the protective film 10 is etched using the remaining resist portion 21 as a mask, and the protective film 10 corresponding to the portion where the bonding pad electrode is formed is removed.
  • the upper surface 109c of the translucent electrode 109 and the n-type contact layer were exposed.
  • a bonding layer 210 of 20 Cr Cr was formed by sputtering so as to cover the exposed upper surface 109c of the transparent electrode 109 and the upper surface 21a of the resist portion 21.
  • a metal reflective layer 217 made of 200 nm Al was formed so as to cover the bonding layer 210. Furthermore, as shown in FIG.
  • a barrier layer (not shown) made of 80 nm Ti is formed so as to cover the metal reflective layer 217, and a bonding layer made of 200 nm Au is covered so as to cover the barrier layer. 219 was formed.
  • the resist portion 21 is stripped with a resist stripping solution to bond a three-layer structure comprising a metal reflective layer 217, a barrier layer, and a bonding layer 219 on the bonding layer 210 as shown in FIG.
  • a p-type electrode 201 in which the pad electrode 220 was laminated was formed. By this step, the p-type electrode 201 having the structure shown in FIG. 12 was formed.
  • the n-side electrode also has the same electrode stack structure as the p-side electrode.
  • the reflectance of the bonding pad electrode of Comparative Example 1 was 90% in the wavelength region of 460 nm. This value was measured with a spectrophotometer using a glass dummy substrate placed in the same chamber when the bonding pad electrode was formed. In addition, a bonding test was performed on 100,000 chips (number of bonding defects), and pad peeling was 50 chips.
  • ⁇ High temperature and high humidity test> In the same manner as in Example 1, a high temperature and high humidity test of the chip was performed. When a light emission test was performed with 100 chips each in an environment of a temperature of 85 ° C. and a relative humidity of 85 RH% (the amount of current applied to the chips was 5 mA, 2000 hours), the number of defects was 65.
  • Example 1 The corrosion resistance test was conducted in the same manner as in Example 1.
  • the semiconductor light-emitting device of Comparative Example 1 was submerged in water in a water tank with a current application value of 20 mA, a forward voltage of 3.0 V, and a light emission output of 20 mW. It was not shining even if it was kept in that state for a few seconds.
  • Comparative Example 2 and Comparative Example 3 Semiconductor light emitting devices of Comparative Example 2 and Comparative Example 3 were manufactured in the same manner as Comparative Example 1 except that the p-type electrode was formed with the materials and thicknesses shown in Table 1. Evaluation was performed in the same manner as in Comparative Example 1, and the evaluation results shown in Table 2 were obtained.
  • Example 21 A semiconductor light emitting device made of a gallium nitride compound semiconductor shown in FIGS. 14 to 16 was manufactured as follows.
  • an underlayer 103 made of undoped GaN having a thickness of 8 ⁇ m was formed on a substrate 101 made of sapphire via a buffer layer 102 made of AlN.
  • an n-contact layer 104a made of Si-doped n-type GaN having a thickness of 2 ⁇ m and an n-cladding layer 104b made of n-type In 0.1 Ga 0.9 N having a thickness of 250 nm were formed.
  • a light-emitting layer 105 having a multiple quantum well structure in which a Si-doped GaN barrier layer having a thickness of 16 nm and an In 0.2 Ga 0.8 N well layer having a thickness of 2.5 nm are stacked five times and finally a barrier layer is provided. Formed. Further, a p-cladding layer 106a made of Mg-doped p-type Al 0.07 Ga 0.93 N having a thickness of 10 nm and a p-contact layer 106b made of Mg-doped p-type GaN having a thickness of 150 nm were sequentially formed.
  • the stacked semiconductor layer 20 was formed by MOCVD under normal conditions well known in the technical field.
  • Formation of electrodes After forming the laminated semiconductor layer 20 in this manner, patterning was performed by a photolithography technique, and a part of the laminated semiconductor layer 20 in a predetermined region was etched to expose a part of the n contact layer 104a. Next, an n-type electrode 108 made of Ti / Pt / Au was sequentially formed on the exposed surface 104c of the n-contact layer 104a by sputtering.
  • a p-type electrode 111 was formed as shown below.
  • the translucent electrode 109 made of IZO having a thickness of 250 nm was formed on the p-type GaN contact layer 106b, and the transparent protective film 10a made of SiO 2 having a thickness of 100 nm was formed on the translucent electrode 109.
  • AZ5200NJ product name: manufactured by AZ Electronic Materials Co., Ltd.
  • a reverse-tapered mask 23 having an opening 23a having an inner wall shape that gradually widens was formed.
  • the transparent protective film 10a exposed from the opening 23a of the mask 23 is removed by RIE (reactive ion etching) from a direction perpendicular to the upper surface 109c of the translucent electrode 109 to form the opening 10d. Then, the upper surface 109c of the translucent electrode 109 was exposed from the opening 10d. Next, the translucent electrode 109 exposed from the opening 23 a of the mask 23 was dry-etched to form a bonding recess 109 a having a depth of 10 nm on the upper surface 109 c of the translucent electrode 109.
  • RIE reactive ion etching
  • a bonding layer 110 made of Cr having a maximum thickness of 10 mm was formed by sputtering so as to cover the bonding recess 109a of the translucent electrode 109.
  • a metal reflective layer 117 made of Pt having a maximum film thickness of 100 nm was formed by sputtering, covering the bonding layer 110 and having an inclined surface 117c that gradually decreases in thickness toward the outside at the outer periphery.
  • the shape of the outer peripheral portion is formed along the inner wall shape of the opening 23a of the mask 23, covers the metal reflection layer 117, and the inclined surface 119c whose thickness gradually decreases toward the outer portion is formed on the outer peripheral portion.
  • a bonding layer 119 made of Au having a maximum thickness of 1100 nm at 120d was formed.
  • the bonding pad electrode 120 composed of the metal reflection layer 117 and the bonding layer 119 was formed.
  • the mask 23 was peeled by being immersed in a resist stripping solution.
  • it is a substantially donut-shaped shape that exposes the central portion of the bonding pad electrode 120, and is a portion that becomes a joint between the outer edge portion (contour line) of the bonding pad electrode 120 and the transparent protective film 10 a
  • An edge protective film 10b made of SiO 2 having a width of 5 ⁇ m and a maximum thickness of 100 nm was formed to cover the outer edge of the bonding pad electrode 120.
  • the semiconductor light emitting device 1 of Example 21 including the p-type electrode 111 shown in FIGS. 14 to 16 was obtained.
  • Example 21 and Comparative Example 4 For the semiconductor light emitting devices of Example 21 and Comparative Example 4, the forward voltage was measured. As a result, in Example 21 and Comparative Example 4, the forward voltage at a current application value of 20 mA was 3.0 V when energized by the probe needle. Thereafter, the semiconductor light emitting devices of Example 21 and Comparative Example 4 were mounted in a TO-18 can package, and the light emission output was measured by a tester. As a result, in both Example 21 and Comparative Example 4, the light emission output at an applied current of 20 mA was 20 mW. Further, in both Example 21 and Comparative Example 4, it was confirmed that the light emission distribution on the light emitting surface emitted light on the entire surface under the positive electrode.
  • Example 21 when the reflectance of the bonding pad electrode produced in Example 21 and Comparative Example 4 was measured, it was 80% in the wavelength region of 460 nm. The reflectance was measured using a spectrophotometer for the same thin film as the bonding pad electrode formed on the glass dummy substrate placed in the chamber when the bonding pad electrode was formed. Further, a bonding test was performed on the semiconductor light emitting elements (chips) of Example 211 and Comparative Example 4. As a result, in Example 21, no pad peeling (bonding failure) was found in one chip among 100,000 chips. On the other hand, in Comparative Example 4, pad peeling (bonding failure) was 3 chips out of 100,000 chips.
  • Example 21 The semiconductor light emitting devices (chips) of Example 21 and Comparative Example 4 were placed in a high-temperature and high-humidifier (Isuzu Seisakusho, ⁇ -SERIES), and 100 chips under an environment of a temperature of 85 ° C. and a relative humidity of 85 RH%.
  • a light emission test (amount of current applied to the chip: 5 mA, 2000 hours) was performed. As a result, the number of defects in Example 21 was 0, but the number of defects in Comparative Example 4 was 20.
  • Example 21 The semiconductor light-emitting elements of Example 21 and Comparative Example 4 were submerged in water in a state where light was emitted with a current application value of 20 mA, a forward voltage of 3.0 V, and a light emission output of 20 mW.
  • the semiconductor light emitting device was held for 10 minutes while being submerged in water in a water tank, then pulled up from the water, and light emission characteristics were measured again.
  • the semiconductor light-emitting element did not shine only by being held for several seconds while being submerged in the water of the water tank.
  • Example 22 to 41 Semiconductor light emitting devices of Examples 22 to 41 were manufactured in the same manner as Example 21 except that the p-type electrode was formed with the material and thickness shown in Table 3. Evaluation was performed in the same manner as in Example 21, and the evaluation results shown in Table 4 were obtained.
  • Comparative Examples 5 to 7 Semiconductor light emitting devices of Comparative Examples 5 to 7 were manufactured in the same manner as Comparative Example 4 except that p-type electrodes were formed with the materials and thicknesses shown in Table 3. Evaluation was performed in the same manner as in Comparative Example 4, and the evaluation results shown in Table 4 were obtained.
  • Example 42 The p-type electrode (ohmic junction layer, junction layer, bonding pad electrode (metal reflection layer, barrier layer, bonding layer)) and n-type electrode have the configurations shown in Table 5 to the gallium nitride compound semiconductor shown in FIGS.
  • a semiconductor light emitting device was manufactured as follows.
  • an underlayer 103 made of undoped GaN having a thickness of 8 ⁇ m was formed on a substrate 101 made of sapphire via a buffer layer 102 made of AlN.
  • an n-contact layer 104a made of Si-doped n-type GaN having a thickness of 2 ⁇ m and an n-cladding layer 104b made of n-type In 0.1 Ga 0.9 N having a thickness of 250 nm were formed.
  • a light-emitting layer 105 having a multiple quantum well structure in which a Si-doped GaN barrier layer having a thickness of 16 nm and an In 0.2 Ga 0.8 N well layer having a thickness of 2.5 nm are stacked five times and finally a barrier layer is provided. Formed. Further, a p-cladding layer 106a made of Mg-doped p-type Al 0.07 Ga 0.93 N having a thickness of 10 nm and a p-contact layer 106b made of Mg-doped p-type GaN having a thickness of 150 nm were sequentially formed.
  • the stacked semiconductor layer 20 was formed by MOCVD under normal conditions well known in the technical field.
  • Formation of electrodes After forming the laminated semiconductor layer 20 in this manner, patterning was performed by a photolithography technique, and a part of the laminated semiconductor layer 20 in a predetermined region was etched to expose a part of the n contact layer 104a. Next, a light-transmitting electrode 109 made of IZO having a thickness of 250 nm is formed on the p-type GaN contact layer 106b, and SiO nm having a thickness of 100 nm is formed on the light-transmitting electrode 109 and the exposed surface 104c of the n-contact layer 104a. A protective film 10a made of 2 was formed.
  • the protective film 10a is removed by RIE (reactive ion etching) from a direction perpendicular to the upper surface 109c of the translucent electrode 109 to form an opening 10d, and the translucent electrode 109 is formed from the opening 10d.
  • the upper surface 109c and the exposed surface 104c of the n contact layer 104a were exposed.
  • the hole 109a was formed by dry etching the translucent electrode 109. Thereafter, heat treatment was performed at a temperature of 650 ° C. in a nitrogen atmosphere to crystallize the amorphous IZO film constituting the translucent electrode 109.
  • AZ5200NJ product name: manufactured by AZ Electronic Materials Co., Ltd.
  • AZ5200NJ product name: manufactured by AZ Electronic Materials Co., Ltd.
  • AZ5200NJ product name: manufactured by AZ Electronic Materials Co., Ltd.
  • a reverse taper type mask 23 having an opening 23a having an inner wall shape whose cross-sectional area gradually increases toward the bottom surface was formed.
  • the opening 23 of the mask 23 formed on the translucent electrode 109 was formed at a position where the hole 109 a of the translucent electrode 109 was exposed from the opening 23.
  • openings of the hole 109a of the translucent electrode 109 or the exposed surface 104c of the n-contact layer 104a, the inner wall 109d of the hole 109a of the translucent electrode 109, and the protective film 10a are formed by sputtering.
  • An ohmic junction layer 9 made of IZO having a thickness of 100 nm was formed so as to continuously cover the end 10c of the portion 10d.
  • a bonding layer 110 made of Cr having a maximum film thickness of 10 nm was formed so as to continuously cover the ohmic bonding layer 9 and the end 10c of the opening 10d of the protective film 10a.
  • a metal reflective layer 117 made of Pt having a maximum film thickness of 100 nm was formed by sputtering, covering the bonding layer 110 and having an inclined surface 117c that gradually decreases in thickness toward the outside at the outer periphery.
  • the shape of the outer peripheral portion is formed along the inner wall shape of the opening 23a of the mask 23, covers the metal reflection layer 117, and the inclined surface 119c whose thickness gradually decreases toward the outer portion is formed on the outer peripheral portion.
  • a bonding layer 119 made of Au having a maximum thickness of 1100 nm at 120d was formed.
  • the bonding pad electrode 120 composed of the metal reflection layer 117 and the bonding layer 119 was formed.
  • the mask 23 was peeled by being immersed in a resist stripping solution.
  • Heat treatment process Subsequently, in order to improve the adhesion between the ohmic bonding layer 9 and the bonding layer 110, heat treatment was performed at a temperature of 360 ° C. in a nitrogen atmosphere. In addition, the adhesion between the ohmic bonding layer 9 and the bonding layer 110 can be improved without the heat treatment step.
  • the edge protective film 10b made of SiO 2 having a maximum thickness of 250 nm was formed over the entire region excluding the region exposing the central portion of the bonding pad electrode 120 when viewed in plan. In this way, the semiconductor light emitting device 1 of Example 42 including the p-type electrode 111 shown in FIGS. 26 to 28 was obtained.
  • Example 43 to 59 The semiconductor light emitting device of Example 42, except that the p-type electrode (ohmic junction layer, junction layer, bonding pad electrode (metal reflective layer, barrier layer, bonding layer)) and n-type electrode have the configurations shown in Table 5
  • the semiconductor light emitting devices of Examples 43 to 59 which are the same as 1 were manufactured.
  • the n-type electrode 108 made of Ti / Au was formed on the exposed surface 104c of the n-contact layer 104a by sputtering, and (1) openings were formed in the p-type electrode 111. (2) not having an ohmic bonding layer, (3) the side surfaces of the bonding layer 110 and the bonding pad electrode 120 of the light transmitting electrode 109. It is formed substantially perpendicular to the upper surface 109c, and the heat treatment temperature is 275 ° C. (4)
  • the semiconductor light emitting element 1 of Example 42 is the same except that the insulating protective film 10b is not formed.
  • the semiconductor light emitting device of Comparative Example 8 was manufactured.
  • the semiconductor light emitting devices of Examples 42 to 59 and Comparative Example 8 were mounted in a TO-18 can package, and the light emission output was measured by a tester.
  • the results are shown in Table 6.
  • the light emission outputs of Examples 42 to 59 were in the range of 19.5 to 23 mW, and the light emission output of Comparative Example 8 was 21 mW.
  • the reflectance of the bonding pad electrodes produced in Examples 42 to 59 and Comparative Example 8 was measured.
  • the reflectance was measured in the wavelength region of 460 nm using a spectrophotometer for the same thin film as the bonding pad electrode formed on the glass dummy substrate placed in the chamber when the bonding pad electrode was formed. The results are shown in Table 6.
  • ⁇ Chip high temperature and high humidity test> The semiconductor light emitting devices (chips) of Examples 42 to 59 and Comparative Example 8 are placed in a high-temperature and high-humidity device (Isuzu Seisakusho, ⁇ -SERIES), and are formed into 100 chips in an environment of a temperature of 85 ° C. and a relative humidity of 85 RH%. On the other hand, a light emission test (amount of current to the chip of 5 mA, 2000 hours) was performed. The results are shown in Table 6. As shown in Table 6, in Examples 48, 49, and 53 to 59, the number of 100 defects was 0. Also, in other examples, the number of defects was 5 or less, which was very small. On the other hand, in Comparative Example 8, the number of defects was 20 out of 100 chips.
  • Example 60 A lamp (package) in which the semiconductor light-emitting element manufactured in Examples 1 to 59 was mounted according to the same method as described in JP-A-2007-194401 could be produced.
  • a backlight incorporating the lamp could be manufactured.
  • the present invention relates to a semiconductor light emitting device, an electrode thereof, a manufacturing method, and a lamp, and more particularly, to manufacture and use a semiconductor light emitting device including an electrode with improved bonding properties and corrosion resistance, the electrode, the manufacturing method, and the lamp. It can be used in the industry.
  • 104 N-type semiconductor layer, 104a ... n contact Layer 104b ... n clad layer 104c exposed surface (semiconductor layer exposed surface) 105 light emitting layer 105a barrier layer 105b well layer 106 p semiconductor layer 106a p clad 106b ... p contact layer, 106c ... upper surface, 108, 118, 128 ... n-type electrode (the other electrode), 108c ... inclined surface, 108d ... outer periphery, 109 ... translucent electrode, 109a ... joining recess (hole) 109b ... bottom surface, 109c ... upper surface, 109d ... inner wall, 110 ... bonding layer, 110c ...

Abstract

Provided are a semiconductor light emitting element having an electrode improved in junction and anticorrosion, a method for manufacturing the element, and a lamp.  The semiconductor light emitting element comprises a substrate, a laminated semiconductor layer including a light emitting layer formed over the substrate, one electrode (111) formed over the upper face of the laminated semiconductor layer, and the other electrode formed over the semiconductor layer exposing face, from which the laminated semiconductor layer is partially cut off.  The one electrode (111) includes a junction layer (110) and a bonding pad electrode (120) formed to cover the junction layer (110).  The bonding pad electrode (120) has a maximum thickness larger than the maximum thickness of the junction layer (110), and is composed of one or two or more layers.  Inclined slopes (110c), (117c) and (119c), which are made gradually thinner toward the outer circumference, are formed in the outer circumference portions (110d) and (120d) of the junction layer (110) and the bonding pad electrode (120).  Thus, it is possible to improve the junction and anticorrosion of the electrode of the semiconductor light emitting element.

Description

半導体発光素子、その電極並びに製造方法及びランプSemiconductor light emitting device, electrode thereof, manufacturing method and lamp
　本発明は、半導体発光素子、その電極並びに製造方法及びランプに関するものであり、特に、接合性および耐食性を向上させた電極を備えた半導体発光素子、その電極並びに製造方法及びランプに関するものである。
  本願は、２００８年６月１６日に、日本に出願された特願２００８－１５７２４８号、２００８年８月１日に、日本に出願された特願２００８－１９９８０２号、２００８年９月５日に、日本に出願された特願２００８－２２８１３３号および２００９年６月２日に、日本に出願された特願２００９－１３３１７７号に基づき優先権を主張し、その内容をここに援用する。 The present invention relates to a semiconductor light emitting device, an electrode thereof, a manufacturing method thereof, and a lamp, and more particularly to a semiconductor light emitting device including an electrode having improved bonding properties and corrosion resistance, an electrode thereof, a manufacturing method thereof, and a lamp.
The present application was filed on June 16, 2008, Japanese Patent Application No. 2008-157248 filed in Japan, August 1, 2008, Japanese Patent Application No. 2008-199802 filed in Japan, September 5, 2008 Priority is claimed based on Japanese Patent Application No. 2008-228133 filed in Japan and Japanese Patent Application No. 2009-133177 filed in Japan on June 2, 2009, the contents of which are incorporated herein by reference.
　近年、短波長光発光素子用の半導体材料として、ＧａＮ系化合物半導体が注目を集めている。ＧａＮ系化合物半導体は、サファイア単結晶を始めとして、種々の酸化物やＩＩＩ－Ｖ族化合物を基板として、その上に有機金属気相化学反応法（ＭＯＣＶＤ法）や分子線エピタキシー法（ＭＢＥ法）等の薄膜形成手段によって形成される。 In recent years, GaN-based compound semiconductors have attracted attention as semiconductor materials for short wavelength light emitting devices. GaN-based compound semiconductors include sapphire single crystals, various oxides and III-V compounds as substrates, and metalorganic vapor phase chemical reaction method (MOCVD method) and molecular beam epitaxy method (MBE method). It is formed by thin film forming means such as.
　ＧａＮ系化合物半導体からなる薄膜は、薄膜の面内方向への電流拡散が小さいという特性がある。さらに、ｐ型のＧａＮ系化合物半導体は、ｎ型のＧａＮ系化合物半導体に比べて抵抗率が高いという特性がある。そのため、ｐ型の半導体層の表面に、金属からなるｐ型電極を積層しただけではｐ型半導体層の面内方向への電流の広がりがほとんど無い。 A thin film made of a GaN compound semiconductor has a characteristic that current diffusion in the in-plane direction of the thin film is small. Furthermore, the p-type GaN-based compound semiconductor has a characteristic that the resistivity is higher than that of the n-type GaN-based compound semiconductor. For this reason, there is almost no spread of current in the in-plane direction of the p-type semiconductor layer simply by stacking a p-type electrode made of metal on the surface of the p-type semiconductor layer.
　このようなＧａＮ系化合物半導体を用いた半導体発光素子では、ｎ型半導体層、発光層、ｐ型半導体層からなるＬＥＤ構造を有する積層半導体層を形成し、最上部のｐ型半導体層にｐ型電極を形成した場合、発光層のうちｐ型電極の直下に位置する部分しか発光しない。そのため、ｐ型電極の直下で発生した発光を半導体発光素子の外部に取り出すためには、ｐ型電極に透光性を持たせることにより、ｐ型電極に対して発光を透過させて取り出す必要がある。 In such a semiconductor light-emitting device using a GaN-based compound semiconductor, a laminated semiconductor layer having an LED structure including an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer is formed, and a p-type semiconductor layer is formed on the uppermost p-type semiconductor layer. When the electrode is formed, only the portion of the light emitting layer located immediately below the p-type electrode emits light. For this reason, in order to take out the light emitted immediately below the p-type electrode to the outside of the semiconductor light emitting device, it is necessary to make the p-type electrode transparent so that the p-type electrode can transmit the emitted light. is there.
　ｐ型電極に透光性を持たせる方法としては、透光性を有するＩＴＯ等の導電性の金属酸化物を用いるか、数１０ｎｍ程度の金属薄膜を用いる方法が知られている。たとえば、特許文献１には、数１０ｎｍ程度の金属薄膜を用いる方法が開示されており、ｐ型電極としてｐ型半導体層上にＮｉとＡｕを各々数１０ｎｍ程度積層させた後、酸素雰囲気下で加熱して合金化処理を行い、ｐ型半導体層の低抵抗化の促進および透光性とオーミック性を有したｐ型電極の形成を同時に行なうことが提案されている。
　しかし、ＩＴＯ等の金属酸化物からなる透光性電極や、数１０ｎｍ程度の金属薄膜からなるオーミック電極は、電極自体の強度が低いため、これら電極自体をボンディングパッド電極として用いることが難しいという問題があった。 As a method for imparting translucency to the p-type electrode, a method using a conductive metal oxide such as ITO having translucency or a metal thin film of about several tens of nm is known. For example, Patent Document 1 discloses a method using a metal thin film of about several tens of nanometers. Ni and Au are stacked on a p-type semiconductor layer of several tens of nanometers each as a p-type electrode, and then in an oxygen atmosphere. It has been proposed to perform alloying treatment by heating to simultaneously promote the reduction in resistance of the p-type semiconductor layer and to form a p-type electrode having translucency and ohmic properties.
However, a translucent electrode made of a metal oxide such as ITO or an ohmic electrode made of a metal thin film of about several tens of nm has a problem that it is difficult to use the electrode itself as a bonding pad electrode because the strength of the electrode itself is low. was there.
　電極自体の強度を向上させるために、ＩＴＯ等の金属酸化物からなる透光性電極や、数１０ｎｍ程度の金属薄膜からなるオーミック電極などのｐ型電極上に、ある程度の厚みを持ったボンディング用のパッド電極を配置したものが用いられてきた。
　しかし、このボンディングパッド電極はある程度の厚みを持った金属材料であるために透光性がなく、透光性のｐ型電極を透過した発光を遮り、結果的に発光の一部を発光素子の外部に取り出せないという問題が発生している。 In order to improve the strength of the electrode itself, for bonding with a certain thickness on a p-type electrode such as a translucent electrode made of a metal oxide such as ITO or an ohmic electrode made of a metal thin film of about several tens of nm. The one in which the pad electrode is arranged has been used.
However, since this bonding pad electrode is a metal material having a certain thickness, it has no translucency and blocks light emitted through the translucent p-type electrode. There is a problem that it cannot be taken out.
　この問題を解消するために、たとえば、特許文献２には、Ａｇ、Ａｌ等の反射膜からなるボンディングパッド電極をｐ型電極上に積層する方法が開示されている。これにより、ｐ型電極を透過した発光がボンディングパッド電極によって発光素子内に反射させ、この反射光をボンディングパッド電極の形成領域以外の箇所から発光素子の外部に取り出すことが可能となった。
　しかし、ｐ型電極としてＩＴＯ等の金属酸化物等を用い、ボンディングパッド電極としてＡｇ、Ａｌ等の反射膜を用いた場合には、ボンディングパッド電極に対してボンディングワイヤ等を接合しようとすると、ボンディングワイヤ接合時の引張応力にボンディングパッド電極が耐えられず、パッド電極が剥がれてしまう場合があった。
　そして、透光性電極からボンディングパッド電極が剥離することにより、これを用いたランプを製造する場合における歩留まりを低下させてしまう場合があった。
　また、従来の半導体発光素子では、耐食性が不十分であり、耐食性を向上させることが要求されていた。 In order to solve this problem, for example, Patent Document 2 discloses a method of laminating a bonding pad electrode made of a reflective film such as Ag or Al on a p-type electrode. As a result, the light transmitted through the p-type electrode is reflected into the light emitting element by the bonding pad electrode, and this reflected light can be taken out of the light emitting element from a place other than the region where the bonding pad electrode is formed.
However, when a metal oxide such as ITO is used as the p-type electrode and a reflective film such as Ag or Al is used as the bonding pad electrode, bonding is attempted when bonding wires or the like are bonded to the bonding pad electrode. In some cases, the bonding pad electrode could not withstand the tensile stress during wire bonding, and the pad electrode would peel off.
In some cases, the bonding pad electrode is peeled off from the translucent electrode, thereby reducing the yield in manufacturing a lamp using the bonding pad electrode.
Further, the conventional semiconductor light emitting device has insufficient corrosion resistance and has been required to improve the corrosion resistance.
特許第２８０３７４２号公報Japanese Patent No. 2803742 特開２００６－６６９０３号公報JP 2006-66903 A
　本発明は、上記事情を鑑みてなされたものであって、優れた接合性および耐食性を有する電極を備えた半導体発光素子、およびその製造方法、これを用いた耐食性に優れ歩留まりよく製造できるランプを提供することを目的とする。 The present invention has been made in view of the above circumstances, and a semiconductor light emitting device including an electrode having excellent bonding properties and corrosion resistance, a manufacturing method thereof, and a lamp that is excellent in corrosion resistance and can be manufactured with high yield using the same. The purpose is to provide.
　上記の目的を達成するために、本発明は以下の構成を採用した。すなわち、
　　（１）　基板と、前記基板上に形成されてなる発光層を含む積層半導体層と、前記積層半導体層の上面に形成された一方の電極と、前記積層半導体層の一部が切り欠けられてなる半導体層露出面上に形成された他方の電極と、を具備する半導体発光素子であって、前記一方の電極または前記他方の電極の少なくともいずれか一方が、接合層と前記接合層を覆うように形成されたボンディングパッド電極とからなり、前記ボンディングパッド電極の最大厚みが、前記接合層の最大厚みに比べて厚く形成され、かつ、１または２以上の層からなり、前記接合層および前記ボンディングパッド電極の外周部にそれぞれ、外周側に向けて膜厚が漸次薄くなるような傾斜面が形成されていることを特徴とする半導体発光素子。 In order to achieve the above object, the present invention employs the following configuration. That is,
(1) A substrate, a laminated semiconductor layer including a light emitting layer formed on the substrate, one electrode formed on an upper surface of the laminated semiconductor layer, and a portion of the laminated semiconductor layer being cut away The other electrode formed on the exposed surface of the semiconductor layer, wherein at least one of the one electrode or the other electrode covers the bonding layer and the bonding layer. The bonding pad electrode is formed such that the maximum thickness of the bonding pad electrode is larger than the maximum thickness of the bonding layer, and the bonding pad electrode includes one or more layers. A semiconductor light emitting element characterized in that an inclined surface is formed on the outer periphery of the pad electrode so that the film thickness gradually decreases toward the outer periphery.
　　（２）　前記接合層が、Ａｌ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｃｏ、Ｚｎ、Ｇｅ、Ｚｒ、Ｎｂ、Ｍｏ、Ｒｕ、Ｈｆ、Ｔａ、Ｗ、Ｒｅ、Ｒｈ、Ｉｒ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなるものであり、最大厚みが１０Å以上１０００Å以下の範囲の薄膜であることを特徴とする（１）に記載の半導体発光素子。 (2) The bonding layer is selected from the group consisting of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh, Ir, and Ni. The semiconductor light-emitting device according to (1), comprising a thin film having a maximum thickness in the range of 10 to 1000 mm.
　　（３）　前記ボンディングパッド電極が、Ａｕ、Ａｌまたはこれらの金属の何れかを含む合金からなるボンディング層からなり、前記ボンディング層の最大厚みが５０ｎｍ以上２０００ｎｍ以下の範囲の薄膜であることを特徴とする（１）または（２）に記載の半導体発光素子。 (3) The bonding pad electrode is made of a bonding layer made of Au, Al, or an alloy containing any of these metals, and the bonding layer is a thin film having a maximum thickness in the range of 50 nm to 2000 nm. The semiconductor light emitting device according to (1) or (2).
　　（４）　前記ボンディングパッド電極が、前記接合層を覆うように形成された金属反射層と、前記金属反射層を覆うように形成されたボンディング層とからなり、前記金属反射層が、Ａｇ、Ａｌ、Ｒｕ、Ｒｈ、Ｐｄ、Ｏｓ、Ｉｒ、Ｐｔ、Ｔｉのうちの何れかまたはこれら金属の何れかを含む合金からなるものであり、最大厚みが２０ｎｍ以上３０００ｎｍ以下の範囲の薄膜であることを特徴とする（１）～（３）のいずれかに記載の半導体発光素子。 (4) The bonding pad electrode includes a metal reflection layer formed so as to cover the bonding layer and a bonding layer formed so as to cover the metal reflection layer, and the metal reflection layer includes Ag, Al. , Ru, Rh, Pd, Os, Ir, Pt, Ti, or an alloy containing any of these metals, and having a maximum thickness in the range of 20 nm to 3000 nm The semiconductor light emitting device according to any one of (1) to (3).
　　（５）　前記一方の電極と前記積層半導体層の上面との間または前記他方の電極と前記半導体層露出面との間に透光性電極が形成されており、前記透光性電極が、Ｉｎ、Ｚｎ、Ａｌ、Ｇａ、Ｔｉ、Ｂｉ、Ｍｇ、Ｗ、Ｃｅ、Ｓｎ、Ｎｉのいずれか一種を含む導電性の酸化物、硫化亜鉛または硫化クロムのうちいずれか一種からなる群より選ばれる透光性の導電性材料から構成されることを特徴とする（１）～（４）のいずれかに記載の半導体発光素子。 (5) A translucent electrode is formed between the one electrode and the upper surface of the stacked semiconductor layer or between the other electrode and the exposed surface of the semiconductor layer, and the translucent electrode is In , Zn, Al, Ga, Ti, Bi, Mg, W, Ce, Sn, a light-transmitting material selected from the group consisting of any one of zinc sulfide and chromium sulfide The semiconductor light-emitting device according to any one of (1) to (4), wherein the semiconductor light-emitting device is made of a conductive material.
　　（６）　前記積層半導体層が、前記基板側からｎ型半導体層、発光層、ｐ型半導体層の順に積層されてなり、前記発光層が多重量子井戸構造であることを特徴とする（１）～（５）のいずれかに記載の半導体発光素子。 (6) The stacked semiconductor layer is formed by stacking an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer in this order from the substrate side, and the light-emitting layer has a multiple quantum well structure (1) The semiconductor light emitting device according to any one of to (5).
　　（７）　前記積層半導体層が、窒化ガリウム系半導体を主体として構成されていることを特徴とする（１）～（６）のいずれかに記載の半導体発光素子。 (7) The semiconductor light-emitting element according to any one of (1) to (6), wherein the stacked semiconductor layer is mainly composed of a gallium nitride-based semiconductor.
　　（８）　（１）～（７）のいずれかに記載の半導体発光素子と、前記半導体発光素子が配置されるとともに前記半導体発光素子の一方の電極とワイヤボンディングされる第１フレームと、前記半導体発光素子の他方の電極とワイヤボンディングされる第２フレームと、前記半導体発光素子を取り囲んで形成されるモールドと、を備えたことを特徴とするランプ。 (8) The semiconductor light emitting element according to any one of (1) to (7), a first frame in which the semiconductor light emitting element is disposed and wire-bonded to one electrode of the semiconductor light emitting element, and the semiconductor A lamp comprising: a second frame wire-bonded to the other electrode of the light-emitting element; and a mold formed surrounding the semiconductor light-emitting element.
　　（９）　基板と、前記基板上に形成されてなる発光層を含む積層半導体層と、前記積層半導体層の上面に形成された一方の電極と、前記積層半導体層の一部が切り欠けられてなる半導体層露出面上に形成された他方の電極と、を具備する半導体発光素子用の電極であって、前記一方の電極または前記他方の電極の少なくともいずれか一方が、接合層と前記接合層を覆うように形成されたボンディングパッド電極とからなり、前記ボンディングパッド電極の最大厚みが、前記接合層の最大厚みに比べて厚く形成され、かつ、１または２以上の層からなり、前記接合層および前記ボンディングパッド電極の外周部にそれぞれ、外周側に向けて膜厚が漸次薄くなるような傾斜面が形成されていることを特徴とする半導体発光素子用の電極。 (9) A substrate, a laminated semiconductor layer including a light emitting layer formed on the substrate, one electrode formed on an upper surface of the laminated semiconductor layer, and a part of the laminated semiconductor layer are cut away The other electrode formed on the exposed surface of the semiconductor layer, and an electrode for a semiconductor light emitting device, wherein at least one of the one electrode or the other electrode is a bonding layer and the bonding layer A bonding pad electrode formed so as to cover the bonding pad electrode, wherein the bonding pad electrode has a maximum thickness that is larger than a maximum thickness of the bonding layer, and includes one or more layers, and the bonding layer An electrode for a semiconductor light emitting element, wherein an inclined surface is formed on the outer peripheral portion of the bonding pad electrode so that the film thickness gradually decreases toward the outer peripheral side.
　　（１０）　前記接合層が、Ａｌ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｃｏ、Ｚｎ、Ｇｅ、Ｚｒ、Ｎｂ、Ｍｏ、Ｒｕ、Ｈｆ、Ｔａ、Ｗ、Ｒｅ、Ｒｈ、Ｉｒ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなるものであり、最大厚みが１０Å以上１０００Å以下の範囲の薄膜であることを特徴とする（９）に記載の半導体発光素子用の電極。 (10) The bonding layer is selected from the group consisting of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh, Ir, and Ni. The electrode for a semiconductor light-emitting element according to (9), which is a thin film comprising at least one kind of element and having a maximum thickness in the range of 10 to 1000 mm.
　　（１１）　前記ボンディングパッド電極が、Ａｕ、Ａｌまたはこれらの金属の何れかを含む合金からなるボンディング層からなり、前記ボンディング層の最大厚みが５０ｎｍ以上２０００ｎｍ以下の範囲の薄膜であることを特徴とする（９）または（１０）に記載の半導体発光素子用の電極。 (11) The bonding pad electrode is made of a bonding layer made of Au, Al, or an alloy containing any of these metals, and the bonding layer is a thin film having a maximum thickness in the range of 50 nm to 2000 nm. The electrode for a semiconductor light-emitting device according to (9) or (10).
　　（１２）　前記ボンディングパッド電極が、前記接合層を覆うように形成された金属反射層と、前記金属反射層を覆うように形成されたボンディング層とからなり、前記金属反射層が、Ａｇ、Ａｌ、Ｒｕ、Ｒｈ、Ｐｄ、Ｏｓ、Ｉｒ、Ｐｔ、Ｔｉのうちの何れかまたはこれら金属の何れかを含む合金からなるものであり、最大厚みが２０ｎｍ以上３０００ｎｍ以下の範囲の薄膜であることを特徴とする（９）～（１１）のいずれか１項に記載の半導体発光素子用の電極。 (12) The bonding pad electrode includes a metal reflection layer formed so as to cover the bonding layer and a bonding layer formed so as to cover the metal reflection layer, and the metal reflection layer includes Ag, Al. , Ru, Rh, Pd, Os, Ir, Pt, Ti, or an alloy containing any of these metals, and having a maximum thickness in the range of 20 nm to 3000 nm (9) The electrode for a semiconductor light-emitting device according to any one of (9) to (11).
　　（１３）　前記一方の電極と前記積層半導体層の上面との間または前記他方の電極と前記半導体層露出面との間に透光性電極が形成されており、前記透光性電極が、Ｉｎ、Ｚｎ、Ａｌ、Ｇａ、Ｔｉ、Ｂｉ、Ｍｇ、Ｗ、Ｃｅ、Ｓｎ、Ｎｉのいずれか一種を含む導電性の酸化物、硫化亜鉛または硫化クロムのうちいずれか一種からなる群より選ばれる透光性の導電性材料から構成されることを特徴とする（９）～（１２）のいずれか１項に記載の半導体発光素子用の電極。 (13) A translucent electrode is formed between the one electrode and the upper surface of the stacked semiconductor layer or between the other electrode and the exposed surface of the semiconductor layer, and the translucent electrode is In , Zn, Al, Ga, Ti, Bi, Mg, W, Ce, Sn, a light-transmitting material selected from the group consisting of any one of zinc sulfide and chromium sulfide (9) The electrode for a semiconductor light-emitting element according to any one of (9) to (12), which is made of a conductive material.
　　（１４）　基板上に、発光層を含む積層半導体層を形成する工程と、前記積層半導体層の一部を切り欠けて半導体層露出面を形成する工程と、前記積層半導体層の上面および前記半導体層露出面に一方の電極および他方の電極を形成する電極形成工程と、を有する半導体発光素子の製造方法であって、前記電極形成工程が、前記積層半導体層の上面または前記半導体層露出面の少なくともいずれか一方の面上に逆テーパー型マスクを形成するマスク形成工程の後、前記積層半導体層の上面または前記半導体層露出面上に接合層を形成し、その後、前記接合層を覆うように前記接合層の最大厚みに比べて最大厚みの厚いボンディングパッド電極を形成して、一方の電極または他方の電極を形成する工程であることを特徴とする半導体発光素子の製造方法。 (14) A step of forming a laminated semiconductor layer including a light emitting layer on a substrate, a step of cutting out part of the laminated semiconductor layer to form a semiconductor layer exposed surface, an upper surface of the laminated semiconductor layer, and the semiconductor An electrode forming step of forming one electrode and the other electrode on the layer exposed surface, wherein the electrode forming step is performed on the upper surface of the stacked semiconductor layer or the exposed surface of the semiconductor layer. After a mask forming step of forming an inversely tapered mask on at least one surface, a bonding layer is formed on the upper surface of the stacked semiconductor layer or the exposed surface of the semiconductor layer, and then covers the bonding layer A semiconductor light emitting device comprising a step of forming a bonding pad electrode having a maximum thickness compared to the maximum thickness of the bonding layer to form one electrode or the other electrode. The method of production.
　　（１５）　前記電極形成工程の前に前記積層半導体層の上面または前記半導体層露出面に透光性電極を形成する工程を有することを特徴とする（１４）に記載の半導体発光素子の製造方法。 (15) The method for manufacturing a semiconductor light-emitting element according to (14), further comprising a step of forming a translucent electrode on the upper surface of the stacked semiconductor layer or the exposed surface of the semiconductor layer before the electrode forming step. .
　　（１６）　前記電極形成工程が、前記逆テーパー型マスクおよび前記接合層を形成した後、前記接合層を覆うように前記接合層の最大厚みに比べて最大厚みの厚い金属反射層を形成し、その後、前記金属反射層を覆うように前記金属反射層の最大厚みに比べて最大厚みの厚いボンディング層を形成して、一方の電極または他方の電極を形成する工程であることを特徴とする（１４）または（１５）に記載の半導体発光素子の製造方法。 (16) After the electrode forming step forms the reverse tapered mask and the bonding layer, a metal reflective layer having a maximum thickness compared to the maximum thickness of the bonding layer is formed so as to cover the bonding layer; Thereafter, a bonding layer having a maximum thickness compared to the maximum thickness of the metal reflection layer is formed so as to cover the metal reflection layer, thereby forming one electrode or the other electrode. The method for producing a semiconductor light-emitting device according to 14) or 15).
　　（１７）　前記電極形成工程における前記接合層、前記金属反射層および前記ボンディング層の形成が、スパッタ法により行われることを特徴とする（１４）～（１６）のいずれかに記載の半導体発光素子の製造方法。 (17) The semiconductor light emitting element according to any one of (14) to (16), wherein the bonding layer, the metal reflective layer, and the bonding layer in the electrode forming step are formed by a sputtering method. Manufacturing method.
　　（１８）　前記マスク形成工程の前に、前記透光性電極の上面および前記積層半導体層の上面または前記半導体層露出面上に保護膜を形成する工程を備えたことを特徴とする（１４）～（１７）のいずれかに記載の半導体発光素子の製造方法。 (18) The method includes a step of forming a protective film on the upper surface of the translucent electrode and the upper surface of the laminated semiconductor layer or on the exposed surface of the semiconductor layer before the mask forming step (14). A method for producing a semiconductor light-emitting device according to any one of (17) to (17).
　　（１９）基板と、前記基板上に形成された発光層を含む積層半導体層と、前記積層半導体層の上面に形成された一方の電極と、前記積層半導体層の一部が切り欠けられてなる半導体層露出面上に形成された他方の電極とを具備する半導体発光素子であって、前記一方の電極または前記他方の電極の少なくともいずれか一方が、上面に接合凹部を有する透光性電極と、前記接合凹部を覆うように形成された接合層と、前記接合層を覆うように形成され、外側に向けて膜厚が漸次薄くなる傾斜面が外周部に形成されているボンディングパッド電極とを備えていることを特徴とする半導体発光素子。 (19) A substrate, a laminated semiconductor layer including a light emitting layer formed on the substrate, one electrode formed on an upper surface of the laminated semiconductor layer, and a part of the laminated semiconductor layer are cut away. A semiconductor light-emitting element including the other electrode formed on the exposed surface of the semiconductor layer, wherein at least one of the one electrode and the other electrode has a bonding recess on an upper surface; A bonding layer formed so as to cover the bonding recess, and a bonding pad electrode formed so as to cover the bonding layer and having an inclined surface with a gradually decreasing thickness toward the outside. A semiconductor light emitting element comprising:
　　（２０）前記接合層が、Ａｌ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｃｏ、Ｚｎ、Ｇｅ、Ｚｒ、Ｎｂ、Ｍｏ、Ｒｕ、Ｈｆ、Ｔａ、Ｗ、Ｒｅ、Ｒｈ、Ｉｒ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなるものであり、最大厚みが１０Å以上４００Å以下の範囲の薄膜であることを特徴とする（１９）に記載の半導体発光素子。 (20) The bonding layer is selected from the group consisting of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh, Ir, and Ni. (19) The semiconductor light emitting device according to (19), wherein the semiconductor light emitting device is a thin film having a maximum thickness in a range of 10 to 400 mm.
　　（２１）前記ボンディングパッド電極が、Ａｕ、Ａｌまたはこれらの金属の何れかを含む合金からなるボンディング層を含むことを特徴とする（１９）または（２０）に記載の半導体発光素子。 (21) The semiconductor light-emitting element according to (19) or (20), wherein the bonding pad electrode includes a bonding layer made of Au, Al, or an alloy containing any of these metals.
　　（２２）前記ボンディングパッド電極が、前記接合層を覆うように形成された金属反射層と、前記金属反射層を覆うように形成されたボンディング層とからなり、前記金属反射層が、Ａｇ、Ａｌ、Ｒｕ、Ｒｈ、Ｐｄ、Ｏｓ、Ｉｒ、Ｐｔ、Ｔｉのうちの何れかまたはこれら金属の何れかを含む合金からなるものであることを特徴とする（２１）に記載の半導体発光素子。 (22) The bonding pad electrode includes a metal reflection layer formed so as to cover the bonding layer and a bonding layer formed so as to cover the metal reflection layer, and the metal reflection layer includes Ag, Al. (21) The semiconductor light-emitting element according to (21), which is made of an alloy containing any one of Ru, Rh, Pd, Os, Ir, Pt, and Ti, or any of these metals.
　　（２３）前記透光性電極が、Ｉｎ、Ｚｎ、Ａｌ、Ｇａ、Ｔｉ、Ｂｉ、Ｍｇ、Ｗ、Ｃｅ、Ｓｎ、Ｎｉのいずれか一種を含む導電性の酸化物、硫化亜鉛または硫化クロムのうちいずれか一種からなる群より選ばれる透光性の導電性材料から構成されることを特徴とする（１９）～（２２）のいずれかに記載の半導体発光素子。 (23) The translucent electrode is a conductive oxide, zinc sulfide, or chromium sulfide containing any one of In, Zn, Al, Ga, Ti, Bi, Mg, W, Ce, Sn, and Ni. (19) The semiconductor light-emitting device according to any one of (19) to (22), which is made of a translucent conductive material selected from the group consisting of any one kind.
　　（２４）前記ボンディングパッド電極の外縁部を覆い、前記ボンディングパッド電極上の一部を露出させる縁部保護膜が形成されていることを特徴とする（１９）～（２３）のいずれかに記載の半導体発光素子。 (24) In any one of (19) to (23), an edge protection film is formed which covers an outer edge of the bonding pad electrode and exposes a part of the bonding pad electrode. Semiconductor light emitting device.
　　（２５）前記透光性電極の上面における前記接合凹部の形成されていない領域を覆うように透明保護膜が形成されており、前記接合層の外縁部および前記ボンディングパッド電極の外縁部が、前記透明保護膜上に配置されていることを特徴とする（１９）～（２４）のいずれかに記載の半導体発光素子。 (25) A transparent protective film is formed so as to cover a region where the bonding recess is not formed on the upper surface of the translucent electrode, and the outer edge portion of the bonding layer and the outer edge portion of the bonding pad electrode are The semiconductor light-emitting device according to any one of (19) to (24), which is disposed on a transparent protective film.
　　（２６）前記積層半導体層が、前記基板側からｎ型半導体層、発光層、ｐ型半導体層の順に積層されてなり、前記発光層が多重量子井戸構造であることを特徴とする（１９）～（２５）のいずれかに記載の半導体発光素子。 (26) The stacked semiconductor layer is formed by stacking an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer in this order from the substrate side, and the light-emitting layer has a multiple quantum well structure (19) The semiconductor light-emitting device according to any one of to (25).
　　（２７）前記積層半導体層が、窒化ガリウム系半導体を主体として構成されていることを特徴とする（１９）～（２６）のいずれかに記載の半導体発光素子。 (27) The semiconductor light-emitting element according to any one of (19) to (26), wherein the stacked semiconductor layer is mainly composed of a gallium nitride-based semiconductor.
　　（２８）（１９）～（２７）のいずれかに記載の半導体発光素子と、前記半導体発光素子が配置されるとともに前記半導体発光素子の一方の電極とワイヤボンディングされる第１フレームと、前記半導体発光素子の他方の電極とワイヤボンディングされる第２フレームと、前記半導体発光素子を取り囲んで形成されるモールドと、を備えたことを特徴とするランプ。 (28) The semiconductor light emitting element according to any one of (19) to (27), a first frame in which the semiconductor light emitting element is disposed and wire-bonded to one electrode of the semiconductor light emitting element, and the semiconductor A lamp comprising: a second frame wire-bonded to the other electrode of the light-emitting element; and a mold formed surrounding the semiconductor light-emitting element.
　　（２９）基板と、前記基板上に形成された発光層を含む積層半導体層と、前記積層半導体層の上面に形成された一方の電極と、前記積層半導体層の一部が切り欠けられてなる半導体層露出面上に形成された他方の電極とを具備する半導体発光素子の製造方法であって、前記一方の電極または前記他方の電極の少なくともいずれか一方を製造する工程が、透光性電極を形成する工程と、前記透光性電極の上面に、底面に向かって断面積が徐々に広くなる内壁形状を有する開口部を備えたマスクを形成する工程と、前記開口部から露出する前記透光性電極の上面をエッチングすることにより接合凹部を形成する工程と、前記接合凹部を覆うように接合層を形成する工程と、前記開口部の内壁形状に沿って外周部の形状を形成することにより、前記接合層を覆い、外側に向けて膜厚が漸次薄くなる傾斜面を外周部に有するボンディングパッド電極を形成する工程と、前記マスクを除去する工程とを備えることを特徴とする半導体発光素子の製造方法。 (29) A substrate, a laminated semiconductor layer including a light emitting layer formed on the substrate, one electrode formed on an upper surface of the laminated semiconductor layer, and a part of the laminated semiconductor layer are cut away. A method of manufacturing a semiconductor light emitting device comprising the other electrode formed on the exposed surface of the semiconductor layer, wherein the step of manufacturing at least one of the one electrode or the other electrode comprises a translucent electrode Forming a mask having an opening having an inner wall shape whose cross-sectional area gradually increases toward the bottom surface on the upper surface of the translucent electrode, and the transparent electrode exposed from the opening. Forming a bonding recess by etching the upper surface of the photoelectrode, forming a bonding layer so as to cover the bonding recess, and forming an outer peripheral shape along the inner wall shape of the opening. By A step of forming a bonding pad electrode having an inclined surface that covers the bonding layer and gradually decreases in thickness toward the outside, and a step of removing the mask. Production method.
　（３０）（２８）に記載のランプが組み込まれている電子機器。 (30) An electronic device incorporating the lamp described in (28).
　（３１）（３０）に記載の電子機器が組み込まれている機械装置。 (31) A mechanical device in which the electronic device according to (30) is incorporated.
　　（３２）基板と、前記基板上に形成された発光層を含む積層半導体層と、前記積層半導体層の上面に形成された一方の電極と、前記積層半導体層の一部が切り欠けられてなる半導体層露出面上に形成された他方の電極とを具備する半導体発光素子であって、前記一方の電極と前記他方の電極のいずれか一方または両方が、前記積層半導体層の上面または前記半導体層露出面上に形成されたオーミック接合層と、前記オーミック接合層上に形成された接合層と、前記接合層を覆うように形成されたボンディングパッド電極とを備えることを特徴とする半導体発光素子。 (32) A substrate, a laminated semiconductor layer including a light emitting layer formed on the substrate, one electrode formed on an upper surface of the laminated semiconductor layer, and a part of the laminated semiconductor layer are cut away. A semiconductor light emitting device comprising the other electrode formed on the exposed surface of the semiconductor layer, wherein either one or both of the one electrode and the other electrode is the upper surface of the stacked semiconductor layer or the semiconductor layer A semiconductor light emitting device comprising: an ohmic bonding layer formed on an exposed surface; a bonding layer formed on the ohmic bonding layer; and a bonding pad electrode formed so as to cover the bonding layer.
　　　（３３）前記接合層が、Ａｌ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｃｏ、Ｚｎ、Ｇｅ、Ｚｒ、Ｎｂ、Ｍｏ、Ｒｕ、Ｈｆ、Ｔａ、Ｗ、Ｒｅ、Ｒｈ、Ｉｒ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなるものであることを特徴とする（３２）に記載の半導体発光素子。 (33) The bonding layer is selected from the group consisting of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh, Ir, and Ni. (32) The semiconductor light-emitting device according to (32), which is composed of at least one element selected from the above.
　　　（３４）前記ボンディングパッド電極が、Ａｕ、Ａｌまたはこれらの金属の何れかを含む合金からなるボンディング層を含むことを特徴とする（３２）または（３３）に記載の半導体発光素子。 (34) The semiconductor light-emitting element according to (32) or (33), wherein the bonding pad electrode includes a bonding layer made of Au, Al, or an alloy containing any of these metals.
　　　（３５）前記ボンディングパッド電極が、前記接合層を覆うように形成された金属反射層と、前記金属反射層を覆うように形成されたボンディング層とからなり、前記金属反射層が、Ａｇ、Ａｌ、Ｒｕ、Ｒｈ、Ｐｄ、Ｏｓ、Ｉｒ、Ｐｔ、Ｔｉのうちの何れかまたはこれら金属の何れかを含む合金からなるものであることを特徴とする（３４）に記載の半導体発光素子。 (35) The bonding pad electrode includes a metal reflection layer formed so as to cover the bonding layer and a bonding layer formed so as to cover the metal reflection layer, and the metal reflection layer includes Ag, Al. , Ru, Rh, Pd, Os, Ir, Pt, Ti, or an alloy containing any one of these metals. The semiconductor light-emitting device according to (34),
　　（３６）前記オーミック接合層が、Ｉｎ、Ｚｎ、Ａｌ、Ｇａ、Ｔｉ、Ｂｉ、Ｍｇ、Ｗ、Ｃｅ、Ｓｎ、Ｎｉのいずれか一種を含む導電性の酸化物、硫化亜鉛または硫化クロムのうちいずれか一種からなる群より選ばれる透光性の導電性材料から構成されることを特徴とする（３２）～（３５）のいずれかに記載の半導体発光素子。 (36) The ohmic junction layer is any one of a conductive oxide, zinc sulfide, or chromium sulfide containing any one of In, Zn, Al, Ga, Ti, Bi, Mg, W, Ce, Sn, and Ni. (32) The semiconductor light-emitting device according to any one of (32) to (35), which is made of a light-transmitting conductive material selected from the group consisting of one kind.
　　（３７）前記積層半導体層が、窒化ガリウム系半導体を主体として構成されていることを特徴とする（３２）～（３６）のいずれかに記載の半導体発光素子。 (37) The semiconductor light-emitting element according to any one of (32) to (36), wherein the stacked semiconductor layer is mainly composed of a gallium nitride-based semiconductor.
　　（３８）前記積層半導体層が、前記基板側からｎ型半導体層、発光層、ｐ型半導体層の順に積層されてなり、前記発光層が多重量子井戸構造であることを特徴とする（３２）～（３７）のいずれかに記載の半導体発光素子。 (38) The laminated semiconductor layer is formed by laminating an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer in this order from the substrate side, and the light emitting layer has a multiple quantum well structure (32) The semiconductor light-emitting device according to any one of to (37).
　　（３９）（３２）～（３８）のいずれか１項に記載の半導体発光素子と、前記半導体発光素子が配置されるとともに前記半導体発光素子の一方の電極とワイヤボンディングされる第１フレームと、前記半導体発光素子の他方の電極とワイヤボンディングされる第２フレームと、前記半導体発光素子を取り囲んで形成されるモールドと、を備えたことを特徴とするランプ。 (39) The semiconductor light emitting element according to any one of (32) to (38), a first frame in which the semiconductor light emitting element is disposed and wire-bonded to one electrode of the semiconductor light emitting element, A lamp comprising: a second frame wire-bonded to the other electrode of the semiconductor light emitting element; and a mold formed surrounding the semiconductor light emitting element.
　　（４０）基板上に発光層を含む積層半導体層を形成する工程と、前記積層半導体層の上面に一方の電極を形成する工程と、前記積層半導体層の一部を切り欠いて半導体層露出面を形成し、前記半導体層露出面上に他方の電極を形成する工程とを具備する半導体発光素子の製造方法において、前記一方の電極を製造する工程と前記他方の電極を製造する工程の両方が、前記積層半導体層の上面または前記半導体層露出面上にオーミック接合層を形成し、前記オーミック接合層上に接合層を形成し、前記接合層を覆うようにボンディングパッド電極を形成するパッド形成工程と、前記オーミック接合層と前記接合層との密着性を高める熱処理を８０℃～７００℃の温度で行う熱処理工程とを含むことを特徴とする半導体発光素子の製造方法。 (40) A step of forming a laminated semiconductor layer including a light emitting layer on a substrate, a step of forming one electrode on the upper surface of the laminated semiconductor layer, and a semiconductor layer exposed surface by cutting out part of the laminated semiconductor layer And forming the other electrode on the exposed surface of the semiconductor layer, wherein both the step of manufacturing the one electrode and the step of manufacturing the other electrode include: A pad forming step of forming an ohmic bonding layer on the upper surface of the laminated semiconductor layer or the exposed surface of the semiconductor layer, forming a bonding layer on the ohmic bonding layer, and forming a bonding pad electrode so as to cover the bonding layer; And a heat treatment step of performing a heat treatment for improving the adhesion between the ohmic bonding layer and the bonding layer at a temperature of 80 ° C. to 700 ° C.
　　（４１）前記一方の電極を製造する工程と前記他方の電極を製造する工程とにおける前記パッド形成工程および前記熱処理工程を同時に行うことを特徴とする　（４０）に記載の半導体発光素子の製造方法。 (41) The method for manufacturing a semiconductor light-emitting element according to (40), wherein the pad forming step and the heat treatment step in the step of manufacturing the one electrode and the step of manufacturing the other electrode are performed simultaneously. .
　　（４２）　（３９）に記載のランプが組み込まれている電子機器。 (42) Electronic equipment incorporating the lamp described in (39).
　　（４３）　（４２）に記載の電子機器が組み込まれている機械装置。 (43) A mechanical device incorporating the electronic device described in (42).
　上記の構成によれば、接合性および耐食性を向上させた電極を備えた半導体発光素子、その製造方法およびランプを提供することができる。 According to the above configuration, it is possible to provide a semiconductor light emitting device including an electrode with improved bondability and corrosion resistance, a manufacturing method thereof, and a lamp.
　本発明の半導体発光素子は、一方の電極が、接合層と接合層を覆うように形成されたボンディングパッド電極とからなり、ボンディングパッド電極の最大厚みが、接合層の最大厚みに比べて厚く形成され、かつ、１または２以上の層からなり、接合層およびボンディングパッド電極の外周側にそれぞれ外周側が漸次薄くなるような傾斜面が形成されている構成なので、外部の空気または水分の接合層への侵入を防止することができ、接合層の耐食性を向上して、半導体発光素子寿命を長くすることができる。 In the semiconductor light emitting device of the present invention, one electrode includes a bonding layer and a bonding pad electrode formed so as to cover the bonding layer, and the maximum thickness of the bonding pad electrode is thicker than the maximum thickness of the bonding layer. In addition, since the inclined surface is formed of one or two or more layers and the outer peripheral side of the bonding layer and the bonding pad electrode is gradually thinned, the external air or moisture bonding layer is formed. Can be prevented, the corrosion resistance of the bonding layer can be improved, and the lifetime of the semiconductor light emitting device can be extended.
　本発明の半導体発光素子は、接合層が、Ａｌ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｃｏ、Ｚｎ、Ｇｅ、Ｚｒ、Ｎｂ、Ｍｏ、Ｒｕ、Ｈｆ、Ｔａ、Ｗ、Ｒｅ、Ｒｈ、Ｉｒ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなるものであり、最大厚みが１０Å以上１０００Å以下の範囲の薄膜である構成なので、透光性電極とボンディングパッド電極との間の接合性を向上させて、ボンディングワイヤ接合時の引張応力によっても剥がれることのない電極とすることができる。 In the semiconductor light emitting device of the present invention, the bonding layer is made of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh, Ir, and Ni. Since it is composed of at least one element selected from the group consisting of a thin film having a maximum thickness in the range of 10 to 1000 mm, the bonding between the translucent electrode and the bonding pad electrode is improved. Further, an electrode that does not peel off due to tensile stress during bonding of the bonding wires can be obtained.
　本発明の半導体発光素子は、Ａｕ、Ａｌまたはこれらの金属の何れかを含む合金からなるボンディング層からなり、前記ボンディング層の最大厚みが５０ｎｍ以上２０００ｎｍ以下の範囲の薄膜である構成なので、ボンディングパッド電極へのワイヤボンディングの接合性を向上させて、ボンディングワイヤ接合時の引張応力によっても剥がれることのない電極とすることができる。 Since the semiconductor light emitting device of the present invention is composed of a bonding layer made of Au, Al, or an alloy containing any of these metals, and the maximum thickness of the bonding layer is a thin film having a range of 50 nm to 2000 nm, a bonding pad By improving the bondability of wire bonding to the electrode, it is possible to obtain an electrode that does not peel off due to tensile stress during bonding wire bonding.
　本発明の半導体発光素子は、ボンディングパッド電極が、接合層を覆うように形成された金属反射層と、金属反射層を覆うように形成されたボンディング層とからなり、金属反射層１１７が、Ａｇ、Ａｌ、Ｒｕ、Ｒｈ、Ｐｄ、Ｏｓ、Ｉｒ、Ｐｔ、Ｔｉのうちの何れかまたはこれら金属の何れかを含む合金からなるものであり、最大厚みが２０ｎｍ以上３０００ｎｍ以下の範囲の薄膜である構成なので、電極の接合性および耐食性を向上させ、半導体発光素子の発光特性を向上させることができる。 The semiconductor light emitting device of the present invention comprises a metal reflective layer in which the bonding pad electrode is formed so as to cover the bonding layer, and a bonding layer formed so as to cover the metal reflective layer, and the metal reflective layer 117 is made of Ag. , Al, Ru, Rh, Pd, Os, Ir, Pt, Ti, or an alloy containing any of these metals, and a maximum thickness of 20 nm to 3000 nm. Therefore, it is possible to improve the bondability and corrosion resistance of the electrodes and improve the light emission characteristics of the semiconductor light emitting device.
　本発明の半導体発光素子用の電極は、一方の電極または他方の電極の少なくともいずれか一方が、接合層と接合層を覆うように形成されたボンディングパッド電極とからなり、ボンディングパッド電極の最大厚みが、接合層の最大厚みに比べて厚く形成され、かつ、１または２以上の層からなり、接合層およびボンディングパッド電極の外周部にそれぞれ、外周側に向けて膜厚が漸次薄くなるような傾斜面が形成されている構成なので、接合性および耐食性を向上させた電極とすることができる。本発明の半導体発光素子用の電極は、発光素子以外の用途にも使用することができる。 The electrode for a semiconductor light emitting device of the present invention comprises a bonding layer and a bonding pad electrode formed so as to cover the bonding layer, at least one of the one electrode and the other electrode, and the maximum thickness of the bonding pad electrode. However, it is formed thicker than the maximum thickness of the bonding layer, and is composed of one or more layers, and the film thickness gradually decreases toward the outer peripheral side at the outer peripheral portion of the bonding layer and the bonding pad electrode, respectively. Since it is the structure in which the inclined surface is formed, it can be set as the electrode which improved bondability and corrosion resistance. The electrode for a semiconductor light emitting device of the present invention can be used for applications other than the light emitting device.
　本発明の半導体発光素子の製造方法は、電極形成工程が、積層半導体層の上面に逆テーパー型マスクを形成した後、積層半導体層の上面上に接合層を形成し、その後、接合層を覆うように接合層の最大厚みに比べて最大厚みの厚いボンディングパッド電極を形成して、一方の電極を形成する工程である構成なので、接合層およびボンディングパッド電極の外周側にそれぞれ外周側が漸次薄くなるような傾斜面を形成することができ、外部の空気または水分の接合層への侵入を防止することができ、接合層の耐食性を向上して、半導体発光素子寿命を長くすることができる。 In the method for manufacturing a semiconductor light emitting device of the present invention, the electrode forming step forms an inversely tapered mask on the upper surface of the laminated semiconductor layer, then forms a bonding layer on the upper surface of the laminated semiconductor layer, and then covers the bonding layer In this way, the bonding pad electrode having a maximum thickness compared to the maximum thickness of the bonding layer is formed, and one electrode is formed. Thus, the outer peripheral side of the bonding layer and the bonding pad electrode is gradually thinner on the outer peripheral side. Such an inclined surface can be formed, external air or moisture can be prevented from entering the bonding layer, the corrosion resistance of the bonding layer can be improved, and the lifetime of the semiconductor light emitting device can be extended.
　本発明の半導体発光素子は、一方の電極または他方の電極の少なくともいずれか一方が、上面に接合凹部を有する透光性電極と、前記接合凹部を覆うように形成された接合層と、前記接合層を覆うように形成され、外周部に外側に向けて膜厚が漸次薄くなる傾斜面が形成されているボンディングパッド電極とを備えたものであるので、透光性電極の接合凹部内に接合層が埋め込まれるように形成されることにより、透光性電極と接合層との高い接合力が得られることと、ボンディングパッド電極が接合層を覆うように形成されていることにより、ボンディングパッド電極と接合層との高い接合力が得られることとによって、透光性電極とボンディングパッド電極との十分に高い接合力が得られ、優れた電極の接合性を有するものとなる。
　しかも、本発明の半導体発光素子によれば、外側に向けて膜厚が漸次薄くなる傾斜面を外周部に有するボンディングパッド電極が、接合層を覆うように形成されているので、ボンディングパッド電極の外周部と、ボンディングパッド電極の外周部の下面との接触面積が十分に確保されたものとなり、優れた接合性が得られるとともに、ボンディングパッド電極の外周部とその下面との間を介して、外部から接合層へ空気や水分が侵入することを効果的に防止することができ、優れた耐食性が得られるものとなる。 The semiconductor light-emitting device of the present invention includes a translucent electrode in which at least one of one electrode or the other electrode has a bonding recess on an upper surface, a bonding layer formed so as to cover the bonding recess, and the bonding And a bonding pad electrode formed so as to cover the layer and having an inclined surface with a gradually decreasing thickness toward the outside at the outer peripheral portion. By forming the layer so as to be embedded, a high bonding force between the translucent electrode and the bonding layer can be obtained, and the bonding pad electrode is formed so as to cover the bonding layer. By obtaining a high bonding force between the bonding layer and the bonding layer, a sufficiently high bonding force between the translucent electrode and the bonding pad electrode can be obtained, and excellent electrode bonding properties can be obtained.
In addition, according to the semiconductor light emitting device of the present invention, the bonding pad electrode having the inclined surface whose thickness is gradually reduced toward the outside is formed so as to cover the bonding layer. The contact area between the outer peripheral portion and the lower surface of the outer peripheral portion of the bonding pad electrode is sufficiently ensured, and excellent bondability is obtained, and between the outer peripheral portion of the bonding pad electrode and the lower surface thereof, Air and moisture can be effectively prevented from entering the bonding layer from the outside, and excellent corrosion resistance can be obtained.
　また、本発明のランプは、優れた接合性および耐食性を有する電極を備えた本発明の半導体発光素子を備えたものであるので、歩留まりよく製造でき、耐食性に優れたものとなる。 In addition, since the lamp of the present invention includes the semiconductor light emitting device of the present invention provided with electrodes having excellent bonding properties and corrosion resistance, it can be manufactured with a high yield and has excellent corrosion resistance.
　また、本発明の半導体発光素子の製造方法は、一方の電極または他方の電極の少なくともいずれか一方を製造する工程が、透光性電極を形成する工程と、前記透光性電極の上面に、底面に向かって断面積が徐々に広くなる内壁形状を有する開口部を備えたマスクを形成する工程と、前記開口部から露出する前記透光性電極の上面をエッチングすることにより接合凹部を形成する工程と、前記接合凹部を覆うように接合層を形成する工程と、前記開口部の内壁形状に沿って外周部の形状を形成することにより、前記接合層を覆い、外側に向けて膜厚が漸次薄くなる傾斜面を外周部に有するボンディングパッド電極を形成する工程と、前記マスクを除去する工程とを備えているので、優れた接合性および耐食性を有する電極を備えた本発明の半導体発光素子を容易に製造できる。 Further, in the method for manufacturing a semiconductor light emitting device of the present invention, the step of manufacturing at least one of one electrode or the other electrode includes a step of forming a translucent electrode, and an upper surface of the translucent electrode. A step of forming a mask having an opening having an inner wall shape whose cross-sectional area gradually increases toward the bottom surface, and a bonding recess is formed by etching the upper surface of the translucent electrode exposed from the opening. Forming a bonding layer so as to cover the bonding recess, and forming an outer peripheral shape along the inner wall shape of the opening, thereby covering the bonding layer and increasing the film thickness toward the outside. Since the method includes a step of forming a bonding pad electrode having an inclined surface that gradually becomes thinner on the outer peripheral portion and a step of removing the mask, the half of the present invention including an electrode having excellent bonding properties and corrosion resistance is provided. The body light-emitting element can be easily manufactured.
　本発明の半導体発光素子は、一方の電極と他方の電極のいずれか一方または両方が、積層半導体層の上面または前記半導体層露出面上に形成されたオーミック接合層と、前記オーミック接合層上に形成された接合層と、前記接合層を覆うように形成されたボンディングパッド電極とを備えるものであるので、一方の電極と他方の電極のいずれか一方または両方が、オーミック接合層上に形成された接合層と、接合層を覆うように形成されたボンディングパッド電極とによって、オーミック接合層とボンディングパッド電極との十分に高い接合力が得られるものとされているので、優れた接合性を有する電極を備えたものとなる。 In the semiconductor light emitting device of the present invention, either one or both of one electrode and the other electrode is formed on the upper surface of the laminated semiconductor layer or the exposed surface of the semiconductor layer, and on the ohmic junction layer. Since the bonding layer formed and a bonding pad electrode formed so as to cover the bonding layer, one or both of the one electrode and the other electrode are formed on the ohmic bonding layer. The bonding layer and the bonding pad electrode formed so as to cover the bonding layer provide a sufficiently high bonding force between the ohmic bonding layer and the bonding pad electrode, and thus have excellent bonding properties. An electrode is provided.
　また、本発明のランプは、優れた接合性を有する一方の電極および他方の電極を備えた本発明の半導体発光素子を備えたものであるので、ボンディングパッド電極にボンディングワイヤを接合する時の引張応力によって、透光性電極からボンディングパッド電極が剥がれることを防止することができ、歩留まりよく製造できるものとなる。 Further, since the lamp of the present invention includes the semiconductor light emitting device of the present invention having one electrode having excellent bonding properties and the other electrode, the tensile force when bonding a bonding wire to the bonding pad electrode is obtained. It is possible to prevent the bonding pad electrode from being peeled off from the translucent electrode due to the stress, and it is possible to manufacture with high yield.
　また、本発明の半導体発光素子の製造方法は、前記一方の電極を製造する工程と前記他方の電極を製造する工程の両方が、前記積層半導体層の上面または前記半導体層露出面上にオーミック接合層を形成し、前記オーミック接合層上に接合層を形成し、前記接合層を覆うようにボンディングパッド電極を形成するパッド形成工程と、前記オーミック接合層と前記接合層との密着性を高める熱処理を８０℃～７００℃の温度で行う熱処理工程とを含むので、オーミック接合層と接合層との密着性に優れた半導体発光素子が得られる。 Further, in the method for manufacturing a semiconductor light emitting device according to the present invention, both the step of manufacturing the one electrode and the step of manufacturing the other electrode are performed in an ohmic contact on the upper surface of the stacked semiconductor layer or the exposed surface of the semiconductor layer. Forming a layer, forming a bonding layer on the ohmic bonding layer, and forming a bonding pad electrode so as to cover the bonding layer; and heat treatment for improving adhesion between the ohmic bonding layer and the bonding layer And a heat treatment step in which the heat treatment is performed at a temperature of 80 ° C. to 700 ° C., a semiconductor light emitting device having excellent adhesion between the ohmic bonding layer and the bonding layer is obtained.
　さらに、本発明の半導体発光素子の製造方法において、前記一方の電極を製造する工程と前記他方の電極を製造する工程とにおける前記パッド形成工程および前記熱処理工程を同時に行う場合には、一方の電極と他方の電極とが同時に形成されるので、一方の電極と他方の電極とを別々に形成した場合と比較して効率よく容易に製造できる。 Furthermore, in the method for manufacturing a semiconductor light emitting device of the present invention, when the pad forming step and the heat treatment step in the step of manufacturing the one electrode and the step of manufacturing the other electrode are performed simultaneously, And the other electrode are formed at the same time, and can be manufactured efficiently and easily as compared with the case where one electrode and the other electrode are formed separately.
本発明の半導体発光素子の一例を示す断面模式図である。It is a cross-sectional schematic diagram which shows an example of the semiconductor light-emitting device of this invention. 本発明の半導体発光素子の一例を示す平面模式図である。It is a plane schematic diagram which shows an example of the semiconductor light-emitting device of this invention. 本発明の半導体発光素子の積層半導体層の一例を示す断面模式図である。It is a cross-sectional schematic diagram which shows an example of the laminated semiconductor layer of the semiconductor light-emitting device of this invention. 本発明の半導体発光素子のｐ型電極の拡大断面図の一例である。It is an example of the expanded sectional view of the p-type electrode of the semiconductor light-emitting device of this invention. 本発明の半導体発光素子のｐ型電極の工程断面図の一例である。It is an example of process sectional drawing of the p-type electrode of the semiconductor light-emitting device of this invention. 本発明の半導体発光素子のｐ型電極のマスク形成工程断面図の一例である。It is an example of the mask formation process sectional drawing of the p-type electrode of the semiconductor light-emitting device of this invention. 本発明の半導体発光素子を示す断面模式図の一例である。It is an example of the cross-sectional schematic diagram which shows the semiconductor light-emitting device of this invention. 本発明の半導体発光素子のｐ型電極の拡大断面図の一例である。It is an example of the expanded sectional view of the p-type electrode of the semiconductor light-emitting device of this invention. 本発明のランプを示す断面模式図の一例である。It is an example of a cross-sectional schematic diagram showing a lamp of the present invention. 本発明の半導体発光素子のｐ型電極の拡大断面図の一例である。It is an example of the expanded sectional view of the p-type electrode of the semiconductor light-emitting device of this invention. 本発明の半導体発光素子のｐ型電極の拡大断面図の一例である。It is an example of the expanded sectional view of the p-type electrode of the semiconductor light-emitting device of this invention. 比較例の半導体発光素子を示す断面模式図である。It is a cross-sectional schematic diagram which shows the semiconductor light-emitting device of a comparative example. 比較例の半導体発光素子のｐ型電極の工程断面図である。It is process sectional drawing of the p-type electrode of the semiconductor light-emitting device of a comparative example. 図１４は本発明の半導体発光素子の一例を示した図であって、半導体発光素子の断面模式図である。FIG. 14 is a view showing an example of the semiconductor light emitting device of the present invention, and is a schematic sectional view of the semiconductor light emitting device. 図１５は図１４に示す半導体発光素子の平面模式図である。FIG. 15 is a schematic plan view of the semiconductor light emitting device shown in FIG. 図１６は図１４に示す半導体発光素子を構成する積層半導体層の拡大断面模式図である。16 is an enlarged schematic cross-sectional view of a laminated semiconductor layer constituting the semiconductor light emitting device shown in FIG. 図１７は図１４に示す半導体発光素子を構成するｐ型電極の拡大断面模式図である。FIG. 17 is an enlarged schematic cross-sectional view of a p-type electrode constituting the semiconductor light emitting device shown in FIG. 図１８は、ｐ型電極を製造する工程を説明するための工程図の一例であり、ｐ型電極の製造される領域の一部のみを拡大して示した拡大断面図である。FIG. 18 is an example of a process diagram for explaining a process of manufacturing the p-type electrode, and is an enlarged cross-sectional view showing only a part of a region where the p-type electrode is manufactured. 図１９は、図１８（ｂ）に示すマスクの製造工程について説明するための工程図の一例であり、１つのｐ型電極の形成される領域のみを示した拡大断面図である。FIG. 19 is an example of a process diagram for explaining the manufacturing process of the mask shown in FIG. 18B, and is an enlarged cross-sectional view showing only a region where one p-type electrode is formed. 図２０は、本発明の半導体発光素子の他の例を示した図であって、半導体発光素子の断面模式図である。FIG. 20 is a diagram showing another example of the semiconductor light emitting device of the present invention, and is a schematic cross-sectional view of the semiconductor light emitting device. 図２１は、本発明の半導体発光素子の他の例を示した図であって、半導体発光素子を構成するｐ型電極の拡大断面模式図である。FIG. 21 is a view showing another example of the semiconductor light emitting device of the present invention, and is an enlarged schematic cross-sectional view of a p-type electrode constituting the semiconductor light emitting device. 図２２は、本発明の半導体発光素子の他の例を示した図であって、半導体発光素子の断面模式図である。FIG. 22 is a view showing another example of the semiconductor light emitting device of the present invention, and is a schematic sectional view of the semiconductor light emitting device. 図２３は、ｐ型電極を製造する工程を説明するための工程図であり、ｐ型電極の製造される領域の一部のみを拡大して示した拡大断面図である。FIG. 23 is a process diagram for describing a process of manufacturing a p-type electrode, and is an enlarged cross-sectional view illustrating only a part of a region where the p-type electrode is manufactured. 本発明のランプの一例を示す断面概略図である。It is a cross-sectional schematic diagram which shows an example of the lamp | ramp of this invention. 本発明の半導体発光素子の効果を説明するための図であって、ｐ型電極の拡大断面模式図である。It is a figure for demonstrating the effect of the semiconductor light-emitting device of this invention, Comprising: It is an expanded cross-sectional schematic diagram of a p-type electrode. 図２６は本発明の半導体発光素子の一例を示した図であって、半導体発光素子の断面模式図である。FIG. 26 is a diagram showing an example of the semiconductor light emitting device of the present invention, and is a schematic sectional view of the semiconductor light emitting device. 図２７は図２６に示す半導体発光素子の平面模式図である。27 is a schematic plan view of the semiconductor light emitting device shown in FIG. 図２８は図２６に示す半導体発光素子を構成する積層半導体層の拡大断面模式図である。FIG. 28 is an enlarged schematic cross-sectional view of a laminated semiconductor layer constituting the semiconductor light emitting device shown in FIG. 図２９は、図２６に示す半導体発光素子を構成する電極を説明するための図であって、図２９（ａ）はｐ型電極の拡大断面模式図であり、図２９（ｂ）はｎ型電極の拡大断面模式図である。29A and 29B are diagrams for explaining the electrodes constituting the semiconductor light emitting device shown in FIG. 26. FIG. 29A is an enlarged schematic cross-sectional view of a p-type electrode, and FIG. 29B is an n-type. It is an expanded section schematic diagram of an electrode. 図３０は、ｐ型電極を製造する工程を説明するための工程図であり、ｐ型電極１１１の製造される領域の一部のみを拡大して示した拡大断面図である。FIG. 30 is a process diagram for explaining a process of manufacturing the p-type electrode, and is an enlarged cross-sectional view showing only a part of a region where the p-type electrode 111 is manufactured. 図３１は、ｎ型電極およびｐ型電極を製造する際に形成されるマスクの製造工程を説明するための工程図であり、１つのｐ型電極の形成される領域のみを示した拡大断面図である。FIG. 31 is a process diagram for explaining a manufacturing process of a mask formed when manufacturing an n-type electrode and a p-type electrode, and is an enlarged sectional view showing only a region where one p-type electrode is formed. It is. 図３２は、ｎ型電極を製造する工程を説明するための工程図であり、ｎ型電極の製造される領域の一部のみを拡大して示した拡大断面図である。FIG. 32 is a process diagram for explaining a process of manufacturing the n-type electrode, and is an enlarged cross-sectional view showing only a part of a region where the n-type electrode is manufactured. 図３３は、ｎ型電極１０８およびｐ型電極１１１を製造する工程を説明するための概略図である。FIG. 33 is a schematic diagram for explaining a process of manufacturing the n-type electrode 108 and the p-type electrode 111. 図３４は、本発明の半導体発光素子の他の例を示した図であって、半導体発光素子の断面模式図である。FIG. 34 is a diagram showing another example of the semiconductor light emitting device of the present invention, and is a schematic cross-sectional view of the semiconductor light emitting device. 図３５は、本発明の半導体発光素子の他の例を示した図であって、半導体発光素子の断面模式図である。FIG. 35 is a diagram showing another example of the semiconductor light emitting device of the present invention, and is a schematic cross-sectional view of the semiconductor light emitting device. 図３６は、ｎ型電極１２８およびｐ型電極１１１ｂを製造する工程を説明するための工程図であって、ｐ型電極１１１ｂの製造される領域の一部のみを拡大して示した拡大断面図である。FIG. 36 is a process diagram for explaining a process of manufacturing the n-type electrode 128 and the p-type electrode 111b, and is an enlarged cross-sectional view showing only a part of a region where the p-type electrode 111b is manufactured. It is. 図３７は、本発明のランプの一例を示す断面概略図である。FIG. 37 is a schematic sectional view showing an example of the lamp of the present invention.
　以下、本発明を実施するための形態について図面を用いて詳細に説明する。なお、以下の説明において参照する図面に図示される各部の大きさや厚さや寸法等は、実際の半導体発光素子等の寸法関係とは異なっている場合がある。
（実施形態１）
　図１～図４は、本発明の実施形態である半導体発光素子の一例を示す図であって、図１は本発明の実施形態である半導体発光素子の断面模式図であり、図２は平面模式図であり、図３は半導体発光素子を構成する積層半導体層の断面模式図であり、図４は図１に示す半導体発光素子を構成するｐ型電極の拡大断面模式図である。 Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. Note that the size, thickness, dimensions, and the like of each part illustrated in the drawings referred to in the following description may differ from the dimensional relationship of an actual semiconductor light emitting element or the like.
(Embodiment 1)
1 to 4 are diagrams showing an example of a semiconductor light emitting device according to an embodiment of the present invention. FIG. 1 is a schematic cross-sectional view of the semiconductor light emitting device according to an embodiment of the present invention, and FIG. FIG. 3 is a schematic diagram, FIG. 3 is a schematic cross-sectional view of a laminated semiconductor layer constituting the semiconductor light-emitting device, and FIG. 4 is an enlarged schematic cross-sectional view of a p-type electrode constituting the semiconductor light-emitting device shown in FIG.
（半導体発光素子）
　図１に示すように、本発明の実施形態である半導体発光素子１は、基板１０１上に、バッファ層１０２、下地層１０３、発光層１０５を含む積層半導体層２０が順次積層されるとともに、積層半導体層２０の上面１０６ｃに透光性電極１０９が積層され、透光性電極１０９の上面１０９ｃの一部に一方の（一の伝導型の）電極１１１が形成され、また、積層半導体層２０の一部が切り欠けられて形成された半導体層露出面１０４ｃ上に他方の（他の伝導型の）電極１０８が形成されて概略構成されている。
　積層半導体層２０は、基板１０１側から、ｎ型半導体層１０４、発光層１０５、ｐ型半導体層１０６がこの順に積層されて構成されている。透光性電極１０９の上面１０９ｃで、一の伝導型の電極１１１が形成されていない部分は、保護膜１０によって覆われている。また、一の伝導型の電極１１１は、接合層１１０と、金属反射層１１７とボンディング層１１９とからなるボンディングパッド電極１２０と、が積層されて構成されている。
　なお、一方の電極１１１はｐ型電極、他方の電極１０８はｎ型電極として以下の説明を行う。 (Semiconductor light emitting device)
As shown in FIG. 1, in a semiconductor light emitting device 1 according to an embodiment of the present invention, a laminated semiconductor layer 20 including a buffer layer 102, a base layer 103, and a light emitting layer 105 is sequentially laminated on a substrate 101. A translucent electrode 109 is stacked on the upper surface 106 c of the semiconductor layer 20, and one (one conductivity type) electrode 111 is formed on a part of the upper surface 109 c of the translucent electrode 109. The other (other conductivity type) electrode 108 is formed on the semiconductor layer exposed surface 104c formed by cutting out part of the semiconductor layer, and is schematically configured.
The stacked semiconductor layer 20 is configured by stacking an n-type semiconductor layer 104, a light emitting layer 105, and a p-type semiconductor layer 106 in this order from the substrate 101 side. A portion of the upper surface 109 c of the translucent electrode 109 where the one conductive type electrode 111 is not formed is covered with the protective film 10. One conductive type electrode 111 is formed by laminating a bonding layer 110 and a bonding pad electrode 120 including a metal reflection layer 117 and a bonding layer 119.
In the following description, one electrode 111 is a p-type electrode and the other electrode 108 is an n-type electrode.
　本発明の実施形態である半導体発光素子１は、ｐ型電極（一の伝導型の電極）１１１とｎ型電極（他の伝導型の電極）１０８との間に電圧を印加して電流を通じることで、発光層１０５から発光が得られる構成とされており、発光層１０５からの光を反射する機能を有するボンディングパッド電極１２０（反射性ボンディングパッド電極）が形成された側から取り出すフェイスアップマウント型の発光素子である。
　発光層１０５からの発光の一部は、透光性電極１０９及び接合層１１０を透過し、接合層１１０とボンディングパッド電極１２０との界面においてボンディングパッド電極１２０によって反射され、再度、積層半導体層２０の内部に導入される。そして、積層半導体層２０に再導入された光は、更に透過と反射を繰り返した後に、ボンディングパッド電極１２０の形成領域以外の箇所から半導体発光素子１の外部に取り出される。 The semiconductor light emitting device 1 according to the embodiment of the present invention applies a voltage between a p-type electrode (one conduction type electrode) 111 and an n-type electrode (another conduction type electrode) 108 to pass a current. Thus, the face-up mount is configured so that light emission can be obtained from the light-emitting layer 105 and taken out from the side on which the bonding pad electrode 120 (reflective bonding pad electrode) having a function of reflecting light from the light-emitting layer 105 is formed. Type light emitting element.
A part of light emitted from the light emitting layer 105 is transmitted through the translucent electrode 109 and the bonding layer 110, reflected by the bonding pad electrode 120 at the interface between the bonding layer 110 and the bonding pad electrode 120, and again, the laminated semiconductor layer 20. Introduced inside. Then, the light reintroduced into the laminated semiconductor layer 20 is further transmitted and reflected, and then extracted outside the semiconductor light emitting element 1 from a location other than the bonding pad electrode 120 formation region.
＜基板＞
　本発明の実施形態である半導体発光素子１の基板１０１としては、ＩＩＩ族窒化物半導体結晶が表面にエピタキシャル成長される基板であれば、特に限定されず、各種の基板を選択して用いることができる。例えば、サファイア、ＳｉＣ、シリコン、酸化亜鉛、酸化マグネシウム、酸化マンガン、酸化ジルコニウム、酸化マンガン亜鉛鉄、酸化マグネシウムアルミニウム、ホウ化ジルコニウム、酸化ガリウム、酸化インジウム、酸化リチウムガリウム、酸化リチウムアルミニウム、酸化ネオジウムガリウム、酸化ランタンストロンチウムアルミニウムタンタル、酸化ストロンチウムチタン、酸化チタン、ハフニウム、タングステン、モリブデン等からなる基板を用いることができる。
　また、上記基板の中でも、特に、ｃ面を主面とするサファイア基板を用いることが好ましい。サファイア基板を用いる場合は、サファイアのｃ面上にバッファ層１０２を形成するとよい。 <Board>
The substrate 101 of the semiconductor light-emitting element 1 according to the embodiment of the present invention is not particularly limited as long as a group III nitride semiconductor crystal is epitaxially grown on the surface, and various substrates can be selected and used. . For example, sapphire, SiC, silicon, zinc oxide, magnesium oxide, manganese oxide, zirconium oxide, manganese zinc iron, magnesium aluminum oxide, zirconium boride, gallium oxide, indium oxide, lithium gallium oxide, lithium aluminum oxide, neodymium gallium oxide A substrate made of lanthanum strontium oxide aluminum tantalum, strontium titanium oxide, titanium oxide, hafnium, tungsten, molybdenum, or the like can be used.
Further, among the above substrates, it is particularly preferable to use a sapphire substrate having a c-plane as a main surface. When using a sapphire substrate, the buffer layer 102 is preferably formed on the c-plane of sapphire.
　なお、上記基板の内、高温でアンモニアに接触することで化学的な変性を引き起こすことが知られている酸化物基板や金属基板等を用いることができ、アンモニアを使用せずにバッファ層１０２を成膜することもでき、またアンモニアを使用する方法では、後述のｎ型半導体層１０４を構成するために下地層１０３を成膜した場合には、バッファ層１０２がコート層としても作用するので、これらの方法は基板１０１の化学的な変質を防ぐ点で効果的である。
　また、バッファ層１０２をスパッタ法により形成した場合、基板１０１の温度を低く抑えることが可能なので、高温で分解してしまう性質を持つ材料からなる基板１０１を用いた場合でも、基板１０１にダメージを与えることなく基板上への各層の成膜が可能である。 Of the above substrates, an oxide substrate or a metal substrate that is known to cause chemical modification by contact with ammonia at a high temperature can be used, and the buffer layer 102 can be formed without using ammonia. In the method using ammonia, when the base layer 103 is formed to form the n-type semiconductor layer 104 described later, the buffer layer 102 also functions as a coat layer. These methods are effective in preventing chemical alteration of the substrate 101.
In addition, when the buffer layer 102 is formed by a sputtering method, the temperature of the substrate 101 can be kept low. Therefore, even when the substrate 101 made of a material that decomposes at a high temperature is used, the substrate 101 is damaged. Each layer can be formed on the substrate without giving.
＜積層半導体層＞
　本発明の実施形態である半導体発光素子１の積層半導体層２０は、例えば、ＩＩＩ族窒化物半導体からなる層であって、図１に示すように、基板１０１上に、ｎ型半導体層１０４、発光層１０５及びｐ型半導体層１０６の各層がこの順で積層されてなる。
　また、図３に示すように、ｎ型半導体層１０４、発光層１０５及びｐ型半導体層１０６の各層は、それぞれ、複数の半導体層から構成してもよい。さらにまた、積層半導体層２０は、さらに下地層１０３、バッファ層１０２を含めて呼んでもよい。
　なお、積層半導体層２０は、ＭＯＣＶＤ法で形成すると結晶性の良いものが得られるが、スパッタ法によっても条件を最適化することで、ＭＯＣＶＤ法よりも優れた結晶性を有する半導体層を形成できる。以下、順次説明する。 <Laminated semiconductor layer>
The stacked semiconductor layer 20 of the semiconductor light emitting device 1 according to the embodiment of the present invention is a layer made of, for example, a group III nitride semiconductor. As shown in FIG. The light emitting layer 105 and the p-type semiconductor layer 106 are stacked in this order.
Further, as shown in FIG. 3, each of the n-type semiconductor layer 104, the light emitting layer 105, and the p-type semiconductor layer 106 may be composed of a plurality of semiconductor layers. Furthermore, the laminated semiconductor layer 20 may be further referred to as including the base layer 103 and the buffer layer 102.
Note that the stacked semiconductor layer 20 can be formed with a good crystallinity when formed by the MOCVD method, but by optimizing the conditions also by the sputtering method, a semiconductor layer having a crystallinity superior to that of the MOCVD method can be formed. . Hereinafter, description will be made sequentially.
＜バッファ層＞
　バッファ層（中間層）１０２は、多結晶のＡｌｘＧａ１－ｘＮ（０≦ｘ≦１）からなるものが好ましく、単結晶のＡｌｘＧａ１－ｘＮ（０≦ｘ≦１）のものがより好ましい。
　バッファ層１０２は、前記したように、ＭＯＣＶＤ法で形成することができるが、スパッタ法により形成してもよい。バッファ層１０２をスパッタ法によりした場合、バッファ層１０２の形成時における基板１０１の温度を低く抑えることが可能なので、高温で分解してしまう性質を持つ材料からなる基板１０１を用いた場合でも、基板１０１にダメージを与えることなく基板１０１上への各層の成膜が可能となり、好ましい。
　バッファ層１０２は、上述のように、例えば、多結晶のＡｌｘＧａ１－ｘＮ（０≦ｘ≦１）からなる厚さ０．０１～０．５μｍのものとすることができる。バッファ層１０２の厚みが０．０１μｍ未満であると、バッファ層１０２により基板１０１と下地層１０３との格子定数の違い緩和する効果が十分に得られない場合がある。また、バッファ層１０２の厚みが０．５μｍを超えると、バッファ層１０２としての機能には変化が無いのにも関わらず、バッファ層１０２の成膜処理時間が長くなり、生産性が低下する虞がある。
　バッファ層１０２は、基板１０１と下地層１０３との格子定数の違いを緩和し、基板１０１の（０００１）Ｃ面上にＣ軸配向した単結晶層の形成を容易にする働きがある。したがって、バッファ層１０２の上に単結晶の下地層１０３を積層すると、より一層結晶性の良い下地層１０３が積層できる。なお、本発明においては、バッファ層形成工程を行なうことが好ましいが、行なわなくても良い。 <Buffer layer>
Buffer layer (intermediate layer) 102 is preferably made of polycrystalline Al x Ga 1-x N (0 ≦ x ≦ 1), the single crystal Al x Ga 1-x N of (0 ≦ x ≦ 1) Those are more preferred.
The buffer layer 102 can be formed by MOCVD as described above, but may be formed by sputtering. When the buffer layer 102 is formed by sputtering, the temperature of the substrate 101 can be kept low when the buffer layer 102 is formed. Therefore, even when the substrate 101 made of a material having a property of decomposing at high temperature is used, Each layer can be formed on the substrate 101 without damaging the substrate 101, which is preferable.
As described above, the buffer layer 102 can be, for example, made of polycrystalline Al x Ga 1-x N (0 ≦ x ≦ 1) and having a thickness of 0.01 to 0.5 μm. When the thickness of the buffer layer 102 is less than 0.01 μm, the buffer layer 102 may not sufficiently obtain an effect of reducing the difference in lattice constant between the substrate 101 and the base layer 103. Further, when the thickness of the buffer layer 102 exceeds 0.5 μm, although the function as the buffer layer 102 is not changed, the film formation processing time of the buffer layer 102 becomes long, and the productivity may be reduced. There is.
The buffer layer 102 has a function of relaxing the difference in lattice constant between the substrate 101 and the base layer 103 and facilitating formation of a C-axis oriented single crystal layer on the (0001) C plane of the substrate 101. Therefore, when the single crystal base layer 103 is stacked over the buffer layer 102, the base layer 103 with higher crystallinity can be stacked. In the present invention, it is preferable to perform the buffer layer forming step, but it may not be performed.
　バッファ層１０２は、ＩＩＩ族窒化物半導体からなる六方晶系の結晶構造を持つものであってもよい。また、バッファ層１０２をなすＩＩＩ族窒化物半導体の結晶は、単結晶構造を有するものであってもよく、単結晶構造を有するものが好ましく用いられる。ＩＩＩ族窒化物半導体の結晶は、成長条件を制御することにより、上方向だけでなく、面内方向にも成長して単結晶構造を形成する。このため、バッファ層１０２の成膜条件を制御することにより、単結晶構造のＩＩＩ族窒化物半導体の結晶からなるバッファ層１０２とすることができる。このような単結晶構造を有するバッファ層１０２を基板１０１上に成膜した場合、バッファ層１０２のバッファ機能が有効に作用するため、その上に成膜されたＩＩＩ族窒化物半導体は良好な配向性及び結晶性を有する結晶膜となる。
　また、バッファ層１０２をなすＩＩＩ族窒化物半導体の結晶は、成膜条件をコントロールすることにより、六角柱を基本とした集合組織からなる柱状結晶（多結晶）とすることも可能である。なお、ここでの集合組織からなる柱状結晶とは、隣接する結晶粒との間に結晶粒界を形成して隔てられており、それ自体は縦断面形状として柱状になっている結晶のことをいう。 The buffer layer 102 may have a hexagonal crystal structure made of a group III nitride semiconductor. Further, the group III nitride semiconductor crystals forming the buffer layer 102 may have a single crystal structure, and those having a single crystal structure are preferably used. By controlling the growth conditions, the group III nitride semiconductor crystal grows not only in the upward direction but also in the in-plane direction to form a single crystal structure. Therefore, by controlling the film formation conditions of the buffer layer 102, the buffer layer 102 made of a crystal of a group III nitride semiconductor having a single crystal structure can be obtained. When the buffer layer 102 having such a single crystal structure is formed on the substrate 101, the buffer function of the buffer layer 102 is effective, so that the group III nitride semiconductor formed thereon has a good orientation. It becomes a crystalline film having the property and crystallinity.
Further, the group III nitride semiconductor crystal forming the buffer layer 102 can be formed into a columnar crystal (polycrystal) having a texture based on a hexagonal column by controlling the film forming conditions. In addition, the columnar crystal formed of the texture here is a crystal that is separated by forming a grain boundary between adjacent crystal grains, and is itself a columnar shape as a longitudinal sectional shape. Say.
＜下地層＞
　下地層１０３としては、ＡｌｘＧａｙＩｎｚＮ（０≦ｘ≦１、０≦ｙ≦１、０≦ｚ≦１、ｘ＋ｙ＋ｚ＝１）が挙げられるが、ＡｌｘＧａ１－ｘＮ（０≦ｘ＜１）を用いると結晶性の良い下地層１０３を形成できるため好ましい。
　下地層１０３の膜厚は０．１μｍ以上が好ましく、より好ましくは０．５μｍ以上であり、１μｍ以上が最も好ましい。この膜厚以上にした方が結晶性の良好なＡｌｘＧａ１－ｘＮ層が得られやすい。
　下地層１０３の結晶性を良くするためには、下地層１０３は不純物をドーピングしない方が望ましい。しかし、ｐ型あるいはｎ型の導電性が必要な場合は、アクセプター不純物あるいはドナー不純物を添加することが出来る。 <Underlayer>
Examples of the base layer 103 include Al x Ga y In z N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1, x + y + z = 1), and Al x Ga 1-x N (0 ≦ x <1) is preferable because the base layer 103 with good crystallinity can be formed.
The film thickness of the underlayer 103 is preferably 0.1 μm or more, more preferably 0.5 μm or more, and most preferably 1 μm or more. An Al x Ga 1-x N layer with good crystallinity is more easily obtained when the thickness is increased.
In order to improve the crystallinity of the base layer 103, the base layer 103 is preferably not doped with impurities. However, when p-type or n-type conductivity is required, acceptor impurities or donor impurities can be added.
＜ｎ型半導体層＞
　図３に示すように、ｎ型半導体層１０４は、通常ｎコンタクト層１０４ａとｎクラッド層１０４ｂとから構成されるのが好ましい。なお、ｎコンタクト層１０４ａはｎクラッド層１０４ｂを兼ねることも可能である。また、前述の下地層をｎ型半導体層１０４に含めてもよい。
　ｎコンタクト層１０４ａは、ｎ型電極を設けるための層である。ｎコンタクト層１０４ａとしては、ＡｌｘＧａ１－ｘＮ層（０≦ｘ＜１、好ましくは０≦ｘ≦０．５、さらに好ましくは０≦ｘ≦０．１）から構成されることが好ましい。
　また、ｎコンタクト層１０４ａにはｎ型不純物がドープされていることが好ましく、ｎ型不純物を１×１０１７～１×１０２０／ｃｍ３、好ましくは１×１０１８～１×１０１９／ｃｍ３の濃度で含有すると、ｎ型電極との良好なオーミック接触の維持の点で好ましい。ｎ型不純物としては、特に限定されないが、例えば、Ｓｉ、ＧｅおよびＳｎ等が挙げられ、好ましくはＳｉおよびＧｅが挙げられる。
　ｎコンタクト層１０４ａの膜厚は、０．５～５μｍとされることが好ましく、１～３μｍの範囲に設定することがより好ましい。ｎコンタクト層１０４ａの膜厚が上記範囲にあると、半導体の結晶性が良好に維持される。 <N-type semiconductor layer>
As shown in FIG. 3, the n-type semiconductor layer 104 is preferably composed of an n-contact layer 104a and an n-clad layer 104b. The n contact layer 104a can also serve as the n clad layer 104b. In addition, the above-described base layer may be included in the n-type semiconductor layer 104.
The n contact layer 104a is a layer for providing an n-type electrode. The n contact layer 104a is preferably composed of an Al x Ga 1-x N layer (0 ≦ x <1, preferably 0 ≦ x ≦ 0.5, more preferably 0 ≦ x ≦ 0.1). .
Also, it is preferable that n-type impurity is doped into the n-contact layer 104a, an n-type impurity 1 × 10 17 ~ 1 × 10 20 / cm 3, preferably 1 × 10 18 ~ 1 × 10 19 / cm If it contains in the density | concentration of 3 , it is preferable at the point of the maintenance of favorable ohmic contact with an n-type electrode. Although it does not specifically limit as an n-type impurity, For example, Si, Ge, Sn, etc. are mentioned, Preferably Si and Ge are mentioned.
The thickness of the n contact layer 104a is preferably 0.5 to 5 μm, and more preferably set to a range of 1 to 3 μm. When the film thickness of the n-contact layer 104a is in the above range, the semiconductor crystallinity is maintained well.
　ｎコンタクト層１０４ａと発光層１０５との間には、ｎクラッド層１０４ｂを設けることが好ましい。ｎクラッド層１０４ｂは、発光層１０５へのキャリアの注入とキャリアの閉じ込めを行なう層である。ｎクラッド層１０４ｂはＡｌＧａＮ、ＧａＮ、ＧａＩｎＮなどで形成することが可能である。また、これらの構造のヘテロ接合や複数回積層した超格子構造としてもよい。ｎクラッド層１０４ｂをＧａＩｎＮで形成する場合には、発光層１０５のＧａＩｎＮのバンドギャップよりも大きくすることが望ましいことは言うまでもない。
　ｎクラッド層１０４ｂの膜厚は、特に限定されないが、好ましくは０．００５～０．５μｍであり、より好ましくは０．００５～０．１μｍである。ｎクラッド層１０４ｂのｎ型ドープ濃度は１×１０１７～１×１０２０／ｃｍ３が好ましく、より好ましくは１×１０１８～１×１０１９／ｃｍ３である。ドープ濃度がこの範囲であると、良好な結晶性の維持および素子の動作電圧低減の点で好ましい。 An n-clad layer 104b is preferably provided between the n-contact layer 104a and the light-emitting layer 105. The n-clad layer 104b is a layer that injects carriers into the light emitting layer 105 and confines carriers. The n-clad layer 104b can be formed of AlGaN, GaN, GaInN, or the like. Alternatively, a heterojunction of these structures or a superlattice structure in which a plurality of layers are stacked may be used. Needless to say, when the n-cladding layer 104b is formed of GaInN, it is desirable to make it larger than the band gap of GaInN of the light emitting layer 105.
The film thickness of the n-clad layer 104b is not particularly limited, but is preferably 0.005 to 0.5 μm, and more preferably 0.005 to 0.1 μm. The n-type doping concentration of the n-clad layer 104b is preferably 1 × 10 17 to 1 × 10 20 / cm 3 , more preferably 1 × 10 18 to 1 × 10 19 / cm 3 . A doping concentration within this range is preferable in terms of maintaining good crystallinity and reducing the operating voltage of the device.
　なお、ｎクラッド層１０４ｂを、超格子構造を含む層とする場合には、詳細な図示を省略するが、１００オングストローム以下の膜厚を有したＩＩＩ族窒化物半導体からなるｎ側第１層と、該ｎ側第１層と組成が異なるとともに１００オングストローム以下の膜厚を有したＩＩＩ族窒化物半導体からなるｎ側第２層とが積層された構造を含むものであっても良い。
　また、ｎクラッド層１０４ｂは、ｎ側第１層とｎ側第２層とが交互に繰返し積層された構造を含んだものであってもよい。また、好ましくは、前記ｎ側第１層又はｎ側第２層の何れかが、活性層（発光層１０５）に接する構成とすれば良い。 When the n-cladding layer 104b is a layer including a superlattice structure, a detailed illustration is omitted, but an n-side first layer made of a group III nitride semiconductor having a thickness of 100 angstroms or less and A structure in which an n-side second layer made of a group III nitride semiconductor having a composition different from that of the n-side first layer and having a thickness of 100 angstroms or less is stacked may be included.
The n-clad layer 104b may include a structure in which n-side first layers and n-side second layers are alternately and repeatedly stacked. Preferably, either the n-side first layer or the n-side second layer is in contact with the active layer (light-emitting layer 105).
　上述のようなｎ側第１層及びｎ側第２層は、例えばＡｌを含むＡｌＧａＮ系（単にＡｌＧａＮと記載することがある）、Ｉｎを含むＧａＩｎＮ系（単にＧａＩｎＮと記載することがある）、ＧａＮの組成とすることができる。
　また、ｎ側第１層及びｎ側第２層は、ＧａＩｎＮ／ＧａＮの交互構造、ＡｌＧａＮ／ＧａＮの交互構造、ＧａＩｎＮ／ＡｌＧａＮの交互構造、組成の異なるＧａＩｎＮ／ＧａＩｎＮの交互構造（本発明における“組成の異なる”との説明は、各元素組成比が異なることを指し、以下同様である）、組成の異なるＡｌＧａＮ／ＡｌＧａＮの交互構造であってもよい。
　本発明においては、ｎ側第１層及びｎ側第２層は、ＧａＩｎＮ／ＧａＮの交互構造又は組成の異なるＧａＩｎＮ／ＧａＩｎＮであることが好ましい。 The n-side first layer and the n-side second layer as described above are, for example, AlGaN-based Al (which may be simply referred to as AlGaN), GaInN-based (which may be simply described as GaInN) including In, The composition may be GaN.
In addition, the n-side first layer and the n-side second layer are composed of an alternating GaInN / GaN structure, an AlGaN / GaN alternating structure, an GaInN / AlGaN alternating structure, and a GaInN / GaInN alternating structure having a different composition (“ The description of “differing composition” means that each elemental composition ratio is different, and the same applies hereinafter), and may be an AlGaN / AlGaN alternating structure having a different composition.
In the present invention, the n-side first layer and the n-side second layer are preferably GaInN / GaInN having different GaInN / GaN structures or different compositions.
　上記ｎ側第１層及びｎ側第２層の超格子層は、それぞれ６０オングストローム以下であることが好ましく、それぞれ４０オングストローム以下であることがより好ましく、それぞれ１０オンストローム～４０オングストロームの範囲であることが最も好ましい。超格子層を形成するｎ側第１層とｎ側第２層の膜厚が１００オングストローム超だと、結晶欠陥が入りやすく好ましくない。
　上記ｎ側第１層及びｎ側第２層は、それぞれドープした構造であってもよく、また、ドープ構造／未ドープ構造の組み合わせであってもよい。ドープされる不純物としては、上記材料組成に対して従来公知のものを、何ら制限無く適用できる。例えば、ｎクラッド層として、ＧａＩｎＮ／ＧａＮの交互構造又は組成の異なるＧａＩｎＮ／ＧａＩｎＮの交互構造のものを用いた場合には、不純物としてＳｉが好適である。
　また、上述のようなｎ側超格子多層膜は、ＧａＩｎＮやＡｌＧａＮ、ＧａＮで代表される組成が同じであっても、ドーピングを適宜ＯＮ、ＯＦＦしながら作製してもよい。 The superlattice layers of the n-side first layer and the n-side second layer are each preferably 60 angstroms or less, more preferably 40 angstroms or less, and each in the range of 10 angstroms to 40 angstroms. Most preferred. If the thicknesses of the n-side first layer and the n-side second layer forming the superlattice layer are more than 100 angstroms, crystal defects are likely to occur, which is not preferable.
The n-side first layer and the n-side second layer may each have a doped structure, or a combination of a doped structure and an undoped structure. As the impurity to be doped, conventionally known impurities can be applied to the material composition without any limitation. For example, when an n-cladding layer having an alternating GaInN / GaN structure or an alternating GaInN / GaInN structure having a different composition is used, Si is suitable as an impurity.
Further, the n-side superlattice multilayer film as described above may be manufactured while doping is appropriately turned on and off even if the composition represented by GaInN, AlGaN, and GaN is the same.
＜発光層＞
　ｎ型半導体層１０４の上に積層される発光層１０５としては、単一量子井戸構造あるいは多重量子井戸構造などの発光層１０５がある。
　図３に示すような、量子井戸構造の井戸層１０５ｂとしては、Ｇａ１－ｙＩｎｙＮ（０＜ｙ＜０．４）からなるＩＩＩ族窒化物半導体層が通常用いられる。井戸層１０５ｂの膜厚としては、量子効果の得られる程度の膜厚、例えば１～１０ｎｍとすることができ、好ましくは２～６ｎｍとすると発光出力の点で好ましい。
　また、多重量子井戸構造の発光層１０５の場合は、上記Ｇａ１－ｙＩｎｙＮを井戸層１０５ｂとし、井戸層１０５ｂよりバンドギャップエネルギーが大きいＡｌｚＧａ１－ｚＮ（０≦ｚ＜０．３）を障壁層１０５ａとする。井戸層１０５ｂおよび障壁層１０５ａには、設計により不純物をドープしてもしなくてもよい。 <Light emitting layer>
As the light emitting layer 105 stacked on the n-type semiconductor layer 104, there is a light emitting layer 105 having a single quantum well structure or a multiple quantum well structure.
As a well layer 105b having a quantum well structure as shown in FIG. 3, a group III nitride semiconductor layer made of Ga 1-y In y N (0 <y <0.4) is usually used. The film thickness of the well layer 105b can be set to a film thickness that can provide a quantum effect, for example, 1 to 10 nm, and preferably 2 to 6 nm in terms of light emission output.
In the case of the light emitting layer 105 having a multiple quantum well structure, the Ga 1-y In y N is used as the well layer 105b, and Al z Ga 1-z N (0 ≦ z <0) having a larger band gap energy than the well layer 105b. .3) is defined as a barrier layer 105a. The well layer 105b and the barrier layer 105a may or may not be doped with impurities by design.
＜ｐ型半導体層＞
　図３に示すように、ｐ型半導体層１０６は、通常、ｐクラッド層１０６ａおよびｐコンタクト層１０６ｂから構成される。また、ｐコンタクト層１０６ｂがｐクラッド層１０６ａを兼ねることも可能である。
　ｐクラッド層１０６ａは、発光層１０５へのキャリアの閉じ込めとキャリアの注入を行なう層である。ｐクラッド層１０６ａとしては、発光層１０５のバンドギャップエネルギーより大きくなる組成であり、発光層１０５へのキャリアの閉じ込めができるものであれば特に限定されないが、好ましくは、ＡｌｘＧａ１－ｘＮ（０＜ｘ≦０．４）のものが挙げられる。
　ｐクラッド層１０６ａが、このようなＡｌＧａＮからなると、発光層へのキャリアの閉じ込めの点で好ましい。ｐクラッド層１０６ａの膜厚は、特に限定されないが、好ましくは１～４００ｎｍであり、より好ましくは５～１００ｎｍである。
　ｐクラッド層１０６ａのｐ型ドープ濃度は、１×１０１８～１×１０２１／ｃｍ３が好ましく、より好ましくは１×１０１９～１×１０２０／ｃｍ３である。ｐ型ドープ濃度が上記範囲であると、結晶性を低下させることなく良好なｐ型結晶が得られる。
　また、ｐクラッド層１０６ａは、複数回積層した超格子構造としてもよい。 <P-type semiconductor layer>
As shown in FIG. 3, the p-type semiconductor layer 106 is generally composed of a p-clad layer 106a and a p-contact layer 106b. The p contact layer 106b can also serve as the p clad layer 106a.
The p-cladding layer 106a is a layer for confining carriers in the light emitting layer 105 and injecting carriers. The p-cladding layer 106a is not particularly limited as long as it has a composition larger than the band gap energy of the light-emitting layer 105 and can confine carriers in the light-emitting layer 105, but is preferably Al x Ga 1-x N (0 <x ≦ 0.4).
When the p-clad layer 106a is made of such AlGaN, it is preferable in terms of confining carriers in the light-emitting layer. The thickness of the p-clad layer 106a is not particularly limited, but is preferably 1 to 400 nm, more preferably 5 to 100 nm.
The p-type doping concentration of the p-clad layer 106a is preferably 1 × 10 18 to 1 × 10 21 / cm 3 , more preferably 1 × 10 19 to 1 × 10 20 / cm 3 . When the p-type dope concentration is in the above range, a good p-type crystal can be obtained without reducing the crystallinity.
The p-clad layer 106a may have a superlattice structure in which a plurality of layers are stacked.
　なお、ｐクラッド層１０６ａを、超格子構造を含む層とする場合には、詳細な図示を省略するが、１００オングストローム以下の膜厚を有したＩＩＩ族窒化物半導体からなるｐ側第１層と、該ｐ側第１層と組成が異なるとともに１００オングストローム以下の膜厚を有したＩＩＩ族窒化物半導体からなるｐ側第２層とが積層された構造を含むものであっても良い。また、ｐ側第１層とｐ側第２層とが交互に繰返し積層された構造を含んだものであっても良い。 When the p-cladding layer 106a is a layer including a superlattice structure, a detailed illustration is omitted, but a p-side first layer made of a group III nitride semiconductor having a thickness of 100 angstroms or less and A structure in which a p-side second layer made of a group III nitride semiconductor having a composition different from that of the p-side first layer and having a film thickness of 100 angstroms or less is stacked may be included. Further, it may include a structure in which p-side first layers and p-side second layers are alternately and repeatedly stacked.
　上述のようなｐ側第１層及びｐ側第２層は、それぞれ異なる組成、例えば、ＡｌＧａＮ、ＧａＩｎＮ又はＧａＮの内の何れの組成であっても良い、また、ＧａＩｎＮ／ＧａＮの交互構造、ＡｌＧａＮ／ＧａＮの交互構造、又はＧａＩｎＮ／ＡｌＧａＮの交互構造であっても良い。
　本発明においては、ｐ側第１層及びｐ側第２層は、ＡｌＧａＮ／ＡｌＧａＮ又はＡｌＧａＮ／ＧａＮの交互構造であることが好ましい。 The p-side first layer and the p-side second layer as described above may have different compositions, for example, any composition of AlGaN, GaInN, or GaN, or an GaInN / GaN alternating structure, AlGaN. An alternating structure of / GaN or an alternating structure of GaInN / AlGaN may be used.
In the present invention, the p-side first layer and the p-side second layer preferably have an AlGaN / AlGaN or AlGaN / GaN alternating structure.
　上記ｐ側第１層及びｐ側第２層の超格子層は、それぞれ６０オングストローム以下であることが好ましく、それぞれ４０オングストローム以下であることがより好ましく、それぞれ１０オングストローム～４０オングストロームの範囲であることが最も好ましい。超格子層を形成するｐ側第１層とｐ側第２層の膜厚が１００オングストローム超だと、結晶欠陥等を多く含む層となり、好ましくない。
　上記ｐ側第１層及びｐ側第２層は、それぞれドープした構造であっても良く、また、ドープ構造／未ドープ構造の組み合わせであっても良い。ドープされる不純物としては、上記材料組成に対して従来公知のものを、何ら制限無く適用できる。例えば、ｐクラッド層として、ＡｌＧａＮ／ＧａＮの交互構造又は組成の異なるＡｌＧａＮ／ＡｌＧａＮの交互構造のものを用いた場合には、不純物としてＭｇが好適である。また、上述のようなｐ側超格子多層膜は、ＧａＩｎＮやＡｌＧａＮ、ＧａＮで代表される組成が同じであっても、ドーピングを適宜ＯＮ、ＯＦＦしながら作製してもよい。 The superlattice layers of the p-side first layer and the p-side second layer are each preferably 60 angstroms or less, more preferably 40 angstroms or less, and each in the range of 10 angstroms to 40 angstroms. Is most preferred. If the thickness of the p-side first layer and the p-side second layer forming the superlattice layer exceeds 100 angstroms, it becomes a layer containing many crystal defects and the like, which is not preferable.
The p-side first layer and the p-side second layer may each have a doped structure, or a combination of a doped structure and an undoped structure. As the impurity to be doped, conventionally known impurities can be applied to the material composition without any limitation. For example, when a p-cladding layer having an AlGaN / GaN alternating structure or an AlGaN / AlGaN alternating structure having a different composition is used, Mg is suitable as an impurity. Further, the p-side superlattice multilayer film as described above may be manufactured while doping is appropriately turned on and off even if the composition represented by GaInN, AlGaN, and GaN is the same.
　ｐコンタクト層１０６ｂは、正極を設けるための層である。ｐコンタクト層１０６ｂは、ＡｌｘＧａ１－ｘＮ（０≦ｘ≦０．４）が好ましい。Ａｌ組成が上記範囲であると、良好な結晶性の維持およびｐオーミック電極との良好なオーミック接触の点で好ましい。
　ｐ型不純物（ドーパント）を１×１０１８～１×１０２１／ｃｍ３の濃度、好ましくは５×１０１９～５×１０２０／ｃｍ３の濃度で含有していると、良好なオーミック接触の維持、クラック発生の防止、良好な結晶性の維持の点で好ましい。ｐ型不純物としては、特に限定されないが、例えば好ましくはＭｇが挙げられる。
　ｐコンタクト層１０６ｂの膜厚は、特に限定されないが、０．０１～０．５μｍが好ましく、より好ましくは０．０５～０．２μｍである。ｐコンタクト層１０６ｂの膜厚がこの範囲であると、発光出力の点で好ましい。 The p contact layer 106b is a layer for providing a positive electrode. The p contact layer 106b is preferably Al x Ga 1-x N (0 ≦ x ≦ 0.4). When the Al composition is in the above range, it is preferable in terms of maintaining good crystallinity and good ohmic contact with the p ohmic electrode.
When a p-type impurity (dopant) is contained at a concentration of 1 × 10 18 to 1 × 10 21 / cm 3 , preferably 5 × 10 19 to 5 × 10 20 / cm 3 , good ohmic contact can be obtained. It is preferable in terms of maintenance, prevention of crack generation, and good crystallinity. Although it does not specifically limit as a p-type impurity, For example, Preferably Mg is mentioned.
The thickness of the p contact layer 106b is not particularly limited, but is preferably 0.01 to 0.5 μm, more preferably 0.05 to 0.2 μm. When the film thickness of the p-contact layer 106b is within this range, it is preferable in terms of light emission output.
＜ｎ型電極＞
　図１に示すように、ｎ型半導体層１０４の露出面１０４ｃにｎ型電極１０８が形成されている。このように、ｎ型電極１０８を形成する際には、エッチング等の手段によって発光層１０５およびｐ半導体層１０６の一部を切り欠け除去してｎ型半導体層１０４のｎコンタクト層を露出させ、この露出面１０４ｃ上にｎ型電極１０８を形成する。
　図２に示すように、平面視したときに、ｎ型電極１０８は円形状とされているが、このような形状に限定されるわけでなく、多角形状など任意の形状とすることができる。また、ｎ型電極１０８はボンディングパットを兼ねており、ボンディングワイヤを接続することができる構成とされている。なお、ｎ型電極１０８としては、周知の各種組成や構造を、この技術分野でよく知られた慣用の手段で設けることができる。 <N-type electrode>
As shown in FIG. 1, an n-type electrode 108 is formed on the exposed surface 104 c of the n-type semiconductor layer 104. Thus, when the n-type electrode 108 is formed, the light emitting layer 105 and a part of the p-semiconductor layer 106 are cut and removed by means such as etching to expose the n-contact layer of the n-type semiconductor layer 104, An n-type electrode 108 is formed on the exposed surface 104c.
As shown in FIG. 2, the n-type electrode 108 has a circular shape when seen in a plan view, but is not limited to such a shape, and may have an arbitrary shape such as a polygonal shape. Further, the n-type electrode 108 also serves as a bonding pad, and can be connected to a bonding wire. As the n-type electrode 108, various known compositions and structures can be provided by conventional means well known in this technical field.
　また、ｎ型電極１０８も、ｐ型電極１１１と同様に、外周側に向けて膜厚が漸次薄くなるような傾斜面を備えた接合層を形成するとともに、これを覆うようにボンディングパッド電極を形成してもよい。また、この際、透過性電極や保護膜を形成しても良い。これにより、外部の空気または水分がｎ型電極１０８の接合層へ侵入することを防止することができ、接合層の耐食性を向上して、半導体発光素子寿命を長くすることができる。 Similarly to the p-type electrode 111, the n-type electrode 108 is also formed with a bonding layer having an inclined surface that gradually decreases in thickness toward the outer peripheral side, and a bonding pad electrode is formed so as to cover this. It may be formed. At this time, a permeable electrode or a protective film may be formed. Thereby, it is possible to prevent external air or moisture from entering the bonding layer of the n-type electrode 108, improve the corrosion resistance of the bonding layer, and extend the lifetime of the semiconductor light emitting device.
＜透光性電極＞
　図１に示すように、ｐ型半導体層１０６の上に透光性電極１０９が積層されている。
　図２に示すように、平面視したときに、透光性電極１０９は、ｎ型電極１０８を形成するために、エッチング等の手段によって一部が除去されたｐ型半導体層１０６の上面１０６ｃのほぼ全面を覆うように形成されているが、このような形状に限定されるわけでなく、隙間を開けて格子状や樹形状に形成してもよい。なお、透光性電極１０９の構造も、従来公知の構造を含めて如何なる構造のものも何ら制限なく用いることができる。
　透光性電極１０９は、ｐ型半導体層１０６との接触抵抗が小さいものが好ましい。また、発光層１０５からの光をボンディングパッド電極１０７が形成された側に取り出すことから、透光性電極１０９は光透過性に優れたものが好ましい。さらにまた、ｐ型半導体層１０６の全面に渡って均一に電流を拡散させるために、透光性電極１０９は優れた導電性を有していることが好ましい。 <Translucent electrode>
As shown in FIG. 1, a translucent electrode 109 is stacked on the p-type semiconductor layer 106.
As shown in FIG. 2, when viewed in plan, the translucent electrode 109 is formed on the upper surface 106c of the p-type semiconductor layer 106, part of which has been removed by means such as etching to form the n-type electrode 108. Although it is formed so as to cover almost the entire surface, it is not limited to such a shape, and it may be formed in a lattice shape or a tree shape with a gap. In addition, the structure of the translucent electrode 109 can be used without any limitation, including a conventionally known structure.
The translucent electrode 109 preferably has a small contact resistance with the p-type semiconductor layer 106. In addition, since the light from the light emitting layer 105 is taken out to the side where the bonding pad electrode 107 is formed, the light-transmitting electrode 109 is preferably excellent in light transmittance. Furthermore, in order to diffuse current uniformly over the entire surface of the p-type semiconductor layer 106, the translucent electrode 109 preferably has excellent conductivity.
　以上のことから、透光性電極１０９の構成材料としては、Ｉｎ、Ｚｎ、Ａｌ、Ｇａ、Ｔｉ、Ｂｉ、Ｍｇ、Ｗ、Ｃｅ、Ｓｎ、Ｎｉのいずれか一種を含む導電性の酸化物、硫化亜鉛または硫化クロムのうちいずれか一種からなる群より選ばれる透光性の導電性材料が好ましい。
　また、導電性の酸化物としては、ＩＴＯ（酸化インジウム錫（Ｉｎ２Ｏ３－ＳｎＯ２））、ＩＺＯ（酸化インジウム亜鉛（Ｉｎ２Ｏ３－ＺｎＯ））、ＡＺＯ（酸化アルミニウム亜鉛（ＺｎＯ－Ａｌ２Ｏ３））、ＧＺＯ（酸化ガリウム亜鉛（ＺｎＯ－Ｇａ２Ｏ３））、フッ素ドープ酸化錫、酸化チタン等が好ましい。
　これらの材料を、この技術分野でよく知られた慣用の手段で設けることによって、透光性電極１０９を形成できる。また、透光性電極１０９を形成した後に、合金化や透明化を目的とした熱アニールを施す場合もあるが、施さなくても構わない。 From the above, the constituent material of the translucent electrode 109 is a conductive oxide, sulfide, including any one of In, Zn, Al, Ga, Ti, Bi, Mg, W, Ce, Sn, and Ni. A translucent conductive material selected from the group consisting of either zinc or chromium sulfide is preferred.
As the conductive oxide, ITO (indium tin oxide (In 2 O 3 —SnO 2 )), IZO (indium zinc oxide (In 2 O 3 —ZnO)), AZO (aluminum zinc oxide (ZnO—Al 2 O 3 )), GZO (gallium zinc oxide (ZnO—Ga 2 O 3 )), fluorine-doped tin oxide, titanium oxide and the like are preferable.
By providing these materials by conventional means well known in this technical field, the translucent electrode 109 can be formed. Further, after forming the translucent electrode 109, thermal annealing may be performed for the purpose of alloying or transparency, but it may not be performed.
　透光性電極１０９は、結晶化された構造のものを使用してよく、特に六方晶構造又はビックスバイト構造を有するＩｎ２Ｏ３結晶を含む透光性電極（例えば、ＩＴＯやＩＺＯ等）を好ましく使用することができる。
　例えば、六方晶構造のＩｎ２Ｏ３結晶を含むＩＺＯを透光性電極１０９として使用する場合、エッチング性に優れたアモルファスのＩＺＯ膜を用いて特定形状に加工することができ、さらにその後、熱処理等によりアモルファス状態から当該結晶を含む構造に転移させることで、アモルファスのＩＺＯ膜よりも透光性の優れた電極に加工することができる。 As the translucent electrode 109, a crystallized structure may be used, and in particular, a translucent electrode (for example, ITO or IZO) containing an In 2 O 3 crystal having a hexagonal crystal structure or a bixbite structure is used. It can be preferably used.
For example, when IZO containing In 2 O 3 crystal having a hexagonal crystal structure is used as the translucent electrode 109, it can be processed into a specific shape using an amorphous IZO film having excellent etching properties, and then heat treatment is performed. By transferring from an amorphous state to a structure including the crystal by, for example, an electrode having a light-transmitting property better than that of an amorphous IZO film.
　また、ＩＺＯ膜としては、比抵抗が最も低くなる組成を使用することが好ましい。
　例えば、ＩＺＯ中のＺｎＯ濃度は１～２０質量％であることが好ましく、５～１５質量％の範囲であることが更に好ましい。１０質量％であると特に好ましい。また、ＩＺＯ膜の膜厚は、低比抵抗、高光透過率を得ることができる３５ｎｍ～１００００ｎｍ（１０μｍ）の範囲であることが好ましい。さらに、生産コストの観点から、ＩＺＯ膜の膜厚は１０００ｎｍ（１μｍ）以下であることが好ましい。
　ＩＺＯ膜のパターニングは、後述の熱処理工程を行なう前に行なうことが望ましい。熱処理により、アモルファス状態のＩＺＯ膜は結晶化されたＩＺＯ膜となるため、アモルファス状態のＩＺＯ膜と比較してエッチングが難しくなる。これに対し、熱処理前のＩＺＯ膜は、アモルファス状態であるため、周知のエッチング液（ＩＴＯ－０７Ｎエッチング液（関東化学社製））を用いて容易に精度良くエッチングすることが可能である。 Further, it is preferable to use a composition having the lowest specific resistance as the IZO film.
For example, the ZnO concentration in IZO is preferably 1 to 20% by mass, and more preferably 5 to 15% by mass. 10% by mass is particularly preferable. The film thickness of the IZO film is preferably in the range of 35 nm to 10000 nm (10 μm) at which low specific resistance and high light transmittance can be obtained. Furthermore, from the viewpoint of production cost, the thickness of the IZO film is preferably 1000 nm (1 μm) or less.
The patterning of the IZO film is preferably performed before the heat treatment process described later. By the heat treatment, the amorphous IZO film becomes a crystallized IZO film, which makes etching difficult compared to the amorphous IZO film. On the other hand, since the IZO film before heat treatment is in an amorphous state, it can be easily and accurately etched using a known etching solution (ITO-07N etching solution (manufactured by Kanto Chemical Co., Inc.)).
　アモルファス状態のＩＺＯ膜のエッチングは、ドライエッチング装置を用いて行なっても良い。このとき、エッチングガスにはＣｌ２、ＳｉＣｌ４、ＢＣｌ３等を用いることができる。アモルファス状態のＩＺＯ膜は、例えば５００℃～１０００℃の熱処理を行ない、条件を制御することで六方晶構造のＩｎ２Ｏ３結晶を含むＩＺＯ膜や、ビックスバイト構造のＩｎ２Ｏ３結晶を含むＩＺＯ膜にすることができる。六方晶構造のＩｎ２Ｏ３結晶を含むＩＺＯ膜は前述したようにエッチングし難いので、上述のエッチング処理の後に熱処理することが好ましい。 The amorphous IZO film may be etched using a dry etching apparatus. At this time, Cl 2 , SiCl 4 , BCl 3, or the like can be used as an etching gas. IZO film in an amorphous state, for example, and was heat-treated in 500 ° C. ~ 1000 ° C., comprising an IZO film and that includes In 2 O 3 crystal having a hexagonal crystal structure for controlling the condition, an In 2 O 3 crystal bixbyite structure An IZO film can be formed. Since an IZO film containing an In 2 O 3 crystal having a hexagonal crystal structure is difficult to etch as described above, it is preferable to perform a heat treatment after the above-described etching treatment.
　ＩＺＯ膜の熱処理は、Ｏ２を含まない雰囲気で行なうことが望ましく、Ｏ２を含まない雰囲気としては、Ｎ２雰囲気などの不活性ガス雰囲気や、またはＮ２などの不活性ガスとＨ２の混合ガス雰囲気などを挙げることができ、Ｎ２雰囲気、またはＮ２とＨ２の混合ガス雰囲気とすることが望ましい。なお、ＩＺＯ膜の熱処理をＮ雰囲気、またはＮ２とＨ２の混合ガス雰囲気中で行なうと、例えば、ＩＺＯ膜を六方晶構造のＩｎ２Ｏ３結晶を含む膜に結晶化させるとともに、ＩＺＯ膜のシート抵抗を効果的に減少させることが可能である。
　また、ＩＺＯ膜の熱処理温度は、５００℃～１０００℃が好ましい。５００℃未満の温度で熱処理を行なった場合、ＩＺＯ膜を十分に結晶化できない恐れが生じ、ＩＺＯ膜の光透過率が十分に高いものとならない場合がある。１０００℃を超える温度で熱処理を行なった場合には、ＩＺＯ膜は結晶化されているが、ＩＺＯ膜の光透過率が十分に高いものとならない場合がある。また、１０００℃を超える温度で熱処理を行なった場合、ＩＺＯ膜の下にある半導体層を劣化させる恐れもある。 Heat treatment of the IZO film is preferably performed in an atmosphere containing no O 2, as the atmosphere containing no O 2, N, such as 2 atmosphere or an inert gas atmosphere, or such as N 2 inert gas and H 2 A mixed gas atmosphere or the like can be given, and it is desirable to use an N 2 atmosphere or a mixed gas atmosphere of N 2 and H 2 . Note that when the heat treatment of the IZO film is performed in an N atmosphere or a mixed gas atmosphere of N 2 and H 2 , for example, the IZO film is crystallized into a film containing an In 2 O 3 crystal having a hexagonal structure, and the IZO film It is possible to effectively reduce the sheet resistance.
The heat treatment temperature of the IZO film is preferably 500 ° C. to 1000 ° C. When heat treatment is performed at a temperature lower than 500 ° C., the IZO film may not be sufficiently crystallized, and the light transmittance of the IZO film may not be sufficiently high. When heat treatment is performed at a temperature exceeding 1000 ° C., the IZO film is crystallized, but the light transmittance of the IZO film may not be sufficiently high. Further, when heat treatment is performed at a temperature exceeding 1000 ° C., the semiconductor layer under the IZO film may be deteriorated.
　アモルファス状態のＩＺＯ膜を結晶化させる場合、成膜条件や熱処理条件などが異なるとＩＺＯ膜中の結晶構造が異なる。しかし、本発明の実施形態においては、接着層との接着性の点において、透光性電極は材料に限定されないが結晶性の材料の方が好ましく、特に結晶性ＩＺＯの場合にはビックスバイト結晶構造のＩｎ２Ｏ３結晶を含むＩＺＯであってもよく、六方晶構造のＩｎ２Ｏ３結晶を含むＩＺＯであってもよい。特に六方晶構造のＩｎ２Ｏ３結晶を含むＩＺＯがよい。
　特に、前述のように、熱処理によって結晶化したＩＺＯ膜は、アモルファス状態のＩＺＯ膜に比べて、接合層１１０やｐ型半導体層１０６との密着性が良いため、本発明の実施形態において大変有効である。 In the case of crystallizing an amorphous IZO film, the crystal structure in the IZO film differs depending on the film formation conditions, heat treatment conditions, and the like. However, in the embodiment of the present invention, in terms of adhesiveness with the adhesive layer, the translucent electrode is not limited to a material, but a crystalline material is preferable, and in particular, in the case of crystalline IZO, bixbite crystal. It may be IZO including an In 2 O 3 crystal having a structure, or IZO including an In 2 O 3 crystal having a hexagonal structure. In particular, IZO containing In 2 O 3 crystal having a hexagonal structure is preferable.
In particular, as described above, an IZO film crystallized by heat treatment has a better adhesion to the bonding layer 110 and the p-type semiconductor layer 106 than an amorphous IZO film, and thus is very effective in the embodiment of the present invention. It is.
＜ｐ型電極＞
　図４は、図１に示す本発明の実施形態である半導体発光素子１のｐ型電極１１１の拡大断面図である。
　図４に示すように、ｐ型電極（一の伝導型の電極）１１１は、透光性電極１０９、接合層１１０とボンディングパッド電極１２０とからなり、ｐ型半導体層１０６上に形成されて概略構成されている。
　透光性電極１０９の上面１０９ｃはＳｉＯ２からなる保護膜１０によって覆われており、保護膜１０の一部が開口されて開口部１０ｄが形成され、開口部１０ｄから透光性電極１０９の上面１０９ｃの一部が露出されている。
　接合層１１０は、開口部１０ｄから露出された透光性電極１０９の上面１０９ｃをほぼ均一の膜厚で覆うともに、開口部１０ｄの外周側では膜厚が厚くされており、さらに、保護膜１０の端部１０ｃを覆うように形成されている。また、保護膜１０の端部１０ｃを覆う接合層１１０の外周部１１０ｄには、外周側に向けて膜厚が漸次薄くなるような傾斜面１１０ｃが形成されている。 <P-type electrode>
4 is an enlarged cross-sectional view of the p-type electrode 111 of the semiconductor light emitting device 1 according to the embodiment of the present invention shown in FIG.
As shown in FIG. 4, the p-type electrode (one conductivity type electrode) 111 includes a translucent electrode 109, a bonding layer 110, and a bonding pad electrode 120, and is formed on the p-type semiconductor layer 106 and schematically. It is configured.
Upper surface 109c of the transparent electrode 109 is covered by a protective film 10 made of SiO 2, a portion of the protective film 10 is being opened openings 10d formed, the upper surface of the transparent electrode 109 through the opening 10d Part of 109c is exposed.
The bonding layer 110 covers the upper surface 109c of the translucent electrode 109 exposed from the opening 10d with a substantially uniform film thickness, and the film thickness is increased on the outer peripheral side of the opening 10d. It is formed so as to cover the end portion 10c. In addition, an inclined surface 110c is formed on the outer peripheral portion 110d of the bonding layer 110 that covers the end portion 10c of the protective film 10 so that the film thickness gradually decreases toward the outer peripheral side.
　ボンディングパッド電極１２０は、接合層１１０の最大厚みに比べて厚く形成された金属反射層１１７とボンディング層１１９とから構成されている。また、ボンディングパッド電極１２０の外周部１２０ｄには、外周側に向けて膜厚が漸次薄くなるような傾斜面１１９ｃが形成されている。
　金属反射層１１７の外周部には、前記外周側に向けて膜厚が漸次薄くなるような傾斜面１１７ｃが形成されている。また、金属反射層１１７は接合層１１０を覆うように形成されている。すなわち、金属反射層１１７は、接合層１１０の傾斜面１１０ｃの先の最先端部、すなわち接合層１１０を平面視したときの輪郭線を形づくる境界部の上を完全に覆うように形成されている。つまり、平面視したときに、金属反射層１１７は接合層１１０を覆って、更に接合層１１０の外周側にまで張り出すように形成される構成なので、接合層１１０のいかなる部分も金属反射層１１７の下から露出しないようにすることができる。 The bonding pad electrode 120 includes a metal reflection layer 117 and a bonding layer 119 that are formed to be thicker than the maximum thickness of the bonding layer 110. In addition, an inclined surface 119c is formed on the outer peripheral portion 120d of the bonding pad electrode 120 so that the film thickness gradually decreases toward the outer peripheral side.
An inclined surface 117c is formed on the outer peripheral portion of the metal reflective layer 117 so that the film thickness gradually decreases toward the outer peripheral side. The metal reflective layer 117 is formed so as to cover the bonding layer 110. In other words, the metal reflection layer 117 is formed so as to completely cover the leading edge of the inclined surface 110c of the bonding layer 110, that is, the boundary that forms the contour line when the bonding layer 110 is viewed in plan. . That is, when viewed in plan, the metal reflective layer 117 is formed so as to cover the bonding layer 110 and further extend to the outer peripheral side of the bonding layer 110, so any portion of the bonding layer 110 can be any metal reflective layer 117. It is possible to prevent exposure from below.
　さらに、ボンディング層１１９の外周部には、前記外周側に向けて膜厚が漸次薄くなるような傾斜面１１９ｃが形成されている。また、ボンディング層１１９は金属反射層１１７を覆うように形成されている。すなわち、ボンディング層１１９は、金属反射層１１７の傾斜面１１７ｃの先の最先端部、すなわち金属反射層１１７を平面視したときの輪郭線を形づくる境界部の上を完全に覆うように形成されている。つまり、平面視したときに、ボンディング層１１９は金属反射層１１７を覆って、更に金属反射層１１７の外周側にまで張り出すように形成される構成なので、金属反射層１１７のいかなる部分もボンディング層１１９の下から露出しないようにすることができる。 Furthermore, an inclined surface 119c is formed on the outer peripheral portion of the bonding layer 119 so that the film thickness gradually decreases toward the outer peripheral side. The bonding layer 119 is formed so as to cover the metal reflective layer 117. In other words, the bonding layer 119 is formed so as to completely cover the tip of the tip of the inclined surface 117c of the metal reflection layer 117, that is, the boundary that forms the contour line when the metal reflection layer 117 is viewed in plan. Yes. That is, since the bonding layer 119 is formed so as to cover the metal reflection layer 117 and project to the outer peripheral side of the metal reflection layer 117 when seen in a plan view, any portion of the metal reflection layer 117 can be bonded to the bonding layer. It is possible to prevent exposure from below 119.
　以上の構成により、接合層１１０は外周部に外周側に向けて膜厚が漸次薄くなるような傾斜面１１０ｃが形成されているとともに、金属反射層１１７およびボンディング層１１９により外部から二重にシールドされる構成なので、保護膜１０とボンディング層１１９との接合面および保護膜１０と金属反射層１１７との接合面を通過しなければ、半導体発光素子１の外部の空気または水分が接合層１１０へ侵入することができず、外部の空気や水分が接合層１１０へ浸入するおそれを大幅に低減することができる。
　これにより、接合層１１０が容易に分解されることはなく、接合層１１０の耐食性を向上させることにより、半導体発光素子の素子寿命を長くすることができる。
　また、接合層１１０の形成の前に、透光性電極１０９の露出された上面１０９ｃはウェットエッチングされて、不純物や欠陥が取り除かれたフレッシュ面とされていることが好ましい。これにより、透光性電極１０９の上面１０９ｃと接合層１１０との密着性を向上させることができる。 With the above configuration, the bonding layer 110 is formed with the inclined surface 110c that gradually decreases in thickness toward the outer peripheral side at the outer peripheral portion, and double-shielded from the outside by the metal reflective layer 117 and the bonding layer 119. Therefore, air or moisture outside the semiconductor light-emitting element 1 does not pass to the bonding layer 110 unless it passes through the bonding surface between the protective film 10 and the bonding layer 119 and the bonding surface between the protective film 10 and the metal reflective layer 117. The possibility that external air or moisture cannot enter the bonding layer 110 can be greatly reduced.
As a result, the bonding layer 110 is not easily decomposed, and by improving the corrosion resistance of the bonding layer 110, the element lifetime of the semiconductor light emitting element can be extended.
In addition, before the bonding layer 110 is formed, the exposed upper surface 109c of the translucent electrode 109 is preferably a fresh surface from which impurities and defects are removed by wet etching. Thereby, the adhesiveness between the upper surface 109c of the translucent electrode 109 and the bonding layer 110 can be improved.
＜接合層＞
　図１に示す接合層１１０は、透光性電極１０９に対するボンディングパッド電極１２０の接合強度を高めるために、透光性電極１０９とボンディングパッド電極１２０との間に積層される。また、接合層１１０は、透光性電極１０９を透過してボンディングパッド電極１２０に照射される発光層１０５からの光を損失なく透過させるために、透光性を有していることが好ましい。 <Junction layer>
The bonding layer 110 shown in FIG. 1 is laminated between the translucent electrode 109 and the bonding pad electrode 120 in order to increase the bonding strength of the bonding pad electrode 120 to the translucent electrode 109. In addition, the bonding layer 110 preferably has a light-transmitting property so that the light from the light-emitting layer 105 that is transmitted through the light-transmitting electrode 109 and irradiated onto the bonding pad electrode 120 is transmitted without loss.
　接合層１１０は、Ａｌ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｃｏ、Ｚｎ、Ｇｅ、Ｚｒ、Ｎｂ、Ｍｏ、Ｒｕ、Ｈｆ、Ｔａ、Ｗ、Ｒｅ、Ｒｈ、Ｉｒ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなるものが好ましい。これにより、接合強度と透光性を同時に発揮させることができる。接合層１１０は、Ｃｒ、Ｔｉ、Ｗ、Ｍｏ、Ｚｒ、Ｈｆ、Ｃｏ、Ｒｈ、Ｉｒ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなるものがより好ましく、さらにＣｒ、Ｔｉ、Ｗ、Ｍｏ、Ｒｈ、Ｃｏ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなるものがさらに好ましい。特に、Ｃｒ、Ｔｉ、Ｍｏ、Ｎｉ、Ｃｏ等の金属を用いることによって、透光性電極１０９に対するボンディングパッド電極１２０の接合強度を格段に高めることができる。 The bonding layer 110 is at least selected from the group consisting of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh, Ir, and Ni. What consists of a kind of element is preferable. Thereby, joint strength and translucency can be exhibited simultaneously. The bonding layer 110 is more preferably made of at least one element selected from the group consisting of Cr, Ti, W, Mo, Zr, Hf, Co, Rh, Ir, and Ni, and more preferably Cr, Ti, W, Mo. It is more preferable to use at least one element selected from the group consisting of Rh, Co, and Ni. In particular, by using a metal such as Cr, Ti, Mo, Ni, and Co, the bonding strength of the bonding pad electrode 120 to the translucent electrode 109 can be significantly increased.
　また、接合層１１０は最大厚みが１０Å以上４００Å以下の範囲の薄膜であることが好ましい。これにより、発光層１０５からの光を遮ることなく効果的に透過させることができる。なお、最大厚みが１０Å未満になると、接合層１１０の強度が低下し、これにより透光性電極１０９に対するボンディングパッド電極１２０の接合強度が低下するので好ましくない。 Further, the bonding layer 110 is preferably a thin film having a maximum thickness in the range of 10 to 400 mm. Thereby, the light from the light emitting layer 105 can be effectively transmitted without being blocked. In addition, when the maximum thickness is less than 10 mm, the strength of the bonding layer 110 is lowered, which is not preferable because the bonding strength of the bonding pad electrode 120 to the translucent electrode 109 is lowered.
＜ボンディングパッド電極＞
　図１に示すように、ボンディングパッド電極１２０は、透光性電極１０９側から順に、金属反射層１１７とボンディング層１１９とが積層された積層体からなる。
　なお、ボンディングパッド電極１２０は、金属反射層１１７のみからなる単層構造であってもよく、金属反射層１１７とボンディング層１１９と間に、ボンディングパッド電極１２０全体の強度を強化するバリア層を挿入して、三層構造としてもよい。 <Bonding pad electrode>
As shown in FIG. 1, the bonding pad electrode 120 is formed of a laminated body in which a metal reflective layer 117 and a bonding layer 119 are laminated in order from the translucent electrode 109 side.
The bonding pad electrode 120 may have a single-layer structure composed of only the metal reflective layer 117, and a barrier layer that enhances the strength of the entire bonding pad electrode 120 is inserted between the metal reflective layer 117 and the bonding layer 119. And it is good also as a three-layer structure.
＜金属反射層＞
　図１に示す金属反射層１１７は、反射率の高い金属で構成することが好ましく、Ｒｕ、Ｒｈ、Ｐｄ、Ｏｓ、Ｉｒ、Ｐｔ等の白金族金属、Ａｌ、Ａｇ、Ｔｉおよびこれらの金属の少なくも一種を含む合金で構成することがより好ましい。これにより、発光層１０５からの光を効果的に反射させることができる。
　なかでも、Ａｌ、Ａｇ、Ｐｔおよびこれらの金属の少なくも一種を含む合金は、電極用の材料として一般的であり、入手のし易さ、取り扱いの容易さなどの点から優れている。
　また、金属反射層１１７は、高い反射率を有する金属で形成した場合、最大厚さが２０～３０００ｎｍであることが望ましい。金属反射層１１７が薄すぎると充分な反射の効果が得られない。厚すぎると特に利点は生じず、工程時間の長時間化と材料の無駄を生じるのみである。更に望ましくは、５０～１０００ｎｍであり、最も望ましいのは１００～５００ｎｍである。 <Metal reflective layer>
The metal reflective layer 117 shown in FIG. 1 is preferably composed of a metal having high reflectance, and platinum group metals such as Ru, Rh, Pd, Os, Ir, and Pt, Al, Ag, Ti, and a small amount of these metals. It is more preferable to use an alloy including one kind. Thereby, the light from the light emitting layer 105 can be reflected effectively.
Among these, Al, Ag, Pt, and an alloy containing at least one of these metals are generally used as electrode materials, and are excellent in terms of easy availability and handling.
Further, when the metal reflective layer 117 is formed of a metal having a high reflectance, it is desirable that the maximum thickness is 20 to 3000 nm. If the metal reflection layer 117 is too thin, a sufficient reflection effect cannot be obtained. If it is too thick, there is no particular advantage, and only a long process time and material waste are caused. More desirably, the thickness is 50 to 1000 nm, and most desirably 100 to 500 nm.
　また、金属反射層１１７は、接合層１１０に密着していることが、発光層１０５からの光を効率良く反射するとともに、ボンディングパッド電極１２０の接合強度を高められる点で好ましい。このため、ボンディングパッド電極１２０が充分な強度を得るためには、金属反射層１１７が接合層１１０を介して透光性電極１０９に強固に接合されていることが必要である。最低限、一般的な方法でボンディングパッドに金線を接続する工程で剥離しない程度の強度が好ましい。特に、Ｒｈ、Ｐｄ、Ｉｒ、Ｐｔおよびこれらの金属の少なくも一種を含む合金は、光の反射性などの点から金属反射層１１７として好適に使用される。 Further, it is preferable that the metal reflective layer 117 is in close contact with the bonding layer 110 in that the light from the light emitting layer 105 can be efficiently reflected and the bonding strength of the bonding pad electrode 120 can be increased. For this reason, in order for the bonding pad electrode 120 to obtain sufficient strength, the metal reflective layer 117 needs to be firmly bonded to the translucent electrode 109 through the bonding layer 110. At a minimum, a strength that does not cause peeling in the step of connecting the gold wire to the bonding pad by a general method is preferable. In particular, Rh, Pd, Ir, Pt, and an alloy containing at least one of these metals are preferably used as the metal reflective layer 117 in view of light reflectivity.
　また、ボンディングパッド電極１２０の反射率は、金属反射層１１７の構成材料によって大きく変わるが、６０％以上であることが望ましい。更には、８０％以上であることが望ましく、９０％以上であればなお良い。反射率は、分光光度計等で比較的容易に測定することが可能である。しかし、ボンディングパッド電極１２０そのものは面積が小さいために反射率を測定することは難しい。そこで、面積の大きい「ダミー基板」、例えばガラス基板、をボンディングパッド電極形成時にチャンバに入れて、同時にダミー基板上に同じボンディングパッド電極を作成して測定するなどの方法を用いて測定することができる。 The reflectance of the bonding pad electrode 120 varies greatly depending on the constituent material of the metal reflective layer 117, but is preferably 60% or more. Further, it is preferably 80% or more, and more preferably 90% or more. The reflectance can be measured relatively easily with a spectrophotometer or the like. However, since the bonding pad electrode 120 itself has a small area, it is difficult to measure the reflectance. Therefore, a “dummy substrate” having a large area, for example, a glass substrate, is placed in the chamber when forming the bonding pad electrode, and at the same time, the same bonding pad electrode is formed on the dummy substrate and measured. it can.
　ボンディングパッド電極１２０は、上述した反射率の高い金属のみで構成することもできる。即ち、ボンディングパッド電極１２０は金属反射層１１７のみから構成されていてもよい。しかし、ボンディングパッド電極１２０として各種の材料を用いた各種の構造のものが知られており、これら公知のものの半導体層側（透光性電極側）に上述の金属反射層を新たに設けてもよいし、また、これら公知のものの半導体層側の最下層を上述の金属反射層に置き換えてもよい。 The bonding pad electrode 120 can be made of only the above-described highly reflective metal. That is, the bonding pad electrode 120 may be composed only of the metal reflective layer 117. However, various types of structures using various materials are known as the bonding pad electrode 120, and even if the above-described metal reflective layer is newly provided on the semiconductor layer side (translucent electrode side) of these known ones. Alternatively, the lowermost layer on the semiconductor layer side of these known ones may be replaced with the above-described metal reflection layer.
＜ボンディング層＞
　図１に示すボンディング層１１９は、Ａｕ、Ａｌまたはこれらの金属の少なくも一種を含む合金からなることが好ましい。ＡｕおよびＡｌはボンディングボールとして使用されることが多い金ボールとの密着性の良い金属なので、Ａｕ、Ａｌまたはこれらの金属の少なくも一種を含む合金を用いることにより、ボンディングワイヤとの密着性に優れたものとすることができる。中でも、特に望ましいのはＡｕである。
　また、ボンディング層１１９の最大厚みは、５０ｎｍ以上２０００ｎｍ以下の範囲のであることが好ましく、更に望ましくは１００ｎｍ以上１５００ｎｍ以下である。
　薄すぎるとボンディングボールとの密着性が悪くなり、厚すぎても特に利点は生ぜず、コスト増大を招くのみである。 <Bonding layer>
The bonding layer 119 shown in FIG. 1 is preferably made of Au, Al, or an alloy containing at least one of these metals. Since Au and Al are metals that have good adhesion to gold balls that are often used as bonding balls, the use of Au, Al, or an alloy containing at least one of these metals improves adhesion to bonding wires. It can be excellent. Of these, Au is particularly desirable.
The maximum thickness of the bonding layer 119 is preferably in the range of 50 nm to 2000 nm, and more preferably 100 nm to 1500 nm.
If it is too thin, the adhesion to the bonding ball will be poor, and if it is too thick, no particular advantage will be produced, and only the cost will increase.
　ボンディングパッド電極１２０に向かった光は、ボンディングパッド電極１２０の最下面（透光性電極側の面）の金属反射層１１７で反射され、一部は散乱されて横方向あるいは斜め方向に進み、一部はボンディングパッド電極１２０の直下に進む。散乱されて横方向や斜め方向に進んだ光は、半導体発光素子１の側面から外部に取り出される。一方、ボンディングパッド電極１２０の直下の方向に進んだ光は、半導体発光素子１の下面でさらに散乱や反射されて、側面や透光性電極１０９（上にボンディングパッド電極が存在しない部分）を通じて外部へ取り出される。 The light directed toward the bonding pad electrode 120 is reflected by the metal reflective layer 117 on the lowermost surface (translucent electrode side surface) of the bonding pad electrode 120, and part of the light is scattered and travels in the lateral direction or the oblique direction. The portion proceeds directly below the bonding pad electrode 120. The light that is scattered and travels in the lateral direction or the oblique direction is extracted from the side surface of the semiconductor light emitting element 1 to the outside. On the other hand, the light traveling in the direction immediately below the bonding pad electrode 120 is further scattered and reflected by the lower surface of the semiconductor light emitting device 1 and is externally transmitted through the side surface and the translucent electrode 109 (the portion where the bonding pad electrode does not exist). Is taken out.
　ボンディングパッド電極１２０は、透光性電極１０９の上であれば、どこへでも形成することができる。例えばｎ型電極１０８から最も遠い位置に形成してもよいし、半導体発光素子１の中心などに形成してもよい。しかし、あまりにもｎ型電極１０８に近接した位置に形成すると、ボンディングした際にワイヤ間、ボール間のショートを生じてしまうため好ましくない。
　また、ボンディングパッド電極１２０の電極面積としては、できるだけ大きいほうがボンディング作業はしやすいものの、発光の取り出しの妨げになる。例えば、チップ面の面積の半分を超えるような面積を覆っては、発光の取り出しの妨げとなり、出力が著しく低下する。逆に小さすぎるとボンディング作業がしにくくなり、製品の収率を低下させる。
　具体的には、ボンディングボールの直径よりもわずかに大きい程度が好ましく、直径１００μｍの円形程度であることが一般的である。
　前述の接合層、金属反射層、ボンディング層等の金属元素において、同一の金属元素を組み込んだ場合でもよく、また異なる金属元素の組み合わせによる構成であってもよい。 The bonding pad electrode 120 can be formed anywhere as long as it is on the translucent electrode 109. For example, it may be formed at a position farthest from the n-type electrode 108 or may be formed at the center of the semiconductor light emitting device 1. However, if it is formed too close to the n-type electrode 108, a short circuit between the wires and between the balls occurs during bonding, which is not preferable.
Further, the electrode area of the bonding pad electrode 120 is as large as possible, but the bonding operation is easy, but it prevents the light emission from being taken out. For example, covering an area that exceeds half the area of the chip surface hinders the extraction of light emission, and the output is significantly reduced. On the other hand, if it is too small, the bonding work becomes difficult and the yield of the product is lowered.
Specifically, it is preferably slightly larger than the diameter of the bonding ball, and generally has a circular shape with a diameter of 100 μm.
In the metal elements such as the bonding layer, the metal reflection layer, and the bonding layer described above, the same metal element may be incorporated, or a combination of different metal elements may be used.
＜バリア層＞
　なお、ボンディングパッド電極１２０を、金属反射層１１７とボンディング層１１９の間にバリア層を挿入して三層構造としても良い。
　バリア層は、ボンディングパッド電極１２０全体の強度を強化する役割を有し、例えば、ボンディングパッド電極１２０の金属反射層の上に形成する。このため、比較的強固な金属材料を使用するか、充分に膜厚を厚くする必要がある。材料として望ましいのは、Ｔｉ、ＣｒまたはＡｌである。中でも、Ｔｉは材料の強度の点で望ましい。 <Barrier layer>
The bonding pad electrode 120 may have a three-layer structure by inserting a barrier layer between the metal reflection layer 117 and the bonding layer 119.
The barrier layer has a role of enhancing the strength of the bonding pad electrode 120 as a whole, and is formed on the metal reflective layer of the bonding pad electrode 120, for example. For this reason, it is necessary to use a relatively strong metal material or to sufficiently increase the film thickness. Desirable materials are Ti, Cr or Al. Among these, Ti is desirable in terms of material strength.
　バリア層は金属反射層１１７が兼ねても良い。良好な反射率を持ち、機械的にも強固な金属材料を厚く形成した場合には、敢えてバリア層を形成する必要はない。例えば、ＡｌまたはＰｔを金属反射層１１７として使用した場合には、バリア層は必ずしも必要ではない。バリア層の最大厚さは２０～３０００ｎｍであることが望ましい。バリア層が薄すぎると充分な強度強化の効果が得られず、厚すぎても特に利点は生ぜず、コスト増大を招くのみである。更に望ましくは、５０～１０００ｎｍであり、最も望ましいのは１００～５００ｎｍである。 The metal reflective layer 117 may also serve as the barrier layer. When a thick metal material having good reflectivity and mechanically strong is formed, it is not necessary to form a barrier layer. For example, when Al or Pt is used as the metal reflection layer 117, the barrier layer is not always necessary. The maximum thickness of the barrier layer is preferably 20 to 3000 nm. If the barrier layer is too thin, a sufficient strength strengthening effect cannot be obtained, and if it is too thick, no particular advantage is produced and only an increase in cost is caused. More desirably, the thickness is 50 to 1000 nm, and most desirably 100 to 500 nm.
　前記実施形態１に関連する実施形態２乃至６については、別途後述して説明する。
（実施形態７）
　図１４～図１７は、本発明の実施形態である半導体発光素子の一例を示す図であって、図１４は本発明の実施形態である半導体発光素子の断面模式図であり、図１５は平面模式図であり、図１６は半導体発光素子を構成する積層半導体層の断面模式図であり、図１７は図１４に示す半導体発光素子を構成するｐ型電極の拡大断面模式図である。
　本実施形態の半導体発光素子１は、図１４に示すように、基板１０１と、基板１０１上に形成された積層半導体層２０と、積層半導体層２０の上面１０６ｃに形成されたｐ型電極１１１（一方の電極）と、積層半導体層２０の一部が切り欠けられてなる半導体層露出面１０４ｃ上に形成されたｎ型電極１０８（他方の電極）とを備えている。 Embodiments 2 to 6 related to the first embodiment will be described later separately.
(Embodiment 7)
14 to 17 are diagrams showing an example of the semiconductor light emitting device according to the embodiment of the present invention. FIG. 14 is a schematic cross-sectional view of the semiconductor light emitting device according to the embodiment of the present invention. FIG. FIG. 16 is a schematic cross-sectional view of a laminated semiconductor layer constituting the semiconductor light-emitting element, and FIG. 17 is an enlarged schematic cross-sectional view of a p-type electrode constituting the semiconductor light-emitting element shown in FIG.
As shown in FIG. 14, the semiconductor light emitting device 1 according to the present embodiment includes a substrate 101, a laminated semiconductor layer 20 formed on the substrate 101, and a p-type electrode 111 ( One electrode) and an n-type electrode 108 (the other electrode) formed on the semiconductor layer exposed surface 104c formed by cutting out a part of the laminated semiconductor layer 20.
　図１４に示すように、積層半導体層２０は、基板１０１側から、ｎ型半導体層１０４、発光層１０５、ｐ型半導体層１０６がこの順に積層されたものである。そして、本実施形態の半導体発光素子１では、ｐ型電極１１１とｎ型電極１０８との間に電圧を印加して電流を通じることで、発光層１０５から発光が得られる構成とされている。また、本実施形態の半導体発光素子１では、ｐ型電極１１１の形成された側から光を取り出すフェイスアップマウント型の発光素子である。
　実施形態７の半導体発光素子においては、実施形態１の半導体発光素子に比べて、基本的には電極が積層半導体層２０の上面における設置される構成が異なる特徴を有する。
　すなわち、実施形態７では、一方の電極または前記他方の電極の少なくともいずれか一方が、上面に接合凹部を有する透光性電極と、前記接合凹部を覆うように形成された接合層と、前記接合層を覆うように形成され、外側に向けて膜厚が漸次薄くなる傾斜面が外周部に形成されているボンディングパッド電極とを備えていることを特徴とする半導体発光素子の構造を提供する。
　従って、実施形態７の半導体発光素子においては、半導体発光素子を構成する基板や発光層を有する積層半導体層の構成は、基本的には実施形態１と同等な範囲で構成することができる。
　以下、前述の実施形態１の半導体発光素子の構成と異なる特徴を記述する為に詳細に説明する。 As shown in FIG. 14, the laminated semiconductor layer 20 is obtained by laminating an n-type semiconductor layer 104, a light emitting layer 105, and a p-type semiconductor layer 106 in this order from the substrate 101 side. In the semiconductor light emitting device 1 of the present embodiment, light emission is obtained from the light emitting layer 105 by applying a voltage between the p-type electrode 111 and the n-type electrode 108 and passing the current. Further, the semiconductor light emitting device 1 of the present embodiment is a face-up mount type light emitting device that extracts light from the side where the p-type electrode 111 is formed.
The semiconductor light emitting device of the seventh embodiment basically has a feature that the configuration in which the electrodes are installed on the upper surface of the laminated semiconductor layer 20 is different from that of the semiconductor light emitting device of the first embodiment.
That is, in Embodiment 7, at least one of one electrode or the other electrode has a translucent electrode having a bonding recess on an upper surface, a bonding layer formed so as to cover the bonding recess, and the bonding There is provided a structure of a semiconductor light emitting device, comprising a bonding pad electrode formed so as to cover a layer and having an inclined surface formed on an outer peripheral portion with a gradually decreasing thickness toward the outside.
Therefore, in the semiconductor light emitting device of the seventh embodiment, the configuration of the substrate constituting the semiconductor light emitting device and the laminated semiconductor layer having the light emitting layer can be basically configured in the same range as in the first embodiment.
Hereinafter, a detailed description will be given to describe different features from the configuration of the semiconductor light emitting device of the first embodiment.
＜ｐ型電極＞
　ｐ型電極１１１は、図１７に示すように、透光性電極１０９と、接合層１１０と、ボンディングパッド電極１２０とを備えている。図１７に示すように、透光性電極１０９の上面１０９ｃには接合凹部１０９ａが設けられている。また、図１４に示すように、透光性電極１０９の上面１０９ｃにおける接合凹部１０９ａの形成されていない領域には、透光性電極１０９を覆うように透明保護膜１０ａが形成されている。言い換えると、接合凹部１０９ａの形成されている領域は、透明保護膜１０ａの一部が開口されてなる開口部１０ｄとされている。開口部１０ｄから露出された接合凹部１０９ａ上には、接合凹部１０９ａを覆うように接合層１１０が形成されており、接合層１１０上には接合層１１０を覆うように、ボンディングパッド電極１２０が形成されている。そして、図１７に示すように、接合層１１０の外縁部およびボンディングパッド電極１２０（金属反射層１１７およびボンディング層１１９）の外縁部が、透明保護膜１０ａ上に配置されている。また、ボンディングパッド電極１２０は、外側に向けて膜厚が漸次薄くなる傾斜面１１９ｃを外周部１２０ｄに備えている。そして、本実施形態の半導体発光素子１においては、図１７に示すように、ボンディングパッド電極１２０の外縁部が、縁部保護膜１０ｂに覆われている。 <P-type electrode>
As shown in FIG. 17, the p-type electrode 111 includes a translucent electrode 109, a bonding layer 110, and a bonding pad electrode 120. As shown in FIG. 17, a bonding recess 109 a is provided on the upper surface 109 c of the translucent electrode 109. As shown in FIG. 14, a transparent protective film 10 a is formed so as to cover the translucent electrode 109 in a region where the bonding recess 109 a is not formed on the upper surface 109 c of the translucent electrode 109. In other words, the region where the bonding recess 109a is formed is an opening 10d in which a part of the transparent protective film 10a is opened. A bonding layer 110 is formed on the bonding recess 109a exposed from the opening 10d so as to cover the bonding recess 109a, and a bonding pad electrode 120 is formed on the bonding layer 110 so as to cover the bonding layer 110. Has been. And as shown in FIG. 17, the outer edge part of the joining layer 110 and the outer edge part of the bonding pad electrode 120 (the metal reflection layer 117 and the bonding layer 119) are arrange | positioned on the transparent protective film 10a. In addition, the bonding pad electrode 120 includes an inclined surface 119c on the outer peripheral portion 120d whose thickness gradually decreases toward the outside. In the semiconductor light emitting device 1 of this embodiment, as shown in FIG. 17, the outer edge portion of the bonding pad electrode 120 is covered with the edge protection film 10b.
「透光性電極」
　透光性電極１０９は、図１４に示すように、ｐ型半導体層１０６の上面１０６ｃに設けられており、図１７に示すように、上面１０９ｃに接合凹部１０９ａを有している。透光性電極１０９の接合凹部１０９ａの深さは、特に限定されないが、透光性電極１０９の厚みの１/１０程度の寸法であることが好ましい。また、接合凹部１０９ａの平面形状は、円形状、多角形状など任意の形状とすることができ、特に限定されないが、ボンディング作業のしやすいものとするために、図１５に示すように、円形状であることが好ましい。 "Translucent electrode"
As shown in FIG. 14, the translucent electrode 109 is provided on the upper surface 106c of the p-type semiconductor layer 106. As shown in FIG. 17, the upper surface 109c has a bonding recess 109a. The depth of the bonding recess 109 a of the translucent electrode 109 is not particularly limited, but is preferably about 1/10 of the thickness of the translucent electrode 109. Further, the planar shape of the bonding recess 109a may be any shape such as a circular shape or a polygonal shape, and is not particularly limited. It is preferable that
　また、透光性電極１０９は、図１５に示すように、平面視したときに、ｐ型半導体層１０６の上面１０６ｃのほぼ全面を覆うように形成されているが、このような形状に限定されるわけでなく、隙間を開けて格子状や樹形状に形成してもよい。
　また、透光性電極１０９の接合凹部１０９ａは、透光性電極１０９上のどこに形成してもよい。例えば、ｎ型電極１０８から最も遠い位置に形成してもよいし、半導体発光素子１の中心に形成してもよい。しかし、あまりにもｎ型電極１０８に近接した位置に形成すると、接合凹部１０９ａ上に形成されるボンディングパッド電極１２０にワイヤをボンディングした際に、ワイヤ間、ボール間のショートを生じてしまうため好ましくない。
　透光性電極１０９の材質面の特徴については、実施形態１の半導体発光素子の説明と同等な範囲を適用することができるので、詳細な説明を省略する。 Further, as shown in FIG. 15, the translucent electrode 109 is formed so as to cover almost the entire upper surface 106c of the p-type semiconductor layer 106 in plan view, but is limited to such a shape. Instead, it may be formed in a lattice shape or a tree shape with a gap.
Further, the bonding recess 109 a of the translucent electrode 109 may be formed anywhere on the translucent electrode 109. For example, it may be formed at a position farthest from the n-type electrode 108 or may be formed at the center of the semiconductor light emitting device 1. However, if it is formed too close to the n-type electrode 108, a short circuit between the wires and between the balls occurs when the wire is bonded to the bonding pad electrode 120 formed on the bonding recess 109a. .
Since the range equivalent to the description of the semiconductor light emitting element of Embodiment 1 can be applied to the characteristics of the material of the translucent electrode 109, detailed description thereof is omitted.
「接合層」
　接合層１１０は、透光性電極１０９に対するボンディングパッド電極１２０の接合強度を高めるために、透光性電極１０９とボンディングパッド電極１２０との間に積層される。図１７に示すように、接合層１１０は、接合凹部１０９ａ内および透明保護膜１０ａの端部１０ｃを覆うように連続して形成されている。そして、本実施形態においては、透光性電極１０９の接合凹部１０９ａ内および透明保護膜１０ａの開口部１０ｄ内に、接合層１１０が埋め込まれるように形成されていることにより、透光性電極１０９と接合層１１０との高い接合力が得られるようになっている。 "Joint layer"
The bonding layer 110 is laminated between the translucent electrode 109 and the bonding pad electrode 120 in order to increase the bonding strength of the bonding pad electrode 120 to the translucent electrode 109. As shown in FIG. 17, the bonding layer 110 is continuously formed so as to cover the bonding recess 109a and the end portion 10c of the transparent protective film 10a. In the present embodiment, since the bonding layer 110 is embedded in the bonding recess 109a of the translucent electrode 109 and the opening 10d of the transparent protective film 10a, the translucent electrode 109 is formed. And a high bonding force between the bonding layer 110 can be obtained.
　また、接合層１１０の厚みは、透光性電極１０９の接合凹部１０９ａの内壁面上および透明保護膜１０ａの開口部１０ｄの内壁面上では略均一とされている。そして、開口部１０ｄの外側では、接合層１１０の厚みが外側に向けて膜厚が漸次薄くなっており、接合層１１０の外周部１１０ｄには、傾斜面１１０ｃが形成されている。 The thickness of the bonding layer 110 is substantially uniform on the inner wall surface of the bonding recess 109a of the translucent electrode 109 and on the inner wall surface of the opening 10d of the transparent protective film 10a. Then, outside the opening 10d, the thickness of the bonding layer 110 gradually decreases toward the outside, and an inclined surface 110c is formed on the outer peripheral portion 110d of the bonding layer 110.
　接合層１１０は、透光性を有していることが好ましい。接合層１１０が透光性を有しているものである場合、ボンディングパッド電極１２０に照射される発光層１０５からの光を損失なく透過させることができる。より詳細には、接合層１１０が透光性を有している場合、発光層１０５からの発光の一部は、透光性電極１０９及び接合層１１０を透過して、接合層１１０とボンディングパッド電極１２０との界面においてボンディングパッド電極１２０（本実施形態においては金属反射層１１７）によって反射されるものとなる。ボンディングパッド電極１２０によって反射された光は、再度、積層半導体層２０の内部に導入されて、透過と反射を繰り返した後に、ボンディングパッド電極１２０の形成領域以外の箇所から半導体発光素子１の外部に取り出される。したがって、接合層１１０が透光性を有しているものである場合、発光層１０５からの光を効率よく半導体発光素子１の外部に取り出すことができる。 The bonding layer 110 preferably has translucency. In the case where the bonding layer 110 has a light-transmitting property, light from the light-emitting layer 105 irradiated to the bonding pad electrode 120 can be transmitted without loss. More specifically, in the case where the bonding layer 110 has a light-transmitting property, part of light emitted from the light-emitting layer 105 is transmitted through the light-transmitting electrode 109 and the bonding layer 110 to be bonded to the bonding layer 110 and the bonding pad. The light is reflected by the bonding pad electrode 120 (in this embodiment, the metal reflection layer 117) at the interface with the electrode 120. The light reflected by the bonding pad electrode 120 is again introduced into the laminated semiconductor layer 20, and after repeated transmission and reflection, the light is reflected to the outside of the semiconductor light emitting device 1 from a location other than the formation region of the bonding pad electrode 120. It is taken out. Therefore, when the bonding layer 110 has a light transmitting property, light from the light emitting layer 105 can be efficiently extracted outside the semiconductor light emitting element 1.
　接合層１１０は、Ａｌ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｃｏ、Ｚｎ、Ｇｅ、Ｚｒ、Ｎｂ、Ｍｏ、Ｒｕ、Ｈｆ、Ｔａ、Ｗ、Ｒｅ、Ｒｈ、Ｉｒ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなるものが好ましい。接合層１１０を上記の材料からなるものとすることにより、透光性電極１０９に対するボンディングパッド電極１２０の接合強度を向上させることができると同時に透光性を発揮させることができる。また、接合層１１０は、Ｃｒ、Ｔｉ、Ｗ、Ｍｏ、Ｚｒ、Ｈｆ、Ｃｏ、Ｒｈ、Ｉｒ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなるものであることがより好ましく、Ｃｒ、Ｔｉ、Ｗ、Ｍｏ、Ｒｈ、Ｃｏ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなるものであることがさらに好ましい。特に、接合層１１０の材料として、Ｃｒ、Ｔｉ、Ｍｏ、Ｎｉ、Ｃｏ等の金属を用いることにより、透光性電極１０９に対するボンディングパッド電極１２０の接合強度を格段に高めることができる。 The bonding layer 110 is at least selected from the group consisting of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh, Ir, and Ni. What consists of a kind of element is preferable. When the bonding layer 110 is made of the above-described material, the bonding strength of the bonding pad electrode 120 to the translucent electrode 109 can be improved and the translucency can be exhibited. The bonding layer 110 is more preferably composed of at least one element selected from the group consisting of Cr, Ti, W, Mo, Zr, Hf, Co, Rh, Ir, and Ni. More preferably, it is made of at least one element selected from the group consisting of W, Mo, Rh, Co, and Ni. In particular, by using a metal such as Cr, Ti, Mo, Ni, or Co as the material of the bonding layer 110, the bonding strength of the bonding pad electrode 120 to the translucent electrode 109 can be significantly increased.
　また、接合層１１０の材料としては、例えば、透光性電極１０９がＩＺＯやＩＴＯ等の金属酸化物等からなり、ボンディングパッド電極１２０がＡｇ、Ａｌ等からなる場合には、金属酸化物に対してもＡｇ、Ａｌに対しても優れた接合性が得られるＣｒを用いることが特に好ましい。 As the material of the bonding layer 110, for example, when the translucent electrode 109 is made of a metal oxide such as IZO or ITO and the bonding pad electrode 120 is made of Ag, Al, or the like, However, it is particularly preferable to use Cr that can provide excellent bondability to Ag and Al.
　また、接合層１１０は、最大厚みが１０Å以上４００Å以下の範囲の薄膜であることが好ましい。接合層１１０の最大厚みを上記範囲とすることにより、発光層１０５からの光を遮ることなく効果的に透過させることができる優れた透光性を有するものとすることができる。なお、上記の最大厚みが１０Å未満になると、接合層１１０の強度が低下し、これにより透光性電極１０９に対するボンディングパッド電極１２０の接合強度が低下するので好ましくない。 Further, the bonding layer 110 is preferably a thin film having a maximum thickness in the range of 10 to 400 mm. By setting the maximum thickness of the bonding layer 110 within the above range, the light can be transmitted effectively without blocking light from the light emitting layer 105. Note that when the maximum thickness is less than 10 mm, the strength of the bonding layer 110 is decreased, and thus the bonding strength of the bonding pad electrode 120 to the translucent electrode 109 is not preferable.
「ボンディングパッド電極」
　ボンディングパッド電極１２０は、金属反射層１１７とボンディング層１１９とが、透光性電極１０９側から順に積層された積層体からなる。なお、ボンディングパッド電極１２０は、ボンディング層１１９のみからなる単層構造や金属反射層１１７のみからなる単層構造であってもよいし、金属反射層１１７とボンディング層１１９との間にバリア層を挿入して、三層構造としたものであってもよい。なお、接合層１１０、金属反射層１１７、ボンディング層１１９、バリヤ層を構成する金属元素においては、同一の金属元素を含んでいてもよいし、それぞれ異なる金属元素の組み合わせであってもよい。 "Bonding pad electrode"
The bonding pad electrode 120 is formed of a laminated body in which a metal reflective layer 117 and a bonding layer 119 are laminated in order from the translucent electrode 109 side. Note that the bonding pad electrode 120 may have a single layer structure including only the bonding layer 119 or a single layer structure including only the metal reflection layer 117, and a barrier layer may be provided between the metal reflection layer 117 and the bonding layer 119. It may be inserted into a three-layer structure. Note that the metal elements constituting the bonding layer 110, the metal reflection layer 117, the bonding layer 119, and the barrier layer may contain the same metal element, or may be a combination of different metal elements.
　本実施形態において、ボンディングパッド電極１２０の反射率は、金属反射層１１７を構成する材料によって大きく変わるが、反射率６０％以上であることが望ましく、反射率８０％以上であることがより望ましく、反射率９０％以上であればなお良い。反射率は、分光光度計等で比較的容易に測定することが可能である。しかし、ボンディングパッド電極１２０そのものは面積が小さいために反射率を測定することは難しい。そこで、例えばボンディングパッド電極を形成するチャンバ内に、透明なガラス製の面積の大きい「ダミー基板」を入れ、ボンディングパッド電極を形成すると同時に、ダミー基板上に同じボンディングパッド電極を作成し、ダミー基板上に形成されたボンディングパッド電極の反射率を測定するなどの方法を用いて測定することができる。 In the present embodiment, the reflectance of the bonding pad electrode 120 varies greatly depending on the material constituting the metal reflective layer 117, but the reflectance is preferably 60% or more, more preferably 80% or more, It is even better if the reflectance is 90% or more. The reflectance can be measured relatively easily with a spectrophotometer or the like. However, since the bonding pad electrode 120 itself has a small area, it is difficult to measure the reflectance. Therefore, for example, a “dummy substrate” made of a transparent glass and having a large area is placed in a chamber for forming the bonding pad electrode, and at the same time, the same bonding pad electrode is formed on the dummy substrate. It can be measured using a method such as measuring the reflectance of the bonding pad electrode formed thereon.
　ボンディングパッド電極１２０の面積は、大きいほどボンディング作業を容易に行うことができるため好ましいが、ボンディングパッド電極１２０の面積が大きいほど光の取り出しが妨げられる。具体的に例えば、ボンディングパッド電極１２０の面積が透光性電極１０９上の面積の半分を超える場合、ボンディングパッド電極１２０が光の取り出しの妨げとなるため、出力が著しく低下する。逆に、ボンディングパッド電極１２０の面積が小さすぎると、ボンディング作業がしにくくなり、製品の歩留まりが低下する。したがって、ボンディングパッド電極１２０の面積は、ボンディングボールの直径よりもわずかに大きい程度の大きさであることが好ましく、具体的には、上面の直径が１００μｍ程度であって、透明保護膜１０ａ側に近づくほど直径の大きくなる略円柱状の形状であることが好ましい。 It is preferable that the bonding pad electrode 120 has a larger area because the bonding operation can be easily performed. However, the larger the bonding pad electrode 120 is, the more light extraction is hindered. Specifically, for example, when the area of the bonding pad electrode 120 exceeds half of the area on the translucent electrode 109, the bonding pad electrode 120 hinders light extraction, and thus the output is significantly reduced. On the contrary, if the area of the bonding pad electrode 120 is too small, the bonding operation becomes difficult and the yield of the product decreases. Therefore, the area of the bonding pad electrode 120 is preferably a size that is slightly larger than the diameter of the bonding ball. Specifically, the upper surface has a diameter of about 100 μm, and the transparent protective film 10a side. It is preferably a substantially cylindrical shape having a diameter that increases as it approaches.
＜金属反射層＞
　金属反射層１１７は接合層１１０を覆うように形成されている。また、金属反射層１１７の外周部には、外側に向けて膜厚が漸次薄くなるような傾斜面１１７ｃが形成されている。したがって、金属反射層１１７は、接合層１１０の傾斜面１１０ｃの透明保護膜１０ａ側の最先端部、すなわち接合層１１０を平面視したときの輪郭線を形づくる境界部上を完全に覆うように形成されている。つまり、金属反射層１１７は、平面視したときに接合層１１０を覆って、更に接合層１１０の外側にまで張り出すように形成されており、接合層１１０のいかなる部分も金属反射層１１７の下から露出しないようにされている。 <Metal reflective layer>
The metal reflective layer 117 is formed so as to cover the bonding layer 110. Further, an inclined surface 117c is formed on the outer peripheral portion of the metal reflective layer 117 so that the film thickness gradually decreases toward the outside. Therefore, the metal reflective layer 117 is formed so as to completely cover the most distal portion of the inclined surface 110c of the bonding layer 110 on the transparent protective film 10a side, that is, the boundary portion that forms the contour line when the bonding layer 110 is viewed in plan view. Has been. In other words, the metal reflection layer 117 is formed so as to cover the bonding layer 110 when viewed in plan and further protrude to the outside of the bonding layer 110, and any part of the bonding layer 110 is below the metal reflection layer 117. Is not exposed from.
　図１４に示す金属反射層１１７は、反射率の高い金属からなるものであり、Ｒｕ、Ｒｈ、Ｐｄ、Ｏｓ、Ｉｒ、Ｐｔ等の白金族金属、Ａｌ、Ａｇ、Ｔｉおよびこれらの金属の少なくも一種を含む合金で構成されることが好ましい。金属反射層１１７を上記の材料からなるものとすることにより、発光層１０５からの光を効果的に反射させることができる。上記の材料の中でも、Ａｌ、Ａｇ、Ｐｔおよびこれらの金属の少なくも一種を含む合金は、入手のし易さ、取り扱いの容易さなどの点で優れている。また、Ｒｈ、Ｐｄ、Ｉｒ、Ｐｔおよびこれらの金属の少なくも一種を含む合金は、光の反射性の点から金属反射層１１７として好適に使用される。 The metal reflective layer 117 shown in FIG. 14 is made of a highly reflective metal, such as a platinum group metal such as Ru, Rh, Pd, Os, Ir, and Pt, Al, Ag, Ti, and at least one of these metals. It is preferable to be comprised with the alloy containing 1 type. By using the metal reflective layer 117 made of the above material, the light from the light emitting layer 105 can be effectively reflected. Among the materials described above, Al, Ag, Pt, and alloys containing at least one of these metals are excellent in terms of easy availability and handling. Further, Rh, Pd, Ir, Pt and an alloy containing at least one of these metals are preferably used as the metal reflective layer 117 from the viewpoint of light reflectivity.
　また、金属反射層１１７は、接合層１１０よりも最大膜厚が厚くなるように形成されることが好ましい。金属反射層１１７を接合層１１０よりも最大膜厚の厚いものとすることで、金属反射層１１７によって、より確実にかつ完全に接合層１１０が覆われたものとなる。
　また、金属反射層１１７は、最大厚さが２０～３０００ｎｍであることが望ましい。金属反射層１１７の厚みが上記範囲よりも薄いと、充分に反射の効果が得らない場合がある。また、金属反射層１１７の厚みが上記範囲よりも厚い場合、特に利点は生じず、工程時間の長時間化と材料の無駄を生じるのみである。金属反射層１１７の厚みは、更に望ましくは、５０～１０００ｎｍであり、最も望ましいのは１００～５００ｎｍである。 The metal reflective layer 117 is preferably formed so that the maximum film thickness is larger than that of the bonding layer 110. By making the metal reflective layer 117 thicker than the bonding layer 110, the metal reflecting layer 117 covers the bonding layer 110 more reliably and completely.
Further, it is desirable that the metal reflective layer 117 has a maximum thickness of 20 to 3000 nm. If the thickness of the metal reflective layer 117 is thinner than the above range, the reflection effect may not be obtained sufficiently. In addition, when the thickness of the metal reflection layer 117 is thicker than the above range, there is no particular advantage, and only a long process time and material waste are caused. The thickness of the metal reflective layer 117 is more desirably 50 to 1000 nm, and most desirably 100 to 500 nm.
　＜ボンディング層＞
　ボンディング層１１９は、金属反射層１１７を覆うように形成されている。また、ボンディング層１１９の外周部（すなわちボンディングパッド電極１２０の外周部１２０ｄ）には、外側に向けて膜厚が漸次薄くなるような傾斜面１１９ｃが形成されている。したがって、ボンディング層１１９は、金属反射層１１７の傾斜面１１７ｃの透明保護膜１０ａ側の最先端部、すなわち金属反射層１１７を平面視したときの輪郭線を形づくる境界部上を完全に覆うように形成されている。つまり、ボンディング層１１９は、平面視したときに金属反射層１１７を覆って、更に金属反射層１１７の外側にまで張り出すように形成されており、金属反射層１１７のいかなる部分もボンディング層１１９の下から露出しないようにされている。 <Bonding layer>
The bonding layer 119 is formed so as to cover the metal reflective layer 117. In addition, an inclined surface 119c is formed on the outer peripheral portion of the bonding layer 119 (that is, the outer peripheral portion 120d of the bonding pad electrode 120) so that the film thickness gradually decreases toward the outside. Accordingly, the bonding layer 119 completely covers the most distal portion of the inclined surface 117c of the metal reflective layer 117 on the transparent protective film 10a side, that is, the boundary forming the contour line when the metal reflective layer 117 is viewed in plan view. Is formed. In other words, the bonding layer 119 is formed so as to cover the metal reflective layer 117 when seen in a plan view and further to the outside of the metal reflective layer 117, and any portion of the metal reflective layer 117 is formed on the bonding layer 119. It is not exposed from the bottom.
　図１４に示すボンディング層１１９は、Ａｕ、Ａｌまたはこれらの金属の少なくも一種を含む合金からなることが好ましい。ＡｕおよびＡｌはボンディングボールとして使用されることが多い金ボールとの密着性の良い金属であるので、ボンディング層１１９として、Ａｕ、Ａｌまたはこれらの金属の少なくも一種を含む合金を用いることにより、ボンディングワイヤとの密着性に優れたボンディング層１１９とすることができる。中でも、特に望ましいのはＡｕである。 The bonding layer 119 shown in FIG. 14 is preferably made of Au, Al, or an alloy containing at least one of these metals. Since Au and Al are metals with good adhesion to gold balls that are often used as bonding balls, by using Au, Al or an alloy containing at least one of these metals as the bonding layer 119, It can be set as the bonding layer 119 excellent in adhesiveness with a bonding wire. Of these, Au is particularly desirable.
　また、ボンディング層１１９の最大厚みは、接合層１１０および金属反射層１１７に比較して、厚くなるように形成することが好ましい。ボンディング層１１９を接合層１１０および金属反射層１１７に比較して最大膜厚の厚いものとすることで、ボンディング層１１９によって、より確実にかつ完全に金属反射層１１７が覆われたものとなる。
　また、ボンディング層１１９の最大厚みは、５０ｎｍ以上２０００ｎｍ以下の範囲のであることが好ましく、更に望ましくは１００ｎｍ以上１５００ｎｍ以下である。ボンディング層１１９の最大厚みが薄すぎるとボンディングボールとの密着性が不十分となる場合がある。また、ボンディング層１１９の最大厚みを上記範囲よりも厚くしても特に利点は生ぜず、コスト増大を招くのみである。 In addition, the maximum thickness of the bonding layer 119 is preferably formed to be thicker than that of the bonding layer 110 and the metal reflective layer 117. By making the bonding layer 119 thicker than the bonding layer 110 and the metal reflection layer 117, the metal reflection layer 117 is more reliably and completely covered by the bonding layer 119.
The maximum thickness of the bonding layer 119 is preferably in the range of 50 nm to 2000 nm, and more preferably 100 nm to 1500 nm. If the maximum thickness of the bonding layer 119 is too thin, adhesion to the bonding ball may be insufficient. Further, even if the maximum thickness of the bonding layer 119 is made larger than the above range, there is no particular advantage and only the cost is increased.
＜バリア層＞
　バリア層は、金属反射層１１７とボンディング層１１９との間に配置され、ボンディングパッド電極１２０全体の強度を強化するものである。バリア層は、比較的強固な金属材料からなるものとされるか、または、充分に厚い膜厚を有するものとされる。バリア層の材料としては、Ｔｉ、ＣｒまたはＡｌなどを用いることできるが、強度に優れたＴｉを用いることが望ましい。また、バリア層の最大厚さは２０～３０００ｎｍであることが望ましい。バリア層の厚みが薄すぎると充分な強度強化の効果が得られない場合がある。また、バリア層の厚みが厚すぎても特に利点は生ぜず、コスト増大を招くのみである。バリア層の厚みは、更に望ましくは、５０～１０００ｎｍであり、最も望ましいのは１００～５００ｎｍである。 <Barrier layer>
The barrier layer is disposed between the metal reflective layer 117 and the bonding layer 119 and enhances the strength of the entire bonding pad electrode 120. The barrier layer is made of a relatively strong metal material, or has a sufficiently thick film thickness. As the material for the barrier layer, Ti, Cr, Al, or the like can be used, but it is desirable to use Ti having excellent strength. The maximum thickness of the barrier layer is preferably 20 to 3000 nm. If the thickness of the barrier layer is too thin, sufficient strength strengthening effects may not be obtained. In addition, if the thickness of the barrier layer is too thick, there is no particular advantage and only an increase in cost is caused. The thickness of the barrier layer is more preferably 50 to 1000 nm, and most preferably 100 to 500 nm.
　なお、金属反射層１１７が、機械的に強固なものである場合には、敢えてバリア層を形成する必要はない。例えば、金属反射層１１７がＡｌまたはＰｔからなるものである場合には、バリア層は必ずしも必要ではない。 In addition, when the metal reflective layer 117 is mechanically strong, it is not necessary to form a barrier layer. For example, when the metal reflective layer 117 is made of Al or Pt, the barrier layer is not always necessary.
「透明保護膜」
　透明保護膜１０ａは、透光性電極１０９および接合層１１０を保護するものである。透明保護膜１０ａは、図１４および図１５に示すように、透光性電極１０９の上面１０９ｃにおける接合凹部１０９ａの形成されていない領域を覆うように形成されており、接合凹部１０９ａの形成されている領域が開口部１０ｄとされている。本実施形態においては、図１７に示すように、接合層１１０が開口部１０ｄの内壁面に接して形成されているとともに、接合層１１０の外縁部が透明保護膜１０ａ上に接して配置されており、透明保護膜１０ａによって、接合層１１０の透明保護膜１０ａに接している部分おける空気または水分の接触が防止されている。また、本実施形態においては、図１７に示すように、ボンディングパッド電極１２０を構成する金属反射層１１７およびボンディング層１１９の外縁部が、透明保護膜１０ａ上に接して配置されており、透明保護膜１０ａとボンディングパッド電極１２０とによって、透光性電極１０９に接していない接合層１１０の外面全面を取り囲んでおり、接合層１１０と空気または水分との接触が効果的に防止されている。 "Transparent protective film"
The transparent protective film 10a protects the translucent electrode 109 and the bonding layer 110. As shown in FIGS. 14 and 15, the transparent protective film 10 a is formed so as to cover a region where the bonding recess 109 a is not formed on the upper surface 109 c of the translucent electrode 109, and the bonding recess 109 a is formed. The area that is present is the opening 10d. In the present embodiment, as shown in FIG. 17, the bonding layer 110 is formed in contact with the inner wall surface of the opening 10d, and the outer edge portion of the bonding layer 110 is disposed on the transparent protective film 10a. In addition, the transparent protective film 10a prevents contact of air or moisture in the portion of the bonding layer 110 that is in contact with the transparent protective film 10a. Further, in the present embodiment, as shown in FIG. 17, the outer edges of the metal reflection layer 117 and the bonding layer 119 constituting the bonding pad electrode 120 are disposed in contact with the transparent protective film 10a. The film 10a and the bonding pad electrode 120 surround the entire outer surface of the bonding layer 110 that is not in contact with the translucent electrode 109, and the contact between the bonding layer 110 and air or moisture is effectively prevented.
　透明保護膜１０ａは、透明で、透光性電極１０９、接合層１１０、ボンディングパッド電極１２０の各層との密着性に優れた材料からなるものとされることが好ましく、具体的にはＳｉＯ２からなるものとされることが好ましい。
　透明保護膜１０ａの厚みは、２０～５００ｎｍとすることが好ましく、５０～３００ｎｍとすることがより好ましい。透明保護膜１０ａの厚みが上記範囲未満であると、透光性電極１０９および接合層１１０を保護する効果が十分に得られない恐れがある。また、透明保護膜１０ａの厚みが上記範囲を超えると、透明性が低下して、光の取り出し性に支障を来たす場合がある。また、透明保護膜１０ａの厚みが上記範囲を超えると、開口部１０ｄの深さと接合凹部１０９ａの深さとを合わせた深さが深くなり、開口部１０ｄの内壁面と接合層１１０との密着性に支障を来たす恐れが生じる。 The transparent protective film 10a is preferably made of a material that is transparent and has excellent adhesion to each of the translucent electrode 109, the bonding layer 110, and the bonding pad electrode 120. Specifically, the transparent protective film 10a is made of SiO 2. It is preferable that
The thickness of the transparent protective film 10a is preferably 20 to 500 nm, and more preferably 50 to 300 nm. If the thickness of the transparent protective film 10a is less than the above range, the effect of protecting the translucent electrode 109 and the bonding layer 110 may not be sufficiently obtained. On the other hand, when the thickness of the transparent protective film 10a exceeds the above range, the transparency may be deteriorated and the light extraction property may be hindered. When the thickness of the transparent protective film 10a exceeds the above range, the depth obtained by combining the depth of the opening 10d and the depth of the bonding recess 109a becomes deep, and the adhesion between the inner wall surface of the opening 10d and the bonding layer 110 is increased. May cause trouble.
「縁部保護膜」
　縁部保護膜１０ｂは、接合層１１０と空気または水分との接触を防止するとともに、半導体発光素子１からのボンディングパッド電極１２０の剥離を防止してボンディングパッド電極１２０の接合力を向上させるものである。縁部保護膜１０ｂは、図１５に示すように、平面視したときにボンディングパッド電極１２０の中央部を露出させる略ドーナッツ状の形状とされている。また、縁部保護膜１０ｂは、図１５および図１７に示すように、平面視したときに、ボンディングパッド電極１２０の外縁部（輪郭線）と透明保護膜１０ａとの継ぎ目となる部分に跨って配置されており、ボンディングパッド電極１２０の外縁部を覆っている。したがって、本実施形態においては、図１７に示すように、ボンディングパッド電極１２０の外縁部は、透明保護膜１０ａと縁部保護膜１０ｂとの間に挟みこまれている。 "Edge protection film"
The edge protective film 10b prevents contact between the bonding layer 110 and air or moisture, and prevents the bonding pad electrode 120 from peeling from the semiconductor light emitting element 1, thereby improving the bonding force of the bonding pad electrode 120. is there. As shown in FIG. 15, the edge protective film 10 b has a substantially donut shape that exposes the central portion of the bonding pad electrode 120 when viewed in plan. Further, as shown in FIGS. 15 and 17, the edge protective film 10b extends over a portion that becomes a joint between the outer edge (contour line) of the bonding pad electrode 120 and the transparent protective film 10a when viewed in plan. It is arranged and covers the outer edge portion of the bonding pad electrode 120. Therefore, in the present embodiment, as shown in FIG. 17, the outer edge portion of the bonding pad electrode 120 is sandwiched between the transparent protective film 10a and the edge protective film 10b.
　縁部保護膜１０ｂは、ボンディングパッド電極１２０と透明保護膜１０ａとの境界部分を中心として面積を広くするほど、縁部保護膜１０ｂを設けることによる効果が大きくなる。しかし、縁部保護膜１０ｂの面積を大きくすると、縁部保護膜１０ｂから露出されるボンディングパッド電極１２０の面積が小さくなって、ボンディング作業の作業性に支障をきたす恐れや、縁部保護膜１０ｂがボンディングパッド電極１２０の形成されていない領域の透明度を低下させて、光の取り出し性に支障を来たす恐れがある。したがって、縁部保護膜１０ｂは、ボンディングパッド電極１２０と透明保護膜１０ａとの境界部分を完全に覆い、かつ、ボンディングパッド電極１２０の頂部を完全に露出するものであることが好ましい。具体的には、縁部保護膜１０ｂは、ボンディングパッド電極１２０と縁部保護膜１０ｂとの境界部分を中心として５～１０μｍの幅を有するものであることが好ましい。 The effect of providing the edge protective film 10b increases as the area of the edge protective film 10b increases with the boundary between the bonding pad electrode 120 and the transparent protective film 10a as the center. However, when the area of the edge protection film 10b is increased, the area of the bonding pad electrode 120 exposed from the edge protection film 10b is reduced, which may hinder the workability of the bonding work, or the edge protection film 10b. However, the transparency of the region where the bonding pad electrode 120 is not formed may be lowered, and the light extraction property may be hindered. Therefore, it is preferable that the edge protection film 10b completely covers the boundary between the bonding pad electrode 120 and the transparent protection film 10a and completely exposes the top of the bonding pad electrode 120. Specifically, the edge protection film 10b preferably has a width of 5 to 10 μm with the boundary portion between the bonding pad electrode 120 and the edge protection film 10b as the center.
　縁部保護膜１０ｂは、透明で、透明保護膜１０ａおよびボンディングパッド電極１２０との密着性に優れた材料からなるものとされることが好ましく、透明保護膜１０ａと同じ材料で形成されることがより好ましい。具体的には、透明保護膜１０ａおよび縁部保護膜１０ｂをＳｉＯ２からなるものすることができる。縁部保護膜１０ｂと透明保護膜１０ａとが同じ材料で形成されている場合、縁部保護膜１０ｂと透明保護膜１０ａとの密着性が非常に良好なものとなるので、縁部保護膜１０ｂを設けることによる効果をより一層向上させることができる。 The edge protective film 10b is preferably made of a material that is transparent and has excellent adhesion to the transparent protective film 10a and the bonding pad electrode 120, and is formed of the same material as the transparent protective film 10a. More preferred. Specifically, it is possible to those made of transparent protective film 10a and the edge protection film 10b of SiO 2. When the edge protective film 10b and the transparent protective film 10a are formed of the same material, the adhesion between the edge protective film 10b and the transparent protective film 10a becomes very good. The effect by providing can be further improved.
（実施形態１２）
　図２６～図２９は、本発明の半導体発光素子の一例を示した図であって、図２６は半導体発光素子の断面模式図であり、図２７は図２６に示す半導体発光素子の平面模式図であり、図２８は図２６に示す半導体発光素子を構成する積層半導体層の拡大断面模式図である。また、図２９は、図２６に示す半導体発光素子を構成する電極を説明するための図であって、図２９（ａ）はｐ型電極の拡大断面模式図であり、図２９（ｂ）はｎ型電極の拡大断面模式図である。
　本実施形態の半導体発光素子１は、図２６に示すように、基板１０１と、基板１０１上に形成された積層半導体層２０と、積層半導体層２０の上面１０６ｃに形成されたｐ型電極１１１（一方の電極）と、積層半導体層２０の一部が切り欠けられてなる露出面１０４ｃ（半導体層露出面）上に形成されたｎ型電極１０８（他方の電極）とを備えている。 Embodiment 12
26 to 29 are diagrams showing an example of the semiconductor light emitting device of the present invention. FIG. 26 is a schematic sectional view of the semiconductor light emitting device, and FIG. 27 is a schematic plan view of the semiconductor light emitting device shown in FIG. FIG. 28 is an enlarged schematic sectional view of a laminated semiconductor layer constituting the semiconductor light emitting device shown in FIG. FIG. 29 is a diagram for explaining the electrodes constituting the semiconductor light emitting device shown in FIG. 26. FIG. 29A is an enlarged schematic cross-sectional view of a p-type electrode, and FIG. It is an expanded sectional schematic diagram of an n-type electrode.
As shown in FIG. 26, the semiconductor light emitting device 1 of the present embodiment includes a substrate 101, a laminated semiconductor layer 20 formed on the substrate 101, and a p-type electrode 111 (on the upper surface 106c of the laminated semiconductor layer 20). One electrode) and an n-type electrode 108 (the other electrode) formed on the exposed surface 104c (semiconductor layer exposed surface) formed by cutting out part of the laminated semiconductor layer 20.
　図２６に示すように、積層半導体層２０は、基板１０１側から、ｎ型半導体層１０４、発光層１０５、ｐ型半導体層１０６がこの順に積層されているものである。そして、本実施形態の半導体発光素子１では、ｐ型電極１１１とｎ型電極１０８との間に電圧を印加して電流を通じることで、発光層１０５から発光が得られる構成とされている。また、本実施形態の半導体発光素子１は、ｐ型電極１１１の形成された側から光を取り出すフェイスアップマウント型の発光素子である。 As shown in FIG. 26, the laminated semiconductor layer 20 is formed by laminating an n-type semiconductor layer 104, a light emitting layer 105, and a p-type semiconductor layer 106 in this order from the substrate 101 side. In the semiconductor light emitting device 1 of this embodiment, light emission is obtained from the light emitting layer 105 by applying a voltage between the p-type electrode 111 and the n-type electrode 108 and passing a current. In addition, the semiconductor light emitting device 1 of the present embodiment is a face-up mount type light emitting device that extracts light from the side where the p-type electrode 111 is formed.
　実施形態１２の半導体発光素子においては、実施形態１の半導体発光素子に比べて、基本的には電極が積層半導体層２０の上面における設置される構成が異なる特徴を有する。
　すなわち、実施形態１２では、前記一方の電極と前記他方の電極のいずれか一方または両方が、前記積層半導体層の上面または前記半導体層露出面上に接して形成されたオーミック接合層と、前記オーミック接合層上に形成された接合層と、前記接合層を覆うように形成されたボンディングパッド電極とを備えることを特徴とする半導体発光素子の構造を提供する。
　従って、実施形態１２の半導体発光素子においては、半導体発光素子を構成する基板や発光層を有する積層半導体層の構成は、基本的には実施形態１や実施形態７と同等な範囲で構成することができる。
　以下、前述の実施形態１や実施形態７の半導体発光素子の構成と異なる特徴を記述する為に詳細に説明する。 The semiconductor light emitting device of the twelfth embodiment is basically different from the semiconductor light emitting device of the first embodiment in that the configuration in which the electrodes are installed on the upper surface of the laminated semiconductor layer 20 is different.
That is, in Embodiment 12, either one or both of the one electrode and the other electrode are in contact with the upper surface of the stacked semiconductor layer or the exposed surface of the semiconductor layer, and the ohmic contact layer is formed. Provided is a structure of a semiconductor light emitting element, comprising: a bonding layer formed on the bonding layer; and a bonding pad electrode formed so as to cover the bonding layer.
Therefore, in the semiconductor light emitting device of the twelfth embodiment, the configuration of the substrate constituting the semiconductor light emitting device and the laminated semiconductor layer having the light emitting layer is basically configured in the same range as the first embodiment and the seventh embodiment. Can do.
In the following, a detailed description will be given in order to describe features different from the configurations of the semiconductor light emitting devices of the first embodiment and the seventh embodiment.
＜ｐ型電極＞
　ｐ型電極１１１は、図２９（ａ）に示すように、透光性電極１０９と、オーミック接合層９と、接合層１１０と、ボンディングパッド電極１２０とを備えている。図２９（ａ）に示すように、透光性電極１０９には、底面１０９ｂに積層半導体層２０の上面１０６ｃの露出された穴部１０９ａが設けられている。また、図２６および図２９（ａ）に示すように、透光性電極１０９の上面１０９ｃにおける穴部１０９ａの形成されていない領域には、透光性電極１０９を覆うように保護膜１０ａが形成されている。言い換えると、穴部１０９ａの形成されている領域は、保護膜１０ａの一部が開口されてなる開口部１０ｄとされている。そして、開口部１０ｄから露出された積層半導体層２０の上面１０６ｃ（穴部１０９ａの底面１０９ｂ）上には、オーミック接合層９が形成されており、積層半導体層２０の上面１０６ｃとオーミック接合されている。また、図２９（ａ）に示すように、オーミック接合層９上には、オーミック接合層９を覆うように接合層１１０が形成され、接合層１１０上には、接合層１１０を覆うようにボンディングパッド電極１２０が形成されている。 <P-type electrode>
As shown in FIG. 29A, the p-type electrode 111 includes a translucent electrode 109, an ohmic bonding layer 9, a bonding layer 110, and a bonding pad electrode 120. As shown in FIG. 29A, the translucent electrode 109 is provided with a hole 109a in which the upper surface 106c of the laminated semiconductor layer 20 is exposed on the bottom surface 109b. Further, as shown in FIGS. 26 and 29A, a protective film 10a is formed so as to cover the translucent electrode 109 in a region where the hole 109a is not formed in the upper surface 109c of the translucent electrode 109. Has been. In other words, the region where the hole 109a is formed is an opening 10d in which a part of the protective film 10a is opened. An ohmic junction layer 9 is formed on the upper surface 106c of the laminated semiconductor layer 20 exposed from the opening 10d (the bottom surface 109b of the hole 109a), and is ohmically joined to the upper surface 106c of the laminated semiconductor layer 20. Yes. Further, as shown in FIG. 29A, a bonding layer 110 is formed on the ohmic bonding layer 9 so as to cover the ohmic bonding layer 9, and bonding is performed on the bonding layer 110 so as to cover the bonding layer 110. A pad electrode 120 is formed.
＜ｎ型電極＞
　ｎ型電極１０８は、図２６に示すように、ｎ型半導体層１０４の露出面１０４ｃに形成されている。ｎ型半導体層１０４の露出面１０４ｃは、エッチング等の手段によって発光層１０５およびｐ半導体層１０６の一部を切り欠き除去して形成されたものである。図２６および図２９（ｂ）に示すように、ｎ型半導体層１０４の露出面１０４ｃ上には、開口部１０ｄを有する保護膜１０ａが形成されている。そして、開口部１０ｄから露出されたｎ型半導体層１０４の露出面１０４ｃ上には、オーミック接合層９が形成されており、ｎ型半導体層１０４とオーミック接合されている。また、図２９（ｂ）に示すように、オーミック接合層９上には、オーミック接合層９を覆うように接合層１１０が形成され、接合層１１０上には、接合層１１０を覆うようにボンディングパッド電極１２０が形成されている。したがって、ｎ型電極１０８は、透光性電極１０９が設けられていないこと以外は、ｐ型電極１１１と同じものとされている。 <N-type electrode>
The n-type electrode 108 is formed on the exposed surface 104c of the n-type semiconductor layer 104 as shown in FIG. The exposed surface 104c of the n-type semiconductor layer 104 is formed by cutting away a part of the light emitting layer 105 and the p semiconductor layer 106 by means such as etching. As shown in FIGS. 26 and 29B, a protective film 10 a having an opening 10 d is formed on the exposed surface 104 c of the n-type semiconductor layer 104. An ohmic junction layer 9 is formed on the exposed surface 104 c of the n-type semiconductor layer 104 exposed from the opening 10 d and is in ohmic contact with the n-type semiconductor layer 104. Also, as shown in FIG. 29B, a bonding layer 110 is formed on the ohmic bonding layer 9 so as to cover the ohmic bonding layer 9, and bonding is performed on the bonding layer 110 so as to cover the bonding layer 110. A pad electrode 120 is formed. Therefore, the n-type electrode 108 is the same as the p-type electrode 111 except that the translucent electrode 109 is not provided.
　また、本実施形態においては、図２９（ａ）および図２９（ｂ）に示すように、ｐ型電極１１１およびｎ型電極１０８を構成するオーミック接合層９および接合層１１０の外縁部およびボンディングパッド電極１２０（金属反射層１１７およびボンディング層１１９）の外縁部は、保護膜１０ａ上に配置されている。また、ボンディングパッド電極１２０は、外側に向けて膜厚が漸次薄くなる傾斜面１１９ｃを外周部１２０ｄに備えている。また、本実施形態の半導体発光素子１においては、図２９（ａ）および図２９（ｂ）に示すように、ボンディングパッド電極１２０の外縁部が、縁部保護膜１０ｂに覆われている。 In this embodiment, as shown in FIGS. 29 (a) and 29 (b), the outer edges of the ohmic junction layer 9 and the junction layer 110 constituting the p-type electrode 111 and the n-type electrode 108, and the bonding pads The outer edge portion of the electrode 120 (the metal reflection layer 117 and the bonding layer 119) is disposed on the protective film 10a. In addition, the bonding pad electrode 120 includes an inclined surface 119c on the outer peripheral portion 120d that gradually decreases in thickness toward the outside. In the semiconductor light emitting device 1 of the present embodiment, as shown in FIGS. 29A and 29B, the outer edge portion of the bonding pad electrode 120 is covered with the edge protection film 10b.
「透光性電極」
　透光性電極１０９は、図２６に示すように、ｐ型半導体層１０６の上面１０６ｃに設けられており、図２９（ａ）に示すように、底面１０９ｂに積層半導体層２０の上面１０６ｃの露出された穴部１０９ａを有している。透光性電極１０９の穴部１０９ａの平面形状は、円形状、多角形状など任意の形状とすることができ、特に限定されないが、ボンディング作業のしやすいものとするために、図２７に示すように、円形状であることが好ましい。 "Translucent electrode"
The translucent electrode 109 is provided on the upper surface 106c of the p-type semiconductor layer 106, as shown in FIG. 26, and the upper surface 106c of the laminated semiconductor layer 20 is exposed on the bottom surface 109b, as shown in FIG. The hole 109a is formed. The planar shape of the hole 109a of the translucent electrode 109 can be any shape such as a circular shape or a polygonal shape, and is not particularly limited. However, in order to facilitate the bonding operation, as shown in FIG. Moreover, it is preferable that it is circular.
　また、透光性電極１０９の穴部１０９ａは、ｐ型半導体層１０６の上面１０６ｃ上のどこに形成してもよく、オーミック接合層９、接合層１１０、ボンディングパッド電極１２０の形成される位置に対応して設けられる。例えば、ｎ型電極１０８から最も遠い位置に形成してもよいし、半導体発光素子１の中心に形成してもよい。しかし、あまりにもｎ型電極１０８に近接した位置に形成すると、穴部１０９ａ上に形成されるボンディングパッド電極１２０にワイヤをボンディングした際に、ワイヤ間、ボール間のショートを生じてしまうため好ましくない。
　また、透光性電極１０９は、図２６および図２７に示すように、平面視したときに、ｐ型半導体層１０６の上面１０６ｃのほぼ全面を覆うように形成されているが、このような形状に限定されるわけでなく、隙間を開けて格子状や樹形状に形成してもよい。 Further, the hole 109a of the translucent electrode 109 may be formed anywhere on the upper surface 106c of the p-type semiconductor layer 106, and corresponds to the position where the ohmic junction layer 9, the junction layer 110, and the bonding pad electrode 120 are formed. Provided. For example, it may be formed at a position farthest from the n-type electrode 108 or may be formed at the center of the semiconductor light emitting device 1. However, if it is formed too close to the n-type electrode 108, a short circuit between the wires and between the balls occurs when the wire is bonded to the bonding pad electrode 120 formed on the hole 109a. .
Further, as shown in FIGS. 26 and 27, the translucent electrode 109 is formed so as to cover almost the entire upper surface 106c of the p-type semiconductor layer 106 in plan view. However, the present invention is not limited to this, and it may be formed in a lattice shape or a tree shape with a gap.
　また、透光性電極１０９は、ｐ型半導体層１０６、オーミック接合層９、接合層１１０との接触抵抗が小さいものであることが好ましい。さらに、透光性電極１０９は、発光層１０５からの光をｐ型電極１１１の形成された側に効率よく取り出すために、光透過性に優れたものであることが好ましい。さらにまた、透光性電極１０９は、ｐ型半導体層１０６の全面に渡って均一に電流を拡散させるために、優れた導電性を有していることが好ましい。 Further, it is preferable that the translucent electrode 109 has a small contact resistance with the p-type semiconductor layer 106, the ohmic junction layer 9, and the junction layer 110. Furthermore, the translucent electrode 109 is preferably excellent in light transmissivity in order to efficiently extract light from the light emitting layer 105 to the side where the p-type electrode 111 is formed. Furthermore, the translucent electrode 109 preferably has excellent conductivity in order to diffuse current uniformly over the entire surface of the p-type semiconductor layer 106.
　以上のことから、透光性電極１０９を構成する材料としては、Ｉｎ、Ｚｎ、Ａｌ、Ｇａ、Ｔｉ、Ｂｉ、Ｍｇ、Ｗ、Ｃｅ、Ｓｎ、Ｎｉのいずれか一種を含む導電性の酸化物、硫化亜鉛または硫化クロムのうちいずれか一種からなる群より選ばれる透光性の導電性材料を用いることが好ましい。
　また、導電性の酸化物としては、ＩＴＯ（酸化インジウム錫（Ｉｎ２Ｏ３－ＳｎＯ２））、ＩＺＯ（酸化インジウム亜鉛（Ｉｎ２Ｏ３－ＺｎＯ））、ＡＺＯ（酸化アルミニウム亜鉛（ＺｎＯ－Ａｌ２Ｏ３））、ＧＺＯ（酸化ガリウム亜鉛（ＺｎＯ－Ｇａ２Ｏ３））、フッ素ドープ酸化錫、酸化チタン等を用いることが好ましい。 From the above, as a material constituting the translucent electrode 109, a conductive oxide containing any one of In, Zn, Al, Ga, Ti, Bi, Mg, W, Ce, Sn, and Ni, It is preferable to use a light-transmitting conductive material selected from the group consisting of any one of zinc sulfide and chromium sulfide.
Examples of the conductive oxide include ITO (indium tin oxide (In 2 O 3 —SnO 2 )), IZO (indium zinc oxide (In 2 O 3 —ZnO)), and AZO (aluminum zinc oxide (ZnO—Al 2 O 3 )), GZO (gallium zinc oxide (ZnO—Ga 2 O 3 )), fluorine-doped tin oxide, titanium oxide, or the like is preferably used.
　また、透光性電極１０９は、結晶化された構造のものを使用することが、透光性の点において好ましい。特に六方晶構造又はビックスバイト構造を有するＩｎ２Ｏ３結晶を含む透光性電極（例えば、ＩＴＯやＩＺＯ等）を好ましく使用することができる。
　透光性電極１０９が、結晶化されたＩＺＯからなるものである場合、ビックスバイト結晶構造のＩｎ２Ｏ３結晶を含むＩＺＯであってもよいし、六方晶構造のＩｎ２Ｏ３結晶を含むＩＺＯであってもよい。特に、六方晶構造のＩｎ２Ｏ３結晶を含むＩＺＯがよい。結晶化したＩＺＯ膜は、アモルファス状態のＩＺＯ膜に比べて、ｐ型半導体層１０６との密着性が良いため、非常に好ましい。 In addition, it is preferable in terms of translucency to use a crystallized structure as the translucent electrode 109. In particular, a translucent electrode (for example, ITO, IZO, etc.) containing an In 2 O 3 crystal having a hexagonal crystal structure or a bixbite structure can be preferably used.
Translucent electrode 109, if made of a crystallized IZO, may be a IZO containing an In 2 O 3 crystal having a bixbyite crystal structure, including In 2 O 3 crystal having a hexagonal crystal structure It may be IZO. In particular, IZO containing In 2 O 3 crystal having a hexagonal structure is preferable. A crystallized IZO film is very preferable because it has better adhesion to the p-type semiconductor layer 106 than an amorphous IZO film.
　また、ＩＺＯ膜としては、比抵抗が最も低くなる組成を使用することが好ましい。例えば、ＩＺＯ中のＺｎＯ濃度は１～２０質量％であることが好ましく、５～１５質量％の範囲であることが更に好ましい。１０質量％であると特に好ましい。
　また、ＩＺＯ膜の膜厚は、低比抵抗、高光透過率を得ることができる３５ｎｍ～１００００ｎｍ（１０μｍ）の範囲であることが好ましい。さらに、生産コストの観点から、ＩＺＯ膜の膜厚は１０００ｎｍ（１μｍ）以下であることが好ましい。 Further, it is preferable to use a composition having the lowest specific resistance as the IZO film. For example, the ZnO concentration in IZO is preferably 1 to 20% by mass, and more preferably 5 to 15% by mass. 10% by mass is particularly preferable.
The film thickness of the IZO film is preferably in the range of 35 nm to 10000 nm (10 μm) at which low specific resistance and high light transmittance can be obtained. Furthermore, from the viewpoint of production cost, the thickness of the IZO film is preferably 1000 nm (1 μm) or less.
「オーミック接合層」
　図２９（ａ）に示すように、ｐ型電極１１１を構成するオーミック接合層９は、積層半導体層２０の上面１０６ｃに設けられており、ｐ型半導体層１０６とオーミック接合されている。また、図２９（ｂ）に示すように、ｎ型電極１０８を構成するオーミック接合層９は、ｎ型半導体層１０４の露出面１０４ｃ上に設けられており、ｎ型半導体層１０４とオーミック接合されている。
　また、図２９（ａ）に示すように、ｐ型電極１１１を構成するオーミック接合層９は、積層半導体層２０の上面１０６ｃ上と透光性電極１０９の穴部１０９ａ内と保護膜１０ａの開口部１０ｄの端部１０ｃとを覆うように連続して形成されている。また、図２９（ｂ）に示すように、ｎ型電極１０８を構成するオーミック接合層９は、ｎ型半導体層１０４の露出面１０４ｃ上と保護膜１０ａの開口部１０ｄの端部１０ｃとを覆うように連続して形成されている。
　また、オーミック接合層９の厚みは、保護膜１０ａの開口部１０ｄ内および開口部１０ｄの内壁面上では略均一とされている。そして、オーミック接合層９の厚みは、開口部１０ｄの外側では、外側に向けて膜厚が漸次薄くなっており、オーミック接合層９の外周部には、傾斜面が形成されている。 "Ohmic junction layer"
As shown in FIG. 29A, the ohmic junction layer 9 constituting the p-type electrode 111 is provided on the upper surface 106 c of the laminated semiconductor layer 20 and is in ohmic contact with the p-type semiconductor layer 106. In addition, as shown in FIG. 29B, the ohmic junction layer 9 constituting the n-type electrode 108 is provided on the exposed surface 104c of the n-type semiconductor layer 104, and is in ohmic contact with the n-type semiconductor layer 104. ing.
Further, as shown in FIG. 29A, the ohmic junction layer 9 constituting the p-type electrode 111 is formed on the upper surface 106c of the laminated semiconductor layer 20, the hole 109a of the translucent electrode 109, and the opening of the protective film 10a. It is formed continuously so as to cover the end portion 10c of the portion 10d. Further, as shown in FIG. 29B, the ohmic junction layer 9 constituting the n-type electrode 108 covers the exposed surface 104c of the n-type semiconductor layer 104 and the end 10c of the opening 10d of the protective film 10a. Are formed continuously.
Further, the thickness of the ohmic bonding layer 9 is substantially uniform in the opening 10d of the protective film 10a and on the inner wall surface of the opening 10d. The thickness of the ohmic junction layer 9 is gradually reduced toward the outside outside the opening 10d, and an inclined surface is formed on the outer peripheral portion of the ohmic junction layer 9.
　オーミック接合層９は、ｐ型半導体層１０６またはｎ型半導体層１０４や、接合層１１０との接触抵抗が小さいものであることが好ましい。また、オーミック接合層９は、発光層１０５からの光をｐ型電極１１１の形成された側に効率よく取り出すために、光透過性に優れたものであることが好ましい。以上のことから、オーミック接合層９を構成する材料としては、透光性電極１０９を構成する材料と同様のものを好ましく用いることができる。 The ohmic junction layer 9 preferably has a low contact resistance with the p-type semiconductor layer 106, the n-type semiconductor layer 104, or the junction layer 110. The ohmic junction layer 9 is preferably excellent in light transmittance in order to efficiently extract light from the light emitting layer 105 to the side where the p-type electrode 111 is formed. From the above, as the material constituting the ohmic junction layer 9, the same material as that constituting the translucent electrode 109 can be preferably used.
　また、オーミック接合層９は、結晶化された構造のものを使用することが、接合層１１０との接着性や透光性の点において好ましい。特に六方晶構造又はビックスバイト構造を有するＩｎ２Ｏ３結晶を含む透光性電極（例えば、ＩＴＯやＩＺＯ等）を好ましく使用することができる。
　オーミック接合層９が、結晶化されたＩＺＯからなるものである場合、透光性電極１０９と同様に、ビックスバイト結晶構造のＩｎ２Ｏ３結晶を含むＩＺＯであってもよいし、六方晶構造のＩｎ２Ｏ３結晶を含むＩＺＯであってもよい。特に、六方晶構造のＩｎ２Ｏ３結晶を含むＩＺＯがよい。結晶化したＩＺＯ膜は、アモルファス状態のＩＺＯ膜に比べて、接合層１１０やｐ型半導体層１０６との密着性が良いため、非常に好ましい。 In addition, it is preferable to use a crystallized structure for the ohmic bonding layer 9 in terms of adhesiveness to the bonding layer 110 and translucency. In particular, a translucent electrode (for example, ITO, IZO, etc.) containing an In 2 O 3 crystal having a hexagonal crystal structure or a bixbite structure can be preferably used.
When the ohmic junction layer 9 is made of crystallized IZO, it may be an IZO containing an In 2 O 3 crystal having a bixbite crystal structure, or a hexagonal crystal structure, similar to the translucent electrode 109. IZO containing In 2 O 3 crystal of N may be used. In particular, IZO containing In 2 O 3 crystal having a hexagonal structure is preferable. A crystallized IZO film is very preferable because it has better adhesion to the bonding layer 110 and the p-type semiconductor layer 106 than an amorphous IZO film.
　また、オーミック接合層９の膜厚は、割れにくく十分な強度が得られるとともに、低比抵抗、高光透過率を得ることができる２ｎｍ～３００ｎｍの範囲であることが好ましく５０ｎｍ～２５０ｎｍの範囲であることがより好ましい。 Further, the thickness of the ohmic bonding layer 9 is preferably in the range of 2 nm to 300 nm, preferably in the range of 50 nm to 250 nm, in which sufficient strength is obtained that is difficult to break and low resistivity and high light transmittance can be obtained. It is more preferable.
「接合層」
　接合層１１０は、オーミック接合層９に対するボンディングパッド電極１２０の接合強度を高めるために、オーミック接合層９とボンディングパッド電極１２０との間に積層される。
　図２９（ａ）に示すように、ｐ型電極１１１を構成する接合層１１０は、オーミック接合層９上と保護膜１０ａの開口部１０ｄの端部１０ｃとを覆うように凹部状に連続して形成されている。このことにより、オーミック接合層９および保護膜１０ａと、接合層１１０との高い接合力が得られるようになっている。また、図２９（ｂ）に示すように、ｎ型電極１０８を構成する接合層１１０は、オーミック接合層９上と保護膜１０ａの開口部１０ｄの端部１０ｃとを覆うように凹部状に連続して形成されている。このことにより、オーミック接合層９および保護膜１０ａと、接合層１１０との高い接合力が得られるようになっている。 "Joint layer"
The bonding layer 110 is laminated between the ohmic bonding layer 9 and the bonding pad electrode 120 in order to increase the bonding strength of the bonding pad electrode 120 to the ohmic bonding layer 9.
As shown in FIG. 29A, the bonding layer 110 constituting the p-type electrode 111 is continuously formed in a concave shape so as to cover the ohmic bonding layer 9 and the end 10c of the opening 10d of the protective film 10a. Is formed. As a result, a high bonding force between the ohmic bonding layer 9 and the protective film 10a and the bonding layer 110 can be obtained. Also, as shown in FIG. 29B, the bonding layer 110 constituting the n-type electrode 108 is continuous in a concave shape so as to cover the ohmic bonding layer 9 and the end 10c of the opening 10d of the protective film 10a. Is formed. As a result, a high bonding force between the ohmic bonding layer 9 and the protective film 10a and the bonding layer 110 can be obtained.
　また、接合層１１０の厚みは、保護膜１０ａの開口部１０ｄ内および開口部１０ｄの内壁面上では略均一とされている。そして、開口部１０ｄの外側では、接合層１１０の厚みは、外側に向けて膜厚が漸次薄くなっており、接合層１１０の外周部１１０ｄには、傾斜面１１０ｃが形成されている。 Further, the thickness of the bonding layer 110 is substantially uniform in the opening 10d of the protective film 10a and on the inner wall surface of the opening 10d. Then, outside the opening 10d, the thickness of the bonding layer 110 gradually decreases toward the outside, and an inclined surface 110c is formed on the outer peripheral portion 110d of the bonding layer 110.
　また、接合層１１０は、透光性を有していることが好ましい。接合層１１０が透光性を有しているものである場合、ｐ型電極１１１においてボンディングパッド電極１２０に照射される発光層１０５からの光を損失なく透過させることができる。より詳細には、接合層１１０が透光性を有している場合、発光層１０５からの発光の一部は、ｐ型電極１１１を構成するオーミック接合層９及び接合層１１０を透過して、接合層１１０とボンディングパッド電極１２０との界面においてボンディングパッド電極１２０（本実施形態においては金属反射層１１７）によって反射されるものとなる。ｐ型電極１１１のボンディングパッド電極１２０によって反射された光は、再度、積層半導体層２０の内部に導入されて、透過と反射を繰り返した後に、ｐ型電極１１１のボンディングパッド電極１２０の形成領域以外の箇所から半導体発光素子１の外部に取り出される。したがって、ｐ型電極１１１を構成する接合層１１０が透光性を有しているものである場合、発光層１０５からの光
をより一層効率よく半導体発光素子１の外部に取り出すことができる。 In addition, the bonding layer 110 preferably has a light-transmitting property. In the case where the bonding layer 110 has a light-transmitting property, the light from the light emitting layer 105 irradiated to the bonding pad electrode 120 in the p-type electrode 111 can be transmitted without loss. More specifically, when the bonding layer 110 has a light-transmitting property, part of light emitted from the light-emitting layer 105 is transmitted through the ohmic bonding layer 9 and the bonding layer 110 constituting the p-type electrode 111, and The light is reflected by the bonding pad electrode 120 (in this embodiment, the metal reflection layer 117) at the interface between the bonding layer 110 and the bonding pad electrode 120. The light reflected by the bonding pad electrode 120 of the p-type electrode 111 is again introduced into the laminated semiconductor layer 20, and after repeating transmission and reflection, the light other than the region where the bonding pad electrode 120 of the p-type electrode 111 is formed Are taken out of the semiconductor light-emitting element 1 from Therefore, when the bonding layer 110 constituting the p-type electrode 111 has a light transmitting property, the light from the light emitting layer 105 can be extracted to the outside of the semiconductor light emitting device 1 more efficiently.
　接合層１１０は、Ａｌ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｃｏ、Ｚｎ、Ｇｅ、Ｚｒ、Ｎｂ、Ｍｏ、Ｒｕ、Ｈｆ、Ｔａ、Ｗ、Ｒｅ、Ｒｈ、Ｉｒ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなるものであることが好ましい。接合層１１０を上記の材料からなるものとすることにより、オーミック接合層９に対するボンディングパッド電極１２０の接合強度を向上させることができると同時に透光性を発揮させることができる。また、接合層１１０は、Ｃｒ、Ｔｉ、Ｗ、Ｍｏ、Ｚｒ、Ｈｆ、Ｃｏ、Ｒｈ、Ｉｒ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなるものであることがより好ましく、Ｃｒ、Ｔｉ、Ｗ、Ｍｏ、Ｒｈ、Ｃｏ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなるものであることがさらに好ましい。特に、接合層１１０の材料として、Ｃｒ、Ｔｉ、Ｍｏ、Ｎｉ、Ｃｏ等の金属を用いることにより、オーミック接合層９に対するボンディングパッド電極１２０の接合強度を格段に高めることができる。 The bonding layer 110 is at least selected from the group consisting of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh, Ir, and Ni. It is preferable that it consists of a kind of element. When the bonding layer 110 is made of the above-described material, the bonding strength of the bonding pad electrode 120 to the ohmic bonding layer 9 can be improved, and at the same time, the translucency can be exhibited. The bonding layer 110 is more preferably composed of at least one element selected from the group consisting of Cr, Ti, W, Mo, Zr, Hf, Co, Rh, Ir, and Ni. More preferably, it is made of at least one element selected from the group consisting of W, Mo, Rh, Co, and Ni. In particular, by using a metal such as Cr, Ti, Mo, Ni, and Co as the material of the bonding layer 110, the bonding strength of the bonding pad electrode 120 to the ohmic bonding layer 9 can be significantly increased.
　また、接合層１１０の材料としては、例えば、オーミック接合層９がＩＺＯやＩＴＯ等の金属酸化物等からなり、ボンディングパッド電極１２０がＡｇ、Ａｌ等からなる場合には、金属酸化物に対してもＡｇ、Ａｌに対しても優れた接合性が得られるＣｒを用いることが特に好ましい。 As the material of the bonding layer 110, for example, when the ohmic bonding layer 9 is made of a metal oxide such as IZO or ITO and the bonding pad electrode 120 is made of Ag, Al, or the like, In particular, it is particularly preferable to use Cr that can provide excellent bondability to Ag and Al.
　また、接合層１１０は、最大厚みが１０Å以上４００Å以下の範囲の薄膜であることが好ましい。接合層１１０の最大厚みを上記範囲とすることにより、発光層１０５からの光を遮ることなく効果的に透過させることができる優れた透光性を有するものとすることができる。なお、上記の最大厚みが１０Å未満になると、接合層１１０の強度が低下し、これによりオーミック接合層９に対するボンディングパッド電極１２０の接合強度が低下するので好ましくない。 Further, the bonding layer 110 is preferably a thin film having a maximum thickness in the range of 10 to 400 mm. By setting the maximum thickness of the bonding layer 110 within the above range, the light can be transmitted effectively without blocking light from the light emitting layer 105. If the maximum thickness is less than 10 mm, the strength of the bonding layer 110 is lowered, which is not preferable because the bonding strength of the bonding pad electrode 120 to the ohmic bonding layer 9 is lowered.
「ボンディングパッド電極」
　図２９（ａ）および図２９（ｂ）に示すように、ボンディングパッド電極１２０は、金属反射層１１７とボンディング層１１９とが、透光性電極１０９側から順に積層された積層体からなる。なお、ボンディングパッド電極１２０は、ボンディング層１１９のみからなる単層構造や金属反射層１１７のみからなる単層構造であってもよいし、金属反射層１１７とボンディング層１１９との間にバリア層を挿入して、三層構造としたものであってもよい。なお、接合層１１０、金属反射層１１７、ボンディング層１１９、バリヤ層を構成する金属元素においては、同一の金属元素を含んでいてもよいし、それぞれ異なる金属元素の組み合わせであってもよい。 "Bonding pad electrode"
As shown in FIGS. 29A and 29B, the bonding pad electrode 120 is formed of a stacked body in which a metal reflective layer 117 and a bonding layer 119 are stacked in this order from the translucent electrode 109 side. Note that the bonding pad electrode 120 may have a single layer structure including only the bonding layer 119 or a single layer structure including only the metal reflection layer 117, and a barrier layer may be provided between the metal reflection layer 117 and the bonding layer 119. It may be inserted into a three-layer structure. Note that the metal elements constituting the bonding layer 110, the metal reflection layer 117, the bonding layer 119, and the barrier layer may contain the same metal element, or may be a combination of different metal elements.
　本実施形態において、ボンディングパッド電極１２０の反射率は、金属反射層１１７を構成する材料によって大きく変わるが、反射率６０％以上であることが望ましく、反射率８０％以上であることがより望ましく、反射率９０％以上であればなお良い。反射率は、分光光度計等で比較的容易に測定することが可能である。しかし、ボンディングパッド電極１２０そのものは面積が小さいために反射率を測定することは難しい。そこで、例えばボンディングパッド電極を形成するチャンバ内に、透明なガラス製の面積の大きい「ダミー基板」を入れ、ボンディングパッド電極を形成すると同時に、ダミー基板上に同じボンディングパッド電極を作成し、ダミー基板上に形成されたボンディングパッド電極の反射率を測定するなどの方法を用いて測定することができる。 In the present embodiment, the reflectance of the bonding pad electrode 120 varies greatly depending on the material constituting the metal reflective layer 117, but the reflectance is preferably 60% or more, more preferably 80% or more, It is even better if the reflectance is 90% or more. The reflectance can be measured relatively easily with a spectrophotometer or the like. However, since the bonding pad electrode 120 itself has a small area, it is difficult to measure the reflectance. Therefore, for example, a “dummy substrate” made of a transparent glass and having a large area is placed in a chamber for forming the bonding pad electrode, and at the same time, the same bonding pad electrode is formed on the dummy substrate. It can be measured using a method such as measuring the reflectance of the bonding pad electrode formed thereon.
　ボンディングパッド電極１２０の面積は、大きいほどボンディング作業を容易に行うことができるため好ましいが、ｎ型電極１０８のボンディングパッド電極１２０の面積が大きいほど、ｎ型半導体層１０４の露出面１０４ｃの面積を大きくしなければならなくなり、発光層１０５の面積が小さくなり好ましくない。また、ｐ型電極１１１のボンディングパッド電極１２０の面積が大きいほど光の取り出しが妨げられる。具体的に例えば、ボンディングパッド電極１２０の面積が透光性電極１０９上の面積の半分を超える場合、ボンディングパッド電極１２０が光の取り出しの妨げとなるため、出力が著しく低下する。逆に、ボンディングパッド電極１２０の面積が小さすぎると、ボンディング作業がしにくくなり、製品の歩留まりが低下する。したがって、ｐ型電極１１１およびｎ型電極１０８を構成するボンディングパッド電極１２０の面積は、ボンディングボールの直径よりもわずかに大きい程度の大きさであることが好ましく、具体的には、上面の直径が１００μｍ程
度であって、保護膜１０ａ側に近づくほど直径の大きくなる略円柱状の形状であることが好ましい。 The larger the area of the bonding pad electrode 120 is, the easier the bonding operation can be performed. However, the larger the area of the bonding pad electrode 120 of the n-type electrode 108, the smaller the area of the exposed surface 104c of the n-type semiconductor layer 104. This is not preferable because the area of the light emitting layer 105 becomes small. Further, the larger the area of the bonding pad electrode 120 of the p-type electrode 111, the more the light extraction is hindered. Specifically, for example, when the area of the bonding pad electrode 120 exceeds half of the area on the translucent electrode 109, the bonding pad electrode 120 hinders light extraction, so that the output is significantly reduced. On the contrary, if the area of the bonding pad electrode 120 is too small, the bonding operation becomes difficult and the yield of the product is lowered. Therefore, the area of the bonding pad electrode 120 that constitutes the p-type electrode 111 and the n-type electrode 108 is preferably a size that is slightly larger than the diameter of the bonding ball. It is preferably about 100 μm, and has a substantially cylindrical shape with a diameter increasing as it approaches the protective film 10a side.
＜金属反射層＞
　図２９（ａ）および図２９（ｂ）に示すように、金属反射層１１７は接合層１１０を覆うように形成されている。金属反射層１１７の外周部には、外側に向けて膜厚が漸次薄くなるような傾斜面１１７ｃが形成されている。したがって、金属反射層１１７は、接合層１１０の傾斜面１１０ｃの保護膜１０ａ側の最先端部、すなわち接合層１１０を平面視したときの輪郭線を形づくる境界部上を完全に覆うように形成されている。つまり、金属反射層１１７は、平面視したときに接合層１１０を覆って、更に接合層１１０の外側にまで張り出すように形成されており、接合層１１０のいかなる部分も金属反射層１１７の下から露出しないようにされている。 <Metal reflective layer>
As shown in FIGS. 29A and 29B, the metal reflective layer 117 is formed so as to cover the bonding layer 110. On the outer peripheral portion of the metal reflection layer 117, an inclined surface 117c is formed so that the film thickness gradually decreases toward the outside. Therefore, the metal reflective layer 117 is formed so as to completely cover the most distal portion of the inclined surface 110c of the bonding layer 110 on the protective film 10a side, that is, the boundary that forms the contour line when the bonding layer 110 is viewed in plan. ing. In other words, the metal reflection layer 117 is formed so as to cover the bonding layer 110 when viewed in plan and further protrude to the outside of the bonding layer 110, and any part of the bonding layer 110 is below the metal reflection layer 117. Is not exposed from.
　金属反射層１１７は、反射率の高い金属からなるものであり、Ｒｕ、Ｒｈ、Ｐｄ、Ｏｓ、Ｉｒ、Ｐｔ等の白金族金属、Ａｌ、Ａｇ、Ｔｉおよびこれらの金属の少なくも一種を含む合金で構成されることが好ましい。金属反射層１１７を上記の材料からなるものとすることにより、ｐ型電極１１１において発光層１０５からの光を効果的に反射させることができる。上記の材料の中でも、Ａｌ、Ａｇ、Ｐｔおよびこれらの金属の少なくも一種を含む合金は、入手のし易さ、取り扱いの容易さなどの点で優れている。また、Ｒｈ、Ｐｄ、Ｉｒ、Ｐｔおよびこれらの金属の少なくも一種を含む合金は、光の反射性の点から金属反射層１１７として好適に使用される。 The metal reflection layer 117 is made of a metal having a high reflectance, and is an alloy containing platinum group metals such as Ru, Rh, Pd, Os, Ir, and Pt, Al, Ag, Ti, and at least one of these metals. It is preferable that it is comprised. By using the metal reflective layer 117 made of the above material, the light from the light emitting layer 105 can be effectively reflected by the p-type electrode 111. Among the materials described above, Al, Ag, Pt, and alloys containing at least one of these metals are excellent in terms of easy availability and handling. Further, Rh, Pd, Ir, Pt and an alloy containing at least one of these metals are preferably used as the metal reflective layer 117 from the viewpoint of light reflectivity.
　また、金属反射層１１７は、接合層１１０よりも最大膜厚が厚くなるように形成されることが好ましい。金属反射層１１７を接合層１１０よりも最大膜厚の厚いものとすることで、金属反射層１１７によって、より確実にかつ完全に接合層１１０が覆われたものとなる。
　また、金属反射層１１７は、最大厚さが２０～３０００ｎｍであることが望ましい。金属反射層１１７の厚みが上記範囲よりも薄いと、充分に反射の効果が得らない場合がある。また、金属反射層１１７の厚みが上記範囲よりも厚い場合、特に利点は生じず、工程時間の長時間化と材料の無駄を生じるのみである。金属反射層１１７の厚みは、更に望ましくは、５０～１０００ｎｍであり、最も望ましいのは１００～５００ｎｍである。 The metal reflective layer 117 is preferably formed so that the maximum film thickness is larger than that of the bonding layer 110. By making the metal reflective layer 117 thicker than the bonding layer 110, the metal reflecting layer 117 covers the bonding layer 110 more reliably and completely.
Further, it is desirable that the metal reflective layer 117 has a maximum thickness of 20 to 3000 nm. If the thickness of the metal reflective layer 117 is thinner than the above range, the reflection effect may not be obtained sufficiently. In addition, when the thickness of the metal reflection layer 117 is thicker than the above range, there is no particular advantage, and only a long process time and material waste are caused. The thickness of the metal reflective layer 117 is more desirably 50 to 1000 nm, and most desirably 100 to 500 nm.
　＜ボンディング層＞
　　図２９（ａ）および図２９（ｂ）に示すように、ボンディング層１１９は、金属反射層１１７を覆うように形成されている。また、ボンディング層１１９の外周部（すなわちボンディングパッド電極１２０の外周部１２０ｄ）には、外側に向けて膜厚が漸次薄くなるような傾斜面１１９ｃが形成されている。したがって、ボンディング層１１９は、金属反射層１１７の傾斜面１１７ｃの保護膜１０ａ側の最先端部、すなわち金属反射層１１７を平面視したときの輪郭線を形づくる境界部上を完全に覆うように形成されている。つまり、ボンディング層１１９は、平面視したときに金属反射層１１７を覆って、更に金属反射層１１７の外側にまで張り出すように形成されており、金属反射層１１７のいかなる部分もボンディング層１１９の下から露出しないようにされている。 <Bonding layer>
As shown in FIGS. 29A and 29B, the bonding layer 119 is formed so as to cover the metal reflective layer 117. In addition, an inclined surface 119c is formed on the outer peripheral portion of the bonding layer 119 (that is, the outer peripheral portion 120d of the bonding pad electrode 120) so that the film thickness gradually decreases toward the outside. Therefore, the bonding layer 119 is formed so as to completely cover the most distal portion of the inclined surface 117c of the metal reflection layer 117 on the protective film 10a side, that is, the boundary portion that forms the contour line when the metal reflection layer 117 is viewed in plan view. Has been. In other words, the bonding layer 119 is formed so as to cover the metal reflective layer 117 when seen in a plan view and further to the outside of the metal reflective layer 117, and any portion of the metal reflective layer 117 is formed on the bonding layer 119. It is not exposed from the bottom.
　図２６に示すボンディング層１１９は、Ａｕ、Ａｌまたはこれらの金属の少なくも一種を含む合金からなることが好ましい。ＡｕおよびＡｌはボンディングボールとして使用されることが多い金ボールとの密着性の良い金属であるので、ボンディング層１１９として、Ａｕ、Ａｌまたはこれらの金属の少なくも一種を含む合金を用いることにより、ボンディングワイヤとの密着性に優れたボンディング層１１９とすることができる。中でも、特に望ましいのはＡｕである。 The bonding layer 119 shown in FIG. 26 is preferably made of Au, Al, or an alloy containing at least one of these metals. Since Au and Al are metals with good adhesion to gold balls that are often used as bonding balls, by using Au, Al or an alloy containing at least one of these metals as the bonding layer 119, It can be set as the bonding layer 119 excellent in adhesiveness with a bonding wire. Of these, Au is particularly desirable.
　また、ボンディング層１１９の最大厚みは、接合層１１０および金属反射層１１７に比較して、厚くなるように形成することが好ましい。ボンディング層１１９を接合層１１０および金属反射層１１７に比較して最大膜厚の厚いものとすることで、ボンディング層１１９によって、より確実にかつ完全に接合層１１０および金属反射層１１７が覆われたものとなる。
　また、ボンディング層１１９の最大厚みは、５０ｎｍ以上２０００ｎｍ以下の範囲のであることが好ましく、更に望ましくは１００ｎｍ以上１５００ｎｍ以下である。ボンディング層１１９の最大厚みが薄すぎるとボンディングボールとの密着性が不十分となる場合がある。また、ボンディング層１１９の最大厚みを上記範囲よりも厚くしても特に利点は生ぜず、コスト増大を招くのみである。 In addition, the maximum thickness of the bonding layer 119 is preferably formed to be thicker than that of the bonding layer 110 and the metal reflective layer 117. By making the bonding layer 119 thicker than the bonding layer 110 and the metal reflection layer 117, the bonding layer 119 covers the bonding layer 110 and the metal reflection layer 117 more reliably and completely by the bonding layer 119. It will be a thing.
The maximum thickness of the bonding layer 119 is preferably in the range of 50 nm to 2000 nm, and more preferably 100 nm to 1500 nm. If the maximum thickness of the bonding layer 119 is too thin, adhesion to the bonding ball may be insufficient. Further, even if the maximum thickness of the bonding layer 119 is made larger than the above range, there is no particular advantage and only the cost is increased.
＜バリア層＞
　バリア層は、金属反射層１１７とボンディング層１１９との間に配置され、ボンディングパッド電極１２０全体の強度を強化するものである。バリア層は、比較的強固な金属材料からなるものとされるか、または、充分に厚い膜厚を有するものとされる。バリア層の材料としては、Ｔｉ、ＣｒまたはＡｌなどを用いることできるが、強度に優れたＴｉを用いることが望ましい。また、バリア層の最大厚さは２０～３０００ｎｍであることが望ましい。バリア層の厚みが薄すぎると充分な強度強化の効果が得られない場合がある。また、バリア層の厚みが厚すぎても特に利点は生ぜず、コスト増大を招くのみである。バリア層の厚みは、更に望ましくは、５０～１０００ｎｍであり、最も望ましいのは１００～５００ｎｍである。 <Barrier layer>
The barrier layer is disposed between the metal reflective layer 117 and the bonding layer 119 and enhances the strength of the entire bonding pad electrode 120. The barrier layer is made of a relatively strong metal material, or has a sufficiently thick film thickness. As the material for the barrier layer, Ti, Cr, Al, or the like can be used, but it is desirable to use Ti having excellent strength. The maximum thickness of the barrier layer is preferably 20 to 3000 nm. If the thickness of the barrier layer is too thin, sufficient strength strengthening effects may not be obtained. In addition, if the thickness of the barrier layer is too thick, there is no particular advantage and only an increase in cost is caused. The thickness of the barrier layer is more preferably 50 to 1000 nm, and most preferably 100 to 500 nm.
　なお、金属反射層１１７が、機械的に強固なものである場合には、敢えてバリア層を形成する必要はない。例えば、金属反射層１１７がＡｌまたはＰｔからなるものである場合には、バリア層は必ずしも必要ではない。 In addition, when the metal reflective layer 117 is mechanically strong, it is not necessary to form a barrier layer. For example, when the metal reflective layer 117 is made of Al or Pt, the barrier layer is not always necessary.
「保護膜」
　保護膜１０ａは、透光性電極１０９および接合層１１０を保護するものである。保護膜１０ａは、図２６および図２７に示すように、透光性電極１０９の上面１０９ｃにおける穴部１０９ａの形成されていない領域およびｎ型半導体層１０４の露出面１０４ｃ上を覆うように形成されており、ｐ型電極１１１のオーミック接合層９が形成される領域（穴部１０９ａの形成されている領域）およびｎ型電極１０８のオーミック接合層９が形成される領域が開口部１０ｄとされている。 "Protective film"
The protective film 10 a protects the translucent electrode 109 and the bonding layer 110. As shown in FIGS. 26 and 27, the protective film 10 a is formed so as to cover a region where the hole 109 a is not formed on the upper surface 109 c of the translucent electrode 109 and the exposed surface 104 c of the n-type semiconductor layer 104. The region where the ohmic junction layer 9 of the p-type electrode 111 is formed (the region where the hole 109a is formed) and the region where the ohmic junction layer 9 of the n-type electrode 108 is formed serve as the opening 10d. Yes.
　本実施形態においては、図２９（ａ）および図２９（ｂ）に示すように、オーミック接合層９が開口部１０ｄの内壁面に接して形成されているとともに、オーミック接合層９の外縁部が保護膜１０ａ上に接して配置されており、保護膜１０ａによって、オーミック接合層９の保護膜１０ａに接している部分における空気または水分の接触が防止されている。
　また、本実施形態においては、図２９（ａ）および図２９（ｂ）に示すように、接合層１１０の外縁部、ボンディングパッド電極１２０を構成する金属反射層１１７およびボンディング層１１９の外縁部が、保護膜１０ａ上に接して配置されており、保護膜１０ａとボンディングパッド電極１２０とによって、オーミック接合層９に接していない接合層１１０の外面全面を取り囲んでおり、接合層１１０と空気または水分との接触が効果的に防止されている。
　さらに、保護膜１０ａは、図２６に示すように、発光層１０５およびｐ半導体層１０６の一部を切り欠き除去して形成された側面と、透光性電極１０９の側面とに連続して形成されている。 In this embodiment, as shown in FIGS. 29A and 29B, the ohmic junction layer 9 is formed in contact with the inner wall surface of the opening 10d, and the outer edge portion of the ohmic junction layer 9 is formed. The protective film 10a is disposed in contact with the protective film 10a, and the protective film 10a prevents contact of air or moisture in a portion of the ohmic bonding layer 9 that is in contact with the protective film 10a.
In this embodiment, as shown in FIGS. 29A and 29B, the outer edge portion of the bonding layer 110, the metal reflective layer 117 constituting the bonding pad electrode 120, and the outer edge portion of the bonding layer 119 are The protective film 10a is disposed in contact with the protective film 10a, and the protective film 10a and the bonding pad electrode 120 surround the entire outer surface of the bonding layer 110 that is not in contact with the ohmic bonding layer 9, and the bonding layer 110 and air or moisture. Is effectively prevented.
Further, as shown in FIG. 26, the protective film 10a is continuously formed on the side surface formed by cutting out part of the light emitting layer 105 and the p semiconductor layer 106 and the side surface of the translucent electrode 109. Has been.
　保護膜１０ａは、透明で、ｎ型半導体層１０４、透光性電極１０９、オーミック接合層９、接合層１１０、ボンディングパッド電極１２０の各層との密着性に優れた材料からなるものとされることが好ましく、具体的にはＳｉＯ２からなるものとされることが好ましい。
　保護膜１０ａの厚みは、２０～５００ｎｍとすることが好ましく、５０～３００ｎｍとすることがより好ましい。保護膜１０ａの厚みが上記範囲未満であると、透光性電極１０９や、ｎ型半導体層１０４、オーミック接合層９、接合層１１０を保護する効果が十分に得られない恐れがある。また、保護膜１０ａの厚みが上記範囲を超えると、透明性が低下して、光の取り出し性に支障を来たす場合がある。また、保護膜１０ａの厚みが上記範囲を超えると、開口部１０ｄの深さが深くなり、開口部１０ｄの内壁面とオーミック接合層９との密着性に支障を来たす恐れが生じる。 The protective film 10a is made of a material that is transparent and has excellent adhesion to the n-type semiconductor layer 104, the translucent electrode 109, the ohmic bonding layer 9, the bonding layer 110, and the bonding pad electrode 120. More specifically, it is preferably made of SiO 2 .
The thickness of the protective film 10a is preferably 20 to 500 nm, and more preferably 50 to 300 nm. If the thickness of the protective film 10a is less than the above range, the effect of protecting the translucent electrode 109, the n-type semiconductor layer 104, the ohmic bonding layer 9, and the bonding layer 110 may not be sufficiently obtained. Further, when the thickness of the protective film 10a exceeds the above range, the transparency may be lowered, and the light extraction property may be hindered. Moreover, when the thickness of the protective film 10a exceeds the above range, the depth of the opening 10d becomes deep, and there is a risk that the adhesion between the inner wall surface of the opening 10d and the ohmic bonding layer 9 may be hindered.
「縁部保護膜」
　縁部保護膜１０ｂは、接合層１１０と空気または水分との接触を防止するとともに、半導体発光素子１からのボンディングパッド電極１２０の剥離を防止してボンディングパッド電極１２０の接合力を向上させるものである。縁部保護膜１０ｂは、図２６および図２７に示すように、平面視したときにボンディングパッド電極１２０の中央部を露出させる領域を除く全域に形成されている。また、縁部保護膜１０ｂは、図２７、図２９（ａ）および図２９（ｂ）に示すように、平面視したときに、ボンディングパッド電極１２０の外縁部（輪郭線）と保護膜１０ａとの継ぎ目となる部分に跨って配置されており、ボンディングパッド電極１２０の外縁部を覆っている。したがって、本実施形態においては、図２９（ａ）および図２９（ｂ）に示すように、ボンディングパッド電極１２０の外縁部は、保護膜１０ａと縁部保護膜１０ｂとの間に挟みこまれている。さらに、縁部保護膜１０ｂは、図２６に示すように、発光層１０５およびｐ半導体層１０６の一部を切り欠き除去して形成された側面と、透光性電極１０９の側面とに、保護膜１０ａを介して連続して形成されている。 "Edge protection film"
The edge protective film 10b prevents contact between the bonding layer 110 and air or moisture, and prevents the bonding pad electrode 120 from peeling from the semiconductor light emitting element 1, thereby improving the bonding force of the bonding pad electrode 120. is there. As shown in FIGS. 26 and 27, the edge protection film 10b is formed over the entire region excluding the region where the central portion of the bonding pad electrode 120 is exposed when viewed in plan. Further, as shown in FIGS. 27, 29 (a), and 29 (b), the edge protective film 10b has an outer edge (contour line) of the bonding pad electrode 120 and the protective film 10a when viewed in plan. Are arranged across the seam of the bonding pad electrode 120 and cover the outer edge of the bonding pad electrode 120. Therefore, in the present embodiment, as shown in FIGS. 29A and 29B, the outer edge portion of the bonding pad electrode 120 is sandwiched between the protective film 10a and the edge protective film 10b. Yes. Further, as shown in FIG. 26, the edge protection film 10 b protects the side surface formed by cutting out part of the light emitting layer 105 and the p semiconductor layer 106 and the side surface of the translucent electrode 109. It is formed continuously through the film 10a.
　縁部保護膜１０ｂは、ボンディングパッド電極１２０と保護膜１０ａとの境界部分を中心として面積を広くするほど、縁部保護膜１０ｂを設けることによる効果が大きくなる。しかし、縁部保護膜１０ｂの面積を大きくすると、縁部保護膜１０ｂから露出されるボンディングパッド電極１２０の面積が小さくなって、ボンディング作業の作業性に支障をきたす恐れや、縁部保護膜１０ｂがボンディングパッド電極１２０の形成されていない領域の透明度を低下させて、光の取り出し性に支障を来たす恐れがある。したがって、縁部保護膜１０ｂは、ボンディングパッド電極１２０と保護膜１０ａとの境界部分を完全に覆い、かつ、ボンディングパッド電極１２０の頂部を露出するものであることが好ましい。具体的には、縁部保護膜１０ｂは、ボンディングパッド電極１２０と縁部保護膜１０ｂとの境界部分を中心として２μｍ以上の幅を有するものであることが好ましい。 The effect of providing the edge protective film 10b increases as the area of the edge protective film 10b increases with the boundary between the bonding pad electrode 120 and the protective film 10a as the center. However, when the area of the edge protection film 10b is increased, the area of the bonding pad electrode 120 exposed from the edge protection film 10b is reduced, which may hinder the workability of the bonding work, or the edge protection film 10b. However, the transparency of the region where the bonding pad electrode 120 is not formed may be lowered, and the light extraction property may be hindered. Therefore, it is preferable that the edge protective film 10b completely covers the boundary between the bonding pad electrode 120 and the protective film 10a and exposes the top of the bonding pad electrode 120. Specifically, the edge protection film 10b preferably has a width of 2 μm or more with the boundary portion between the bonding pad electrode 120 and the edge protection film 10b as the center.
　縁部保護膜１０ｂは、透明で、保護膜１０ａおよびボンディングパッド電極１２０との密着性に優れた材料からなるものとされることが好ましく、保護膜１０ａと同じ材料で形成されることがより好ましい。具体的には、保護膜１０ａおよび縁部保護膜１０ｂをＳｉＯ２からなるものすることができる。縁部保護膜１０ｂと保護膜１０ａとが同じ材料で形成されている場合、縁部保護膜１０ｂと保護膜１０ａとの密着性が非常に良好なものとなるので、縁部保護膜１０ｂを設けることによる効果をより一層向上させることができる。 The edge protective film 10b is preferably made of a material that is transparent and has excellent adhesion to the protective film 10a and the bonding pad electrode 120, and more preferably formed of the same material as the protective film 10a. . Specifically, the protective film 10a and the edge protection film 10b may be those composed of SiO 2. When the edge protection film 10b and the protection film 10a are formed of the same material, the adhesion between the edge protection film 10b and the protection film 10a becomes very good, so the edge protection film 10b is provided. The effect by this can be further improved.
（実施形態１の半導体発光素子の製造方法）
　次に、本発明の実施形態１である半導体発光素子の製造方法の一例について説明する。
　本発明の実施形態１である半導体発光素子の製造方法は、基板上に、発光層を含む積層半導体層を形成する工程と、前記積層半導体層の一部を切り欠けて半導体層露出面を形成する工程と、前記積層半導体層の上面および前記半導体層露出面に一方の（一の伝導型の）電極および他方の（他の伝導型の）電極を形成する電極形成工程と、を有する。
　発光層を含む積層半導体層を形成する工程は、バッファ層形成工程、下地層形成工程、ｎ型半導体層形成工程、発光層形成工程、ｐ型半導体層形成工程とからなる。さらに、ｎ型電極形成工程で、ｎ型電極を形成する。さらに、ｐ型電極形成工程で、マスク形成工程とボンディング電極形成工程を用いて、ｐ型電極を形成する。なお、本実施形態１では、ｐ型半導体層形成工程の後、ｐ型電極形成工程で透光性電極形成工程を行う。 (Method for Manufacturing Semiconductor Light Emitting Element of Embodiment 1)
Next, an example of a method for manufacturing the semiconductor light emitting element according to the first embodiment of the present invention will be described.
A method for manufacturing a semiconductor light-emitting device according to Embodiment 1 of the present invention includes a step of forming a laminated semiconductor layer including a light-emitting layer on a substrate, and forming a semiconductor layer exposed surface by cutting out part of the laminated semiconductor layer. And an electrode forming step of forming one (one conductivity type) electrode and the other (other conductivity type) electrode on the upper surface of the laminated semiconductor layer and the exposed surface of the semiconductor layer.
The step of forming the laminated semiconductor layer including the light emitting layer includes a buffer layer forming step, a base layer forming step, an n-type semiconductor layer forming step, a light emitting layer forming step, and a p-type semiconductor layer forming step. Further, an n-type electrode is formed in the n-type electrode forming step. Further, in the p-type electrode forming step, the p-type electrode is formed using the mask forming step and the bonding electrode forming step. In the first embodiment, the translucent electrode forming step is performed in the p-type electrode forming step after the p-type semiconductor layer forming step.
＜バッファ層形成工程＞
　先ず、サファイア基板等の基板１０１を用意し、前処理を施す。前処理としては、例えば、スパッタ装置のチャンバ内に基板１０１を配置し、バッファ層１０２を形成する前にスパッタするなどの方法によって行うことができる。具体的には、チャンバ内において、基板１０１をＡｒやＮ２のプラズマ中に曝す事によって上面を洗浄する前処理を行なってもよい。ＡｒガスやＮ２ガスなどのプラズマを基板１０１に作用させることで、基板１０１の上面に付着した有機物や酸化物を除去することができる。 <Buffer layer forming step>
First, a substrate 101 such as a sapphire substrate is prepared and pre-processed. The pretreatment can be performed by, for example, a method in which the substrate 101 is disposed in a chamber of a sputtering apparatus and sputtering is performed before the buffer layer 102 is formed. Specifically, a pretreatment for cleaning the upper surface may be performed by exposing the substrate 101 to Ar or N 2 plasma in the chamber. By causing plasma such as Ar gas or N 2 gas to act on the substrate 101, organic substances and oxides attached to the upper surface of the substrate 101 can be removed.
　次に、基板１０１の上面に、スパッタ法によって、バッファ層１０２を積層する。
　スパッタ法によって、単結晶構造を有するバッファ層１０２を形成する場合、チャンバ内の窒素原料と不活性ガスの流量に対する窒素流量の比を、窒素原料が５０％～１００％、望ましくは７５％となるようにすることが望ましい。
　また、スパッタ法によって、柱状結晶（多結晶）有するバッファ層１０２を形成する場合、チャンバ内の窒素原料と不活性ガスの流量に対する窒素流量の比を、窒素原料が１％～５０％、望ましくは２５％となるようにすることが望ましい。なお、バッファ層１０２は、上述したスパッタ法だけでなく、ＭＯＣＶＤ法で形成することもできる。 Next, the buffer layer 102 is stacked on the upper surface of the substrate 101 by sputtering.
When the buffer layer 102 having a single crystal structure is formed by sputtering, the ratio of the nitrogen flow rate to the flow rate of the nitrogen source material and the inert gas in the chamber is 50% to 100%, preferably 75%. It is desirable to do so.
Further, when the buffer layer 102 having columnar crystals (polycrystal) is formed by sputtering, the ratio of the nitrogen flow rate to the nitrogen source flow rate in the chamber to the flow rate of the inert gas is preferably 1% to 50% for the nitrogen source. It is desirable to be 25%. Note that the buffer layer 102 can be formed not only by the sputtering method described above but also by the MOCVD method.
＜下地層形成工程＞
　次に、バッファ層を形成した後、バッファ層１０２の形成された基板１０１の上面に、単結晶の下地層１０３を形成する。下地層１０３は、スパッタ法スパッタ法又はＭＯＣＶＤ法を用いて成膜することが望ましい。スパッタ法を用いる場合には、ＭＯＣＶＤ法やＭＢＥ法等と比較して、装置を簡便な構成とすることが可能となる。下地層１０３をスパッタ法で成膜する際、窒素等のＶ族原料をリアクタ内に流通させるリアクティブスパッタ法によって成膜する方法とすることが好ましい。
　一般に、スパッタ法においては、ターゲット材料の純度が高い程、成膜後の薄膜の結晶性等の膜質が良好となる。下地層１０３をスパッタ法によって成膜する場合、原料となるターゲット材料としてＩＩＩ族窒化物半導体を用い、Ａｒガス等の不活性ガスのプラズマによるスパッタを行なうことも可能であるが、リアクティブスパッタ法においてターゲット材料に用いるＩＩＩ族金属単体並びにその混合物は、ＩＩＩ族窒化物半導体と比較して高純度化が可能である。このため、リアクティブスパッタ法では、成膜される下地層１０３の結晶性をより向上させることが可能となる。 <Underlayer formation process>
Next, after forming the buffer layer, a single crystal base layer 103 is formed on the upper surface of the substrate 101 on which the buffer layer 102 is formed. The base layer 103 is desirably formed by sputtering or sputtering. When the sputtering method is used, the apparatus can have a simple configuration as compared with the MOCVD method, the MBE method, or the like. When forming the underlayer 103 by sputtering, it is preferable to use a reactive sputtering method in which a group V material such as nitrogen is circulated in the reactor.
In general, in the sputtering method, the higher the purity of the target material, the better the film quality such as crystallinity of the thin film after film formation. When the underlayer 103 is formed by sputtering, it is possible to use a group III nitride semiconductor as a target material as a raw material and perform sputtering by plasma of an inert gas such as Ar gas. The group III metal alone and the mixture thereof used as the target material in can be highly purified as compared with the group III nitride semiconductor. For this reason, in the reactive sputtering method, the crystallinity of the underlying layer 103 to be formed can be further improved.
　下地層１０３を成膜する際の基板１０１の温度、つまり、下地層１０３の成長温度は、８００℃以上とすることが好ましく、より好ましくは９００℃以上の温度であり、１０００℃以上の温度とすることが最も好ましい。これは、下地層１０３を成膜する際の基板１０１の温度を高くすることによって原子のマイグレーションが生じやすくなり、転位のループ化が容易に進行するからである。また、下地層１０３を成膜する際の基板１０１の温度は、結晶の分解する温度よりも低温である必要があるため、１２００℃未満とすることが好ましい。下地層１０３を成膜する際の基板１０１の温度が上記温度範囲内であれば、結晶性の良い下地層１０３が得られる。 The temperature of the substrate 101 when the base layer 103 is formed, that is, the growth temperature of the base layer 103 is preferably 800 ° C. or higher, more preferably 900 ° C. or higher, and 1000 ° C. or higher. Most preferably. This is because by increasing the temperature of the substrate 101 when forming the base layer 103, atom migration easily occurs and dislocation looping easily proceeds. In addition, the temperature of the substrate 101 when the base layer 103 is formed needs to be lower than the temperature at which the crystal is decomposed, and is preferably less than 1200 ° C. If the temperature of the substrate 101 when forming the base layer 103 is within the above temperature range, the base layer 103 with good crystallinity can be obtained.
＜ｎ型半導体層形成工程＞
　下地層１０３の形成後、ｎコンタクト層１０４ａ及びｎクラッド層１０４ｂを積層してｎ型半導体層１０４を形成する。ｎコンタクト層１０４ａ及びｎクラッド層１０４ｂは、スパッタ法で形成してもよく、ＭＯＣＶＤ法で形成してもよい。 <N-type semiconductor layer forming step>
After forming the base layer 103, the n-type semiconductor layer 104 is formed by stacking the n-contact layer 104a and the n-cladding layer 104b. The n contact layer 104a and the n clad layer 104b may be formed by sputtering or MOCVD.
＜発光層形成工程＞
　発光層１０５の形成は、スパッタ法、ＭＯＣＶＤ法のいずれの方法でもよいが、特にＭＯＣＶＤ法が好ましい。具体的には、障壁層１０５ａと井戸層１０５ｂとを交互に繰り返して積層し、且つ、ｎ型半導体層１０４側及びｐ型半導体層１０６側に障壁層１０５ａが配される順で積層すればよい。
＜ｐ型半導体層形成工程＞
　また、ｐ型半導体層１０６の形成は、スパッタ法、ＭＯＣＶＤ法のいずれの方法でもよい。具体的には、ｐクラッド層１０６ａと、ｐコンタクト層１０６ｂとを順次積層すればよい。 <Light emitting layer forming step>
The light emitting layer 105 can be formed by either sputtering or MOCVD, but MOCVD is particularly preferable. Specifically, the barrier layers 105a and the well layers 105b are alternately and repeatedly stacked, and the barrier layers 105a may be stacked in the order in which the barrier layers 105a are disposed on the n-type semiconductor layer 104 side and the p-type semiconductor layer 106 side. .
<P-type semiconductor layer forming step>
Further, the p-type semiconductor layer 106 may be formed by either sputtering or MOCVD. Specifically, the p-cladding layer 106a and the p-contact layer 106b may be sequentially stacked.
＜ｎ型電極形成工程＞
　公知のフォトリソグラフィーの手法によってパターニングして、所定の領域の積層半導体層２０の一部をエッチングしてｎコンタクト層１０４ａの一部を露出させる。次に、ｎコンタクト層１０４ａの露出面１０４ｃにスパッタ法などによりｎ型電極１０８を形成する。 <N-type electrode formation process>
Patterning is performed by a known photolithography technique, and a part of the laminated semiconductor layer 20 in a predetermined region is etched to expose a part of the n contact layer 104a. Next, the n-type electrode 108 is formed on the exposed surface 104c of the n-contact layer 104a by sputtering or the like.
＜ｐ型電極形成工程＞
　ｐ型電極形成工程は、透光性電極形成工程と電極形成工程とからなる。
＜透光性電極形成工程＞
　マスクでｎ型電極をカバーして、エッチング除去せずに残したｐ型半導体層１０６上に、スパッタ法などの公知の方法を用いて、透光性電極１０９を形成する。
　なお、ｎ型電極形成工程の前に、透光性電極を形成した後、透光性電極を形成した状態で、所定の領域の積層半導体層２０の一部をエッチングしてｎコンタクト層１０４ａを形成して、ｎ型電極１０８を形成してもよい。 <P-type electrode formation process>
The p-type electrode forming step includes a translucent electrode forming step and an electrode forming step.
<Translucent electrode forming step>
The n-type electrode is covered with a mask, and the light-transmitting electrode 109 is formed on the p-type semiconductor layer 106 left without being removed by etching using a known method such as sputtering.
In addition, after forming the translucent electrode before the n-type electrode forming step, with the translucent electrode formed, a part of the laminated semiconductor layer 20 in a predetermined region is etched to form the n contact layer 104a. The n-type electrode 108 may be formed.
＜電極形成工程＞
　図５は、電極形成工程を説明する工程断面図である。
　電極形成工程は、接合層を形成した後、接合層を覆うように金属反射層を形成し、更に金属反射層を覆うようにボンディング層を形成するとともに、接合層、金属反射層およびボンディング層の側面を中心側よりも外周側が薄くなるように傾斜させて形成する工程である。
　まず、透光性電極１０９の上面１０９ｃ上にＳｉＯ２からなる保護膜１０を形成した後、図５（ａ）に示すように、保護膜１０上にレジスト２１を塗布する。 <Electrode formation process>
FIG. 5 is a process cross-sectional view illustrating an electrode forming process.
In the electrode forming step, after forming the bonding layer, the metal reflection layer is formed so as to cover the bonding layer, and further the bonding layer is formed so as to cover the metal reflection layer, and the bonding layer, the metal reflection layer, and the bonding layer In this step, the side surface is inclined so that the outer peripheral side is thinner than the center side.
First, after forming the protective film 10 made of SiO 2 on the upper surface 109c of the translucent electrode 109, a resist 21 is applied on the protective film 10 as shown in FIG.
　次に、図５（ｂ）に示すように、ボンディングパッド電極を形成する部分に対応する部分のレジスト２１を除去することによって、逆テーパー型の架橋高分子からなる硬化部（逆テーパー型マスク）２３を形成する。逆テーパー型マスク２３を形成する方法としては、ｎ型フォトレジストを用いる方法またはイメージ反転型フォトレジストを用いる方法などの公知の方法があるが、本実施形態１では、イメージ反転型フォトレジストを用いる方法について説明する。
　図６は、図５（ｂ）に示す逆テーパー型マスク形成工程を説明する断面工程図である。 Next, as shown in FIG. 5B, the portion of the resist 21 corresponding to the portion where the bonding pad electrode is to be formed is removed, thereby forming a cured portion (reverse taper type mask) made of a reverse taper type crosslinked polymer. 23 is formed. As a method of forming the inverse tapered mask 23, there are known methods such as a method using an n-type photoresist or a method using an image inversion type photoresist. In the first embodiment, an image inversion type photoresist is used. A method will be described.
FIG. 6 is a cross-sectional process diagram for explaining the reverse taper mask forming process shown in FIG.
＜マスク形成工程＞
　マスク形成工程は、透光性電極上に不溶性レジストを塗布してレジスト部を形成するレジスト塗布工程と、レジスト部の一部をマスクして露光することにより、露光により形成された可溶部と露光されずに残された不溶部とを形成する一部露光工程と、加熱により前記可溶部を硬化部とする硬化工程と、レジスト部を全面露光して、前記不溶部を可溶部とする全面露光工程と、レジスト剥離液に浸漬することにより前記可溶部を剥離する剥離工程と、を有する。 <Mask formation process>
The mask formation step includes: a resist coating step of forming a resist portion by applying an insoluble resist on the translucent electrode; and a soluble portion formed by exposure by masking and exposing a part of the resist portion. A partial exposure step for forming an insoluble portion left unexposed, a curing step in which the soluble portion becomes a cured portion by heating, and a resist portion is fully exposed to form the insoluble portion as a soluble portion. A whole surface exposure step, and a peeling step of peeling the soluble portion by dipping in a resist stripping solution.
＜レジスト塗布工程＞
　まず、透光性電極１０９上の保護膜１０上に不溶性レジストを塗布して、これを乾燥してレジスト部２１とする。イメージ反転型フォトレジストとしては、たとえば、ＡＺ５２００ＮＪ（製品名：ＡＺエレクトロニックマテリアルズ株式会社製）などを用いる。
＜一部露光工程＞
　次に、断面視したときに、図６（ａ）に示すように、レジスト部２１の上面に電極を形成する位置をカバーするようにマスク２５を配置して、マスク２５側から基板１側へ矢印に示すように所定強さ及び波長の光を照射することにより、光が照射された部分のレジスト部２１を光反応させて、可溶性のレジスト部（可溶部）２２とする。
　この光反応は光の強さに応じて進行するので、光照射面側では光反応の進行が早く、透光性電極１０９側では光反応の進行が遅くなる。そのため、可溶性のレジスト部（可溶部）２２は、断面視したときに、図６（ａ）に示すように、マスク２５でカバーされた部分（電極を形成する位置）向けて、その側面が下方に向かうほど内側に後退した逆テーパー形状（逆傾斜形状）となるように形成される。
　なお、マスクされた部分のレジスト部２１は、不溶性のレジスト部（不溶部）２１として残され、断面視したときに側面が上方に向かうほど内側に後退したテーパー形状（傾斜形状）となるように形成される。 <Resist application process>
First, an insoluble resist is applied on the protective film 10 on the translucent electrode 109 and dried to form a resist portion 21. As the image reversal type photoresist, for example, AZ5200NJ (product name: manufactured by AZ Electronic Materials Co., Ltd.) is used.
<Partial exposure process>
Next, when viewed in cross section, as shown in FIG. 6A, a mask 25 is disposed on the upper surface of the resist portion 21 so as to cover the position where the electrode is formed, and from the mask 25 side to the substrate 1 side. By irradiating light of a predetermined intensity and wavelength as indicated by the arrow, the resist portion 21 in the portion irradiated with light is photoreacted to form a soluble resist portion (soluble portion) 22.
Since this photoreaction proceeds according to the intensity of light, the photoreaction progresses quickly on the light irradiation surface side, and the photoreaction progresses slowly on the translucent electrode 109 side. Therefore, the side surface of the soluble resist portion (soluble portion) 22 is directed toward the portion (position where the electrode is formed) covered with the mask 25 as shown in FIG. It forms so that it may become reverse taper shape (reverse inclination shape) which retreated inside, so that it goes below.
The masked portion of the resist portion 21 remains as an insoluble resist portion (insoluble portion) 21 and has a tapered shape (inclined shape) that recedes inward as the side faces upward when viewed in cross section. It is formed.
＜硬化工程＞
　次に、たとえば、ホットプレートまたはオーブンなどを用いて、この基板１を加熱することにより、図６（ｂ）に示すように、溶解性のレジスト部２２を熱反応により架橋させて、架橋高分子からなる硬化部２３とする。
＜全面露光工程＞
　次に、図６（ｃ）に示すように、マスクを用いず、不溶性のレジスト部（不溶部）２１および架橋高分子からなる硬化部２３の表面側に光を照射することにより、図６（ａ）で溶解性のレジスト２２に変換されなかった不溶性のレジスト部（不溶部）２１を光反応させて、溶解性のレジスト部（可溶部）２２とする。
＜剥離工程＞
　最後に、所定の現像液を用いて、溶解性のレジスト部（可溶部）２２を溶解除去することにより、図６（ｄ）に示すように、側面が下方に向かうほど内側に後退した逆テーパー形状（逆傾斜形状）、つまり、逆テーパー型の架橋高分子からなる硬化部（逆テーパー型マスク）２３を形成することができる。 <Curing process>
Next, by heating the substrate 1 using, for example, a hot plate or an oven, the soluble resist portion 22 is cross-linked by a thermal reaction as shown in FIG. It is set as the hardening part 23 which consists of.
<Full exposure process>
Next, as shown in FIG. 6C, without using a mask, light is irradiated to the surface side of the insoluble resist portion (insoluble portion) 21 and the hardened portion 23 made of a crosslinked polymer, so that FIG. The insoluble resist part (insoluble part) 21 that has not been converted into the soluble resist 22 in a) is photoreacted to form a soluble resist part (soluble part) 22.
<Peeling process>
Finally, by dissolving and removing the soluble resist portion (soluble portion) 22 using a predetermined developer, as shown in FIG. A cured portion (reverse taper type mask) 23 made of a taper shape (reverse inclination shape), that is, a reverse taper type crosslinked polymer can be formed.
　再び、図５に戻り、図５（ｃ）に示すように、透光性電極１０９の上面１０９ｃに垂直な方向からＳｉＯ２からなる保護膜１０のＲＩＥ（反応性イオンエッチング）を行い、ボンディングパッド電極を形成する部分に対応する部分の保護膜１０を除去して、透光性電極１０９の上面１０９ｃを露出させる。
　ＲＩＥ（反応性イオンエッチング）は、直進性が高く、回り込みが少ないエッチング方法であるので、エッチング方向から影となる保護膜１０はほとんどエッチング除去されず、図５（ｃ）に示すように保護膜１０の端部１０ｃが残される。
　この後、透光性電極１０９の露出された上面１０９ｃをウェットエッチングすることが好ましい。これにより、上面１０９ｃを不純物や欠陥が取り除かれたフレッシュ面とすることができ、上面１０９ｃに接合する接合層１１０との密着性を向上させることができる。 Returning to FIG. 5 again, as shown in FIG. 5C, RIE (reactive ion etching) of the protective film 10 made of SiO 2 is performed from a direction perpendicular to the upper surface 109c of the translucent electrode 109, and a bonding pad is formed. The portion of the protective film 10 corresponding to the portion where the electrode is to be formed is removed, and the upper surface 109c of the translucent electrode 109 is exposed.
RIE (Reactive Ion Etching) is an etching method that has high straightness and little wraparound, so that the protective film 10 that is shaded from the etching direction is hardly removed by etching, and the protective film as shown in FIG. Ten end portions 10c are left.
Thereafter, the exposed upper surface 109c of the translucent electrode 109 is preferably wet etched. Accordingly, the upper surface 109c can be a fresh surface from which impurities and defects are removed, and adhesion with the bonding layer 110 bonded to the upper surface 109c can be improved.
　次に、スパッタ法により、透光性電極１０９の上面１０９ｃおよび架橋高分子からなる硬化部（逆テーパー型マスク）２３の上に接合層１１０を形成する。このとき、スパッタ条件を制御したスパッタ法を用いることにより、スパッタ材料によらず、カバレッジ性を高くして接合層１１０を成膜することができる。これにより、接合層１１０は、透光性電極１０９の上面１０９ｃ全面にほぼ均一に形成されるとともに、保護膜１０の端部１０ｃを一部わずかに覆うように形成される。 Next, the bonding layer 110 is formed on the upper surface 109c of the translucent electrode 109 and the cured portion (reverse taper type mask) 23 made of a crosslinked polymer by sputtering. At this time, by using a sputtering method in which sputtering conditions are controlled, the bonding layer 110 can be formed with high coverage regardless of the sputtering material. As a result, the bonding layer 110 is formed substantially uniformly over the entire upper surface 109 c of the translucent electrode 109 and is formed so as to partially cover the end portion 10 c of the protective film 10.
　次に、金属反射層１１７を形成する。このとき、接合層１１０の形成の場合と同様に、スパッタ条件を制御したスパッタ法を用いることにより、スパッタ材料によらず、カバレッジ性を高くして、金属反射層１１７を成膜することができる。また、接合層１１０よりも膜厚が厚くなるように金属反射層１１７を形成することにより、金属反射層１１７は、接合層１１０を完全に覆うように形成される。 Next, a metal reflection layer 117 is formed. At this time, as in the case of forming the bonding layer 110, by using a sputtering method in which the sputtering conditions are controlled, the metal reflective layer 117 can be formed with high coverage regardless of the sputtering material. . Further, the metal reflective layer 117 is formed so as to completely cover the bonding layer 110 by forming the metal reflective layer 117 so as to be thicker than the bonding layer 110.
　次に、ボンディング層１１９を形成する。このとき、スパッタ条件を制御したスパッタ法を用いることにより、スパッタ材料によらず、カバレッジ性を高くして、ボンディング層１１９を成膜することができる。また、ボンディング層１１９は、接合層１１０および金属反射層１１７に比較して非常に厚くなるように形成するので、図５（ｄ）に示すように、金属反射層１１７を完全に覆うように形成される。
　最後に、レジスト剥離液に浸漬することにより、架橋高分子からなる硬化部（逆テーパー型マスク）２３を剥離する。これにより、図５（ｅ）に示すように、金属反射層１１７とボンディング層１１９とからなるボンディングパッド電極１２０を有するｐ型電極１１１を形成する。 Next, a bonding layer 119 is formed. At this time, by using a sputtering method in which sputtering conditions are controlled, the bonding layer 119 can be formed with high coverage regardless of the sputtering material. Further, the bonding layer 119 is formed so as to be much thicker than the bonding layer 110 and the metal reflective layer 117, so that the metal reflective layer 117 is completely covered as shown in FIG. Is done.
Finally, the cured portion (reverse taper type mask) 23 made of a crosslinked polymer is peeled off by immersing in a resist stripping solution. Thereby, as shown in FIG. 5E, the p-type electrode 111 having the bonding pad electrode 120 composed of the metal reflection layer 117 and the bonding layer 119 is formed.
　このように、ボンディング電極形成工程における接合層１１０、金属反射層１１７およびボンディング層１１９の形成がスパッタ法により行われる構成なので、逆テーパー型マスク２３のスパッタ方向から影となる部分では、膜厚に応じて傾斜角度の異なる層を形成することができる。これにより、接合層１１０およびボンディングパッド電極１２０の外周部にそれぞれ、外周側に向けて膜厚が漸次薄くなるような傾斜面１１０ｃ、１１７ｃ、１１９ｃを形成することができる。 As described above, since the formation of the bonding layer 110, the metal reflective layer 117, and the bonding layer 119 in the bonding electrode forming step is performed by the sputtering method, the film thickness is reduced in the portion that is shaded from the sputtering direction of the reverse tapered mask 23. Accordingly, layers having different inclination angles can be formed. Thereby, the inclined surfaces 110c, 117c, and 119c can be formed on the outer peripheral portions of the bonding layer 110 and the bonding pad electrode 120 so that the film thickness gradually decreases toward the outer peripheral side.
　なお、接合層１１０を形成する前に、接合層１１０を形成する領域の透光性電極１０９の表面を洗浄する前処理を施しても良い。洗浄の方法としてはプラズマなどに曝すドライプロセスによるものと薬液に接触させるウェットプロセスによるものがあるが、工程の簡便さの観点より、ドライプロセスが望ましい。
　このようにして、図１～図３に示す半導体発光素子１を製造する。 Note that before the bonding layer 110 is formed, pretreatment for cleaning the surface of the light-transmitting electrode 109 in a region where the bonding layer 110 is formed may be performed. As a cleaning method, there are a dry process that is exposed to plasma or the like and a wet process that is brought into contact with a chemical solution. The dry process is desirable from the viewpoint of simplicity of the process.
In this way, the semiconductor light emitting device 1 shown in FIGS. 1 to 3 is manufactured.
　本発明の実施形態である半導体発光素子１は、一方の電極１１１が、接合層１１０と接合層１１０を覆うように形成されたボンディングパッド電極１２０とからなり、ボンディングパッド電極１２０の最大厚みが、接合層１１０の最大厚みに比べて厚く形成され、かつ、１または２以上の層からなり、接合層１１０およびボンディングパッド電極１２０の外周部１１０ｄ、１２０ｄにそれぞれ、外周側に向けて膜厚が漸次薄くなるような傾斜面１１０ｃ、１１７ｃ、１１９ｃが形成されている構成なので、外部の空気または水分の接合層１１０への侵入を防止することができ、接合層１１０の耐食性を向上して、半導体発光素子寿命を長くすることができる。 In the semiconductor light emitting device 1 according to the embodiment of the present invention, one electrode 111 includes a bonding layer 110 and a bonding pad electrode 120 formed so as to cover the bonding layer 110, and the maximum thickness of the bonding pad electrode 120 is It is formed thicker than the maximum thickness of the bonding layer 110, and is composed of one or more layers. The outer layer 110d and 120d of the bonding layer 110 and the bonding pad electrode 120 are gradually increased in thickness toward the outer periphery. Since the thin inclined surfaces 110c, 117c, and 119c are formed, it is possible to prevent external air or moisture from entering the bonding layer 110, improve the corrosion resistance of the bonding layer 110, and emit semiconductor light. The device life can be extended.
　本発明の実施形態である半導体発光素子１は、接合層１１０が、Ａｌ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｃｏ、Ｚｎ、Ｇｅ、Ｚｒ、Ｎｂ、Ｍｏ、Ｒｕ、Ｈｆ、Ｔａ、Ｗ、Ｒｅ、Ｒｈ、Ｉｒ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなるものであり、最大厚みが１０Å以上１０００Å以下の範囲の薄膜である構成なので、透光性電極１０９とボンディングパッド電極１２０との間の接合性を向上させて、ボンディングワイヤ接合時の引張応力によっても剥がれることのない電極とすることができる。 In the semiconductor light emitting device 1 according to the embodiment of the present invention, the bonding layer 110 has Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Since it is composed of at least one element selected from the group consisting of Rh, Ir and Ni and is a thin film having a maximum thickness in the range of 10 to 1000 mm, the translucent electrode 109 and the bonding pad electrode 120 Thus, an electrode that does not peel off due to tensile stress during bonding of the bonding wires can be obtained.
　本発明の実施形態である半導体発光素子１は、Ａｕ、Ａｌまたはこれらの金属の何れかを含む合金からなるボンディング層からなり、前記ボンディング層の最大厚みが５０ｎｍ以上２０００ｎｍ以下の範囲の薄膜である構成なので、ボンディングパッド電極１２０へのワイヤボンディングの接合性を向上させて、ボンディングワイヤ接合時の引張応力によっても剥がれることのない電極とすることができる。 A semiconductor light-emitting device 1 according to an embodiment of the present invention is a thin film having a bonding layer made of Au, Al, or an alloy containing any of these metals, and a maximum thickness of the bonding layer in a range of 50 nm to 2000 nm. Since it is a structure, it can be set as the electrode which improves the bondability of the wire bonding to the bonding pad electrode 120, and does not peel even by the tensile stress at the time of bonding wire bonding.
　本発明の実施形態である半導体発光素子１は、ボンディングパッド電極１２０が、接合層１１０を覆うように形成された金属反射層１１７と、金属反射層１１７を覆うように形成されたボンディング層１２０とからなり、金属反射層１１７が、Ａｇ、Ａｌ、Ｒｕ、Ｒｈ、Ｐｄ、Ｏｓ、Ｉｒ、Ｐｔ、Ｔｉのうちの何れかまたはこれら金属の何れかを含む合金からなるものであり、最大厚みが２０ｎｍ以上３０００ｎｍ以下の範囲の薄膜である構成なので、電極の接合性および耐食性を向上させ、半導体発光素子の発光特性を向上させることができる。 In the semiconductor light emitting device 1 according to the embodiment of the present invention, the bonding pad electrode 120 includes a metal reflective layer 117 formed so as to cover the bonding layer 110, and a bonding layer 120 formed so as to cover the metal reflective layer 117. The metal reflective layer 117 is made of Ag, Al, Ru, Rh, Pd, Os, Ir, Pt, Ti or an alloy containing any of these metals, and has a maximum thickness of 20 nm. Since the thin film has a thickness in the range of 3000 nm or less, the bonding property and corrosion resistance of the electrodes can be improved, and the light emission characteristics of the semiconductor light emitting element can be improved.
　本発明の実施形態である半導体発光素子１は、一の伝導型の電極１１１と積層半導体層２０の上面１０６ｃとの間に透光性電極１０９が形成されており、透光性電極１０９が、Ｉｎ、Ｚｎ、Ａｌ、Ｇａ、Ｔｉ、Ｂｉ、Ｍｇ、Ｗ、Ｃｅ、Ｓｎ、Ｎｉのいずれか一種を含む導電性の酸化物、硫化亜鉛または硫化クロムのうちいずれか一種からなる群より選ばれる透光性の導電性材料から構成される構成なので、電極の接合性および耐食性を向上させ、半導体発光素子の発光特性を向上させることができる。 In the semiconductor light emitting device 1 according to the embodiment of the present invention, a translucent electrode 109 is formed between one conductive electrode 111 and the upper surface 106c of the laminated semiconductor layer 20, and the translucent electrode 109 is A conductive oxide containing any one of In, Zn, Al, Ga, Ti, Bi, Mg, W, Ce, Sn, and Ni, a transparent material selected from the group consisting of any one of zinc sulfide and chromium sulfide. Since the structure is made of a light conductive material, the bonding property and corrosion resistance of the electrodes can be improved, and the light emission characteristics of the semiconductor light emitting element can be improved.
本発明の実施形態である半導体発光素子１は、積層半導体層２０が、基板１０１側から、ｎ型半導体層１０４、発光層１０５、ｐ型半導体層１０６の順に積層されてなり、前記発光層１０５が多重量子井戸構造である構成なので、電極の接合性および耐食性を向上させ、半導体発光素子の発光特性を向上させることができる。 In the semiconductor light emitting device 1 according to the embodiment of the present invention, the laminated semiconductor layer 20 is formed by laminating the n-type semiconductor layer 104, the light-emitting layer 105, and the p-type semiconductor layer 106 in this order from the substrate 101 side. Since the structure has a multi-quantum well structure, it is possible to improve the bondability and corrosion resistance of the electrodes and improve the light emission characteristics of the semiconductor light emitting device.
　本発明の実施形態である半導体発光素子１は、積層半導体層２０が、窒化ガリウム系半導体を主体として構成されている構成なので、電極の接合性および耐食性を向上させ、半導体発光素子の発光特性を向上させることができる。 In the semiconductor light emitting device 1 according to the embodiment of the present invention, since the laminated semiconductor layer 20 is mainly composed of a gallium nitride-based semiconductor, the bonding property and corrosion resistance of the electrodes are improved, and the light emitting characteristics of the semiconductor light emitting device are improved. Can be improved.
　本発明の実施形態である半導体発光素子１用の電極は、一方の電極１１１または他方の電極１０８の少なくともいずれか一方が、接合層１１０と接合層１１０を覆うように形成されたボンディングパッド電極１２０とからなり、ボンディングパッド電極１２０の最大厚みが、接合層１１０の最大厚みに比べて厚く形成され、かつ、１または２以上の層からなり、接合層１１０およびボンディングパッド電極１２０の外周部１１０ｄ、１２０ｄにそれぞれ、外周側に向けて膜厚が漸次薄くなるような傾斜面１１０ｃ、１１７ｃ、１１９ｃが形成されている構成なので、接合性および耐食性を向上させた電極とすることができる。 The electrode for the semiconductor light emitting device 1 according to the embodiment of the present invention includes a bonding pad electrode 120 formed so that at least one of the one electrode 111 and the other electrode 108 covers the bonding layer 110 and the bonding layer 110. The bonding pad electrode 120 has a maximum thickness that is larger than the maximum thickness of the bonding layer 110, and is composed of one or more layers. The outer peripheral portion 110d of the bonding layer 110 and the bonding pad electrode 120, Since the inclined surfaces 110c, 117c, and 119c are formed in 120d so that the film thickness gradually decreases toward the outer peripheral side, it is possible to obtain an electrode with improved bondability and corrosion resistance.
　本発明の実施形態である半導体発光素子１用の電極は、接合層１１０が、Ａｌ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｃｏ、Ｚｎ、Ｇｅ、Ｚｒ、Ｎｂ、Ｍｏ、Ｒｕ、Ｈｆ、Ｔａ、Ｗ、Ｒｅ、Ｒｈ、Ｉｒ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなるものであり、最大厚みが１０Å以上１０００Å以下の範囲の薄膜である構成なので、接合性および耐食性を向上させた電極とすることができる。 In the electrode for the semiconductor light emitting device 1 according to the embodiment of the present invention, the bonding layer 110 has Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, and W. , Re, Rh, Ir, Ni, and at least one element selected from the group consisting of a thin film having a maximum thickness in the range of 10 mm to 1000 mm, so that the electrode has improved bondability and corrosion resistance It can be.
　本発明の実施形態である半導体発光素子１用の電極は、ボンディングパッド電極１２０が、Ａｕ、Ａｌまたはこれらの金属の何れかを含む合金からなるボンディング層１１９からなり、ボンディング層１１９の最大厚みが５０ｎｍ以上２０００ｎｍ以下の範囲の薄膜である構成なので、金ワイヤーとのボンディング性および耐食性を向上させた電極とすることができる。 In the electrode for the semiconductor light emitting device 1 according to the embodiment of the present invention, the bonding pad electrode 120 is made of a bonding layer 119 made of Au, Al, or an alloy containing any of these metals, and the bonding layer 119 has a maximum thickness. Since it is a structure which is a thin film of the range of 50 nm or more and 2000 nm or less, it can be set as the electrode which improved the bondability and corrosion resistance with a gold wire.
　本発明の実施形態である半導体発光素子１用の電極は、ボンディングパッド電極１２０が、接合層１１０を覆うように形成された金属反射層１１７と、金属反射層１１７を覆うように形成されたボンディング層１１９とからなり、金属反射層１１７が、Ａｇ、Ａｌ、Ｒｕ、Ｒｈ、Ｐｄ、Ｏｓ、Ｉｒ、Ｐｔ、Ｔｉのうちの何れかまたはこれら金属の何れかを含む合金からなるものであり、最大厚みが２０ｎｍ以上３０００ｎｍ以下の範囲の薄膜である構成なので、光の取り出し効率を向上させた電極とすることができる。 In the electrode for the semiconductor light emitting device 1 according to the embodiment of the present invention, the bonding pad electrode 120 is formed so as to cover the bonding layer 110, and the bonding is formed so as to cover the metal reflecting layer 117. The metal reflective layer 117 is made of Ag, Al, Ru, Rh, Pd, Os, Ir, Pt, Ti or an alloy containing any of these metals, and the maximum Since the thin film has a thickness in the range of 20 nm to 3000 nm, an electrode with improved light extraction efficiency can be obtained.
　本発明の実施形態である半導体発光素子１用の電極は、一方の電極１１１と積層半導体層２０の上面１０６ｃとの間または他方の電極１０８と半導体層露出面１０４ｃとの間に透光性電極１０９が形成されており、透光性電極１０９が、Ｉｎ、Ｚｎ、Ａｌ、Ｇａ、Ｔｉ、Ｂｉ、Ｍｇ、Ｗ、Ｃｅ、Ｓｎ、Ｎｉのいずれか一種を含む導電性の酸化物、硫化亜鉛または硫化クロムのうちいずれか一種からなる群より選ばれる透光性の導電性材料から構成される構成なので、接合性および耐食性を向上させた電極とすることができる。 The electrode for the semiconductor light emitting device 1 according to the embodiment of the present invention is a translucent electrode between one electrode 111 and the upper surface 106c of the laminated semiconductor layer 20 or between the other electrode 108 and the semiconductor layer exposed surface 104c. 109, and the translucent electrode 109 is a conductive oxide containing any one of In, Zn, Al, Ga, Ti, Bi, Mg, W, Ce, Sn, Ni, zinc sulfide, Since it is the structure comprised from the translucent electroconductive material chosen from the group which consists of either 1 type among chromium sulfide, it can be set as the electrode which improved bondability and corrosion resistance.
　本発明の実施形態である半導体発光素子の製造方法は、電極形成工程が、積層半導体層２０の上面１０６ｃに逆テーパー型マスク２３を形成した後、積層半導体層２０の上面１０６ｃ上に接合層１１０を形成し、その後、接合層１１０を覆うように接合層１１０の最大厚みに比べて最大厚みの厚いボンディングパッド電極１２０を形成して、一方の電極１１１を形成する工程である構成なので、接合層１１０およびボンディングパッド電極１２０の外周部１１０ｄ、１２０ｄにそれぞれ外周側が漸次薄くなるような傾斜面１１０ｃ、１１７ｃ、１１９ｃを形成することができ、外部の空気または水分の接合層１１０への侵入を防止することができ、接合層１１０の耐食性を向上して、半導体発光素子寿命を長くすることができる。 In the method for manufacturing a semiconductor light emitting device according to the embodiment of the present invention, the electrode forming step forms the inverse tapered mask 23 on the upper surface 106 c of the stacked semiconductor layer 20, and then the bonding layer 110 on the upper surface 106 c of the stacked semiconductor layer 20. After that, the bonding pad electrode 120 having a maximum thickness compared to the maximum thickness of the bonding layer 110 is formed so as to cover the bonding layer 110, and the one electrode 111 is formed. Inclined surfaces 110c, 117c, and 119c can be formed on the outer peripheral portions 110d and 120d of the 110 and the bonding pad electrode 120 so that the outer peripheral side gradually becomes thinner, thereby preventing external air or moisture from entering the bonding layer 110. Therefore, the corrosion resistance of the bonding layer 110 can be improved, and the lifetime of the semiconductor light emitting device can be extended.
　本発明の実施形態である半導体発光素子の製造方法は、前記電極形成工程の前に積層半導体層２０の上面１０６ｃまたは半導体層露出面１０４ｃに透光性電極１０９を形成する工程を有する構成なので、電極の接合性および耐食性を向上させ、半導体発光素子の発光特性を向上させることができる。 Since the method for manufacturing a semiconductor light emitting device according to an embodiment of the present invention includes a step of forming the translucent electrode 109 on the upper surface 106c of the stacked semiconductor layer 20 or the exposed surface 104c of the semiconductor layer before the electrode forming step, Electrode bondability and corrosion resistance can be improved, and the light emission characteristics of the semiconductor light emitting device can be improved.
　本発明の実施形態である半導体発光素子の製造方法は、電極形成工程が、逆テーパー型マスク２３および接合層１１０を形成した後、接合層１１０を覆うように接合層１１０の最大厚みに比べて最大厚みの厚い金属反射層１１７を形成し、その後、金属反射層１１７を覆うように金属反射層１１７の最大厚みに比べて最大厚みの厚いボンディング層１２０を形成して、一方の電極１１１を形成する工程である構成なので、接合層１１０およびボンディングパッド電極１２０の外周部１１０ｄ、１２０ｄにそれぞれ外周側が漸次薄くなるような傾斜面１１０ｃ、１１７ｃ、１１９ｃを形成することができ、外部の空気または水分の接合層１１０への侵入を防止することができ、接合層１１０の耐食性を向上して、半導体発光素子寿命を長くすることができる。 In the method for manufacturing a semiconductor light emitting device according to the embodiment of the present invention, the electrode forming step forms the inverse tapered mask 23 and the bonding layer 110 and then covers the bonding layer 110 so as to cover the bonding layer 110. A metal reflective layer 117 having a maximum thickness is formed, and then a bonding layer 120 having a maximum thickness compared to the maximum thickness of the metal reflective layer 117 is formed so as to cover the metal reflective layer 117, and one electrode 111 is formed. Therefore, the inclined surfaces 110c, 117c, and 119c can be formed on the outer peripheral portions 110d and 120d of the bonding layer 110 and the bonding pad electrode 120 so that the outer peripheral sides become gradually thinner. Intrusion into the bonding layer 110 can be prevented, the corrosion resistance of the bonding layer 110 is improved, and the lifetime of the semiconductor light emitting device is extended. It is possible.
　本発明の実施形態である半導体発光素子の製造方法は、ボンディング電極形成工程における接合層１１０、金属反射層１１７およびボンディング層１１９の形成が、スパッタ法により行われる構成なので、逆テーパー型マスク２３のスパッタ方向から影となる部分では、膜厚に応じて傾斜角度の異なる層を形成することができる。これにより、接合層１１０およびボンディングパッド電極１２０の外周部１１０ｄ、１２０ｄにそれぞれ外周側が漸次薄くなるような傾斜面１１０ｃ、１１７ｃ、１１９ｃを形成することができ、外部の空気または水分の接合層１１０への侵入を防止することができ、接合層１１０の耐食性を向上して、半導体発光素子寿命を長くすることができる。 In the method of manufacturing a semiconductor light emitting device according to the embodiment of the present invention, since the formation of the bonding layer 110, the metal reflection layer 117, and the bonding layer 119 in the bonding electrode forming step is performed by the sputtering method, In a portion shaded from the sputtering direction, layers having different inclination angles can be formed according to the film thickness. Thereby, the inclined surfaces 110c, 117c, and 119c can be formed on the outer peripheral portions 110d and 120d of the bonding layer 110 and the bonding pad electrode 120 so that the outer peripheral sides become gradually thinner. Can be prevented, the corrosion resistance of the bonding layer 110 can be improved, and the lifetime of the semiconductor light emitting device can be extended.
　本発明の実施形態である半導体発光素子の製造方法は、マスク形成工程の前に、透光性電極１０９の上面１０９ｃに保護膜１０を形成する工程を備えた構成なので、透光性電極１０９の上面を保護することができる。 Since the method of manufacturing a semiconductor light emitting device according to the embodiment of the present invention includes a step of forming the protective film 10 on the upper surface 109c of the translucent electrode 109 before the mask forming step, The top surface can be protected.
（実施形態２）
　図７は、本発明の実施形態である半導体発光素子の別の一例を示す断面模式図である。
　図７に示すように、本発明の実施形態である半導体発光素子２は、ｎ型半導体層１０４上に形成された保護膜１０に開口された露出面１０４ｃ上に別の接合層１３０が形成され、別の接合層１３０を覆うようにｎ型電極１０８が形成されているほかは実施形態１と同様の構成とされている。なお、実施形態１と同じ部材には同じ符号を付して示している。 (Embodiment 2)
FIG. 7 is a schematic cross-sectional view showing another example of the semiconductor light emitting device according to the embodiment of the present invention.
As shown in FIG. 7, in the semiconductor light emitting device 2 according to the embodiment of the present invention, another bonding layer 130 is formed on the exposed surface 104 c opened in the protective film 10 formed on the n-type semiconductor layer 104. The configuration is the same as that of the first embodiment except that the n-type electrode 108 is formed so as to cover another bonding layer 130. The same members as those in the first embodiment are denoted by the same reference numerals.
　接合層１３０の外周部１３０ｄに、外周側に向けて膜厚が漸次薄くなるような傾斜面１３０ｃが形成されている。
　ボンディングパッド電極を兼ねるｎ型電極１０８の最大厚みは、接合層１３０の最大厚みに比べて厚く形成され、かつ、１層で形成されている。ボンディングパッド電極を兼ねるｎ型電極１０８の外周部１０８ｄに、外周側に向けて膜厚が漸次薄くなるような傾斜面１０８ｃが形成されている。これにより、外部の空気または水分の接合層１３０への侵入を防止することができ、接合層１３０の耐食性を向上して、半導体発光素子寿命を長くすることができる。 An inclined surface 130c is formed on the outer peripheral portion 130d of the bonding layer 130 so that the film thickness gradually decreases toward the outer peripheral side.
The maximum thickness of the n-type electrode 108 that also serves as a bonding pad electrode is formed to be thicker than the maximum thickness of the bonding layer 130 and is formed of one layer. An inclined surface 108c is formed on the outer peripheral portion 108d of the n-type electrode 108 serving also as a bonding pad electrode so that the film thickness gradually decreases toward the outer peripheral side. Thereby, it is possible to prevent external air or moisture from entering the bonding layer 130, improve the corrosion resistance of the bonding layer 130, and extend the lifetime of the semiconductor light emitting device.
　このように、ｎ型電極１０８とｎ型半導体層１０４との間に、ｎ型電極用の接合層１３０を形成してもよい。
　接合層１３０は、ｐ型電極１１１の接合層１１０と同様の材料からなることが好ましく、また、最大厚みも同様の範囲、１０Å以上１０００Å以下の範囲であることが好ましい。これにより、ｎ型半導体層１０４に対するｎ型電極１０８の接合強度を格段に高めることができる。 Thus, the n-type electrode bonding layer 130 may be formed between the n-type electrode 108 and the n-type semiconductor layer 104.
The bonding layer 130 is preferably made of the same material as that of the bonding layer 110 of the p-type electrode 111, and the maximum thickness is preferably in the same range and in the range of 10 to 1000 mm. Thereby, the bonding strength of the n-type electrode 108 to the n-type semiconductor layer 104 can be significantly increased.
　更に、接合層１３０として、上記の透光性の導電性材料からなる層と、Ａｌ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｃｏ、Ｚｎ、Ｇｅ、Ｚｒ、Ｎｂ、Ｍｏ、Ｒｕ、Ｈｆ、Ｔａ、Ｗ、Ｒｅ、Ｒｈ、Ｉｒ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなる金属膜との積層構造を採用してもよい。この場合、ｎ型半導体層１０４上に、透光性の導電性材料からなる層と、Ｃｒ等の金属膜とを順次積層すればよい。 Further, as the bonding layer 130, a layer made of the above-described translucent conductive material, Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W Alternatively, a laminated structure with a metal film made of at least one element selected from the group consisting of Re, Rh, Ir, and Ni may be adopted. In this case, a layer made of a light-transmitting conductive material and a metal film such as Cr may be sequentially stacked on the n-type semiconductor layer 104.
　なお、接合層１３０を形成する場合は、ｎ型電極１０８として、ボンディングパッド電極１２０と同一構成の電極を用いることがより望ましい。すなわち、ボンディングパッド電極１２０が金属反射層１１７とボンディング層１１９との二層構造である場合には、ｎ型電極１０８が、Ａｇ、Ａｌ、Ｐｔ属元素のうちの何れかまたはこれら金属の何れかを含む合金からなる金属反射層と、ボンディング層とを少なくとも含む積層構造であることが好ましい。
　この際、ｎ型電極１０８とｎ型半導体層１０４との間に接合層１３０を形成する場合は、ｐ型電極１１１の透光性電極１０９を形成した後、ｐ型電極１１１の接合層１１０を形成するのと同時にｎ型電極１０８用の接合層１３０を形成し、その後、ｐ型電極１１１のボンディングパッド電極１２０を形成するのと同時にｎ型電極１０８を形成すればよい。 When the bonding layer 130 is formed, it is more preferable to use an electrode having the same configuration as the bonding pad electrode 120 as the n-type electrode 108. That is, when the bonding pad electrode 120 has a two-layer structure of the metal reflection layer 117 and the bonding layer 119, the n-type electrode 108 is any one of Ag, Al, Pt group elements or any of these metals. A laminated structure including at least a metal reflective layer made of an alloy containing and a bonding layer is preferable.
At this time, when the bonding layer 130 is formed between the n-type electrode 108 and the n-type semiconductor layer 104, the light-transmitting electrode 109 of the p-type electrode 111 is formed, and then the bonding layer 110 of the p-type electrode 111 is formed. The bonding layer 130 for the n-type electrode 108 is formed simultaneously with the formation, and then the n-type electrode 108 may be formed simultaneously with the formation of the bonding pad electrode 120 of the p-type electrode 111.
　なお、ｎ型電極１０８は、ｎ型半導体層１０４側から順に、金属反射層、バリア層、ボンディング層が順次積層された積層体からなる三層構造であってもよい。
　また、ｎ型電極１０８は、金属反射層を兼ねるボンディング層のみからなる単層構造であってもよい。 The n-type electrode 108 may have a three-layer structure including a stacked body in which a metal reflective layer, a barrier layer, and a bonding layer are sequentially stacked from the n-type semiconductor layer 104 side.
The n-type electrode 108 may have a single-layer structure including only a bonding layer that also serves as a metal reflection layer.
　本発明の実施形態である半導体発光素子は、他方の電極１０８が、接合層１３０と接合層１３０を覆うように形成された他方の電極を兼ねるボンディングパッド電極１０８とからなり、ボンディングパッド電極１０８の最大厚みが、接合層１１０の最大厚みに比べて厚く形成され、かつ、１層からなり、接合層１３０およびボンディングパッド電極１０８の外周部１３０ｄ、１０８ｄに、それぞれ外周側に向けて膜厚が漸次薄くなるような傾斜面１３０ｃ、１０８ｃが形成されている構成なので、外部の空気または水分の接合層１３０への侵入を防止することができ、接合層１３０の耐食性を向上して、半導体発光素子寿命を長くすることができる。 In the semiconductor light emitting device according to the embodiment of the present invention, the other electrode 108 includes a bonding layer 130 and a bonding pad electrode 108 that also serves as the other electrode formed so as to cover the bonding layer 130. The maximum thickness is formed thicker than the maximum thickness of the bonding layer 110, and is formed of one layer. The film thickness gradually increases toward the outer peripheral side of the bonding layer 130 and the outer peripheral portions 130d and 108d of the bonding pad electrode 108, respectively. Since the thin inclined surfaces 130c and 108c are formed, it is possible to prevent external air or moisture from entering the bonding layer 130, improve the corrosion resistance of the bonding layer 130, and improve the lifetime of the semiconductor light emitting device. Can be lengthened.
（実施形態３）
　図８は、本発明の実施形態である半導体発光素子のさらに別の一例を示す断面模式図であって、ｐ型電極の拡大断面図である。
　図８に示すように、本発明の実施形態である半導体発光素子は、図では省略しているが、ｐ型電極１１２の透光性電極１０９上に保護膜を形成しないほかは実施形態１と同様の構成とされている。なお、実施形態１と同じ部材には同じ符号を付して示している。 (Embodiment 3)
FIG. 8 is a schematic cross-sectional view showing still another example of the semiconductor light emitting device according to the embodiment of the present invention, and is an enlarged cross-sectional view of a p-type electrode.
As shown in FIG. 8, the semiconductor light emitting device according to the embodiment of the present invention is omitted in the drawing, but the protective film is not formed on the translucent electrode 109 of the p-type electrode 112. It is set as the same structure. The same members as those in the first embodiment are denoted by the same reference numerals.
　このように、保護膜を設けない場合でも、接合層１１０を覆うように金属反射層１１７が形成されており、金属反射層１１７を覆うようにボンディング層１１９が形成されている。また、接合層１１０、金属反射層１１７およびボンディング層１１９の外周部１１０ｄ、１２０ｄは、外周側に向けて膜厚が漸次薄くなるように形成された傾斜面１１０ｃ、１１７ｃおよび１１９ｃとされているので、外部の空気または水分は、透光性電極１０９とボンディング層１１９との接合面および透光性電極１０９と金属反射層１１７との接合面を通過しなければ接合層１１０へ侵入することができず、外部の空気または水分の接合層１１０への侵入は困難となる。これにより、接合層１１０が容易に分解されることはなく、半導体発光素子の素子寿命を長くすることができる。 As described above, even when the protective film is not provided, the metal reflective layer 117 is formed so as to cover the bonding layer 110, and the bonding layer 119 is formed so as to cover the metal reflective layer 117. Further, the outer peripheral portions 110d and 120d of the bonding layer 110, the metal reflection layer 117, and the bonding layer 119 are inclined surfaces 110c, 117c, and 119c formed so that the film thickness gradually decreases toward the outer peripheral side. External air or moisture can enter the bonding layer 110 unless it passes through the bonding surface between the translucent electrode 109 and the bonding layer 119 and the bonding surface between the translucent electrode 109 and the metal reflective layer 117. Therefore, it is difficult for external air or moisture to enter the bonding layer 110. Thereby, the bonding layer 110 is not easily decomposed, and the element lifetime of the semiconductor light emitting element can be extended.
　本発明の実施形態である半導体発光素子１は、ボンディングパッド電極１２０が、接合層１１０を覆うように形成された金属反射層１１７と、金属反射層１１７を覆うように形成されたボンディング層１１９とからなり、接合層１１０、金属反射層１１７およびボンディング層１１９の外周部１１０ｄ、１２０ｄが、それぞれ外周側に向けて膜厚が漸次薄くなるように形成された傾斜面１１０ｃ、１１７ｃおよび１１９ｃとされている構成なので、外部の空気または水分の接合層１１０への侵入を防止することができ、半導体発光素子の耐食性を向上して、素子寿命を長くすることができる。 The semiconductor light emitting device 1 according to the embodiment of the present invention includes a metal reflection layer 117 formed so that the bonding pad electrode 120 covers the bonding layer 110, and a bonding layer 119 formed so as to cover the metal reflection layer 117. The outer peripheral portions 110d and 120d of the bonding layer 110, the metal reflective layer 117, and the bonding layer 119 are inclined surfaces 110c, 117c, and 119c formed so that the film thickness gradually decreases toward the outer peripheral side, respectively. With this configuration, it is possible to prevent external air or moisture from entering the bonding layer 110, improve the corrosion resistance of the semiconductor light emitting device, and extend the device life.
（実施形態４：ランプ）
　図９は、本発明の実施形態であるランプの一例を示す断面概略図である。尚、以下の説明において参照する図面で、図示される各部の大きさや厚さや寸法等は、実際の半導体発光素子等の寸法関係とは異なっている。
　図９に示すように、本発明の実施形態であるランプ３は、砲弾型であり、本発明の実施形態である半導体発光素子１が用いられている。
　なお、本発明の実施形態であるランプ３は、例えば、半導体発光素子１と蛍光体とを組み合わせてなるものであって、当業者周知の手段によって当業者周知の構成とすることができる。また、半導体発光素子１と蛍光体と組み合わせることによって発光色を変えることができることが知られているが、このような技術を本発明の実施形態であるランプにおいても何ら制限されることなく採用することが可能である。 (Embodiment 4: Lamp)
FIG. 9 is a schematic cross-sectional view showing an example of a lamp according to an embodiment of the present invention. In the drawings to be referred to in the following description, the size, thickness, dimensions, and the like of each part shown in the drawings are different from the dimensional relationships of actual semiconductor light emitting elements and the like.
As shown in FIG. 9, the lamp 3 according to the embodiment of the present invention is a shell type, and the semiconductor light emitting element 1 according to the embodiment of the present invention is used.
The lamp 3 according to the embodiment of the present invention is, for example, a combination of the semiconductor light emitting element 1 and a phosphor, and can have a configuration well known to those skilled in the art by means known to those skilled in the art. Further, it is known that the emission color can be changed by combining the semiconductor light emitting element 1 and the phosphor, but such a technique is adopted without any limitation in the lamp which is an embodiment of the present invention. It is possible.
　図９に示すように、半導体発光素子１のｐ型電極１１１のボンディングパッド電極１２０がワイヤ３３でフレーム３１に接合され、半導体発光素子１のｎ型電極１０８（ボンディングパッド）がワイヤ３４で他方のフレーム３２に接合されて、実装されている。また、半導体発光素子１の周辺は、透明な樹脂からなるモールド３５で封止されている。 As shown in FIG. 9, the bonding pad electrode 120 of the p-type electrode 111 of the semiconductor light emitting device 1 is bonded to the frame 31 by the wire 33, and the n-type electrode 108 (bonding pad) of the semiconductor light emitting device 1 is connected by the wire 34 to the other side. The frame 32 is joined and mounted. Further, the periphery of the semiconductor light emitting element 1 is sealed with a mold 35 made of a transparent resin.
　本発明の実施形態であるランプ３は、先に記載の半導体発光素子１と、半導体発光素子１が配置されるとともに半導体発光素子１の一の伝導型の電極（ｐ型電極）１１１のボンディングパッド電極１２０とワイヤボンディングされる第１フレーム３１と、半導体発光素子１の他の伝導型の電極（ｎ型電極）１０８とワイヤボンディングされる第２フレーム３２と、半導体発光素子１を取り囲んで形成されるモールド３５と、を備えた構成なので、優れた発光特性を備えるとともに、外部の空気または水分の接合層１１０への侵入を防止することができ、接合層１１０の耐食性を向上して、半導体発光素子の素子寿命を長くしたランプとすることができる。 A lamp 3 according to an embodiment of the present invention includes a semiconductor light-emitting element 1 described above, and a bonding pad on which the semiconductor light-emitting element 1 is disposed and one conductive type electrode (p-type electrode) 111 is disposed. The first frame 31 is wire-bonded to the electrode 120, the second frame 32 is wire-bonded to another conductive electrode (n-type electrode) 108 of the semiconductor light emitting device 1, and the semiconductor light emitting device 1 is formed. The mold 35 is provided with an excellent light emitting characteristic, can prevent external air or moisture from entering the bonding layer 110, improves the corrosion resistance of the bonding layer 110, and emits semiconductor light. It is possible to obtain a lamp having a long element life.
　本発明の実施形態であるランプ３は、一般用途の砲弾型、携帯のバックライト用途のサイドビュー型、表示器に用いられるトップビュー型等いかなる用途にも用いることができる。 The lamp 3 according to the embodiment of the present invention can be used for any purposes such as a general-purpose shell type, a side view type for portable backlight use, and a top view type used for a display.
（実施形態５）
　図１０は、本発明の実施形態である半導体発光素子のさらに別の一例を示す断面模式図であって、ｐ型電極の拡大断面図である。
　図１０に示すように、本発明の実施形態である半導体発光素子は、ｐ型電極１１１の外周部、すなわち、ｐ型電極１１１を平面視したときの輪郭線を形づくる境界部の上を完全に覆うように別の保護膜１１が形成されているほかは実施形態１と同様の構成とされている。なお、実施形態１と同じ部材には同じ符号を付して示している。 (Embodiment 5)
FIG. 10 is a schematic cross-sectional view showing still another example of the semiconductor light emitting device according to the embodiment of the present invention, and is an enlarged cross-sectional view of a p-type electrode.
As shown in FIG. 10, the semiconductor light emitting device according to the embodiment of the present invention completely covers the outer periphery of the p-type electrode 111, that is, the boundary that forms the contour line when the p-type electrode 111 is viewed in plan. The structure is the same as that of the first embodiment except that another protective film 11 is formed so as to cover it. The same members as those in the first embodiment are denoted by the same reference numerals.
　図１０に示すように、ｐ型電極１１１は、透光性電極１０９、接合層１１０とボンディングパッド電極１２０とからなり、ｐ型半導体層１０６に形成されて概略構成されている。
　透光性電極１０９の上面１０９ｃはＳｉＯ２からなる保護膜１０によって覆われており、保護膜１０の一部が開口されて開口部１０ｄが形成され、開口部１０ｄから透光性電極１０９の上面１０９ｃの一部が露出されている。
　接合層１１０は、開口部１０ｄから露出された透光性電極１０９の上面１０９ｃをほぼ均一の膜厚で覆うともに、開口部１０ｄの外周側では膜厚が厚くされており、さらに、保護膜１０の端部１０ｃを覆うように形成されている。また、保護膜１０の端部１０ｃを覆う接合層１１０の外周部１１０ｄには、外周側に向けて膜厚が漸次薄くなるような傾斜面１１０ｃが形成されている。
　ボンディングパッド電極１２０は、接合層１１０の最大厚みに比べて厚く形成された金属反射層１１７とボンディング層１１９とから構成されている。また、ボンディングパッド電極１２０の外周部１２０ｄには、外周側に向けて膜厚が漸次薄くなるような傾斜面１１９ｃが形成されている。
　金属反射層１１７の外周部には、前記外周側に向けて膜厚が漸次薄くなるような傾斜面１１７ｃが形成されている。また、金属反射層１１７は接合層１１０を覆うように形成されている。すなわち、金属反射層１１７は、接合層１１０の傾斜面１１０ｃの先の最先端部、すなわち接合層１１０を平面視したときの輪郭線を形づくる境界部の上を完全に覆うように形成されている。つまり、平面視したときに、金属反射層１１７は接合層１１０を覆って、更に接合層１１０の外周側にまで張り出すように形成される構成なので、接合層１１０のいかなる部分も金属反射層１１７の下から露出しないようにすることができる。 As shown in FIG. 10, the p-type electrode 111 includes a translucent electrode 109, a bonding layer 110, and a bonding pad electrode 120, and is schematically formed by being formed on the p-type semiconductor layer 106.
Upper surface 109c of the transparent electrode 109 is covered by a protective film 10 made of SiO 2, a portion of the protective film 10 is being opened openings 10d formed, the upper surface of the transparent electrode 109 through the opening 10d Part of 109c is exposed.
The bonding layer 110 covers the upper surface 109c of the translucent electrode 109 exposed from the opening 10d with a substantially uniform film thickness, and the film thickness is increased on the outer peripheral side of the opening 10d. It is formed so as to cover the end portion 10c. In addition, an inclined surface 110c is formed on the outer peripheral portion 110d of the bonding layer 110 that covers the end portion 10c of the protective film 10 so that the film thickness gradually decreases toward the outer peripheral side.
The bonding pad electrode 120 includes a metal reflection layer 117 and a bonding layer 119 that are formed to be thicker than the maximum thickness of the bonding layer 110. In addition, an inclined surface 119c is formed on the outer peripheral portion 120d of the bonding pad electrode 120 so that the film thickness gradually decreases toward the outer peripheral side.
An inclined surface 117c is formed on the outer peripheral portion of the metal reflective layer 117 so that the film thickness gradually decreases toward the outer peripheral side. The metal reflective layer 117 is formed so as to cover the bonding layer 110. In other words, the metal reflection layer 117 is formed so as to completely cover the leading edge of the inclined surface 110c of the bonding layer 110, that is, the boundary that forms the contour line when the bonding layer 110 is viewed in plan. . That is, when viewed in plan, the metal reflective layer 117 is formed so as to cover the bonding layer 110 and further extend to the outer peripheral side of the bonding layer 110, so any portion of the bonding layer 110 can be any metal reflective layer 117. It is possible to prevent exposure from below.
　さらに、ボンディング層１１９の外周部には、前記外周側に向けて膜厚が漸次薄くなるような傾斜面１１９ｃが形成されている。また、ボンディング層１１９は金属反射層１１７を覆うように形成されている。すなわち、ボンディング層１１９は、金属反射層１１７の傾斜面１１７ｃの先の最先端部、すなわち金属反射層１１７を平面視したときの輪郭線を形づくる境界部の上を完全に覆うように形成されている。つまり、平面視したときに、ボンディング層１１９は金属反射層１１７を覆って、更に金属反射層１１７の外周側にまで張り出すように形成される構成なので、金属反射層１１７のいかなる部分もボンディング層１１９の下から露出しないようにすることができる。 Furthermore, an inclined surface 119c is formed on the outer peripheral portion of the bonding layer 119 so that the film thickness gradually decreases toward the outer peripheral side. The bonding layer 119 is formed so as to cover the metal reflective layer 117. In other words, the bonding layer 119 is formed so as to completely cover the tip of the tip of the inclined surface 117c of the metal reflection layer 117, that is, the boundary that forms the contour line when the metal reflection layer 117 is viewed in plan. Yes. That is, since the bonding layer 119 is formed so as to cover the metal reflection layer 117 and project to the outer peripheral side of the metal reflection layer 117 when seen in a plan view, any portion of the metal reflection layer 117 can be bonded to the bonding layer. It is possible to prevent exposure from below 119.
　別の保護膜１１は、ボンディングパッド電極１２０ｐ型電極１１１を平面視したときの輪郭線を形づくる境界部を覆うように形成されている。すなわち、別の保護膜１１は、保護膜１０上に積層され、その端部１１ｃがボンディング層１１９の傾斜面（テーパー面）１１９ｃを完全に覆うように傾斜面１１９ｃ上に乗り上げられ、さらに、ボンディング層１１９の上面１１９ｄまで一部を覆うように形成されている。
　ボンディング層１１９と保護膜１０との境界が別の保護膜１１で覆われるので、ボンディング層１１９と保護膜１０との境界からの水分の浸入を防止できるので、外部の空気または水分が接合層１１０へ侵入することは容易ではない。そのため、接合層１１０が容易に分解されることはなく、半導体発光素子の素子寿命をより長くすることができる。
　なお、別の保護膜１１は、ボンディングパッド電極１２０を平面視したときの輪郭線を形づくる境界部の上を完全に覆うように形成されていれば良く、ｐ型電極１１１をほとんど覆い、コンタクトを取れる露出領域を一部に設けるように形成していてもよい。 Another protective film 11 is formed so as to cover a boundary portion that forms a contour line when the bonding pad electrode 120 p-type electrode 111 is viewed in plan. That is, another protective film 11 is laminated on the protective film 10, and the end portion 11c rides on the inclined surface 119c so as to completely cover the inclined surface (tapered surface) 119c of the bonding layer 119. The layer 119 is formed so as to partially cover the upper surface 119d.
Since the boundary between the bonding layer 119 and the protective film 10 is covered with another protective film 11, moisture can be prevented from entering from the boundary between the bonding layer 119 and the protective film 10. It is not easy to get into. Therefore, the bonding layer 110 is not easily decomposed, and the element lifetime of the semiconductor light emitting element can be extended.
The other protective film 11 only needs to be formed so as to completely cover the boundary that forms the contour line when the bonding pad electrode 120 is viewed in plan, and almost covers the p-type electrode 111 and contacts. You may form so that the exposure area | region which can be taken is provided in part.
　別の保護膜１１の材料としては、接合層１１０を外部の空気または水分から保護できる材料であれば良い。たとえば、別の保護膜１１の材料としてＳｉＯ２を用いることが好ましい。これにより、別の保護膜１１を密着性を高く形成することができ、別の保護膜１１が容易に剥がれることはないようにすることができる。これにより、ｐ型電極１１１を強固に固定することができる。 The material of the other protective film 11 may be any material that can protect the bonding layer 110 from external air or moisture. For example, it is preferable to use SiO 2 as the material of the other protective film 11. Thereby, another protective film 11 can be formed with high adhesion, and the other protective film 11 can be prevented from being easily peeled off. Thereby, the p-type electrode 111 can be firmly fixed.
　保護膜１１の材料としては、保護膜１０と同種の材料を用いることが好ましい。たとえば、保護膜１０の材料としてもＳｉＯ２を用いた場合には、保護膜１１の材料としてもＳｉＯ２を用いることが好ましい。これにより、別の保護膜１１と保護膜１０の間の密着性を高くすることができ、別の保護膜１１と保護膜１０とが容易に剥がれることはないようにすることができる。これにより、ｐ型電極１１１を強固に固定することができる。 As the material of the protective film 11, it is preferable to use the same material as that of the protective film 10. For example, when SiO 2 is used as the material of the protective film 10, it is preferable to use SiO 2 as the material of the protective film 11. Thereby, the adhesiveness between the another protective film 11 and the protective film 10 can be made high, and it can prevent that another protective film 11 and the protective film 10 peel easily. Thereby, the p-type electrode 111 can be firmly fixed.
（実施形態６）
　図１１は、本発明の実施形態である半導体発光素子のさらに別の一例を示す断面模式図であって、ｐ型電極の拡大断面図である。
　図１１に示すように、本発明の実施形態である半導体発光素子は、ボンディングパッド電極１２０を平面視したときの輪郭線を形づくる境界部の上を完全に覆うように別の保護膜１１が形成されているほかは実施形態３と同様の構成とされている。なお、実施形態３と同じ部材には同じ符号を付して示している。 (Embodiment 6)
FIG. 11 is a schematic cross-sectional view showing still another example of the semiconductor light emitting device according to the embodiment of the present invention, and is an enlarged cross-sectional view of a p-type electrode.
As shown in FIG. 11, in the semiconductor light emitting device according to the embodiment of the present invention, another protective film 11 is formed so as to completely cover the boundary that forms the outline when the bonding pad electrode 120 is viewed in plan. Other than that, the configuration is the same as that of the third embodiment. The same members as those in the third embodiment are denoted by the same reference numerals.
　図１１に示すように、ｐ型電極１１２は、透光性電極１０９、接合層１１０とボンディングパッド電極１２０とからなり、ｐ型半導体層１０６上に形成されて概略構成されている。
　ｐ型電極１１２に対応する位置と大きさで形成された接合層１１０は、透光性電極１０９の上面１０９ｃをほぼ均一の膜厚で覆うともに、接合層１１０の外周部１１０ｄには、外周側に向けて膜厚が漸次薄くなるような傾斜面１１０ｃが形成されている。
　ボンディングパッド電極１２０は、接合層１１０の最大厚みに比べて厚く形成された金属反射層１１７とボンディング層１１９とから構成されている。また、ボンディングパッド電極１２０の外周部１２０ｄには、外周側に向けて膜厚が漸次薄くなるような傾斜面１１９ｃが形成されている。
　金属反射層１１７の外周部には、前記外周側に向けて膜厚が漸次薄くなるような傾斜面１１７ｃが形成されている。また、金属反射層１１７は接合層１１０を覆うように形成されている。すなわち、金属反射層１１７は、接合層１１０の傾斜面１１０ｃの先の最先端部、すなわち接合層１１０を平面視したときの輪郭線を形づくる境界部の上を完全に覆うように形成されている。つまり、平面視したときに、金属反射層１１７は接合層１１０を覆って、更に接合層１１０の外周側にまで張り出すように形成される構成なので、接合層１１０のいかなる部分も金属反射層１１７の下から露出しないようにすることができる。 As shown in FIG. 11, the p-type electrode 112 includes a translucent electrode 109, a bonding layer 110, and a bonding pad electrode 120, and is formed on the p-type semiconductor layer 106 and schematically configured.
The bonding layer 110 formed at a position and size corresponding to the p-type electrode 112 covers the upper surface 109c of the translucent electrode 109 with a substantially uniform film thickness, and the outer peripheral portion 110d of the bonding layer 110 has an outer peripheral side. An inclined surface 110c is formed so that the film thickness gradually decreases toward the surface.
The bonding pad electrode 120 includes a metal reflection layer 117 and a bonding layer 119 that are formed to be thicker than the maximum thickness of the bonding layer 110. In addition, an inclined surface 119c is formed on the outer peripheral portion 120d of the bonding pad electrode 120 so that the film thickness gradually decreases toward the outer peripheral side.
An inclined surface 117c is formed on the outer peripheral portion of the metal reflective layer 117 so that the film thickness gradually decreases toward the outer peripheral side. The metal reflective layer 117 is formed so as to cover the bonding layer 110. In other words, the metal reflection layer 117 is formed so as to completely cover the leading edge of the inclined surface 110c of the bonding layer 110, that is, the boundary that forms the contour line when the bonding layer 110 is viewed in plan. . That is, when viewed in plan, the metal reflective layer 117 is formed so as to cover the bonding layer 110 and further extend to the outer peripheral side of the bonding layer 110, so any portion of the bonding layer 110 can be any metal reflective layer 117. It is possible to prevent exposure from below.
　さらに、ボンディング層１１９の外周部には、前記外周側に向けて膜厚が漸次薄くなるような傾斜面１１９ｃが形成されている。また、ボンディング層１１９は金属反射層１１７を覆うように形成されている。すなわち、ボンディング層１１９は、金属反射層１１７の傾斜面１１７ｃの先の最先端部、すなわち金属反射層１１７を平面視したときの輪郭線を形づくる境界部の上を完全に覆うように形成されている。つまり、平面視したときに、ボンディング層１１９は金属反射層１１７を覆って、更に金属反射層１１７の外周側にまで張り出すように形成される構成なので、金属反射層１１７のいかなる部分もボンディング層１１９の下から露出しないようにすることができる。なお、ボンディング層１１９を平面視したときの輪郭線を形づくる境界部が、ｐ型電極１１１を平面視したときの輪郭線を形づくる境界部である。 Furthermore, an inclined surface 119c is formed on the outer peripheral portion of the bonding layer 119 so that the film thickness gradually decreases toward the outer peripheral side. The bonding layer 119 is formed so as to cover the metal reflective layer 117. In other words, the bonding layer 119 is formed so as to completely cover the tip of the tip of the inclined surface 117c of the metal reflection layer 117, that is, the boundary that forms the contour line when the metal reflection layer 117 is viewed in plan. Yes. That is, since the bonding layer 119 is formed so as to cover the metal reflection layer 117 and project to the outer peripheral side of the metal reflection layer 117 when seen in a plan view, any portion of the metal reflection layer 117 can be bonded to the bonding layer. It is possible to prevent exposure from below 119. Note that the boundary part that forms the contour line when the bonding layer 119 is viewed in plan is the boundary part that forms the contour line when the p-type electrode 111 is viewed in plan.
　別の保護膜１１は、ボンディングパッド電極１２０を平面視したときの輪郭線を形づくる境界部を覆うように形成されている。すなわち、別の保護膜１１は、透光性電極１０９上上に積層され、その端部１１ｃがボンディング層１１９の傾斜面（テーパー面）１１９ｃを完全に覆うように傾斜面１１９ｃ上に乗り上げられ、さらに、ボンディング層１１９の上面１１９ｄの一部まで覆うように形成されている。
　ボンディング層１１９と透光性電極１０９との境界が別の保護膜１１で覆われるので、ボンディング層１１９と透光性電極１０９との境界からの水分の浸入を防止できるので、外部の空気または水分が接合層１１０へ侵入することは容易ではない。そのため、接合層１１０が容易に分解されることはなく、半導体発光素子の素子寿命をより長くすることができる。
　なお、別の保護膜１１は、ボンディングパッド電極１２０を平面視したときの輪郭線を形づくる境界部の上を完全に覆うように形成されていれば良く、ｐ型電極１１２をほとんど覆い、コンタクトを取れる露出領域を一部に設けるように形成していてもよい。 Another protective film 11 is formed so as to cover a boundary portion that forms a contour line when the bonding pad electrode 120 is viewed in plan. That is, another protective film 11 is laminated on the translucent electrode 109, and the end portion 11c rides on the inclined surface 119c so as to completely cover the inclined surface (tapered surface) 119c of the bonding layer 119, Further, it is formed so as to cover a part of the upper surface 119d of the bonding layer 119.
Since the boundary between the bonding layer 119 and the translucent electrode 109 is covered with another protective film 11, moisture can be prevented from entering from the boundary between the bonding layer 119 and the translucent electrode 109. It is not easy to penetrate into the bonding layer 110. Therefore, the bonding layer 110 is not easily decomposed, and the element lifetime of the semiconductor light emitting element can be extended.
The other protective film 11 only needs to be formed so as to completely cover the boundary that forms the contour line when the bonding pad electrode 120 is viewed in plan, and almost covers the p-type electrode 112 and contacts. You may form so that the exposure area | region which can be taken is provided in part.
　別の保護膜１１の材料としては、接合層１１０を外部の空気または水分から保護できる材料であれば良い。たとえば、別の保護膜１１の材料としてＳｉＯ２を用いることが好ましい。これにより、別の保護膜１１を密着性を高く形成することができ、別の保護膜１１が容易に剥がれることはないようにすることができる。これにより、ｐ型電極１１２を強固に固定することができる。 The material of the other protective film 11 may be any material that can protect the bonding layer 110 from external air or moisture. For example, it is preferable to use SiO 2 as the material of the other protective film 11. Thereby, another protective film 11 can be formed with high adhesion, and the other protective film 11 can be prevented from being easily peeled off. Thereby, the p-type electrode 112 can be firmly fixed.
（実施形態７の半導体発光素子の製造方法）
　次に、本発明の半導体発光素子の製造方法について説明する。本実施形態７の半導体発光素子の製造方法は、図１４に示す半導体発光素子１の製造方法である。
　図１４に示す半導体発光素子１を製造するには、まず、基板１０１上に積層半導体層２０を形成する。積層半導体層２０は、ＭＯＣＶＤ法で形成すると結晶性の良いものが得られるが、スパッタ法によっても条件を最適化することで、ＭＯＣＶＤ法よりも優れた結晶性を有するものが得られる。 (Method for Manufacturing Semiconductor Light Emitting Element of Embodiment 7)
Next, the manufacturing method of the semiconductor light emitting device of the present invention will be described. The manufacturing method of the semiconductor light emitting device of Embodiment 7 is the manufacturing method of the semiconductor light emitting device 1 shown in FIG.
In order to manufacture the semiconductor light emitting device 1 shown in FIG. 14, first, the laminated semiconductor layer 20 is formed on the substrate 101. When the stacked semiconductor layer 20 is formed by the MOCVD method, a layer having good crystallinity can be obtained. However, by optimizing the conditions also by the sputtering method, a layer having crystallinity superior to the MOCVD method can be obtained.
　以下、バッファ層形成工程、下地層形成工程、ｎ型半導体層形成工程、発光層形成工程、ｐ型半導体層形成工程を含む「積層半導体層の形成」は、前述の実施形態１の半導体発光素子の製造方法に準じて行われる。そして、このようにして積層半導体層２０の形成を形成した後、ｎ型電極１０８とｐ型電極１１１とを形成する。 Hereinafter, the “layered semiconductor layer formation” including the buffer layer forming step, the base layer forming step, the n-type semiconductor layer forming step, the light-emitting layer forming step, and the p-type semiconductor layer forming step is referred to as the semiconductor light-emitting device of the first embodiment. It is performed according to the manufacturing method. Then, after forming the stacked semiconductor layer 20 in this manner, the n-type electrode 108 and the p-type electrode 111 are formed.
＜ｎ型電極形成工程＞
　まず、公知のフォトリソグラフィーの手法によってパターニングし、所定の領域の積層半導体層２０の一部をエッチングしてｎコンタクト層１０４ａの一部を露出させる。次に、スパッタ法などにより、ｎコンタクト層１０４ａの露出面１０４ｃにｎ型電極１０８を形成する。 <N-type electrode formation process>
First, patterning is performed by a known photolithography technique, and a part of the laminated semiconductor layer 20 in a predetermined region is etched to expose a part of the n contact layer 104a. Next, the n-type electrode 108 is formed on the exposed surface 104c of the n contact layer 104a by sputtering or the like.
＜ｐ型電極形成工程＞
　次に、図１８を用いて、ｐ型電極１１１を製造する工程について説明する。図１８は、ｐ型電極を製造する工程を説明するための工程図であり、ｐ型電極１１１の製造される領域の一部のみを拡大して示した拡大断面図である。
　図１８（ａ）に示すように、本実施形態のｐ型電極１１１を製造するには、まず、ｐ型半導体層１０６上に透光性電極１０９を形成する。透光性電極１０９は、ｎ型電極１０８の形成されたｎコンタクト層１０４ａの露出面１０４ｃなど、透光性電極１０９の形成される領域以外の領域を覆うマスクを形成した後、ｐ型半導体層１０６上にスパッタ法などの公知の方法を用いて形成し、その後、マスクを除去する方法などにより形成される。なお、透光性電極１０９は、ｎ型電極１０８を形成した後に形成してもよいが、ｎ型電極１０８を形成するための積層半導体層２０のエッチングの前に形成してもよい。 <P-type electrode formation process>
Next, the process of manufacturing the p-type electrode 111 will be described with reference to FIG. FIG. 18 is a process diagram for explaining a process of manufacturing the p-type electrode, and is an enlarged cross-sectional view showing only a part of a region where the p-type electrode 111 is manufactured.
As shown in FIG. 18A, in order to manufacture the p-type electrode 111 of this embodiment, first, the translucent electrode 109 is formed on the p-type semiconductor layer 106. The translucent electrode 109 is formed by forming a mask that covers a region other than the region where the translucent electrode 109 is formed, such as the exposed surface 104c of the n contact layer 104a where the n-type electrode 108 is formed, and then forming a p-type semiconductor layer. It is formed on the film 106 using a known method such as a sputtering method, and then formed by a method of removing the mask. Note that the translucent electrode 109 may be formed after the n-type electrode 108 is formed, but may be formed before the etching of the stacked semiconductor layer 20 for forming the n-type electrode 108.
　次に、図１８（ａ）に示すように、透光性電極１０９の上面１０９ｃに透明保護膜１０ａを形成し、透明保護膜１０ａ上にレジスト２１を塗布して乾燥させる。
　次に、ボンディングパッド電極１２０を形成する部分に対応する部分のレジスト２１を除去することによって、透明保護膜１０ａの形成された透光性電極１０９の上面１０９ｃに、底面に向かって断面積が徐々に広くなる内壁形状を有する開口部２３ａを備えた図１８（ｂ）に示す逆テーパー型のマスク２３を形成する。逆テーパー型のマスク２３を形成する方法としては、ｎ型フォトレジストを用いる方法やイメージ反転型フォトレジストを用いる方法などが挙げられる。本実施形態では、図１９を用いて、イメージ反転型フォトレジストを用いて図１８（ｂ）に示すマスクを形成する方法を説明する。図１９は、図１８（ｂ）に示すマスクの製造工程を説明するための工程図であり、１つのｐ型電極１１１の形成される領域のみを示した拡大断面図である。 Next, as shown in FIG. 18A, a transparent protective film 10a is formed on the upper surface 109c of the translucent electrode 109, and a resist 21 is applied on the transparent protective film 10a and dried.
Next, by removing the portion of the resist 21 corresponding to the portion where the bonding pad electrode 120 is to be formed, the cross-sectional area of the upper surface 109c of the transparent electrode 109 on which the transparent protective film 10a is formed gradually increases toward the bottom surface. A reverse-tapered mask 23 shown in FIG. 18 (b) having an opening 23a having an inner wall shape that becomes wider is formed. Examples of the method for forming the inverse taper type mask 23 include a method using an n-type photoresist and a method using an image inversion type photoresist. In the present embodiment, a method of forming the mask shown in FIG. 18B using an image inversion type photoresist will be described with reference to FIG. FIG. 19 is a process diagram for explaining the manufacturing process of the mask shown in FIG. 18B, and is an enlarged sectional view showing only a region where one p-type electrode 111 is formed.
　本実施形態では、レジスト２１として、イメージ反転型フォトレジストである不溶性のレジストを用いる。イメージ反転型フォトレジストとしては、例えば、ＡＺ５２００ＮＪ（製品名：ＡＺエレクトロニックマテリアルズ株式会社製）などが用いられる。
　次に、図１９（ａ）に示すように、レジスト２１上方の所定の位置をカバーするようにマスク２５を配置し、図１９（ａ）において矢印で示すように、マスク２５側からレジスト２１側へ所定の強さ及び波長の光を照射する。このことにより、光が照射された部分のレジスト２１を光反応させて、可溶部２２とする。この光反応は光の強さに応じて進行するので、光照射面側では光反応の進行が早く、透光性電極１０９側では光反応の進行が遅くなる。そのため、図１９（ａ）に示すように、可溶部２２は、断面視したときに、側面が下方に向かうほど内側に後退した逆テーパー形状（逆傾斜形状）となるように形成される。また、マスク２５でカバーされた部分のレジスト２１は、不溶性のレジスト（不溶部）２１として残され、断面視したときに側面が上方に向かうほど内側に後退したテーパー形状（傾斜形状）となるように形成される。 In this embodiment, an insoluble resist that is an image reversal type photoresist is used as the resist 21. As the image reversal type photoresist, for example, AZ5200NJ (product name: manufactured by AZ Electronic Materials Co., Ltd.) is used.
Next, as shown in FIG. 19A, a mask 25 is disposed so as to cover a predetermined position above the resist 21, and from the mask 25 side to the resist 21 side as shown by an arrow in FIG. Is irradiated with light of a predetermined intensity and wavelength. As a result, the portion of the resist 21 irradiated with light is photoreacted to form a soluble portion 22. Since this photoreaction proceeds according to the intensity of light, the photoreaction progresses quickly on the light irradiation surface side, and the photoreaction progresses slowly on the translucent electrode 109 side. Therefore, as shown in FIG. 19A, the fusible portion 22 is formed to have a reverse taper shape (reverse inclination shape) that recedes inward as the side faces downward when viewed in cross section. In addition, the resist 21 in the portion covered with the mask 25 is left as an insoluble resist (insoluble portion) 21 so as to have a tapered shape (inclined shape) that recedes inward as the side faces upward when viewed in cross section. Formed.
　次に、ホットプレートやオーブンなどの加熱装置を用いて、加熱することにより、図１９（ｂ）に示すように、可溶部２２を熱反応させて、架橋高分子からなる硬化部（マスク）２３とする。その後、図１９（ｃ）に示すように、マスクを用いずに、不溶性のレジスト２１および架橋高分子からなる硬化部（マスク）２３の表面側に所定の強さ及び波長の光を照射することにより、図１９（ａ）を用いて説明した光反応により可溶部２２に変換されなかった不溶性のレジスト２１を光反応させて、可溶部２２とする。
　最後に、所定の現像液を用いて、図１９（ｃ）に示す可溶部２２を溶解除去することにより、図１９（ｄ）に示すように、側面が下方に向かうほど内側に後退した開口部２３ａを有する逆テーパー形状（逆傾斜形状）の架橋高分子からなるマスク２３が得られる。 Next, by heating using a heating device such as a hot plate or an oven, as shown in FIG. 19B, the fusible part 22 is thermally reacted to form a cured part (mask) made of a crosslinked polymer. 23. Thereafter, as shown in FIG. 19C, the surface side of the insoluble resist 21 and the cured portion (mask) 23 made of the crosslinked polymer is irradiated with light of a predetermined intensity and wavelength without using a mask. Thus, the insoluble resist 21 that has not been converted into the soluble portion 22 by the photoreaction described with reference to FIG.
Finally, by using a predetermined developer to dissolve and remove the soluble portion 22 shown in FIG. 19 (c), as shown in FIG. 19 (d), the opening recedes inward as the side faces downward. A mask 23 made of a cross-linked polymer having an inversely tapered shape (inversely inclined shape) having a portion 23a is obtained.
　続いて、図１８（ｂ）に示すマスク２３の開口部２３ａから露出する透明保護膜１０ａを、透光性電極１０９の上面１０９ｃに垂直な方向からＲＩＥ（反応性イオンエッチング）することにより除去して、図１８（ｃ）に示すように、開口部１０ｄを形成し、開口部１０ｄから透光性電極１０９の上面１０９ｃを露出させる。ＲＩＥ（反応性イオンエッチング）は、直進性が高く、回り込みが少ないエッチング方法であるので、エッチング方向（図１８においては上方）から見てマスク２３の影となる領域の透明保護膜１０ａは、ほとんどエッチング除去されず、図１８（ｃ）に示すように、透明保護膜１０ａの端部１０ｃが残される。 Subsequently, the transparent protective film 10a exposed from the opening 23a of the mask 23 shown in FIG. 18B is removed by RIE (reactive ion etching) from a direction perpendicular to the upper surface 109c of the translucent electrode 109. Then, as shown in FIG. 18C, an opening 10d is formed, and the upper surface 109c of the translucent electrode 109 is exposed from the opening 10d. Since RIE (Reactive Ion Etching) is an etching method with high straightness and less wraparound, the transparent protective film 10a in the region that is a shadow of the mask 23 when viewed from the etching direction (upward in FIG. 18) The end portion 10c of the transparent protective film 10a remains as shown in FIG. 18C without being removed by etching.
　次に、図１８（ｃ）に示すように、マスク２３の開口部２３ａから露出する透光性電極１０９をエッチングすることにより、透光性電極１０９の上面１０９ｃに接合凹部１０９ａを形成する。接合凹部１０９ａを形成することにより、透光性電極１０９から現れた接合凹部１０９ａの内面は、透光性電極１０９の上面１０９ｃと比較して、接合層１１０との密着性に優れている。
　ここでエッチングされる透光性電極１０９が、例えば、アモルファス状態のＩＺＯ膜である場合、エッチング性に優れ、容易に特定形状の接合凹部１０９ａを形成することができる。アモルファス状態のＩＺＯ膜は、周知のエッチング液（例えば、ＩＴＯ－０７Ｎエッチング液（関東化学社製））を用いて容易に精度良くエッチングすることが可能である。また、アモルファス状態のＩＺＯ膜のエッチングは、ドライエッチング装置を用いて行なっても良い。このときのエッチングガスとしては、Ｃｌ２、ＳｉＣｌ４、ＢＣｌ３等を用いることができる。 Next, as shown in FIG. 18C, the translucent electrode 109 exposed from the opening 23a of the mask 23 is etched to form a bonding recess 109a in the upper surface 109c of the translucent electrode 109. By forming the bonding recess 109 a, the inner surface of the bonding recess 109 a that appears from the translucent electrode 109 has better adhesion to the bonding layer 110 than the upper surface 109 c of the translucent electrode 109.
When the translucent electrode 109 to be etched here is, for example, an amorphous IZO film, the bonding recess 109a having a specific shape can be easily formed with excellent etching properties. The amorphous IZO film can be easily and accurately etched using a known etching solution (for example, ITO-07N etching solution (manufactured by Kanto Chemical Co., Inc.)). In addition, the amorphous IZO film may be etched using a dry etching apparatus. As an etching gas at this time, Cl 2 , SiCl 4 , BCl 3, or the like can be used.
　また、アモルファス状態のＩＺＯ膜は、熱処理を行なうことにより、六方晶構造のＩｎ２Ｏ３結晶を含むＩＺＯ膜や、ビックスバイト構造のＩｎ２Ｏ３結晶を含むＩＺＯ膜にすることが好ましい。熱処理等によりアモルファス状態から上記の結晶を含む構造に転移させることで、アモルファスのＩＺＯ膜よりも接合層１１０との密着性および透光性の優れた透光性電極１０９とすることができる。しかし、六方晶構造のＩｎ２Ｏ３結晶を含むＩＺＯ膜はエッチングし難いものであるので、上述のエッチング処理の後に熱処理することが好ましい。 Furthermore, the IZO film in an amorphous state, by performing the heat treatment, the IZO film and containing an In 2 O 3 crystal having a hexagonal structure, it is preferable that the IZO film containing an In 2 O 3 crystal having a bixbyite structure. By transferring from an amorphous state to a structure including the above crystal by heat treatment or the like, the light-transmitting electrode 109 having better adhesion to the bonding layer 110 and light-transmitting property than the amorphous IZO film can be obtained. However, since an IZO film containing an In 2 O 3 crystal having a hexagonal crystal structure is difficult to etch, it is preferable to perform heat treatment after the above-described etching treatment.
　アモルファス状態のＩＺＯ膜を結晶化させる場合、成膜条件や熱処理条件などが異なるとＩＺＯ膜中の結晶構造が異なる。ＩＺＯ膜を結晶化させるための熱処理は、Ｏ２を含まない雰囲気で行なうことが望ましく、Ｏ２を含まない雰囲気としては、Ｎ２雰囲気などの不活性ガス雰囲気や、またはＮ２などの不活性ガスとＨ２の混合ガス雰囲気などを挙げることができ、Ｎ２雰囲気、またはＮ２とＨ２の混合ガス雰囲気とすることが望ましい。なお、ＩＺＯ膜の熱処理をＮ２雰囲気、またはＮ２とＨ２の混合ガス雰囲気中で行なうと、例えば、ＩＺＯ膜を六方晶構造のＩｎ２Ｏ３結晶を含む膜に結晶化させるとともに、ＩＺＯ膜のシート抵抗を効果的に減少させることが可能である。 In the case of crystallizing an amorphous IZO film, the crystal structure in the IZO film differs depending on the film formation conditions, heat treatment conditions, and the like. Heat treatment for crystallizing the IZO film is preferably performed in an atmosphere containing no O 2, as the atmosphere containing no O 2, or an inert gas atmosphere such as N 2 atmosphere, or an inert, such as N 2 A mixed gas atmosphere of gas and H 2 can be given, and an N 2 atmosphere or a mixed gas atmosphere of N 2 and H 2 is desirable. Note that when the heat treatment of the IZO film is performed in an N 2 atmosphere or a mixed gas atmosphere of N 2 and H 2 , for example, the IZO film is crystallized into a film containing In 2 O 3 crystals having a hexagonal structure, and IZO It is possible to effectively reduce the sheet resistance of the membrane.
　また、ＩＺＯ膜を結晶化させるための熱処理温度は、５００℃～１０００℃が好ましい。５００℃未満の温度で熱処理を行なった場合、ＩＺＯ膜を十分に結晶化できない恐れが生じ、ＩＺＯ膜の光透過率が十分に高いものとならない場合がある。また、１０００℃を超える温度で熱処理を行なった場合には、ＩＺＯ膜は結晶化されているが、ＩＺＯ膜の光透過率が十分に高いものとならない場合がある。また、１０００℃を超える温度で熱処理を行なった場合、ＩＺＯ膜の下にある半導体層を劣化させる恐れもある。 Further, the heat treatment temperature for crystallizing the IZO film is preferably 500 ° C. to 1000 ° C. When heat treatment is performed at a temperature lower than 500 ° C., the IZO film may not be sufficiently crystallized, and the light transmittance of the IZO film may not be sufficiently high. When heat treatment is performed at a temperature exceeding 1000 ° C., the IZO film is crystallized, but the light transmittance of the IZO film may not be sufficiently high. In addition, when heat treatment is performed at a temperature exceeding 1000 ° C., the semiconductor layer under the IZO film may be deteriorated.
　次に、図１８（ｄ）に示すように、スパッタ法により、透光性電極１０９の接合凹部１０９ａを覆うように接合層１１０を形成する。このとき、スパッタ条件を制御したスパッタ法を用いることにより、接合層１１０のカバレッジ性を高くすることができる。これにより、接合層１１０は、透光性電極１０９の接合凹部１０９ａの全面と、透明保護膜１０ａの開口部１０ｄの内壁面上の全面と、透明保護膜１０ａの端部１０ｃの一部とを覆うように形成され、接合層１１０の外周部１１０ｄに、外側に向けて膜厚が漸次薄くなる傾斜面１１０ｃが形成される。 Next, as shown in FIG. 18D, the bonding layer 110 is formed by sputtering to cover the bonding recess 109a of the translucent electrode 109. At this time, the coverage of the bonding layer 110 can be increased by using a sputtering method in which the sputtering conditions are controlled. As a result, the bonding layer 110 includes the entire surface of the bonding recess 109a of the translucent electrode 109, the entire surface of the inner wall surface of the opening 10d of the transparent protective film 10a, and a part of the end 10c of the transparent protective film 10a. An inclined surface 110c is formed on the outer peripheral portion 110d of the bonding layer 110 so as to cover and gradually decrease in thickness toward the outside.
　なお、接合層１１０を形成する前には、接合層１１０の形成される透光性電極１０９の接合凹部１０９ａの表面を洗浄する前処理を施しても良い。ここでの洗浄の方法としてはプラズマなどに曝すドライプロセスによる方法や、薬液に接触させるウェットプロセスによる方法などが挙げられるが、工程の簡便さの観点よりドライプロセスによる方法を用いることが望ましい。 Note that before forming the bonding layer 110, a pretreatment may be performed to clean the surface of the bonding recess 109a of the translucent electrode 109 on which the bonding layer 110 is formed. Examples of the cleaning method include a dry process method exposed to plasma and the like, and a wet process method in contact with a chemical solution, but it is desirable to use a dry process method from the viewpoint of simplicity of the process.
　次に、スパッタ法により、金属反射層１１７を形成する。このとき、接合層１１０の形成の場合と同様に、スパッタ条件を制御したスパッタ法を用いることにより、金属反射層１１７のカバレッジ性を高くすることができ、接合層１１０を覆い、外側に向けて膜厚が漸次薄くなる傾斜面１１７ｃを外周部に有する金属反射層１１７が形成される。 Next, a metal reflection layer 117 is formed by sputtering. At this time, similarly to the case of forming the bonding layer 110, by using the sputtering method in which the sputtering conditions are controlled, the coverage of the metal reflective layer 117 can be increased, and the bonding layer 110 is covered and directed outward. A metal reflection layer 117 having an inclined surface 117c whose thickness is gradually reduced at the outer peripheral portion is formed.
　次に、スパッタ法により、ボンディング層１１９を形成する。このとき、スパッタ条件を制御したスパッタ法を用いることにより、ボンディング層１１９のカバレッジ性を高くすることができ、マスク２３の開口部２３ａの内壁形状に沿って外周部の形状が形成され、金属反射層１１７を覆い、外側に向けて膜厚が漸次薄くなる傾斜面１１９ｃを外周部１２０ｄに有するボンディング層１１９（ボンディングパッド電極１２０）が形成される。 Next, a bonding layer 119 is formed by sputtering. At this time, by using a sputtering method in which the sputtering conditions are controlled, the coverage of the bonding layer 119 can be increased, and the shape of the outer peripheral portion is formed along the shape of the inner wall of the opening 23a of the mask 23. A bonding layer 119 (bonding pad electrode 120) is formed that covers the layer 117 and has an inclined surface 119c that gradually decreases in thickness toward the outside at the outer peripheral portion 120d.
　その後、レジスト剥離液に浸漬することにより、架橋高分子からなるマスク２３を剥離する。これにより、図１８（ｅ）に示すように、金属反射層１１７とボンディング層１１９とからなるボンディングパッド電極１２０が形成される。 Thereafter, the mask 23 made of a crosslinked polymer is peeled off by being immersed in a resist stripping solution. As a result, as shown in FIG. 18E, a bonding pad electrode 120 composed of the metal reflection layer 117 and the bonding layer 119 is formed.
　本実施形態においては、底面に向かって断面積が徐々に広くなる内壁形状を有する開口部２３ａを備えたマスク２３を形成し、接合層１１０、金属反射層１１７およびボンディング層１１９をカバレッジ性の高いスパッタ法により形成するので、スパッタ方向から見てマスク２３の影となる領域では、接合層１１０、金属反射層１１７およびボンディング層１１９を構成する各層の膜厚に応じて傾斜角度の異なる層が形成される。これにより、接合層１１０、金属反射層１１７およびボンディング層１１９の外周部にそれぞれ、外側に向けて膜厚が漸次薄くなる傾斜面１１０ｃ、１１７ｃ、１１９ｃが形成される。 In the present embodiment, a mask 23 having an opening 23a having an inner wall shape whose cross-sectional area gradually increases toward the bottom surface is formed, and the bonding layer 110, the metal reflective layer 117, and the bonding layer 119 have high coverage. Since it is formed by the sputtering method, a layer having a different inclination angle is formed in the shadowed area of the mask 23 when viewed from the sputtering direction according to the thickness of each layer constituting the bonding layer 110, the metal reflection layer 117, and the bonding layer 119. Is done. As a result, inclined surfaces 110c, 117c, and 119c are formed on the outer peripheral portions of the bonding layer 110, the metal reflective layer 117, and the bonding layer 119, respectively, with the thickness gradually decreasing toward the outside.
　次に、従来から公知の方法を用いて、平面視したときに、ボンディングパッド電極１２０の中央部を露出させる略ドーナッツ状の形状であって、ボンディングパッド電極１２０の外縁部（輪郭線）と透明保護膜１０ａとの継ぎ目となる部分に跨ってボンディングパッド電極１２０の外縁部を覆う縁部保護膜１０ｂを形成する。
　本実施形態においては、ボンディングパッド電極１２０が、外側に向けて膜厚が漸次薄くなる傾斜面１１９ｃが外周部１２０ｄに形成されているものであるので、縁部保護膜１０ｂがボンディングパッド電極１２０の傾斜面１１９ｃに容易に均一な厚みで形成されるものとなる。このことにより、ボンディングパッド電極１２０の外縁部（輪郭線）と透明保護膜１０ａとの継ぎ目となる部分上に縁部保護膜１０ｂの形成されない部分が生じることが防止され、ボンディングパッド電極１２０の外縁部（輪郭線）と透明保護膜１０ａとの継ぎ目となる部分に跨る縁部保護膜１０ｂを均一な膜厚で容易に密着させて形成できる。
　このようにして、図１４～図１６に示すｐ型電極１１１を備える半導体発光素子１が形成される。 Next, using a conventionally known method, when viewed in plan, it has a substantially donut shape that exposes the central portion of the bonding pad electrode 120, and is transparent to the outer edge portion (contour line) of the bonding pad electrode 120. An edge protective film 10b that covers the outer edge of the bonding pad electrode 120 is formed across a portion that becomes a joint with the protective film 10a.
In the present embodiment, since the bonding pad electrode 120 has an inclined surface 119c whose thickness is gradually decreased toward the outside, formed on the outer peripheral portion 120d, the edge protection film 10b is formed on the bonding pad electrode 120. The inclined surface 119c is easily formed with a uniform thickness. This prevents a portion where the edge protection film 10b is not formed on a portion that becomes a joint between the outer edge (contour line) of the bonding pad electrode 120 and the transparent protection film 10a, and the outer edge of the bonding pad electrode 120 is prevented. The edge protective film 10b straddling the portion that becomes the joint between the portion (contour line) and the transparent protective film 10a can be formed by easily adhering to the uniform film thickness.
In this way, the semiconductor light emitting element 1 including the p-type electrode 111 shown in FIGS. 14 to 16 is formed.
　本実施形態の半導体発光素子１においては、ｐ型電極１１１が、上面１０９ｃに接合凹部１０９ａを有する透光性電極１０９と、接合凹部１０９ａを覆うように形成された接合層１１０と、接合層１１０を覆うように形成され、外周部１２０ｄに外側に向けて膜厚が漸次薄くなる傾斜面１１９ｃが形成されているボンディングパッド電極１２０とを備えているので、接合層１１０によって透光性電極１０９とボンディングパッド電極１２０との十分に高い接合力が得られ、ｐ型電極１１１の接合性に優れたものとなる。
　しかも、本実施形態の半導体発光素子１によれば、外側に向けて膜厚が漸次薄くなる傾斜面１１９ｃを外周部１２０ｄに有するボンディングパッド電極１２０が、接合層１１０を覆うように形成されているので、接合層１１０への外部からの空気や水分の侵入を効果的に防止することができ、優れた耐食性が得られるものとなる。 In the semiconductor light emitting device 1 of the present embodiment, the p-type electrode 111 includes the translucent electrode 109 having the bonding recess 109a on the upper surface 109c, the bonding layer 110 formed so as to cover the bonding recess 109a, and the bonding layer 110. The bonding pad electrode 120 is formed on the outer peripheral portion 120d and has an inclined surface 119c that gradually decreases in thickness toward the outer side. A sufficiently high bonding force with the bonding pad electrode 120 is obtained, and the bonding property of the p-type electrode 111 is excellent.
In addition, according to the semiconductor light emitting device 1 of the present embodiment, the bonding pad electrode 120 having the inclined surface 119c whose thickness is gradually decreased toward the outside on the outer peripheral portion 120d is formed so as to cover the bonding layer 110. Therefore, intrusion of air and moisture from the outside to the bonding layer 110 can be effectively prevented, and excellent corrosion resistance can be obtained.
　ここで、本実施形態の半導体発光素子１の効果を、例えば、図２５に示すｐ型電極を備えた半導体発光素子を例に挙げて説明する。なお、図２５においては、半導体発光素子に備えられたｐ型電極のみを示し、基板および積層半導体層の図示を省略している。図２５に示すｐ型電極２０１では、本実施形態の半導体発光素子１と異なり、縁部保護膜１０ｂが形成されていないし、透光性電極１０９の上面１０９ｃに接合凹部１０９ａが形成されておらず、接合層２１０、ボンディングパッド電極２２０を構成する金属反射層２１７およびボンディング層２１９の側面が透光性電極１０９の上面１０９ｃに対してほぼ垂直に形成されている。 Here, the effect of the semiconductor light emitting device 1 of the present embodiment will be described by taking, for example, a semiconductor light emitting device including a p-type electrode shown in FIG. In FIG. 25, only the p-type electrode provided in the semiconductor light emitting element is shown, and the substrate and the laminated semiconductor layer are not shown. In the p-type electrode 201 shown in FIG. 25, unlike the semiconductor light emitting device 1 of the present embodiment, the edge protection film 10b is not formed, and the bonding recess 109a is not formed on the upper surface 109c of the translucent electrode 109. The side surfaces of the bonding layer 210, the metal reflective layer 217 constituting the bonding pad electrode 220, and the bonding layer 219 are formed substantially perpendicular to the upper surface 109c of the translucent electrode 109.
　図２５に示すｐ型電極２０１では、外部の空気または水分が、透明保護膜１０ａと金属反射層２１７との間から容易に侵入し、接合層２１０へ到達する。空気または水分が接合層２１０へ到達すると、接合層２１０が劣化して半導体発光素子の素子寿命を短くするという問題を生じる。特に、接合層２１０がＣｒからなるものである場合には、接合層２１０へ到達した空気または水分によってＣｒが容易に酸化または水酸化反応し、接合層２１０が分解消失されるため、この問題が顕著となる。さらに、Ｃｒの酸化または水酸化反応は、図２５に示すｐ型電極２０１を備えた半導体発光素子にバイアスが印加されることにより加速されるので、簡単に接合層２１０が分解消失されてしまう恐れがあった。 In the p-type electrode 201 shown in FIG. 25, external air or moisture easily enters from between the transparent protective film 10a and the metal reflective layer 217 and reaches the bonding layer 210. When air or moisture reaches the bonding layer 210, the bonding layer 210 deteriorates, causing a problem that the element lifetime of the semiconductor light emitting element is shortened. In particular, when the bonding layer 210 is made of Cr, Cr is easily oxidized or hydroxylated by air or moisture that reaches the bonding layer 210, and the bonding layer 210 is decomposed and lost. Become prominent. Further, since the oxidation or hydroxylation reaction of Cr is accelerated by applying a bias to the semiconductor light emitting device including the p-type electrode 201 shown in FIG. 25, the bonding layer 210 may be easily decomposed and lost. was there.
　これに対し、本実施形態の半導体発光素子１においては、接合層１１０を覆うように形成され、外側に向けて膜厚が漸次薄くなる傾斜面１１９ｃが外周部１２０ｄに形成されているボンディングパッド電極１２０を備えているので、接合層１１０のいかなる部分もボンディングパッド電極１２０の下から露出しないようにされている。したがって、本実施形態の半導体発光素子１によれば、半導体発光素子１の外部の空気または水分が接合層１１０へ侵入することを効果的に防止でき、接合層１１０がＣｒからなるものである場合であっても、優れた耐食性と、接合層１１０による透光性電極１０９とボンディングパッド電極１２０との優れた接合性とが得られる。 On the other hand, in the semiconductor light emitting device 1 of the present embodiment, the bonding pad electrode is formed so as to cover the bonding layer 110, and the inclined surface 119c is formed on the outer peripheral portion 120d so that the film thickness gradually decreases toward the outside. Since 120 is provided, no part of the bonding layer 110 is exposed from below the bonding pad electrode 120. Therefore, according to the semiconductor light emitting device 1 of the present embodiment, air or moisture outside the semiconductor light emitting device 1 can be effectively prevented from entering the bonding layer 110, and the bonding layer 110 is made of Cr. Even so, excellent corrosion resistance and excellent bondability between the translucent electrode 109 and the bonding pad electrode 120 by the bonding layer 110 can be obtained.
　また、本実施形態の半導体発光素子１において、接合層１１０を、Ａｌ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｃｏ、Ｚｎ、Ｇｅ、Ｚｒ、Ｎｂ、Ｍｏ、Ｒｕ、Ｈｆ、Ｔａ、Ｗ、Ｒｅ、Ｒｈ、Ｉｒ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなり、最大厚みが１０Å以上４００Å以下の範囲である薄膜とした場合、透光性電極１０９とボンディングパッド電極１２０との間の接合性をより一層向上させることができる。 In the semiconductor light emitting device 1 of the present embodiment, the bonding layer 110 is formed of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh. When the thin film is made of at least one element selected from the group consisting of Ir, Ni, and has a maximum thickness in the range of 10 to 400 mm, the bonding property between the translucent electrode 109 and the bonding pad electrode 120 Can be further improved.
　さらに、本実施形態の半導体発光素子１においては、透光性電極１０９の上面１０９ｃにおける接合凹部１０９ａの形成されていない領域を覆うように透明保護膜１０ａが形成されており、接合層１１０の外縁部およびボンディングパッド電極１２０の外縁部が、透明保護膜１０ａ上に配置されているので、より一層優れた耐食性および接合性が得られる。 Further, in the semiconductor light emitting device 1 of the present embodiment, the transparent protective film 10a is formed so as to cover the region where the bonding recess 109a is not formed on the upper surface 109c of the translucent electrode 109, and the outer edge of the bonding layer 110 is formed. And the outer edge of the bonding pad electrode 120 are disposed on the transparent protective film 10a, so that even better corrosion resistance and bondability can be obtained.
　また、本実施形態の半導体発光素子１においては、ボンディングパッド電極１２０が、金属反射層１１７とボンディング層１１９とからなるものであり、接合層１１０のいかなる部分も金属反射層１１７の下から露出しないようにされているとともに、金属反射層１１７のいかなる部分もボンディング層１１９の下から露出しないようにされており、金属反射層１１７およびボンディング層１１９により接合層１１０が二重に覆われている。さらに、本実施形態の半導体発光素子１においては、ボンディングパッド電極１２０の外縁部が、透明保護膜１０ａ上に配置されている。よって、本実施形態の半導体発光素子１においては、透明保護膜１０ａとボンディング層１１９との接合面と、透明保護膜１０ａと金属反射層１１７との接合面とを通過しなければ、半導体発光素子１の外部の空気または水分が接合層１１０へ侵入することはできない。したがって、半導体発光素子１の外部の空気または水分が接合層１１０へ侵入することを、より効果的に防止できる。 Further, in the semiconductor light emitting device 1 of the present embodiment, the bonding pad electrode 120 is composed of the metal reflective layer 117 and the bonding layer 119, and no part of the bonding layer 110 is exposed from under the metal reflective layer 117. In addition, any part of the metal reflection layer 117 is not exposed from below the bonding layer 119, and the bonding layer 110 is double covered with the metal reflection layer 117 and the bonding layer 119. Furthermore, in the semiconductor light emitting device 1 of the present embodiment, the outer edge portion of the bonding pad electrode 120 is disposed on the transparent protective film 10a. Therefore, in the semiconductor light emitting device 1 of the present embodiment, the semiconductor light emitting device does not pass through the joint surface between the transparent protective film 10a and the bonding layer 119 and the joint surface between the transparent protective film 10a and the metal reflective layer 117. 1 outside air or moisture cannot enter the bonding layer 110. Therefore, it is possible to more effectively prevent air or moisture outside the semiconductor light emitting element 1 from entering the bonding layer 110.
　また、本実施形態の半導体発光素子１においては、ボンディングパッド電極１２０の外縁部を覆い、ボンディングパッド電極１２０上の一部を露出させる縁部保護膜１０ｂが形成されているので、より一層優れた耐食性および接合性が得られる。 Further, in the semiconductor light emitting device 1 of the present embodiment, the edge protection film 10b that covers the outer edge of the bonding pad electrode 120 and exposes a part on the bonding pad electrode 120 is formed, so that it is further excellent. Corrosion resistance and bondability are obtained.
　また、本実施形態の半導体発光素子１の製造方法は、ｐ型電極１１１を製造する工程が、透光性電極１０９を形成する工程と、透明保護膜１０ａの形成された透光性電極１０９の上面に、底面に向かって断面積が徐々に広くなる内壁形状を有する開口部２３ａを備えたマスク２３を形成する工程と、開口部２３ａから露出する透光性電極１０９の上面１０９ｃをエッチングすることにより接合凹部１０９ａを形成する工程と、接合凹部１０９ａを覆うように接合層１１０を形成する工程と、開口部２３ａの内壁形状に沿って外周部１２０ｄの形状を形成することにより、接合層１１０を覆い、外側に向けて膜厚が漸次薄くなる傾斜面１１９ｃを外周部１２０ｄに有するボンディングパッド電極１２０を形成する工程と、マスク２３を除去する工程とを備えているので、優れた接合性および耐食性を有するｐ型電極１１１を備えた本実施形態の半導体発光素子１を容易に製造できる。 Further, in the method for manufacturing the semiconductor light emitting device 1 according to the present embodiment, the step of manufacturing the p-type electrode 111 includes the step of forming the translucent electrode 109 and the step of forming the translucent electrode 109 on which the transparent protective film 10a is formed. Forming a mask 23 having an opening 23a having an inner wall shape whose cross-sectional area gradually increases toward the bottom surface on the upper surface, and etching the upper surface 109c of the translucent electrode 109 exposed from the opening 23a. Forming the bonding recess 109a, forming the bonding layer 110 so as to cover the bonding recess 109a, and forming the shape of the outer peripheral portion 120d along the inner wall shape of the opening 23a. A step of forming a bonding pad electrode 120 having an inclined surface 119c that gradually decreases in thickness toward the outside and having an outer peripheral portion 120d; and the mask 23 is removed. Since a process can easily manufacture the semiconductor light emitting element 1 of this embodiment having the p-type electrode 111 having excellent bonding and corrosion resistance.
　また、本実施形態の半導体発光素子１の製造方法は、開口部２３ａから露出する透光性電極１０９の上面１０９ｃをエッチングすることにより接合凹部１０９ａを形成する工程と、接合凹部１０９ａを覆うように接合層１１０を形成する工程とを備えているので、接合凹部１０９ａを形成することにより透光性電極１０９から現れた接合凹部１０９ａの内面に接して接合層１１０が形成されることになる。接合凹部１０９ａを形成することにより透光性電極１０９から現れた接合凹部１０９ａの内面は、透光性電極１０９の上面１０９ｃと比較して、接合層１１０との密着性に優れているので、本実施形態の製造方法によれば、透光性電極１０９の上面１０９ｃに接合層１１０を形成する場合と比較して、接合層１１０との密着性に優れたｐ型電極１１１が得られる。 Further, in the method of manufacturing the semiconductor light emitting device 1 according to the present embodiment, the step of forming the bonding recess 109a by etching the upper surface 109c of the translucent electrode 109 exposed from the opening 23a and the bonding recess 109a are covered. Forming the bonding layer 110, the bonding layer 110 is formed in contact with the inner surface of the bonding recess 109 a that emerges from the translucent electrode 109 by forming the bonding recess 109 a. Since the inner surface of the bonding recess 109a that emerges from the translucent electrode 109 by forming the bonding recess 109a is superior in adhesion to the bonding layer 110 compared to the upper surface 109c of the translucent electrode 109, this According to the manufacturing method of the embodiment, the p-type electrode 111 having excellent adhesion to the bonding layer 110 can be obtained as compared with the case where the bonding layer 110 is formed on the upper surface 109 c of the translucent electrode 109.
（実施形態８：半導体発光素子）
　図２０は、本発明の半導体発光素子の他の例を示した図であって、半導体発光素子の断面模式図である。図２０に示す本実施形態の半導体発光素子２が、図１４に示す半導体発光素子１と異なるところは、ｎ型電極１０８のみであり、ｎ型電極１０８以外は図１４に示す半導体発光素子１と同様とされている。したがって、実施形態７と同じ部材には同じ符号付し、説明を省略する。 (Embodiment 8: Semiconductor light emitting device)
FIG. 20 is a view showing another example of the semiconductor light emitting device of the present invention, and is a schematic cross-sectional view of the semiconductor light emitting device. The semiconductor light emitting device 2 of the present embodiment shown in FIG. 20 is different from the semiconductor light emitting device 1 shown in FIG. 14 only in the n-type electrode 108, and other than the n-type electrode 108, the semiconductor light emitting device 1 shown in FIG. The same is said. Therefore, the same members as those of the seventh embodiment are denoted by the same reference numerals, and description thereof is omitted.
　図２０に示す本実施形態の半導体発光素子２においては、ｎ型電極１０８として、ボンディングパッド電極１２０がボンディング層１１９のみからなる単層構造とされているところ以外はｐ型電極１１１と同じ電極が形成されている。したがって、本実施形態の半導体発光素子２を構成するｎ型電極１０８は、金属反射層１１７を形成しないことを除き、ｐ型電極１１１と同様にして形成できる。 In the semiconductor light emitting device 2 of the present embodiment shown in FIG. 20, the same electrode as the p-type electrode 111 is used as the n-type electrode 108 except that the bonding pad electrode 120 has a single-layer structure composed of only the bonding layer 119. Is formed. Therefore, the n-type electrode 108 constituting the semiconductor light emitting element 2 of the present embodiment can be formed in the same manner as the p-type electrode 111 except that the metal reflective layer 117 is not formed.
　図２０に示す本実施形態の半導体発光素子２においては、図１４に示す半導体発光素子１と同様に、ｐ型電極１１１の接合性に優れたものとなる。
　さらに、図２０に示す本実施形態の半導体発光素子２においては、ｎ型電極１０８が、上面１０９ｃに接合凹部１０９ａを有する透光性電極１０９と、接合凹部１０９ａを覆うように形成された接合層１１０と、接合層１１０を覆うように形成され、外周部１２０ｄに外側に向けて膜厚が漸次薄くなる傾斜面１１９ｃが形成されているボンディングパッド電極１２０とを備えているので、接合層１１０によって透光性電極１０９とボンディングパッド電極１２０との十分に高い接合力が得られ、ｎ型電極１０８の接合性に優れたものとなる。 In the semiconductor light emitting device 2 of this embodiment shown in FIG. 20, the bonding property of the p-type electrode 111 is excellent as in the semiconductor light emitting device 1 shown in FIG.
Further, in the semiconductor light emitting device 2 of the present embodiment shown in FIG. 20, the n-type electrode 108 has a translucent electrode 109 having a bonding recess 109a on the upper surface 109c and a bonding layer formed so as to cover the bonding recess 109a. 110 and the bonding pad electrode 120 formed so as to cover the bonding layer 110 and formed with an inclined surface 119c whose thickness gradually decreases toward the outside on the outer peripheral portion 120d. A sufficiently high bonding force between the translucent electrode 109 and the bonding pad electrode 120 is obtained, and the bonding property of the n-type electrode 108 is excellent.
　また、図２０に示す本実施形態の半導体発光素子２においては、ｐ型電極１１１およびｎ型電極１０８を構成するボンディングパッド電極１２０が、外側に向けて膜厚が漸次薄くなる傾斜面１１９ｃを外周部１２０ｄに有するものであって、接合層１１０を覆うように形成されているので、接合層１１０への外部からの空気や水分の侵入を効果的に防止することができ、優れた耐食性が得られるものとなる。 Further, in the semiconductor light emitting device 2 of the present embodiment shown in FIG. 20, the bonding pad electrode 120 constituting the p-type electrode 111 and the n-type electrode 108 has an inclined surface 119c whose thickness is gradually reduced toward the outer periphery. Since the portion 120d is formed so as to cover the bonding layer 110, air and moisture can be effectively prevented from entering the bonding layer 110 from the outside, and excellent corrosion resistance is obtained. It will be.
　また、本実施形態の半導体発光素子２の製造方法は、ｐ型電極１１１およびｎ型電極１０８を製造する工程が、透光性電極１０９を形成する工程と、透明保護膜１０ａの形成された透光性電極１０９の上面１０９ｃに、底面に向かって断面積が徐々に広くなる内壁形状を有する開口部２３ａを備えたマスク２３を形成する工程と、開口部２３ａから露出する透光性電極１０９の上面１０９ｃをエッチングすることにより接合凹部１０９ａを形成する工程と、接合凹部１０９ａを覆うように接合層１１０を形成する工程と、開口部２３ａの内壁形状に沿って外周部１２０ｄの形状を形成することにより、接合層１１０を覆い、外側に向けて膜厚が漸次薄くなる傾斜面１１９ｃを外周部１２０ｄに有するボンディングパッド電極１２０を形成する工程と、マスク２３を除去する工程とを備えているので、優れた接合性および耐食性を有するｐ型電極１１１およびｎ型電極１０８を備えた本実施形態の半導体発光素子２を製造できる。 Further, in the method for manufacturing the semiconductor light emitting device 2 of the present embodiment, the process of manufacturing the p-type electrode 111 and the n-type electrode 108 includes the process of forming the translucent electrode 109 and the transparent film on which the transparent protective film 10a is formed. A step of forming a mask 23 having an opening 23a having an inner wall shape whose cross-sectional area gradually increases toward the bottom surface on the upper surface 109c of the photoconductive electrode 109, and the translucent electrode 109 exposed from the opening 23a. Forming the bonding recess 109a by etching the upper surface 109c, forming the bonding layer 110 so as to cover the bonding recess 109a, and forming the shape of the outer peripheral portion 120d along the inner wall shape of the opening 23a. Thus, the bonding pad electrode 120 is formed which covers the bonding layer 110 and has an inclined surface 119c whose thickness is gradually reduced toward the outside at the outer peripheral portion 120d. A step, since a step of removing the mask 23, can be manufactured semiconductor light-emitting element 2 of this embodiment having the p-type electrode 111 and n-type electrode 108 having excellent bondability and corrosion resistance.
（実施形態９：半導体発光素子）
　図２１は、本発明の半導体発光素子の他の例を示した図であって、半導体発光素子を構成するｐ型電極の拡大断面模式図である。図２１に示す本実施形態の半導体発光素子が、図１４に示す半導体発光素子１と異なるところは、透明保護膜１０ａおよび縁部保護膜１０ｂが形成されていないことのみであり、それ以外は図１４に示す半導体発光素子１と同様とされている。したがって、実施形態７と同じ部材には同じ符号付し、説明を省略する。
　また、本実施形態の半導体発光素子を構成するｐ型電極１１２は、透明保護膜１０ａおよび縁部保護膜１０ｂを形成しないことを除き、図１４に示すｐ型電極１１１と同様にして形成できる。 (Embodiment 9: Semiconductor light emitting device)
FIG. 21 is a view showing another example of the semiconductor light emitting device of the present invention, and is an enlarged schematic cross-sectional view of a p-type electrode constituting the semiconductor light emitting device. The semiconductor light emitting device of this embodiment shown in FIG. 21 is different from the semiconductor light emitting device 1 shown in FIG. 14 only in that the transparent protective film 10a and the edge protective film 10b are not formed. 14 is the same as the semiconductor light emitting device 1 shown in FIG. Therefore, the same members as those of the seventh embodiment are denoted by the same reference numerals, and description thereof is omitted.
Further, the p-type electrode 112 constituting the semiconductor light emitting device of this embodiment can be formed in the same manner as the p-type electrode 111 shown in FIG. 14 except that the transparent protective film 10a and the edge protective film 10b are not formed.
　図２１に示す本実施形態の半導体発光素子のように、透明保護膜１０ａおよび縁部保護膜１０ｂを設けない場合でも、ｐ型電極１１２が、上面１０９ｃに接合凹部１０９ａを有する透光性電極１０９と、接合凹部１０９ａを覆うように形成された接合層１１０と、接合層１１０を覆うように形成され、外周部１２０ｄに外側に向けて膜厚が漸次薄くなる傾斜面１１９ｃが形成されているボンディングパッド電極１２０とを備えているので、接合層１１０によって透光性電極１０９とボンディングパッド電極１２０との十分に高い接合力が得られ、ｐ型電極１１２の接合性に優れたものとなる。
　しかも、図２１に示す半導体発光素子においても、外側に向けて膜厚が漸次薄くなる傾斜面１１９ｃを外周部１２０ｄに有するボンディングパッド電極１２０が、接合層１１０を覆うように形成されているので、接合層１１０への外部からの空気や水分の侵入を効果的に防止することができ、優れた耐食性が得られるものとなる。 Even in the case where the transparent protective film 10a and the edge protective film 10b are not provided as in the semiconductor light emitting device of this embodiment shown in FIG. 21, the p-type electrode 112 has the translucent electrode 109 having the bonding recess 109a on the upper surface 109c. A bonding layer 110 formed so as to cover the bonding recess 109a, and an inclined surface 119c formed so as to cover the bonding layer 110 and gradually decreasing in thickness toward the outside on the outer peripheral portion 120d. Since the pad electrode 120 is provided, a sufficiently high bonding force between the translucent electrode 109 and the bonding pad electrode 120 is obtained by the bonding layer 110, and the bonding property of the p-type electrode 112 is excellent.
Moreover, in the semiconductor light emitting device shown in FIG. 21 as well, the bonding pad electrode 120 having the inclined surface 119c whose thickness gradually decreases toward the outer side at the outer peripheral portion 120d is formed so as to cover the bonding layer 110. Intrusion of air and moisture from the outside to the bonding layer 110 can be effectively prevented, and excellent corrosion resistance can be obtained.
（実施形態１０：半導体発光素子）
　図２２は、本発明の半導体発光素子の他の例を示した図であって、半導体発光素子の断面模式図である。図２２に示す本実施形態の半導体発光素子１ａが、図１４に示す半導体発光素子１と異なるところは、透明保護膜１０ａが形成されておらず、平面視したときに、ボンディングパッド電極１２０の中央部を露出させる領域を除く、透光性電極１０９の上面１０９ｃ全面に上面保護膜１０が設けられているところである。それ以外は図１４に示す半導体発光素子１と同様とされている。したがって、実施形態７と同じ部材には同じ符号付し、説明を省略する。
　上面保護膜１０は、図１４に示す半導体発光素子１における透明保護膜１０ａと同様の材料からなる同様の厚みを有するものとすることができる。 (Embodiment 10: Semiconductor light emitting device)
FIG. 22 is a view showing another example of the semiconductor light emitting device of the present invention, and is a schematic sectional view of the semiconductor light emitting device. The semiconductor light emitting device 1a of the present embodiment shown in FIG. 22 is different from the semiconductor light emitting device 1 shown in FIG. 14 in that the transparent protective film 10a is not formed and the center of the bonding pad electrode 120 is viewed in plan view. The upper surface protective film 10 is provided on the entire upper surface 109c of the translucent electrode 109 excluding the region where the portion is exposed. The rest is the same as the semiconductor light emitting device 1 shown in FIG. Therefore, the same members as those of the seventh embodiment are denoted by the same reference numerals, and description thereof is omitted.
The upper surface protective film 10 can have the same thickness made of the same material as the transparent protective film 10a in the semiconductor light emitting device 1 shown in FIG.
　図２２に示す半導体発光素子１ａを製造するには、まず、図１４に示す半導体発光素子１と同様にして積層半導体層２０の形成を形成した後、ｎ型電極１０８を形成する。
　その後、以下に示すようにしてｐ型電極１１１ａを製造する。図２３は、ｐ型電極を製造する工程を説明するための工程図であり、ｐ型電極１１１ａの製造される領域の一部のみを拡大して示した拡大断面図である。
　図２３（ａ）に示すように、本実施形態のｐ型電極１１１ａを製造するには、まず、図１４に示す半導体発光素子１と同様にして、ｐ型半導体層１０６上に透光性電極１０９を形成する。 In order to manufacture the semiconductor light emitting device 1a shown in FIG. 22, first, the stacked semiconductor layer 20 is formed in the same manner as the semiconductor light emitting device 1 shown in FIG. 14, and then the n-type electrode 108 is formed.
Thereafter, the p-type electrode 111a is manufactured as follows. FIG. 23 is a process diagram for explaining a process of manufacturing the p-type electrode, and is an enlarged cross-sectional view showing only a part of a region where the p-type electrode 111a is manufactured.
As shown in FIG. 23A, in order to manufacture the p-type electrode 111a of the present embodiment, first, a light-transmitting electrode is formed on the p-type semiconductor layer 106 in the same manner as the semiconductor light emitting device 1 shown in FIG. 109 is formed.
　次に、図２３（ａ）に示すように、透明保護膜１０ａ上にレジスト２１を塗布して乾燥させ、図１４に示す半導体発光素子１と同様にして、透光性電極１０９の上面１０９ｃに、底面に向かって断面積が徐々に広くなる内壁形状を有する開口部２３ａを備えた図２３（ｂ）に示す逆テーパー型のマスク２３を形成する。 Next, as shown in FIG. 23A, a resist 21 is applied on the transparent protective film 10a and dried, and the upper surface 109c of the translucent electrode 109 is formed in the same manner as the semiconductor light emitting device 1 shown in FIG. Then, a reverse taper type mask 23 shown in FIG. 23 (b) having an opening 23a having an inner wall shape whose cross-sectional area gradually increases toward the bottom surface is formed.
　続いて、図２３（ｂ）に示すマスク２３の開口部２３ａから露出する透光性電極１０９を、図１４に示す半導体発光素子１と同様にしてエッチングすることにより、図２３（ｃ）に示すように、透光性電極１０９の上面１０９ｃに接合凹部１０９ａを形成する。 Subsequently, the transparent electrode 109 exposed from the opening 23a of the mask 23 shown in FIG. 23B is etched in the same manner as the semiconductor light emitting device 1 shown in FIG. As described above, the bonding recess 109 a is formed on the upper surface 109 c of the translucent electrode 109.
　次に、図２３（ｄ）に示すように、図１４に示す半導体発光素子１と同様にして、接合層１１０、金属反射層１１７、ボンディング層１１９を形成する。その後、図１４に示す半導体発光素子１と同様にして、マスク２３を剥離する。これにより、図２３（ｅ）に示すように、金属反射層１１７とボンディング層１１９とからなるボンディングパッド電極１２０が形成される。本実施形態においても、図１４に示す半導体発光素子１と同様に、接合層１１０、金属反射層１１７およびボンディング層１１９の外周部にそれぞれ、外側に向けて膜厚が漸次薄くなる傾斜面１１０ｃ、１１７ｃ、１１９ｃが形成される。 Next, as shown in FIG. 23D, the bonding layer 110, the metal reflection layer 117, and the bonding layer 119 are formed in the same manner as the semiconductor light emitting device 1 shown in FIG. Thereafter, the mask 23 is peeled in the same manner as the semiconductor light emitting device 1 shown in FIG. As a result, as shown in FIG. 23E, a bonding pad electrode 120 composed of the metal reflective layer 117 and the bonding layer 119 is formed. Also in the present embodiment, similar to the semiconductor light emitting device 1 shown in FIG. 14, the inclined surface 110 c whose film thickness gradually decreases toward the outside on the outer peripheral portions of the bonding layer 110, the metal reflection layer 117, and the bonding layer 119, respectively. 117c and 119c are formed.
　次に、従来から公知の方法を用いて、平面視したときに、ボンディングパッド電極１２０の中央部を露出させる領域を除く、透光性電極１０９の上面１０９ｃ全面に、上面保護膜１０を形成する。このようにして、図２２に示すｐ型電極１１１ａを備える半導体発光素子１ａが形成される。 Next, the upper surface protective film 10 is formed on the entire upper surface 109c of the translucent electrode 109 excluding a region exposing the central portion of the bonding pad electrode 120 when viewed in plan using a conventionally known method. . Thus, the semiconductor light emitting element 1a including the p-type electrode 111a shown in FIG. 22 is formed.
　　本実施形態の半導体発光素子１ａにおいても、図１４に示す半導体発光素子１と同様に、接合性および耐食性に得られるものとなる。
　また、本実施形態の半導体発光素子１ａにおいては、平面視したときに、ボンディングパッド電極１２０の中央部を露出させる領域を除く、透光性電極１０９の上面１０９ｃ全面に上面保護膜１０が設けられているので、より一層優れた耐食性および接合性が得られる。 Also in the semiconductor light emitting device 1a of the present embodiment, similar to the semiconductor light emitting device 1 shown in FIG. 14, the bonding property and the corrosion resistance are obtained.
Further, in the semiconductor light emitting device 1a of the present embodiment, the upper surface protective film 10 is provided on the entire upper surface 109c of the translucent electrode 109 excluding the region where the central portion of the bonding pad electrode 120 is exposed in plan view. Therefore, further excellent corrosion resistance and bondability can be obtained.
（実施形態１１：ランプ）
　図２４は、本発明のランプの一例を示す断面概略図である。図２４に示すように、本実施形態のランプ３は、砲弾型であり、半導体発光素子として図１４に示す本発明の半導体発光素子１が実装されたものである。なお、ランプ３は、例えば、半導体発光素子１と蛍光体とを組み合わせてなるものであり、当業者周知の手段によって当業者周知の構成とすることができる。また、半導体発光素子１と蛍光体と組み合わせることによって発光色を変えることができることが知られているが、このような技術を本実施形態のランプにおいても何ら制限されることなく採用することが可能である。 (Embodiment 11: lamp)
FIG. 24 is a schematic sectional view showing an example of the lamp of the present invention. As shown in FIG. 24, the lamp 3 of the present embodiment is a shell type, and is mounted with the semiconductor light emitting device 1 of the present invention shown in FIG. 14 as a semiconductor light emitting device. The lamp 3 is, for example, a combination of the semiconductor light emitting element 1 and a phosphor, and can be configured as known to those skilled in the art by means known to those skilled in the art. In addition, it is known that the emission color can be changed by combining the semiconductor light emitting element 1 and the phosphor, but such a technique can be adopted without any limitation in the lamp of this embodiment. It is.
　本実施形態のランプ３は、図２４に示すように、半導体発光素子１のｐ型電極１１１のボンディングパッド電極１２０にワイヤ３３で接合されたフレーム３１と、半導体発光素子１のｎ型電極１０８（ボンディングパッド）にワイヤ３４で接合された他方のフレーム３２と、半導体発光素子１の周辺を取り囲んで形成された透明な樹脂からなるモールド３５とを備えている。 As shown in FIG. 24, the lamp 3 according to the present embodiment includes a frame 31 bonded to the bonding pad electrode 120 of the p-type electrode 111 of the semiconductor light-emitting element 1 with a wire 33 and an n-type electrode 108 ( The other frame 32 joined to the bonding pad) by a wire 34 and a mold 35 made of a transparent resin formed so as to surround the periphery of the semiconductor light emitting element 1.
　本実施形態のランプ３は、半導体発光素子として、優れた接合性および耐食性を有するｐ型電極１１１を備えた図１４に示す本発明の半導体発光素子１を用いたものであるので、ｐ型電極１１２の接合性に優れ、歩留まりよく製造できるとともに、耐食性に優れたものとなる。 Since the lamp 3 of the present embodiment uses the semiconductor light-emitting element 1 of the present invention shown in FIG. 14 provided with the p-type electrode 111 having excellent bonding properties and corrosion resistance as the semiconductor light-emitting element, the p-type electrode is used. 112 is excellent in bondability, can be manufactured with high yield, and has excellent corrosion resistance.
　本実施形態のランプ３は、一般用途の砲弾型、携帯のバックライト用途のサイドビュー型、表示器に用いられるトップビュー型等いかなる用途にも用いることができる。 The lamp 3 of the present embodiment can be used for any purposes such as a general-use bullet type, a side view type for a portable backlight, and a top view type used for a display.
　また、本発明の半導体発光素子から作製したランプ３は、前述のような優れた効果があるので、この技術によって作製したランプを組み込んだバックライト、携帯電話、ディスプレイ、各種パネル類、コンピュータ、ゲーム機、照明などの電子機器や、その電子機器を組み込んだ自動車などの機械装置類は、製品としての使用上の高い信頼性を与えることができる。特に、バックライト、携帯電話、ディスプレイ、ゲーム機、照明などの、バッテリ駆動させる機器類において、優れた耐食性、高信頼性のある発光素子を具備した製品を提供することができ、好ましい。 Further, since the lamp 3 manufactured from the semiconductor light emitting device of the present invention has the excellent effects as described above, a backlight, a mobile phone, a display, various panels, a computer, a game incorporating the lamp manufactured by this technology. Electronic devices such as machines and lighting, and mechanical devices such as automobiles incorporating the electronic devices can give high reliability in use as products. In particular, in a battery-driven device such as a backlight, a cellular phone, a display, a game machine, and lighting, a product including a light-emitting element with excellent corrosion resistance and high reliability can be provided, which is preferable.
（実施形態１２の半導体発光素子の製造方法）
　次に、本発明の半導体発光素子の製造方法について説明する。本実施形態１２の半導体発光素子の製造方法は、図２６に示す半導体発光素子１の製造方法である。
　図２６に示す半導体発光素子１を製造するには、まず、基板１０１上に積層半導体層２０を形成する。積層半導体層２０は、ＭＯＣＶＤ法で形成すると結晶性の良いものが得られるが、スパッタ法によっても条件を最適化することで、ＭＯＣＶＤ法よりも優れた結晶性を有するものが得られる。以下、バッファ層形成工程、下地層形成工程、ｎ型半導体層形成工程、発光層形成工程、ｐ型半導体層形成工程を含む「積層半導体層の形成」は、前述の実施形態１の半導体発光素子の製造方法に準じて行われる。そして、このようにして積層半導体層２０の形成を形成した後、ｎ型電極１０８とｐ型電極１１１とを形成する。 (Method for Manufacturing Semiconductor Light Emitting Element of Embodiment 12)
Next, the manufacturing method of the semiconductor light emitting device of the present invention will be described. The manufacturing method of the semiconductor light emitting device of the twelfth embodiment is a manufacturing method of the semiconductor light emitting device 1 shown in FIG.
In order to manufacture the semiconductor light emitting device 1 shown in FIG. 26, first, the laminated semiconductor layer 20 is formed on the substrate 101. When the stacked semiconductor layer 20 is formed by the MOCVD method, a layer having good crystallinity can be obtained. However, by optimizing the conditions also by the sputtering method, a layer having crystallinity superior to the MOCVD method can be obtained. Hereinafter, the “layered semiconductor layer formation” including the buffer layer forming step, the base layer forming step, the n-type semiconductor layer forming step, the light-emitting layer forming step, and the p-type semiconductor layer forming step is referred to as the semiconductor light-emitting device of the first embodiment. It is performed according to the manufacturing method. Then, after forming the stacked semiconductor layer 20 in this manner, the n-type electrode 108 and the p-type electrode 111 are formed.
　本実施形態においては、図３０～図３３を用い、ｎ型電極１０８を製造する工程とｐ型電極１１１を製造する工程とにおいて、オーミック接合層９、接合層１１０、ボンディングパッド電極１２０の各層を同時に形成し、オーミック接合層９と接合層１１０との密着性を高める熱処理を同時に行う製造方法について説明する。
　図３３は、ｎ型電極１０８およびｐ型電極１１１を製造する工程を説明するための概略図である。図３０は、ｐ型電極を製造する工程を説明するための工程図であり、ｐ型電極１１１の製造される領域の一部のみを拡大して示した拡大断面図である。また、図３１は、ｎ型電極１０８およびｐ型電極１１１を製造する際に形成されるマスクの製造工程を説明するための工程図であり、１つのｐ型電極１１１の形成される領域のみを示した拡大断面図である。また、図３２は、ｎ型電極を製造する工程を説明するための工程図であり、ｎ型電極の製造される領域の一部のみを拡大して示した拡大断面図である。 In this embodiment, referring to FIGS. 30 to 33, the ohmic junction layer 9, the junction layer 110, and the bonding pad electrode 120 are formed in the steps of manufacturing the n-type electrode 108 and the p-type electrode 111. A manufacturing method will be described in which heat treatment is performed at the same time and heat treatment for improving the adhesion between the ohmic bonding layer 9 and the bonding layer 110 is performed simultaneously.
FIG. 33 is a schematic diagram for explaining a process of manufacturing the n-type electrode 108 and the p-type electrode 111. FIG. 30 is a process diagram for explaining a process of manufacturing the p-type electrode, and is an enlarged cross-sectional view showing only a part of a region where the p-type electrode 111 is manufactured. FIG. 31 is a process diagram for explaining a manufacturing process of a mask formed when manufacturing the n-type electrode 108 and the p-type electrode 111, and shows only a region where one p-type electrode 111 is formed. It is the expanded sectional view shown. FIG. 32 is a process diagram for explaining a process of manufacturing the n-type electrode, and is an enlarged cross-sectional view showing only a part of a region where the n-type electrode is manufactured.
　まず、図３３（ａ）に示す積層半導体層２０を公知のフォトリソグラフィーの手法によってパターニングし、所定の領域の積層半導体層２０の一部をエッチングしてｎコンタクト層１０４ａの一部を露出させる。
　次に、図３３（ｂ）に示すように、積層半導体層２０のｐ型半導体層１０６上に透光性電極１０９を形成する。透光性電極１０９は、ｎ型電極１０８を形成する領域であるｎコンタクト層１０４ａの露出面１０４ｃなど、透光性電極１０９の形成される領域以外の領域を覆うマスクを形成した後、ｐ型半導体層１０６上にスパッタ法などの公知の方法を用いて形成し、その後、マスクを除去する方法などにより形成される。なお、透光性電極１０９は、ｎ型電極１０８を形成するための積層半導体層２０のエッチングの後に形成してもよいが、ｎ型電極１０８を形成するための積層半導体層２０のエッチングの前に形成してもよい。 First, the laminated semiconductor layer 20 shown in FIG. 33A is patterned by a known photolithography technique, and a part of the laminated semiconductor layer 20 in a predetermined region is etched to expose a part of the n contact layer 104a.
Next, as shown in FIG. 33B, a translucent electrode 109 is formed on the p-type semiconductor layer 106 of the stacked semiconductor layer 20. The translucent electrode 109 is formed by forming a mask that covers a region other than the region where the translucent electrode 109 is formed, such as the exposed surface 104c of the n contact layer 104a, which is a region where the n-type electrode 108 is formed, and then p-type. It is formed on the semiconductor layer 106 by a known method such as a sputtering method and then formed by a method of removing the mask. The translucent electrode 109 may be formed after the etching of the laminated semiconductor layer 20 for forming the n-type electrode 108, but before the etching of the laminated semiconductor layer 20 for forming the n-type electrode 108. You may form in.
　次に、図３０（ａ）に示す透光性電極１０９の上面１０９ｃに保護膜１０ａを形成すると同時に、図３２（ａ）に示すｎ型半導体層１０４の露出面１０４ｃ上に保護膜１０ａを形成する。 Next, the protective film 10a is formed on the upper surface 109c of the translucent electrode 109 shown in FIG. 30A, and at the same time, the protective film 10a is formed on the exposed surface 104c of the n-type semiconductor layer 104 shown in FIG. To do.
　続いて、保護膜１０ａを、透光性電極１０９の上面１０９ｃおよびｎ型半導体層１０４の露出面１０４ｃに垂直な方向からＲＩＥ（反応性イオンエッチング）することにより除去して、図３０（ａ）および図３２（ａ）に示すように、開口部１０ｄを形成し、開口部１０ｄから透光性電極１０９の上面１０９ｃおよびｎ型半導体層１０４の露出面１０４ｃを露出させる。ＲＩＥ（反応性イオンエッチング）は、直進性が高く、回り込みが少ないエッチング方法であるので、図３０（ａ）および図３２（ａ）に示すように、保護膜１０ａの端部１０ｃが略直角形状に残される。 Subsequently, the protective film 10a is removed by RIE (reactive ion etching) from a direction perpendicular to the upper surface 109c of the translucent electrode 109 and the exposed surface 104c of the n-type semiconductor layer 104, and FIG. And as shown to Fig.32 (a), the opening part 10d is formed and the upper surface 109c of the translucent electrode 109 and the exposed surface 104c of the n-type semiconductor layer 104 are exposed from the opening part 10d. RIE (Reactive Ion Etching) is an etching method with high straightness and less wraparound, so that the end portion 10c of the protective film 10a has a substantially right-angle shape as shown in FIGS. 30 (a) and 32 (a). Left behind.
　次に、保護膜１０ａの開口部１０ｄから露出する透光性電極１０９をエッチングすることにより、図３０（ａ）および図３３（ａ）に示すように、透光性電極１０９に穴部１０９ａを形成する。穴部１０９ａを形成することにより、透光性電極１０９から現れた穴部１０９ａの内壁１０９ｄは、透光性電極１０９の上面１０９ｃと比較して、オーミック接合層９との密着性に優れている。ここでエッチングされる透光性電極１０９が、例えば、アモルファス状態のＩＺＯ膜である場合、エッチング性に優れ、容易に特定形状の穴部１０９ａを形成することができる。アモルファス状態のＩＺＯ膜は、周知のエッチング液（例えば、ＩＴＯ－０７Ｎエッチング液（関東化学社製））を用いて容易に精度良くエッチングすることが可能である。また、アモルファス状態のＩＺＯ膜のエッチングは、ドライエッチング装置を用いて行なっても良い。このときのエッチングガスとしては、Ｃｌ２、ＳｉＣｌ４、ＢＣｌ３等を用いることができる。 Next, by etching the translucent electrode 109 exposed from the opening 10d of the protective film 10a, a hole 109a is formed in the translucent electrode 109 as shown in FIGS. 30 (a) and 33 (a). Form. By forming the hole 109a, the inner wall 109d of the hole 109a that emerges from the translucent electrode 109 is superior in adhesion to the ohmic bonding layer 9 compared to the upper surface 109c of the translucent electrode 109. . When the translucent electrode 109 etched here is, for example, an amorphous IZO film, the hole 109a having a specific shape can be easily formed with excellent etching properties. The amorphous IZO film can be easily and accurately etched using a known etching solution (for example, ITO-07N etching solution (manufactured by Kanto Chemical Co., Inc.)). In addition, the amorphous IZO film may be etched using a dry etching apparatus. As an etching gas at this time, Cl 2 , SiCl 4 , BCl 3, or the like can be used.
　ここで、透光性電極１０９が、例えば、アモルファス状態のＩＺＯ膜である場合、熱処理を行なうことにより、アモルファス状態のＩＺＯ膜を六方晶構造のＩｎ２Ｏ３結晶を含むＩＺＯ膜や、ビックスバイト構造のＩｎ２Ｏ３結晶を含むＩＺＯ膜にすることが好ましい。熱処理によりアモルファス状態から上記の結晶を含む構造に転移させることで、アモルファスのＩＺＯ膜よりもオーミック接合層９および接合層１１０との密着性および透光性の優れた透光性電極１０９とすることができる。しかし、六方晶構造のＩｎ２Ｏ３結晶を含むＩＺＯ膜はエッチングし難いものであるので、上述のエッチング処理の後に熱処理することが好ましい。 Here, when the translucent electrode 109 is, for example, an amorphous IZO film, by performing heat treatment, the amorphous IZO film is converted into an IZO film containing a hexagonal In 2 O 3 crystal, a bixbyite, or the like. It is preferable to form an IZO film including an In 2 O 3 crystal having a structure. By transferring from an amorphous state to a structure including the above crystal by heat treatment, a light-transmitting electrode 109 having better adhesion and light-transmitting properties to the ohmic bonding layer 9 and the bonding layer 110 than an amorphous IZO film is obtained. Can do. However, since an IZO film containing an In 2 O 3 crystal having a hexagonal crystal structure is difficult to etch, it is preferable to perform heat treatment after the above-described etching treatment.
　アモルファス状態のＩＺＯ膜を結晶化させる場合、成膜条件や熱処理条件などが異なるとＩＺＯ膜中の結晶構造が異なる。ＩＺＯ膜を結晶化させるための熱処理は、Ｏ２を含まない雰囲気で行なうことが望ましく、Ｏ２を含まない雰囲気としては、Ｎ２雰囲気などの不活性ガス雰囲気や、またはＮ２などの不活性ガスとＨ２の混合ガス雰囲気などを挙げることができ、Ｎ２雰囲気、またはＮ２とＨ２の混合ガス雰囲気とすることが望ましい。なお、ＩＺＯ膜の熱処理をＮ２雰囲気、またはＮ２とＨ２の混合ガス雰囲気中で行なうと、例えば、ＩＺＯ膜を六方晶構造のＩｎ２Ｏ３結晶を含む膜に結晶化させるとともに、ＩＺＯ膜のシート抵抗を効果的に減少させることが可能である。 In the case of crystallizing an amorphous IZO film, the crystal structure in the IZO film differs depending on the film formation conditions, heat treatment conditions, and the like. Heat treatment for crystallizing the IZO film is preferably performed in an atmosphere containing no O 2, as the atmosphere containing no O 2, or an inert gas atmosphere such as N 2 atmosphere, or an inert, such as N 2 A mixed gas atmosphere of gas and H 2 can be given, and an N 2 atmosphere or a mixed gas atmosphere of N 2 and H 2 is desirable. Note that when the heat treatment of the IZO film is performed in an N 2 atmosphere or a mixed gas atmosphere of N 2 and H 2 , for example, the IZO film is crystallized into a film containing In 2 O 3 crystals having a hexagonal structure, and IZO It is possible to effectively reduce the sheet resistance of the membrane.
　また、ＩＺＯ膜を結晶化させるための熱処理温度は、２５０℃～１０００℃が好ましく、５００℃～７００℃がより好ましい。２５０℃未満の温度で熱処理を行なった場合、ＩＺＯ膜を十分に結晶化できない恐れが生じ、ＩＺＯ膜の光透過率が十分に高いものとならない場合がある。また、１０００℃を超える温度で熱処理を行なった場合には、ＩＺＯ膜は結晶化されているが、ＩＺＯ膜の光透過率が十分に高いものとならない場合がある。また、１０００℃を超える温度で熱処理を行なった場合、ＩＺＯ膜の下にある半導体層を劣化させる恐れもある。 In addition, the heat treatment temperature for crystallizing the IZO film is preferably 250 ° C. to 1000 ° C., more preferably 500 ° C. to 700 ° C. When heat treatment is performed at a temperature lower than 250 ° C., the IZO film may not be sufficiently crystallized, and the light transmittance of the IZO film may not be sufficiently high. When heat treatment is performed at a temperature exceeding 1000 ° C., the IZO film is crystallized, but the light transmittance of the IZO film may not be sufficiently high. In addition, when heat treatment is performed at a temperature exceeding 1000 ° C., the semiconductor layer under the IZO film may be deteriorated.
　なお、透光性電極１０９を構成するＩＺＯ膜を結晶化させるための熱処理は、透光性電極１０９に穴部１０９ａを形成した後すぐに行なってもよいが、オーミック接合層９上に接合層１１０を形成した後に行ってもよい。接合層１１０を形成した後に透光性電極１０９を構成するＩＺＯ膜を結晶化させるための熱処理を行う場合には、ＩＺＯ膜を結晶化させるための熱処理と、オーミック接合層９と接合層１１０との密着性を向上させるための熱処理とを同時に行うことができるので、熱処理を行う回数を少なくすることができ、製造工程を簡略化することができ、好ましい。 Note that the heat treatment for crystallizing the IZO film constituting the translucent electrode 109 may be performed immediately after the hole 109a is formed in the translucent electrode 109, but the bonding layer is formed on the ohmic bonding layer 9. This may be done after forming 110. In the case of performing heat treatment for crystallizing the IZO film constituting the light-transmitting electrode 109 after the bonding layer 110 is formed, the heat treatment for crystallizing the IZO film, the ohmic bonding layer 9, the bonding layer 110, Since the heat treatment for improving the adhesiveness can be performed at the same time, the number of heat treatments can be reduced, and the manufacturing process can be simplified, which is preferable.
　その後、保護膜１０ａ上にレジストを塗布して乾燥させ、ボンディングパッド電極１２０を形成する部分に対応する部分のレジストを除去することによって、図３０（ｂ）に示す保護膜１０ａの形成された透光性電極１０９の上面１０９ｃおよび図３２（ｂ）に示す保護膜１０ａの形成されたｎ型半導体層１０４の露出面１０４ｃ上に、底面に向かって断面積が徐々に広くなる内壁形状を有する開口部２３ａを備えた逆テーパー型のマスク２３を形成する（図３３（ｃ）参照）。なお、図３０（ｂ）および図３３（ｃ）に示すように、透光性電極１０９上に形成されるマスク２３の開口部２３ａは、透光性電極１０９の穴部１０９ａが露出される位置に形成する。 Thereafter, a resist is applied onto the protective film 10a and dried, and the resist corresponding to the part where the bonding pad electrode 120 is formed is removed, thereby removing the transparent film on which the protective film 10a shown in FIG. On the upper surface 109c of the photoelectrode 109 and the exposed surface 104c of the n-type semiconductor layer 104 on which the protective film 10a shown in FIG. 32B is formed, an opening having an inner wall shape whose sectional area gradually increases toward the bottom surface. A reverse taper type mask 23 having a portion 23a is formed (see FIG. 33C). As shown in FIGS. 30B and 33C, the opening 23a of the mask 23 formed on the translucent electrode 109 is a position where the hole 109a of the translucent electrode 109 is exposed. To form.
　図３０（ｂ）および図３２（ｂ）、図３３（ｃ）に示す逆テーパー型のマスク２３を形成する方法としては、ｎ型フォトレジストを用いる方法やイメージ反転型フォトレジストを用いる方法などが挙げられる。本実施形態では、図３１を用い、イメージ反転型フォトレジストを用いて図３０（ｂ）および図３２（ｂ）に示すマスクを形成する方法を説明する。 As a method of forming the inverse taper type mask 23 shown in FIGS. 30B, 32B, and 33C, there are a method using an n-type photoresist, a method using an image reversal photoresist, and the like. Can be mentioned. In this embodiment, a method for forming the masks shown in FIGS. 30B and 32B using an image inversion type photoresist will be described with reference to FIG.
　本実施形態では、図３１（ａ）に示すレジスト２１として、イメージ反転型フォトレジストである不溶性のレジストを用いる。イメージ反転型フォトレジストとしては、例えば、ＡＺ５２００ＮＪ（製品名：ＡＺエレクトロニックマテリアルズ株式会社製）などが用いられる。
　　次に、図３１（ａ）に示すように、レジスト２１上方の所定の位置をカバーするようにマスク２５を配置し、図３１（ａ）において矢印で示すように、マスク２５側からレジスト２１側へ所定の強さ及び波長の光を照射する。このことにより、光が照射された部分のレジスト２１を光反応させて、可溶部２２とする。この光反応は光の強さに応じて進行するので、光照射面側では光反応の進行が早く、透光性電極１０９側では光反応の進行が遅くなる。そのため、図３１（ａ）に示すように、可溶部２２は、断面視したときに、側面が下方に向かうほど内側に後退した逆テーパー形状（逆傾斜形状）となるように形成される。また、マスク２５でカバーされた部分のレジスト２１は、不溶性のレジスト（不溶部）２１として残され、断面視したときに側面が上方に向かうほど内側に後退したテーパー形状（傾斜形状）となるように形成される。 In this embodiment, as the resist 21 shown in FIG. 31A, an insoluble resist which is an image reversal type photoresist is used. As the image reversal type photoresist, for example, AZ5200NJ (product name: manufactured by AZ Electronic Materials Co., Ltd.) is used.
Next, as shown in FIG. 31A, the mask 25 is disposed so as to cover a predetermined position above the resist 21, and from the mask 25 side to the resist 21 side as shown by an arrow in FIG. Is irradiated with light of a predetermined intensity and wavelength. As a result, the portion of the resist 21 irradiated with light is photoreacted to form a soluble portion 22. Since this photoreaction proceeds according to the intensity of light, the photoreaction progresses quickly on the light irradiation surface side, and the photoreaction progresses slowly on the translucent electrode 109 side. Therefore, as shown in FIG. 31A, the fusible portion 22 is formed to have a reverse taper shape (reverse inclination shape) that recedes inward as the side faces downward when viewed in cross section. In addition, the resist 21 in the portion covered with the mask 25 is left as an insoluble resist (insoluble portion) 21 so as to have a tapered shape (inclined shape) that recedes inward as the side faces upward when viewed in cross section. Formed.
　次に、ホットプレートやオーブンなどの加熱装置を用いて、加熱することにより、図３１（ｂ）に示すように、可溶部２２を熱反応させて、架橋高分子からなる硬化部（マスク）２３とする。
　その後、図３１（ｃ）に示すように、マスクを用いずに、不溶性のレジスト２１および架橋高分子からなる硬化部（マスク）２３の表面側に所定の強さ及び波長の光を照射することにより、図３１（ａ）を用いて説明した光反応により可溶部２２に変換されなかった不溶性のレジスト２１を光反応させて、可溶部２２とする。
　　最後に、所定の現像液を用いて、図３１（ｃ）に示す可溶部２２を溶解除去することにより、図３１（ｄ）に示すように、側面が下方に向かうほど内側に後退した開口部２３ａを有する逆テーパー形状（逆傾斜形状）の架橋高分子からなるマスク２３が得られる。 Next, by using a heating device such as a hot plate or an oven, as shown in FIG. 31 (b), the soluble part 22 is thermally reacted to form a cured part (mask) made of a crosslinked polymer. 23.
Thereafter, as shown in FIG. 31 (c), light of a predetermined intensity and wavelength is irradiated on the surface side of the hardened portion (mask) 23 made of the insoluble resist 21 and the crosslinked polymer without using a mask. Thus, the insoluble resist 21 that has not been converted to the soluble portion 22 by the photoreaction described with reference to FIG.
Finally, by using a predetermined developer to dissolve and remove the soluble portion 22 shown in FIG. 31 (c), as shown in FIG. 31 (d), the opening recedes inward as the side faces downward. A mask 23 made of a cross-linked polymer having an inversely tapered shape (inversely inclined shape) having a portion 23a is obtained.
　「パッド形成工程」
　次に、スパッタ法により、図３０（ｃ）に示す積層半導体層２０の上面１０６ｃ（穴部１０９ａの底面１０９ｂ）上および図３２（ｃ）に示すｎ型半導体層１０４の露出面１０４ｃ上に、透光性電極１０９の穴部１０９ａの内壁１０９ｄと保護膜１０ａの開口部１０ｄの端部１０ｃとを覆うように、透光性電極１０９を構成する材料と同様の材料を用いて、オーミック接合層９を形成する。 "Pad formation process"
Next, by sputtering, the upper surface 106c (bottom surface 109b of the hole 109a) of the stacked semiconductor layer 20 shown in FIG. 30C and the exposed surface 104c of the n-type semiconductor layer 104 shown in FIG. An ohmic junction layer is formed using a material similar to the material constituting the translucent electrode 109 so as to cover the inner wall 109d of the hole 109a of the translucent electrode 109 and the end 10c of the opening 10d of the protective film 10a. 9 is formed.
　次に、図３０（ｄ）および図３２（ｄ）に示すように、スパッタ法により、オーミック接合層９上と保護膜１０ａの開口部１０ｄの端部１０ｃとを覆うように接合層１１０を形成する。このとき、スパッタ条件を制御したスパッタ法を用いることにより、接合層１１０のカバレッジ性を高くすることができる。これにより、接合層１１０は、オーミック接合層９上の全面と、保護膜１０ａの端部１０ｃの一部とを覆うように形成され、接合層１１０の外周部１１０ｄに、外側に向けて膜厚が漸次薄くなる傾斜面１１０ｃが形成される。 Next, as shown in FIGS. 30D and 32D, the bonding layer 110 is formed by sputtering to cover the ohmic bonding layer 9 and the end 10c of the opening 10d of the protective film 10a. To do. At this time, the coverage of the bonding layer 110 can be increased by using a sputtering method in which the sputtering conditions are controlled. Thus, the bonding layer 110 is formed so as to cover the entire surface of the ohmic bonding layer 9 and a part of the end portion 10c of the protective film 10a, and the film thickness is formed on the outer peripheral portion 110d of the bonding layer 110 toward the outside. As a result, an inclined surface 110c is formed which becomes gradually thinner.
　なお、接合層１１０を形成する前には、接合層１１０の形成されるオーミック接合層９上や保護膜１０ａの開口部１０ｄの端部１０ｃの表面を洗浄する前処理を施しても良い。
ここでの洗浄の方法としてはプラズマなどに曝すドライプロセスによる方法や、薬液に接触させるウェットプロセスによる方法などが挙げられるが、工程の簡便さの観点よりドライプロセスによる方法を用いることが望ましい。 Note that before the bonding layer 110 is formed, a pretreatment may be performed to clean the surface of the ohmic bonding layer 9 where the bonding layer 110 is formed or the end 10c of the opening 10d of the protective film 10a.
Examples of the cleaning method include a dry process method exposed to plasma and the like, and a wet process method in contact with a chemical solution, but it is desirable to use a dry process method from the viewpoint of simplicity of the process.
　次に、スパッタ法により、金属反射層１１７を形成する。このとき、接合層１１０の形成の場合と同様に、スパッタ条件を制御したスパッタ法を用いる。このことにより、金属反射層１１７のカバレッジ性を高くすることができ、接合層１１０を覆い、外側に向けて膜厚が漸次薄くなる傾斜面１１７ｃを外周部に有する金属反射層１１７が形成される。 Next, a metal reflection layer 117 is formed by sputtering. At this time, similarly to the formation of the bonding layer 110, a sputtering method in which the sputtering conditions are controlled is used. As a result, the coverage of the metal reflective layer 117 can be enhanced, and the metal reflective layer 117 is formed that covers the bonding layer 110 and has an inclined surface 117c that gradually decreases in thickness toward the outer periphery. .
　次に、スパッタ法により、ボンディング層１１９を形成する。このとき、スパッタ条件を制御したスパッタ法を用いる。このことにより、ボンディング層１１９のカバレッジ性を高くすることができ、マスク２３の開口部２３ａの内壁形状に沿って外周部の形状が形成され、金属反射層１１７を覆い、外側に向けて膜厚が漸次薄くなる傾斜面１１９ｃを外周部１２０ｄに有するボンディング層１１９（ボンディングパッド電極１２０）が形成される（図３３（ｄ）参照）。 Next, a bonding layer 119 is formed by sputtering. At this time, a sputtering method with controlled sputtering conditions is used. As a result, the coverage of the bonding layer 119 can be increased, the outer peripheral shape is formed along the inner wall shape of the opening 23a of the mask 23, the metal reflective layer 117 is covered, and the film thickness is directed outward. As a result, a bonding layer 119 (bonding pad electrode 120) having an inclined surface 119c that gradually becomes thinner at the outer peripheral portion 120d is formed (see FIG. 33D).
　その後、レジスト剥離液に浸漬することにより、架橋高分子からなるマスク２３を剥離する。これにより、図３０（ｅ）および図３２（ｅ）に示すように、金属反射層１１７とボンディング層１１９とからなるボンディングパッド電極１２０が形成される。 Thereafter, the mask 23 made of a crosslinked polymer is peeled off by being immersed in a resist stripping solution. As a result, as shown in FIGS. 30E and 32E, a bonding pad electrode 120 including the metal reflective layer 117 and the bonding layer 119 is formed.
　本実施形態においては、底面に向かって断面積が徐々に広くなる内壁形状を有する開口部２３ａを備えたマスク２３を形成し、接合層１１０、金属反射層１１７およびボンディング層１１９をカバレッジ性の高いスパッタ法により形成するので、スパッタ方向から見てマスク２３の影となる領域では、接合層１１０、金属反射層１１７およびボンディング層１１９を構成する各層の膜厚に応じて傾斜角度の異なる層が形成される。これにより、接合層１１０、金属反射層１１７およびボンディング層１１９の外周部にそれぞれ、外側に向けて膜厚が漸次薄くなる傾斜面１１０ｃ、１１７ｃ、１１９ｃが形成される。 In the present embodiment, a mask 23 having an opening 23a having an inner wall shape whose cross-sectional area gradually increases toward the bottom surface is formed, and the bonding layer 110, the metal reflective layer 117, and the bonding layer 119 have high coverage. Since it is formed by the sputtering method, a layer having a different inclination angle is formed in the shadowed area of the mask 23 when viewed from the sputtering direction according to the thickness of each layer constituting the bonding layer 110, the metal reflection layer 117, and the bonding layer 119. Is done. As a result, inclined surfaces 110c, 117c, and 119c are formed on the outer peripheral portions of the bonding layer 110, the metal reflective layer 117, and the bonding layer 119, respectively, with the thickness gradually decreasing toward the outside.
　「熱処理工程」
　その後、オーミック接合層９と接合層１１０との密着性を高めるために、８０℃～７００℃の温度で熱処理を行う。ここでの熱処理は、アモルファス状態のＩＺＯ膜からなる透光性電極１０９を結晶化させるための熱処理と同様に行うことができる。したがって、例えば、オーミック接合層９がアモルファス状態のＩＺＯ膜である場合、ここでの熱処理により、アモルファス状態のＩＺＯ膜が六方晶構造のＩｎ２Ｏ３結晶を含むＩＺＯ膜や、ビックスバイト構造のＩｎ２Ｏ３結晶を含むＩＺＯ膜とされる。熱処理によりアモルファス状態から上記の結晶を含む構造に転移させることで、アモルファスのＩＺＯ膜よりも接合層１１０との密着性および透光性に優れたオーミック接合層９とすることができる。 "Heat treatment process"
Thereafter, heat treatment is performed at a temperature of 80 ° C. to 700 ° C. in order to improve the adhesion between the ohmic bonding layer 9 and the bonding layer 110. The heat treatment here can be performed in the same manner as the heat treatment for crystallizing the translucent electrode 109 made of an amorphous IZO film. Therefore, for example, in the case where the ohmic junction layer 9 is an amorphous IZO film, the heat treatment here causes the amorphous IZO film to include an IZO film containing a hexagonal In 2 O 3 crystal or a bixbite structure InZO. The IZO film contains 2 O 3 crystals. By transferring from an amorphous state to a structure including the above crystal by heat treatment, the ohmic junction layer 9 having better adhesion and translucency than the amorphous IZO film can be obtained.
　次に、従来から公知の方法を用いて、平面視したときに、ボンディングパッド電極１２０の中央部を露出させる略ドーナッツ状の形状であって、ボンディングパッド電極１２０の外縁部（輪郭線）と保護膜１０ａとの継ぎ目となる部分に跨ってボンディングパッド電極１２０の外縁部を覆う縁部保護膜１０ｂを形成する（図３３（ｄ）参照）。本実施形態においては、縁部保護膜１０ｂを、平面視したときにボンディングパッド電極１２０の中央部を露出させる領域を除く全域に形成する。
　ここで、本実施形態においては、ボンディングパッド電極１２０が、外側に向けて膜厚が漸次薄くなる傾斜面１１９ｃが外周部１２０ｄに形成されているものであるので、縁部保護膜１０ｂがボンディングパッド電極１２０の傾斜面１１９ｃに容易に均一な厚みで形成されるものとなる。このことにより、ボンディングパッド電極１２０の外縁部（輪郭線）と保護膜１０ａとの継ぎ目となる部分上に、縁部保護膜１０ｂの形成されない部分の生じることが防止され、ボンディングパッド電極１２０の外縁部（輪郭線）と保護膜１０ａとの継ぎ目となる部分に跨る縁部保護膜１０ｂを、均一な膜厚で容易に密着させて形成できる。
　このようにして、図２６に示すｎ型電極１０８とｐ型電極１１１を備える半導体発光素子１が形成される。 Next, using a conventionally known method, when viewed in plan, it has a substantially donut shape that exposes the central portion of the bonding pad electrode 120, and protects the outer edge portion (contour line) of the bonding pad electrode 120. An edge protective film 10b that covers the outer edge of the bonding pad electrode 120 is formed across a portion that becomes a joint with the film 10a (see FIG. 33D). In the present embodiment, the edge protective film 10b is formed over the entire region excluding the region where the central portion of the bonding pad electrode 120 is exposed when viewed in plan.
Here, in this embodiment, since the bonding pad electrode 120 is formed with the inclined surface 119c whose thickness is gradually decreased toward the outer side at the outer peripheral portion 120d, the edge protection film 10b is formed as the bonding pad. The inclined surface 119c of the electrode 120 is easily formed with a uniform thickness. This prevents the formation of a portion where the edge protection film 10b is not formed on the joint portion between the outer edge portion (contour line) of the bonding pad electrode 120 and the protection film 10a. The edge protective film 10b straddling the portion that becomes the joint between the portion (contour line) and the protective film 10a can be formed in a uniform film thickness by being easily adhered.
In this way, the semiconductor light emitting device 1 including the n-type electrode 108 and the p-type electrode 111 shown in FIG. 26 is formed.
　本実施形態の半導体発光素子１においては、ｎ型電極１０８およびｐ型電極１１１が、積層半導体層２０の上面１０６ｃまたはｎコンタクト層１０４ａの露出面１０４ｃ上に形成されたオーミック接合層９と、オーミック接合層９上に形成された接合層１１０と、接合層１１０を覆うように形成されたボンディングパッド電極１２０とを備えるものであり、ｎ型電極１０８とｐ型電極１１１の両方が、接合層１１０とボンディングパッド電極１２０とによって、オーミック接合層９とボンディングパッド電極１２０との十分に高い接合力が得られるものとされているので、優れた接合性を有するｎ型電極１０８およびｐ型電極１１１を備えたものとなる。 In the semiconductor light emitting device 1 of the present embodiment, the n-type electrode 108 and the p-type electrode 111 are connected to the ohmic junction layer 9 formed on the upper surface 106c of the stacked semiconductor layer 20 or the exposed surface 104c of the n contact layer 104a, and the ohmic contact layer 9 is formed. A bonding layer 110 formed on the bonding layer 9 and a bonding pad electrode 120 formed so as to cover the bonding layer 110 are provided. Both the n-type electrode 108 and the p-type electrode 111 are connected to the bonding layer 110. And the bonding pad electrode 120 provide a sufficiently high bonding force between the ohmic bonding layer 9 and the bonding pad electrode 120. Therefore, the n-type electrode 108 and the p-type electrode 111 having excellent bonding properties are obtained. It will be prepared.
　さらに、本実施形態の半導体発光素子１によれば、外側に向けて膜厚が漸次薄くなる傾斜面１１９ｃを外周部１２０ｄに有するボンディングパッド電極１２０が、接合層１１０を覆うように形成されているので、接合層１１０のいかなる部分もボンディングパッド電極１２０の下から露出しないようにされている。したがって、本実施形態の半導体発光素子１によれば、半導体発光素子１の外部の空気または水分が接合層１１０へ侵入することを効果的に防止でき、優れた耐食性が得られるとともに、接合層１１０による積層半導体層２０および透光性電極１０９とボンディングパッド電極１２０との優れた接合性とが得られる。 Furthermore, according to the semiconductor light emitting device 1 of the present embodiment, the bonding pad electrode 120 having the inclined surface 119c whose thickness is gradually reduced toward the outside on the outer peripheral portion 120d is formed so as to cover the bonding layer 110. Therefore, any part of the bonding layer 110 is not exposed from below the bonding pad electrode 120. Therefore, according to the semiconductor light emitting device 1 of the present embodiment, air or moisture outside the semiconductor light emitting device 1 can be effectively prevented from entering the bonding layer 110, and excellent corrosion resistance can be obtained and the bonding layer 110 can be obtained. The laminated semiconductor layer 20 and the translucent electrode 109 and the excellent bonding property between the bonding pad electrode 120 can be obtained.
　さらに、本実施形態の半導体発光素子１においては、ｐ型電極１１１のオーミック接合層９が形成される領域およびｎ型電極１０８のオーミック接合層９が形成される領域を除く領域を覆うように保護膜１０ａが形成されており、接合層１１０の外縁部およびボンディングパッド電極１２０の外縁部が、保護膜１０ａ上に配置されているので、より一層優れた耐食性および接合性が得られる。 Furthermore, in the semiconductor light emitting device 1 of the present embodiment, protection is performed so as to cover a region excluding the region where the ohmic junction layer 9 of the p-type electrode 111 is formed and the region where the ohmic junction layer 9 of the n-type electrode 108 is formed. Since the film 10a is formed and the outer edge portion of the bonding layer 110 and the outer edge portion of the bonding pad electrode 120 are disposed on the protective film 10a, much more excellent corrosion resistance and bondability can be obtained.
　また、本実施形態の半導体発光素子１においては、ボンディングパッド電極１２０が、金属反射層１１７とボンディング層１１９とからなるものであり、接合層１１０のいかなる部分も金属反射層１１７の下から露出しないようにされているとともに、金属反射層１１７のいかなる部分もボンディング層１１９の下から露出しないようにされており、金属反射層１１７およびボンディング層１１９により接合層１１０が二重に覆われている。さらに、本実施形態の半導体発光素子１においては、ボンディングパッド電極１２０の外縁部が、保護膜１０ａ上に配置されている。よって、本実施形態の半導体発光素子１においては、保護膜１０ａとボンディング層１１９との接合面と、保護膜１０ａと金属反射層１１７との接合面とを通過しなければ、半導体発光素子１の外部の空気または水分が接合層１１０へ侵入することはできない。したがって、本実施形態においては、半導体発光素子１の外部の空気または水分が接合層１１０へ侵入することを効果的に防止でき、接合層１１０の劣化に起因する接合性および耐食性の劣化を効果的に防止できる。 Further, in the semiconductor light emitting device 1 of the present embodiment, the bonding pad electrode 120 is composed of the metal reflective layer 117 and the bonding layer 119, and no part of the bonding layer 110 is exposed from under the metal reflective layer 117. In addition, any part of the metal reflection layer 117 is not exposed from below the bonding layer 119, and the bonding layer 110 is double covered with the metal reflection layer 117 and the bonding layer 119. Furthermore, in the semiconductor light emitting device 1 of the present embodiment, the outer edge portion of the bonding pad electrode 120 is disposed on the protective film 10a. Therefore, in the semiconductor light emitting device 1 of the present embodiment, the semiconductor light emitting device 1 of the semiconductor light emitting device 1 has to pass through the joint surface between the protective film 10a and the bonding layer 119 and the joint surface between the protective film 10a and the metal reflective layer 117. External air or moisture cannot enter the bonding layer 110. Therefore, in the present embodiment, air or moisture outside the semiconductor light emitting element 1 can be effectively prevented from entering the bonding layer 110, and the deterioration of the bonding property and corrosion resistance due to the deterioration of the bonding layer 110 is effective. Can be prevented.
　また、本実施形態の半導体発光素子１においては、ボンディングパッド電極１２０の外縁部を覆い、ボンディングパッド電極１２０上の一部を露出させる縁部保護膜１０ｂが形成されているので、より一層優れた耐食性および接合性が得られる。しかも、本実施形態の半導体発光素子１によれば、外側に向けて膜厚が漸次薄くなる傾斜面１１９ｃを外周部１２０ｄに有するボンディングパッド電極１２０が、接合層１１０を覆うように形成されているので、ボンディングパッド電極１２０の外周部１２０ｄと、ボンディングパッド電極１２０の外周部１２０ｄの下面（本実施形態においては、保護膜１０ａ））との接触面積が十分に確保されたものとなり、優れた接合性が得られるとともに、ボンディングパッド電極１２０の外周部１２０ｄとその下面との間を介して、外部から接合層１１０へ空気や水分が侵入することを効果的に防止することができ、より一層優れた耐食性が得られる。 Further, in the semiconductor light emitting device 1 of the present embodiment, the edge protection film 10b that covers the outer edge of the bonding pad electrode 120 and exposes a part on the bonding pad electrode 120 is formed, so that it is further excellent. Corrosion resistance and bondability are obtained. In addition, according to the semiconductor light emitting device 1 of the present embodiment, the bonding pad electrode 120 having the inclined surface 119c whose thickness is gradually reduced toward the outside on the outer peripheral portion 120d is formed so as to cover the bonding layer 110. Therefore, the contact area between the outer peripheral portion 120d of the bonding pad electrode 120 and the lower surface of the outer peripheral portion 120d of the bonding pad electrode 120 (the protective film 10a in this embodiment) is sufficiently secured, and excellent bonding is achieved. In addition, it is possible to effectively prevent air and moisture from entering the bonding layer 110 from the outside through the gap between the outer peripheral portion 120d of the bonding pad electrode 120 and the lower surface thereof, which is even better. Corrosion resistance is obtained.
　　また、本実施形態の半導体発光素子１においては、ｎ型電極１０８に透光性電極１０９が設けられていないこと以外は、ｎ型電極１０８とｐ型電極１１１とが同じものとされているので、ｎ型電極１０８とｐ型電極１１１とが同時に形成可能なものとなり、容易に製造できる生産性に優れたものとなる。 Further, in the semiconductor light emitting device 1 of this embodiment, the n-type electrode 108 and the p-type electrode 111 are the same except that the translucent electrode 109 is not provided on the n-type electrode 108. Thus, the n-type electrode 108 and the p-type electrode 111 can be formed at the same time, and the productivity can be easily manufactured.
　例えば、本実施形態の半導体発光素子１において、ｎ型電極として、ｎコンタクト層１０４ａの露出面１０４ｃ上に当該露出面からＴｉ／Ａｕなどの金属からなるものが形成されている場合、ｎ型電極とｐ型電極１１１とを同時に形成することはしない。 For example, in the semiconductor light emitting device 1 of the present embodiment, when the n-type electrode is formed of a metal such as Ti / Au from the exposed surface on the exposed surface 104c of the n contact layer 104a, the n-type electrode And the p-type electrode 111 are not formed simultaneously.
　これに対し、本実施形態の半導体発光素子１においては、ｎ型電極１０８に透光性電極１０９が設けられていないこと以外は、ｎ型電極１０８とｐ型電極１１１とが接合とそれを覆うボンデイングパット電極を同じものとする場合、ｎ型電極１０８とｐ型電極１１１の両方の製造条件を容易に最適化することができる。したがって、本実施形態の半導体発光素子１においては、ｎ型電極１０８およびｐ型電極１１１の製造条件を最適化することにより、オーミック接合層９と接合層１１０との密着性に優れたｎ型電極１０８およびｐ型電極１１１を備えたものとすることができる。 In contrast, in the semiconductor light emitting device 1 of the present embodiment, the n-type electrode 108 and the p-type electrode 111 cover and cover the n-type electrode 108 except that the translucent electrode 109 is not provided. If the bonding pad electrodes are the same, the manufacturing conditions for both the n-type electrode 108 and the p-type electrode 111 can be easily optimized. Therefore, in the semiconductor light emitting device 1 of the present embodiment, the n-type electrode excellent in the adhesion between the ohmic junction layer 9 and the junction layer 110 is obtained by optimizing the manufacturing conditions of the n-type electrode 108 and the p-type electrode 111. 108 and the p-type electrode 111 may be provided.
　また、本実施形態の半導体発光素子１の製造方法においては、ｎ型電極１０８を製造する工程とｐ型電極１１１を製造する工程の両方が、オーミック接合層９と接合層１１０との密着性を高める２５０℃～７００℃の熱処理を行う工程を備えているので、オーミック接合層９との密着性に優れた接合層１１０が得られ、オーミック接合層９とボンディングパッド電極１２０との接合性に優れた半導体発光素子１が得られる。 Further, in the method for manufacturing the semiconductor light emitting device 1 according to the present embodiment, both of the process of manufacturing the n-type electrode 108 and the process of manufacturing the p-type electrode 111 improve the adhesion between the ohmic junction layer 9 and the junction layer 110. Since the heat treatment is performed at a temperature of 250 ° C. to 700 ° C., the bonding layer 110 having excellent adhesion with the ohmic bonding layer 9 is obtained, and the bonding between the ohmic bonding layer 9 and the bonding pad electrode 120 is excellent. A semiconductor light emitting device 1 can be obtained.
　また、本実施形態の半導体発光素子１の製造方法においては、ｎ型電極１０８を製造する工程とｐ型電極１１１を製造する工程の両方が、積層半導体層２０の上面１０６ｃまたはｎコンタクト層１０４ａの露出面１０４ｃ上にオーミック接合層９を形成する工程と、オーミック接合層９上に接合層１１０を形成する工程と、接合層１１０を覆うようにボンディングパッド電極１２０を形成する工程と、オーミック接合層９と接合層１１０との密着性を向上させるために２５０℃～７００℃の温度で熱処理を行う工程とを備えているので、ｎ型電極１０８を製造する工程とｐ型電極１１１を製造する工程において、オーミック接合層９、接合層１１０、ボンディングパッド電極１２０に用いる材料を同じとすることができ、ｎ型電極１０８およびｐ型電極１１１に用いる材料が全て異なる場合と比較して容易に製造できる。 Further, in the method for manufacturing the semiconductor light emitting device 1 of the present embodiment, both the step of manufacturing the n-type electrode 108 and the step of manufacturing the p-type electrode 111 are performed on the upper surface 106c of the stacked semiconductor layer 20 or the n-contact layer 104a. Forming the ohmic bonding layer 9 on the exposed surface 104c, forming the bonding layer 110 on the ohmic bonding layer 9, forming the bonding pad electrode 120 so as to cover the bonding layer 110, and ohmic bonding layer In order to improve the adhesion between the adhesive layer 9 and the bonding layer 110, a process of performing a heat treatment at a temperature of 250 ° C. to 700 ° C. is provided. Therefore, a process of manufacturing the n-type electrode 108 and a process of manufacturing the p-type electrode 111 , The materials used for the ohmic bonding layer 9, the bonding layer 110, and the bonding pad electrode 120 can be the same. Material used for the fine p-type electrode 111 can be easily manufactured as compared with the case where all different.
　また、本実施形態の半導体発光素子１の製造方法においては、ｎ型電極１０８を製造する工程とｐ型電極１１１を製造する工程とにおいて、パッド形成工程および熱処理工程を同時に行っているので、これらを別々に行う場合と比較して、容易に効率よく製造でき、生産性に優れている。
　なお、本実施形態の半導体発光素子１の製造方法においては、容易に効率よく製造するために、ｎ型電極１０８を構成するオーミック接合層９、接合層１１０、ボンディングパッド電極１２０と、ｐ型電極１１１を構成するオーミック接合層９、接合層１１０、ボンディングパッド電極１２０とを同時に形成する場合を例に挙げて説明したが、オーミック接合層９、接合層１１０、ボンディングパッド電極１２０をｎ型電極１０８とｐ型電極１１１とにおいてそれぞれ別々に形成してもよいし、ｎ型電極１０８とｐ型電極１１１とを構成するオーミック接合層９、接合層１１０、ボンディングパッド電極１２０のうちの一部のみを別々に形成してもよい。 In the method for manufacturing the semiconductor light emitting device 1 of the present embodiment, the pad forming step and the heat treatment step are simultaneously performed in the step of manufacturing the n-type electrode 108 and the step of manufacturing the p-type electrode 111. Compared with the case where the process is performed separately, it can be manufactured easily and efficiently, and the productivity is excellent.
In the method for manufacturing the semiconductor light emitting device 1 of the present embodiment, the ohmic junction layer 9, the junction layer 110, the bonding pad electrode 120, and the p-type electrode constituting the n-type electrode 108 are used for easy and efficient production. The ohmic junction layer 9, the junction layer 110, and the bonding pad electrode 120 that form the layer 111 are described as an example, but the ohmic junction layer 9, the junction layer 110, and the bonding pad electrode 120 are used as the n-type electrode 108. And the p-type electrode 111 may be formed separately, or only a part of the ohmic junction layer 9, the junction layer 110, and the bonding pad electrode 120 constituting the n-type electrode 108 and the p-type electrode 111 is formed. You may form separately.
　また、本実施形態の半導体発光素子１の製造方法では、保護膜１０ａの開口部１０ｄから露出する透光性電極１０９の上面１０９ｃをエッチングすることにより穴部１０９ａを形成する工程と、穴部１０９ａの内壁１０９ｄ上にオーミック接合層９を形成する工程とを備えているので、穴部１０９ａを形成することにより透光性電極１０９から現れた穴部１０９ａの内壁１０９ｄに接してオーミック接合層９が形成されることになる。穴部１０９ａを形成することにより透光性電極１０９から現れた穴部１０９ａの内壁１０９ｄは、透光性電極１０９の上面１０９ｃと比較して、オーミック接合層９との密着性に優れているので、本実施形態の製造方法によれば、透光性電極１０９の上面１０９ｃにオーミック接合層９を形成する場合と比較して、オーミック接合層９の密着性に優れたｐ型電極１１１が得られる。 Further, in the method for manufacturing the semiconductor light emitting device 1 of the present embodiment, the step of forming the hole 109a by etching the upper surface 109c of the translucent electrode 109 exposed from the opening 10d of the protective film 10a, and the hole 109a Forming the ohmic junction layer 9 on the inner wall 109d of the first electrode, so that the ohmic junction layer 9 comes into contact with the inner wall 109d of the hole 109a that emerges from the translucent electrode 109 by forming the hole 109a. Will be formed. The inner wall 109d of the hole 109a that emerges from the translucent electrode 109 by forming the hole 109a is superior in adhesion to the ohmic bonding layer 9 compared to the upper surface 109c of the translucent electrode 109. According to the manufacturing method of the present embodiment, the p-type electrode 111 having excellent adhesion of the ohmic junction layer 9 can be obtained as compared with the case where the ohmic junction layer 9 is formed on the upper surface 109c of the translucent electrode 109. .
（実施形態１３：半導体発光素子）
　図３４は、本発明の半導体発光素子の他の例を示した図であって、半導体発光素子の断面模式図である。図３４に示す本実施形態の半導体発光素子１ａが、図２６に示す半導体発光素子１と異なるところは、保護膜１０ａおよび縁部保護膜１０ｂが形成されていないことのみであり、それ以外は図２６に示す半導体発光素子１と同様とされている。したがって、実施形態１２と同じ部材には同じ符号付し、説明を省略する。
　また、本実施形態の半導体発光素子１ａは、保護膜１０ａおよび縁部保護膜１０ｂを形成しないことを除き、図２６に示す半導体発光素子１と同様にして形成できる。 (Embodiment 13: Semiconductor light emitting device)
FIG. 34 is a diagram showing another example of the semiconductor light emitting device of the present invention, and is a schematic cross-sectional view of the semiconductor light emitting device. The semiconductor light emitting device 1a of the present embodiment shown in FIG. 34 is different from the semiconductor light emitting device 1 shown in FIG. 26 only in that the protective film 10a and the edge protective film 10b are not formed. This is the same as the semiconductor light emitting device 1 shown in FIG. Therefore, the same members as those of the twelfth embodiment are denoted by the same reference numerals, and description thereof is omitted.
Further, the semiconductor light emitting device 1a of the present embodiment can be formed in the same manner as the semiconductor light emitting device 1 shown in FIG. 26 except that the protective film 10a and the edge protective film 10b are not formed.
　図３４に示す本実施形態の半導体発光素子１ａにおいても、ｎ型電極１１８およびｐ型電極１１１ａが、積層半導体層２０の上面１０６ｃまたはｎコンタクト層１０４ａの露出面１０４ｃ上に形成されたオーミック接合層９と、オーミック接合層９上に形成された接合層１１０と、接合層１１０を覆うように形成されたボンディングパッド電極１２０とを備えるものであるので、ｎ型電極１１８とｐ型電極１１１ａの両方が、接合層１１０とボンディングパッド電極１２０とによって、オーミック接合層９とボンディングパッド電極１２０との十分に高い接合力が得られるものとされている。 Also in the semiconductor light emitting device 1a of the present embodiment shown in FIG. 34, the n-type electrode 118 and the p-type electrode 111a are formed on the upper surface 106c of the laminated semiconductor layer 20 or the exposed surface 104c of the n-contact layer 104a. 9, the bonding layer 110 formed on the ohmic bonding layer 9, and the bonding pad electrode 120 formed so as to cover the bonding layer 110, both the n-type electrode 118 and the p-type electrode 111 a are provided. However, a sufficiently high bonding force between the ohmic bonding layer 9 and the bonding pad electrode 120 can be obtained by the bonding layer 110 and the bonding pad electrode 120.
　また、図３４に示す本実施形態の半導体発光素子１ａの製造方法においても、ｎ型電極１１８を製造する工程とｐ型電極１１１ａを製造する工程の両方が、オーミック接合層９と接合層１１０との密着性を高める２５０℃～７００℃の熱処理を行う工程を備えているので、オーミック接合層９との密着性に優れた接合層１１０が得られ、オーミック接合層９とボンディングパッド電極１２０との接合性に優れた半導体発光素子１ａが得られる。 Also in the method of manufacturing the semiconductor light emitting device 1a of the present embodiment shown in FIG. 34, both the step of manufacturing the n-type electrode 118 and the step of manufacturing the p-type electrode 111a are performed by the ohmic junction layer 9 and the junction layer 110. Since the step of performing a heat treatment at 250 ° C. to 700 ° C. for improving the adhesion of the substrate is obtained, the bonding layer 110 having excellent adhesion to the ohmic bonding layer 9 is obtained, and the ohmic bonding layer 9 and the bonding pad electrode 120 are bonded to each other. A semiconductor light emitting device 1a having excellent bonding properties is obtained.
　また、図３４に示す本実施形態の半導体発光素子１ａにおいても、図２６に示す半導体発光素子１と同様に、ｎ型電極１１８に透光性電極１０９が設けられていないこと以外は、ｎ型電極１１８とｐ型電極１１１ａとが同じものとされているので、ｎ型電極１１８とｐ型電極１１１ａとが同時に形成可能なものとなり、容易に効率よく製造できる生産性に優れたものとなる。また、図３４に示す本実施形態の半導体発光素子１ａにおいても、ｎ型電極１１８とｐ型電極１１１ａの両方を最適な条件で製造できる。 Also, in the semiconductor light emitting device 1a of the present embodiment shown in FIG. 34, similarly to the semiconductor light emitting device 1 shown in FIG. 26, except that the translucent electrode 109 is not provided on the n type electrode 118, the n type is also provided. Since the electrode 118 and the p-type electrode 111a are the same, the n-type electrode 118 and the p-type electrode 111a can be formed at the same time, and the productivity can be easily and efficiently manufactured. Also in the semiconductor light emitting device 1a of this embodiment shown in FIG. 34, both the n-type electrode 118 and the p-type electrode 111a can be manufactured under optimum conditions.
（実施形態１４：半導体発光素子）
　図３５は、本発明の半導体発光素子の他の例を示した図であって、半導体発光素子の断面模式図である。図３５に示す本実施形態の半導体発光素子１ｂが、図２６に示す半導体発光素子１と異なるところは、保護膜１０ａが形成されておらず、平面視したときに、ボンディングパッド電極１２０の中央部の露出させる領域を除く、透光性電極１０９の上面１０９ｃ全面とｎコンタクト層１０４ａの露出面１０４ｃ上の全面に上面保護膜１０が設けられているところである。それ以外は図２６に示す半導体発光素子１と同様とされている。したがって、実施形態１２と同じ部材には同じ符号付し、説明を省略する。
　上面保護膜１０は、図２６に示す半導体発光素子１における保護膜１０ａと同様の材料からなる同様の厚みを有するものとすることができる。 (Embodiment 14: Semiconductor light emitting device)
FIG. 35 is a diagram showing another example of the semiconductor light emitting device of the present invention, and is a schematic cross-sectional view of the semiconductor light emitting device. The semiconductor light emitting device 1b of the present embodiment shown in FIG. 35 is different from the semiconductor light emitting device 1 shown in FIG. 26 in that the protective film 10a is not formed and the center portion of the bonding pad electrode 120 is viewed in plan view. The upper surface protective film 10 is provided on the entire upper surface 109c of the translucent electrode 109 and the entire exposed surface 104c of the n contact layer 104a except for the exposed region. The rest is the same as the semiconductor light emitting device 1 shown in FIG. Therefore, the same members as those of the twelfth embodiment are denoted by the same reference numerals, and description thereof is omitted.
The upper surface protective film 10 can have the same thickness made of the same material as the protective film 10a in the semiconductor light emitting device 1 shown in FIG.
　図３５に示す半導体発光素子１ｂを製造するには、まず、図２６に示す半導体発光素子１と同様にして積層半導体層２０の形成を形成した後、以下に示すようにしてｎ型電極１２８とｐ型電極１１１ｂとを製造する。本実施形態においては、図３６を用いて、ｎ型電極１０８を製造する工程とｐ型電極１１１を製造する工程とを同時に行う製造方法について説明する。
　図３６は、ｎ型電極１２８およびｐ型電極１１１ｂを製造する工程を説明するための工程図であって、ｐ型電極１１１ｂの製造される領域の一部のみを拡大して示した拡大断面図である。なお、ｎ型電極１２８を形成する工程は、透光性電極１０９を設ける工程を行わないことを除いてｐ型電極１１１ｂを形成する工程と同じであるので、図３６においては、ｎ型電極１２８の製造される領域の図示を省略する。 To manufacture the semiconductor light emitting device 1b shown in FIG. 35, first, the stacked semiconductor layer 20 is formed in the same manner as the semiconductor light emitting device 1 shown in FIG. A p-type electrode 111b is manufactured. In the present embodiment, a manufacturing method for simultaneously performing the process of manufacturing the n-type electrode 108 and the process of manufacturing the p-type electrode 111 will be described with reference to FIG.
FIG. 36 is a process diagram for explaining a process of manufacturing the n-type electrode 128 and the p-type electrode 111b, and is an enlarged cross-sectional view showing only a part of a region where the p-type electrode 111b is manufactured. It is. Note that the step of forming the n-type electrode 128 is the same as the step of forming the p-type electrode 111b except that the step of providing the translucent electrode 109 is not performed. The illustration of the area where the product is manufactured is omitted.
　まず、図２６に示す半導体発光素子１と同様にして、積層半導体層２０のｎコンタクト層１０４ａの一部を露出させ、図２６に示す半導体発光素子１と同様にして、積層半導体層２０のｐ型半導体層１０６上に透光性電極１０９を形成する。 First, a part of the n-contact layer 104a of the laminated semiconductor layer 20 is exposed in the same manner as in the semiconductor light emitting device 1 shown in FIG. 26, and p of the laminated semiconductor layer 20 is obtained in the same manner as in the semiconductor light emitting device 1 shown in FIG. A translucent electrode 109 is formed on the type semiconductor layer 106.
　続いて、図２６に示す半導体発光素子１と同様にして透光性電極１０９をエッチングすることにより、図３６（ａ）に示すように、透光性電極１０９に穴部１０９ａを形成する。
　ここで形成された透光性電極１０９が、アモルファス状態のＩＺＯ膜である場合、図２６に示す半導体発光素子１と同様にして熱処理を行なうことにより、アモルファス状態のＩＺＯ膜を結晶化させることが好ましい。 Subsequently, by etching the translucent electrode 109 in the same manner as the semiconductor light emitting device 1 shown in FIG. 26, a hole 109a is formed in the translucent electrode 109 as shown in FIG.
When the translucent electrode 109 formed here is an amorphous IZO film, the amorphous IZO film can be crystallized by performing heat treatment in the same manner as the semiconductor light emitting element 1 shown in FIG. preferable.
　次に、透光性電極１０９の上面１０９ｃにレジスト２１を塗布すると同時に、ｎコンタクト層１０４ａの露出面１０４ｃ上にレジスト２１を塗布し、レジスト２１を乾燥させ、図２６に示す半導体発光素子１と同様にして、ボンディングパッド電極１２０を形成する部分に対応する部分のレジスト２１を除去することによって、図３６（ｂ）に示すように、透光性電極１０９の上面１０９ｃおよびｎコンタクト層１０４ａの露出面１０４ｃ上に、底面に向かって断面積が徐々に広くなる内壁形状を有する開口部２３ａを備えた逆テーパー型のマスク２３を形成する。なお、図３６（ｂ）に示すように、透光性電極１０９上に形成されるマスク２３の開口部２３ａは、透光性電極１０９の穴部１０９ａが露出される位置に形成する。 Next, simultaneously with applying the resist 21 on the upper surface 109c of the translucent electrode 109, the resist 21 is applied on the exposed surface 104c of the n-contact layer 104a, and the resist 21 is dried, and the semiconductor light emitting device 1 shown in FIG. Similarly, by removing the portion of the resist 21 corresponding to the portion where the bonding pad electrode 120 is to be formed, the upper surface 109c of the translucent electrode 109 and the n-contact layer 104a are exposed as shown in FIG. On the surface 104c, an inversely tapered mask 23 having an opening 23a having an inner wall shape whose cross-sectional area gradually increases toward the bottom surface is formed. 36B, the opening 23a of the mask 23 formed on the translucent electrode 109 is formed at a position where the hole 109a of the translucent electrode 109 is exposed.
　「パッド形成工程」
　次に、図３６（ｃ）に示すように、図２６に示す半導体発光素子１と同様にして、積層半導体層２０の上面１０６ｃ（穴部１０９ａの底面１０９ｂ）上およびｎコンタクト層１０４ａの露出面１０４ｃ上に、透光性電極１０９を構成する材料と同様の材料を用いてオーミック接合層９を形成する。 "Pad formation process"
Next, as shown in FIG. 36 (c), in the same manner as the semiconductor light emitting device 1 shown in FIG. 26, the upper surface 106c of the laminated semiconductor layer 20 (the bottom surface 109b of the hole 109a) and the exposed surface of the n contact layer 104a. On the 104c, the ohmic junction layer 9 is formed using a material similar to the material constituting the translucent electrode 109.
　次に、図３６（ｄ）に示すように、図２６に示す半導体発光素子１と同様にして、接合層１１０、金属反射層１１７、ボンディング層１１９を順に形成する。その後、図２６に示す半導体発光素子１と同様にして、マスク２３を剥離する。これにより、図３６（ｅ）に示すように、金属反射層１１７とボンディング層１１９とからなるボンディングパッド電極１２０が形成される。本実施形態においても、図２６に示す半導体発光素子１と同様に、接合層１１０、金属反射層１１７およびボンディング層１１９の外周部にそれぞれ、外側に向けて膜厚が漸次薄くなる傾斜面１１０ｃ、１１７ｃ、１１９ｃが形成される。 Next, as shown in FIG. 36D, the bonding layer 110, the metal reflective layer 117, and the bonding layer 119 are sequentially formed in the same manner as the semiconductor light emitting device 1 shown in FIG. Thereafter, the mask 23 is removed in the same manner as the semiconductor light emitting device 1 shown in FIG. As a result, as shown in FIG. 36E, a bonding pad electrode 120 composed of the metal reflective layer 117 and the bonding layer 119 is formed. Also in the present embodiment, similar to the semiconductor light emitting device 1 shown in FIG. 26, the inclined surface 110 c that gradually decreases in thickness toward the outside on the outer peripheral portions of the bonding layer 110, the metal reflection layer 117, and the bonding layer 119, respectively. 117c and 119c are formed.
　「熱処理工程」
　次に、図２６に示す半導体発光素子１と同様にして、オーミック接合層９と接合層１１０との密着性を向上させるための熱処理を行う。 "Heat treatment process"
Next, in the same manner as in the semiconductor light emitting device 1 shown in FIG. 26, heat treatment for improving the adhesion between the ohmic junction layer 9 and the junction layer 110 is performed.
　次に、従来から公知の方法を用いて、平面視したときに、ボンディングパッド電極１２０の中央部を露出させる領域を除く、透光性電極１０９の上面１０９ｃ全面とｎコンタクト層１０４ａの露出面１０４ｃ上の全面とに、上面保護膜１０を形成する。このようにして、図３５に示すｎ型電極１２８およびｐ型電極１１１ｂを備える半導体発光素子１ｂが形成される。 Next, by using a conventionally known method, the entire upper surface 109c of the translucent electrode 109 and the exposed surface 104c of the n contact layer 104a excluding the region exposing the central portion of the bonding pad electrode 120 when viewed in plan. A top protective film 10 is formed on the entire upper surface. Thus, the semiconductor light emitting element 1b including the n-type electrode 128 and the p-type electrode 111b shown in FIG. 35 is formed.
　図３５に示す本実施形態の半導体発光素子１ａにおいても、ｎ型電極１２８およびｐ型電極１１１ｂが、積層半導体層２０の上面１０６ｃまたはｎコンタクト層１０４ａの露出面１０４ｃ上に形成されたオーミック接合層９と、オーミック接合層９上に形成された接合層１１０と、接合層１１０を覆うように形成されたボンディングパッド電極１２０とを備えるものであるので、ｎ型電極１２８とｐ型電極１１１ｂの両方が、接合層１１０とボンディングパッド電極１２０とによって、オーミック接合層９とボンディングパッド電極１２０との十分に高い接合力が得られるものとされている。 Also in the semiconductor light emitting device 1a of this embodiment shown in FIG. 35, the n-type electrode 128 and the p-type electrode 111b are formed on the upper surface 106c of the laminated semiconductor layer 20 or the exposed surface 104c of the n-contact layer 104a. 9, the bonding layer 110 formed on the ohmic bonding layer 9, and the bonding pad electrode 120 formed so as to cover the bonding layer 110, both the n-type electrode 128 and the p-type electrode 111 b are provided. However, a sufficiently high bonding force between the ohmic bonding layer 9 and the bonding pad electrode 120 can be obtained by the bonding layer 110 and the bonding pad electrode 120.
　また、図３５に示す本実施形態の半導体発光素子１ｂの製造方法においても、ｎ型電極１２８を製造する工程とｐ型電極１１１ｂを製造する工程の両方が、オーミック接合層９と接合層１１０との密着性を高める２５０℃～７００℃の熱処理を行う工程を備えているので、オーミック接合層９との密着性に優れた接合層１１０が得られ、オーミック接合層９とボンディングパッド電極１２０との接合性に優れた半導体発光素子１ｂが得られる。 Also, in the method of manufacturing the semiconductor light emitting device 1b of this embodiment shown in FIG. 35, both the process of manufacturing the n-type electrode 128 and the process of manufacturing the p-type electrode 111b are performed by the ohmic junction layer 9 and the junction layer 110. Since the step of performing a heat treatment at 250 ° C. to 700 ° C. for improving the adhesion of the substrate is obtained, the bonding layer 110 having excellent adhesion to the ohmic bonding layer 9 is obtained, and the ohmic bonding layer 9 and the bonding pad electrode 120 are bonded to each other. A semiconductor light emitting device 1b having excellent bonding properties is obtained.
　また、本実施形態の半導体発光素子１ｂにおいても、図２６に示す半導体発光素子１と同様に、ｎ型電極１２８に透光性電極１０９が設けられていないこと以外は、ｎ型電極１２８とｐ型電極１１１ｂとが同じものとされているので、ｎ型電極１２８とｐ型電極１１１ｂとが同時に形成可能なものとなり、容易に効率よく製造できる生産性に優れたものとなる。また、図３５に示す本実施形態の半導体発光素子１ｂにおいても、ｎ型電極１２８とｐ型電極１１１ｂの両方を最適な条件で製造できる。 Also in the semiconductor light emitting device 1b of the present embodiment, similarly to the semiconductor light emitting device 1 shown in FIG. 26, except that the n-type electrode 128 is not provided with the translucent electrode 109, the n-type electrode 128 and p Since the mold electrode 111b is the same, the n-type electrode 128 and the p-type electrode 111b can be formed at the same time, and the productivity that can be easily and efficiently manufactured is excellent. Also in the semiconductor light emitting device 1b of this embodiment shown in FIG. 35, both the n-type electrode 128 and the p-type electrode 111b can be manufactured under optimum conditions.
（実施形態１５：ランプ）
　図３７は、本発明のランプの一例を示す断面概略図である。図３７に示すように、本実施形態のランプ３は、砲弾型であり、半導体発光素子として図２６に示す本発明の半導体発光素子１が実装されたものである。なお、ランプ３は、例えば、半導体発光素子１と蛍光体とを組み合わせてなるものであり、当業者周知の手段によって当業者周知の構成とすることができる。また、半導体発光素子１と蛍光体と組み合わせることによって発光色を変えることができることが知られているが、このような技術を本実施形態のランプにおいても何ら制限されることなく採用することが可能である。 (Embodiment 15: lamp)
FIG. 37 is a schematic sectional view showing an example of the lamp of the present invention. As shown in FIG. 37, the lamp 3 of the present embodiment is a shell type, and is mounted with the semiconductor light emitting device 1 of the present invention shown in FIG. 26 as a semiconductor light emitting device. The lamp 3 is, for example, a combination of the semiconductor light emitting element 1 and a phosphor, and can be configured as known to those skilled in the art by means known to those skilled in the art. In addition, it is known that the emission color can be changed by combining the semiconductor light emitting element 1 and the phosphor, but such a technique can be adopted without any limitation in the lamp of this embodiment. It is.
　本実施形態のランプ３は、図３７に示すように、半導体発光素子１のｐ型電極１１１のボンディングパッド電極１２０にワイヤ３３で接合されたフレーム３１と、半導体発光素子１のｎ型電極１０８のボンディングパッド電極１２０にワイヤ３４で接合された他方のフレーム３２と、半導体発光素子１の周辺を取り囲んで形成された透明な樹脂からなるモールド３５とを備えている。 As shown in FIG. 37, the lamp 3 according to the present embodiment includes a frame 31 bonded to the bonding pad electrode 120 of the p-type electrode 111 of the semiconductor light emitting element 1 with a wire 33, and an n-type electrode 108 of the semiconductor light emitting element 1. The other frame 32 joined to the bonding pad electrode 120 with a wire 34 and a mold 35 made of a transparent resin formed so as to surround the periphery of the semiconductor light emitting element 1 are provided.
　また、本実施形態のランプ３は、半導体発光素子として、優れた接合性および耐食性を有するｎ型電極１０８およびｐ型電極１１１を備えた本発明の半導体発光素子を備えたものであるので、耐食性に優れ、歩留まりよく製造できる優れたものとなる。 In addition, the lamp 3 according to the present embodiment includes the semiconductor light emitting device of the present invention including the n-type electrode 108 and the p-type electrode 111 having excellent bonding properties and corrosion resistance as the semiconductor light emitting device. It is excellent in that it can be manufactured with good yield.
　本実施形態のランプ３は、一般用途の砲弾型、携帯のバックライト用途のサイドビュー型、表示器に用いられるトップビュー型等いかなる用途にも用いることができる。 The lamp 3 of the present embodiment can be used for any purposes such as a general-use bullet type, a side view type for a portable backlight, and a top view type used for a display.
　また、本発明の半導体発光素子から作製したランプ３は、前述のような優れた効果があるので、この技術によって作製したランプを組み込んだバックライト、携帯電話、ディスプレイ、各種パネル類、コンピュータ、ゲーム機、照明などの電子機器や、その電子機器を組み込んだ自動車などの機械装置類は、製品としての使用上の高い信頼性を与えることができる。特に、バックライト、携帯電話、ディスプレイ、ゲーム機、照明などの、バッテリ駆動させる機器類において、優れた耐食性、高信頼性のある発光素子を具備した製品を提供することができ、好ましい。
　以下、本発明を実施例に基づいて具体的に説明する。しかし、本発明はこれらの実施例にのみ限定されるものではない。 Further, since the lamp 3 manufactured from the semiconductor light emitting device of the present invention has the excellent effects as described above, a backlight, a mobile phone, a display, various panels, a computer, a game incorporating the lamp manufactured by this technology. Electronic devices such as machines and lighting, and mechanical devices such as automobiles incorporating the electronic devices can give high reliability in use as products. In particular, in a battery-driven device such as a backlight, a cellular phone, a display, a game machine, and lighting, a product including a light-emitting element with excellent corrosion resistance and high reliability can be provided, which is preferable.
Hereinafter, the present invention will be specifically described based on examples. However, the present invention is not limited only to these examples.
（実施形態１乃至実施形態６に係る実施例）
（実施例１）
＜半導体発光素子の作製＞
　窒化ガリウム系化合物半導体からなる半導体発光素子（以下、実施例１の半導体発光素子）を次にようにして製造した。
　まず、サファイアからなる基板上に、ＡｌＮからなるバッファ層を介して、厚さ８μｍのアンドープＧａＮからなる下地層を形成した。次に、厚さ２μｍのＳｉドープｎ型ＧａＮコンタクト層、厚さ２５０ｎｍのｎ型Ｉｎ０．１Ｇａ０．９Ｎクラッド層を形成した後、厚さ１６ｎｍのＳｉドープＧａＮ障壁層および厚さ２．５ｎｍのＩｎ０．２Ｇａ０．８Ｎ井戸層を５回積層し、最後に障壁層を設けた多重量子井戸構造の発光層を形成した。さらに、厚さ１０ｎｍのＭｇドープｐ型Ａｌ０．０７Ｇａ０．９３Ｎクラッド層、厚さ１５０ｎｍのＭｇドープｐ型ＧａＮコンタクト層を順に形成した。
　なお、窒化ガリウム系化合物半導体層の積層は、ＭＯＣＶＤ法により、当該技術分野においてよく知られた通常の条件で行なった。 (Example according to Embodiments 1 to 6)
Example 1
<Fabrication of semiconductor light emitting device>
A semiconductor light emitting device made of a gallium nitride compound semiconductor (hereinafter, the semiconductor light emitting device of Example 1) was manufactured as follows.
First, an underlayer made of undoped GaN having a thickness of 8 μm was formed on a substrate made of sapphire via a buffer layer made of AlN. Next, after forming a Si-doped n-type GaN contact layer having a thickness of 2 μm and an n-type In 0.1 Ga 0.9 N cladding layer having a thickness of 250 nm, a Si-doped GaN barrier layer having a thickness of 16 nm and a thickness of 2 A .5 nm In 0.2 Ga 0.8 N well layer was stacked five times, and finally a light emitting layer having a multiple quantum well structure in which a barrier layer was provided was formed. Further, a Mg-doped p-type Al 0.07 Ga 0.93 N cladding layer having a thickness of 10 nm and an Mg-doped p-type GaN contact layer having a thickness of 150 nm were sequentially formed.
The gallium nitride-based compound semiconductor layer was stacked by MOCVD under normal conditions well known in the technical field.
　次に、ｐ型ＧａＮコンタクト層上に、厚さ２００ｎｍのＩＴＯからなる透光性電極を形成した後、ＳｉＯ２からなる保護膜を形成した。
　さらに、実施形態１で示したマスク形成工程にしたがって、逆テーパー型マスクを形成した。レジストとしては、ＡＺ５２００ＮＪ（製品名：ＡＺエレクトロニックマテリアルズ株式会社製）を用いた。
　この逆テーパー型マスクを具備した状態で、ＳｉＯ２からなる保護膜をエッチングして、透光性電極の上面の一部とｎ型コンタクト層を露出させた後、スパッタ法により、２０ÅのＣｒからなる接合層を形成した。さらに、接合層の上に、２００ｎｍのＲｈからなる金属反射層、８０ｎｍのＴｉからなるバリア層、２００ｎｍのＡｕからなるボンディング層の３層構造のボンディングパッド電極を形成した。その後、レジスト剥離液を用いて、逆テーパー型マスクを除去した。ｎ側電極も、前記ｐ側電極と同じ電極積層構造とした。 Next, after forming a translucent electrode made of ITO having a thickness of 200 nm on the p-type GaN contact layer, a protective film made of SiO 2 was formed.
Further, an inversely tapered mask was formed according to the mask forming process shown in the first embodiment. As the resist, AZ5200NJ (product name: manufactured by AZ Electronic Materials Co., Ltd.) was used.
In the state equipped with the reverse taper type mask, the protective film made of SiO 2 is etched to expose a part of the upper surface of the translucent electrode and the n-type contact layer. A bonding layer was formed. Further, a bonding pad electrode having a three-layer structure including a metal reflection layer made of 200 nm Rh, a barrier layer made of 80 nm Ti, and a bonding layer made of 200 nm Au was formed on the bonding layer. Then, the reverse taper type mask was removed using a resist stripping solution. The n-side electrode also has the same electrode stack structure as the p-side electrode.
＜半導体発光素子の評価＞
　実施例１の半導体発光素子について、順方向電圧を測定したところ、プローブ針による通電で電流印加値２０ｍＡにおける順方向電圧が３．０Ｖであった。その後、ＴＯ－１８缶パッケージに実装してテスターによって発光出力を計測したところ印加電流２０ｍＡにおける発光出力は１９．５ｍＷを示した。またその発光面の発光分布は正極下の全面で発光しているのが確認できた。 <Evaluation of semiconductor light emitting device>
When the forward voltage was measured for the semiconductor light-emitting device of Example 1, the forward voltage at a current application value of 20 mA was 3.0 V when energized by the probe needle. After that, when mounted on a TO-18 can package and measured for light output by a tester, the light output at an applied current of 20 mA was 19.5 mW. Moreover, it was confirmed that the light emission distribution on the light emitting surface emitted light on the entire surface under the positive electrode.
　更に、本実施例で作製したボンディングパッド電極の反射率は４６０ｎｍの波長領域で７０％であった。この値は、ボンディングパッド電極形成時に同じチャンバに入れたガラス製のダミー基板を用いて、分光光度計で測定した。
　また、ボンディングテストを１００，０００チップについて実施したが（ボンディング不良数）、パッド剥れは１チップもなかった。 Furthermore, the reflectance of the bonding pad electrode produced in this example was 70% in the wavelength region of 460 nm. This value was measured with a spectrophotometer using a glass dummy substrate placed in the same chamber when the bonding pad electrode was formed.
In addition, a bonding test was performed on 100,000 chips (number of bonding failures), but there was no pad peeling.
＜高温高湿度試験＞
　常法に従って、チップの高温高湿度試験を実施した。試験方法としては、チップを高温高湿器（いすゞ製作所、μーＳＥＲＩＥＳ）内に入れ、温度８５℃、相対湿度８５ＲＨ％の環境下でそれぞれ１００個のチップ数の発光試験（チップへの通電量は５ｍＡ、２０００時間）をしたところ、不良数は０個であった。 <High temperature and high humidity test>
The chip was subjected to a high temperature and high humidity test according to a conventional method. As a test method, a chip is placed in a high-temperature and high-humidity device (Isuzu Seisakusho, μ-SERIES), and a light emission test of 100 chips each in an environment of a temperature of 85 ° C. and a relative humidity of 85 RH% (amount of power applied to the chip). 5 mA, 2000 hours), the number of defects was 0.
＜耐食性試験＞
　電流印加値２０ｍＡ、順方向電圧が３．０Ｖ、発光出力は１９．５ｍＷの発光させた状態で、実施例１の半導体発光素子を水槽の水中に沈めた。その状態のまま、１０分間保持した後、水中から引き上げて、再び発光特性を測定した。水中に沈める前と発光特性はほとんど変わらなかった。 <Corrosion resistance test>
The semiconductor light emitting device of Example 1 was submerged in water in a water tank with a current application value of 20 mA, a forward voltage of 3.0 V, and a light emission output of 19.5 mW. After being kept for 10 minutes in that state, it was pulled up from the water and the luminescence characteristics were measured again. The light emission characteristics were almost the same as before submerging in water.
（実施例２～２０）
　表１に示す材料及び厚さでｐ型電極を形成した他は実施例１と同様にして、実施例２～２０の半導体発光素子を製造した。
　実施例１と同様に評価を行い、表２に示す評価結果が得られた。 (Examples 2 to 20)
Semiconductor light emitting devices of Examples 2 to 20 were manufactured in the same manner as Example 1 except that the p-type electrode was formed with the material and thickness shown in Table 1.
Evaluation was performed in the same manner as in Example 1, and the evaluation results shown in Table 2 were obtained.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
（比較例１）
　図１２は、比較例１の半導体発光素子のｐ型電極を示す拡大断面図である。図１２に示すように、この半導体発光素子のｐ型電極２０１は、ＩＴＯからなる透光性電極１０９、Ｃｒからなる接合層２１０及びボンディングパッド電極２２０によって構成されている。
　透光性電極１０９の上面１０９ｃはＳｉＯ２からなる保護膜１０によって覆われており、保護膜１０の一部が開口されて露出された透光性電極１０９の上面１０９ｃに接合層２１０が均一な厚さで形成されている。接合層２１０の上にはＡｌからなる金属反射層２１７が形成され、金属反射層２１７の上にはＴｉからなるバリア層、Ａｕからなるボンディング層２１９がこの順序で形成されている。また、接合層２１０、金属反射層２１７、バリア層（図示略）およびボンディング層２１９各層の側面はそれぞれ透光性電極１０９の上面１０９ｃに対してほぼ垂直に形成されている。 (Comparative Example 1)
FIG. 12 is an enlarged cross-sectional view showing a p-type electrode of the semiconductor light emitting device of Comparative Example 1. As shown in FIG. 12, the p-type electrode 201 of this semiconductor light emitting element is composed of a translucent electrode 109 made of ITO, a bonding layer 210 made of Cr, and a bonding pad electrode 220.
The upper surface 109c of the translucent electrode 109 is covered with the protective film 10 made of SiO 2, and the bonding layer 210 is uniform on the upper surface 109c of the translucent electrode 109 exposed by opening a part of the protective film 10. It is formed with a thickness. A metallic reflective layer 217 made of Al is formed on the bonding layer 210, and a barrier layer made of Ti and a bonding layer 219 made of Au are formed on the metallic reflective layer 217 in this order. The side surfaces of the bonding layer 210, the metal reflection layer 217, the barrier layer (not shown), and the bonding layer 219 are formed substantially perpendicular to the upper surface 109 c of the translucent electrode 109.
　比較例１の半導体発光素子は、以下のようにして形成した。
　まず、実施例１と同様にして、ＭＯＣＶＤ法により、当該技術分野においてよく知られた通常の条件で、窒化ガリウム系化合物半導体層の積層を行なった。
　次に、ｐ型ＧａＮコンタクト層上に厚さ２００ｎｍのＩＴＯからなる透光性電極１０９を形成した。
　次に、図１３（ａ）に示すように、透光性電極１０９の上面１０９ｃ上にＳｉＯ２からなる保護膜１０を形成した後、保護膜１０上にレジストを塗布乾燥してレジスト部２１を形成した。
　次に、図１３（ｂ）に示すように、通常のフォトリソグラフィー法を用いて、ボンディングパッド電極を形成する部分に対応する部分のレジスト部２１を露光して可溶性のレジストとした後、これを所定の現像液で除去して、保護膜１０の上面に対して垂直な端面を有するレジスト部２１を形成した。 The semiconductor light emitting device of Comparative Example 1 was formed as follows.
First, in the same manner as in Example 1, a gallium nitride-based compound semiconductor layer was laminated by MOCVD under normal conditions well known in the technical field.
Next, a translucent electrode 109 made of ITO having a thickness of 200 nm was formed on the p-type GaN contact layer.
Next, as shown in FIG. 13A, after forming the protective film 10 made of SiO 2 on the upper surface 109c of the translucent electrode 109, a resist is applied and dried on the protective film 10 to form the resist portion 21. Formed.
Next, as shown in FIG. 13B, the resist portion 21 corresponding to the portion where the bonding pad electrode is formed is exposed to form a soluble resist by using a normal photolithography method. The resist part 21 having an end surface perpendicular to the upper surface of the protective film 10 was formed by removing with a predetermined developer.
　次に、図１３（ｃ）に示すように、残されたレジスト部２１をマスクとして、保護膜１０のエッチングを行い、ボンディングパッド電極を形成する部分に対応する部分の保護膜１０を除去して、透光性電極１０９の上面１０９ｃとｎ型コンタクト層を露出させた。
　次に、スパッタ法により、露出された透光性電極１０９の上面１０９ｃおよびレジスト部２１の上面２１ａを覆うように、２０ÅのＣｒからなる接合層２１０を形成した。さらに、接合層２１０を覆うように２００ｎｍのＡｌからなる金属反射層２１７を形成した。さらにまた、図１３（ｄ）に示すように、金属反射層２１７を覆うように８０ｎｍのＴｉからなるバリア層（図示略）を形成し、前記バリア層を覆うように２００ｎｍのＡｕからなるボンディング層２１９を形成した。
　最後に、レジスト剥離液によりレジスト部２１を剥離することにより、図１３（ｅ）に示すように、接合層２１０上に金属反射層２１７とバリア層とボンディング層２１９とからなる３層構造のボンディングパッド電極２２０が積層されたｐ型電極２０１を形成した。
　この工程により、図１２に示す構造のｐ型電極２０１を形成した。なお、ｎ側電極も、前記ｐ側電極と同じ電極積層構造とした。 Next, as shown in FIG. 13C, the protective film 10 is etched using the remaining resist portion 21 as a mask, and the protective film 10 corresponding to the portion where the bonding pad electrode is formed is removed. The upper surface 109c of the translucent electrode 109 and the n-type contact layer were exposed.
Next, a bonding layer 210 of 20 Ｃｒ Cr was formed by sputtering so as to cover the exposed upper surface 109c of the transparent electrode 109 and the upper surface 21a of the resist portion 21. Furthermore, a metal reflective layer 217 made of 200 nm Al was formed so as to cover the bonding layer 210. Furthermore, as shown in FIG. 13 (d), a barrier layer (not shown) made of 80 nm Ti is formed so as to cover the metal reflective layer 217, and a bonding layer made of 200 nm Au is covered so as to cover the barrier layer. 219 was formed.
Finally, the resist portion 21 is stripped with a resist stripping solution to bond a three-layer structure comprising a metal reflective layer 217, a barrier layer, and a bonding layer 219 on the bonding layer 210 as shown in FIG. A p-type electrode 201 in which the pad electrode 220 was laminated was formed.
By this step, the p-type electrode 201 having the structure shown in FIG. 12 was formed. The n-side electrode also has the same electrode stack structure as the p-side electrode.
＜半導体発光素子の評価＞
　比較例１の半導体発光素子について、順方向電圧を測定したところ、プローブ針による通電で電流印加値２０ｍＡにおける順方向電圧が３．０Ｖであった。その後、ＴＯ－１８缶パッケージに実装してテスターによって発光出力を計測したところ印加電流２０ｍＡにおける発光出力は２０ｍＷを示した。またその発光面の発光分布は正極下の全面で発光しているのが確認できた。このように、発光特性は実施例１と同様であった。 <Evaluation of semiconductor light emitting device>
When the forward voltage was measured for the semiconductor light emitting device of Comparative Example 1, the forward voltage at a current application value of 20 mA was 3.0 V when energized by the probe needle. After that, when mounted on a TO-18 can package and measured for light output by a tester, the light output at an applied current of 20 mA was 20 mW. Moreover, it was confirmed that the light emission distribution on the light emitting surface emitted light on the entire surface under the positive electrode. Thus, the light emission characteristics were the same as in Example 1.
　更に、比較例１のボンディングパッド電極の反射率は４６０ｎｍの波長領域で９０％であった。この値は、ボンディングパッド電極形成時に同じチャンバに入れたガラス製のダミー基板を用いて、分光光度計で測定した。
　また、ボンディングテストを１００，０００チップについて実施したが（ボンディング不良数）、パッド剥れは５０チップであった。 Furthermore, the reflectance of the bonding pad electrode of Comparative Example 1 was 90% in the wavelength region of 460 nm. This value was measured with a spectrophotometer using a glass dummy substrate placed in the same chamber when the bonding pad electrode was formed.
In addition, a bonding test was performed on 100,000 chips (number of bonding defects), and pad peeling was 50 chips.
＜高温高湿度試験＞
　実施例１と同様にして、チップの高温高湿度試験を実施した。温度８５℃、相対湿度８５ＲＨ％の環境下でそれぞれ１００個のチップ数の発光試験（チップへの通電量は５ｍＡ、２０００時間）をしたところ、不良数は６５個であった。 <High temperature and high humidity test>
In the same manner as in Example 1, a high temperature and high humidity test of the chip was performed. When a light emission test was performed with 100 chips each in an environment of a temperature of 85 ° C. and a relative humidity of 85 RH% (the amount of current applied to the chips was 5 mA, 2000 hours), the number of defects was 65.
＜耐食性試験＞
　実施例１と同様にして、耐食性試験を行った。電流印加値２０ｍＡ、順方向電圧が３．０Ｖ、発光出力は２０ｍＷの発光させた状態で、比較例１の半導体発光素子を水槽の水中に沈めた。その状態のまま数秒間保持しただけで光らなくなった。 <Corrosion resistance test>
The corrosion resistance test was conducted in the same manner as in Example 1. The semiconductor light-emitting device of Comparative Example 1 was submerged in water in a water tank with a current application value of 20 mA, a forward voltage of 3.0 V, and a light emission output of 20 mW. It was not shining even if it was kept in that state for a few seconds.
（比較例２及び比較例３）
　表１に示す材料及び厚さでｐ型電極を形成した他は比較例１と同様にして、比較例２及び比較例３の半導体発光素子を製造した。
　比較例１と同様に評価を行い、表２に示す評価結果が得られた。 (Comparative Example 2 and Comparative Example 3)
Semiconductor light emitting devices of Comparative Example 2 and Comparative Example 3 were manufactured in the same manner as Comparative Example 1 except that the p-type electrode was formed with the materials and thicknesses shown in Table 1.
Evaluation was performed in the same manner as in Comparative Example 1, and the evaluation results shown in Table 2 were obtained.
（実施形態７乃至実施形態１１に係る実施例）
（実施例２１）
　図１４～図１６に示す窒化ガリウム系化合物半導体からなる半導体発光素子を次のようにして製造した。 (Examples according to Embodiments 7 to 11)
(Example 21)
A semiconductor light emitting device made of a gallium nitride compound semiconductor shown in FIGS. 14 to 16 was manufactured as follows.
「積層半導体層の形成」
　まず、サファイアからなる基板１０１上に、ＡｌＮからなるバッファ層１０２を介して、厚さ８μｍのアンドープＧａＮからなる下地層１０３を形成した。次に、厚さ２μｍのＳｉドープｎ型ＧａＮからなるｎコンタクト層１０４ａ、厚さ２５０ｎｍのｎ型Ｉｎ０．１Ｇａ０．９Ｎからなるｎクラッド層１０４ｂを形成した。その後、厚さ１６ｎｍのＳｉドープＧａＮ障壁層および厚さ２．５ｎｍのＩｎ０．２Ｇａ０．８Ｎ井戸層を５回積層し、最後に障壁層を設けた多重量子井戸構造の発光層１０５を形成した。さらに、厚さ１０ｎｍのＭｇドープｐ型Ａｌ０．０７Ｇａ０．９３Ｎからなるｐクラッド層１０６ａ、厚さ１５０ｎｍのＭｇドープｐ型ＧａＮからなるｐコンタクト層１０６ｂを順に形成した。なお、積層半導体層２０の形成は、ＭＯＣＶＤ法により、当該技術分野においてよく知られた通常の条件で行なった。 "Formation of laminated semiconductor layers"
First, an underlayer 103 made of undoped GaN having a thickness of 8 μm was formed on a substrate 101 made of sapphire via a buffer layer 102 made of AlN. Next, an n-contact layer 104a made of Si-doped n-type GaN having a thickness of 2 μm and an n-cladding layer 104b made of n-type In 0.1 Ga 0.9 N having a thickness of 250 nm were formed. Thereafter, a light-emitting layer 105 having a multiple quantum well structure in which a Si-doped GaN barrier layer having a thickness of 16 nm and an In 0.2 Ga 0.8 N well layer having a thickness of 2.5 nm are stacked five times and finally a barrier layer is provided. Formed. Further, a p-cladding layer 106a made of Mg-doped p-type Al 0.07 Ga 0.93 N having a thickness of 10 nm and a p-contact layer 106b made of Mg-doped p-type GaN having a thickness of 150 nm were sequentially formed. The stacked semiconductor layer 20 was formed by MOCVD under normal conditions well known in the technical field.
「電極の形成」
　このようにして積層半導体層２０を形成した後、フォトリソグラフィーの手法によってパターニングし、所定の領域の積層半導体層２０の一部をエッチングしてｎコンタクト層１０４ａの一部を露出させた。次に、スパッタ法により、ｎコンタクト層１０４ａの露出面１０４ｃに順次Ｔｉ／Ｐｔ／Ａｕからなるｎ型電極１０８を形成した。 "Formation of electrodes"
After forming the laminated semiconductor layer 20 in this manner, patterning was performed by a photolithography technique, and a part of the laminated semiconductor layer 20 in a predetermined region was etched to expose a part of the n contact layer 104a. Next, an n-type electrode 108 made of Ti / Pt / Au was sequentially formed on the exposed surface 104c of the n-contact layer 104a by sputtering.
　その後、以下に示すようにｐ型電極１１１を形成した。まず、ｐ型ＧａＮコンタクト層１０６ｂ上に、厚さ２５０ｎｍのＩＺＯからなる透光性電極１０９を形成し、透光性電極１０９上に厚さ１００ｎｍのＳｉＯ２からなる透明保護膜１０ａを形成した。
　次に、イメージ反転型フォトレジストとしてＡＺ５２００ＮＪ（製品名：ＡＺエレクトロニックマテリアルズ株式会社製）を用いて、透明保護膜１０ａの形成された透光性電極１０９の上面に、底面に向かって断面積が徐々に広くなる内壁形状を有する開口部２３ａを備えた逆テーパー型のマスク２３を形成した。 Thereafter, a p-type electrode 111 was formed as shown below. First, the translucent electrode 109 made of IZO having a thickness of 250 nm was formed on the p-type GaN contact layer 106b, and the transparent protective film 10a made of SiO 2 having a thickness of 100 nm was formed on the translucent electrode 109.
Next, using AZ5200NJ (product name: manufactured by AZ Electronic Materials Co., Ltd.) as an image reversal type photoresist, a cross-sectional area is formed on the top surface of the translucent electrode 109 on which the transparent protective film 10a is formed, toward the bottom surface. A reverse-tapered mask 23 having an opening 23a having an inner wall shape that gradually widens was formed.
　続いて、マスク２３の開口部２３ａから露出する透明保護膜１０ａを、透光性電極１０９の上面１０９ｃに垂直な方向からＲＩＥ（反応性イオンエッチング）することにより除去して、開口部１０ｄを形成し、開口部１０ｄから透光性電極１０９の上面１０９ｃを露出させた。
　次に、マスク２３の開口部２３ａから露出する透光性電極１０９を、ドライエッチングすることにより、透光性電極１０９の上面１０９ｃに深さ１０ｎｍの接合凹部１０９ａを形成した。 Subsequently, the transparent protective film 10a exposed from the opening 23a of the mask 23 is removed by RIE (reactive ion etching) from a direction perpendicular to the upper surface 109c of the translucent electrode 109 to form the opening 10d. Then, the upper surface 109c of the translucent electrode 109 was exposed from the opening 10d.
Next, the translucent electrode 109 exposed from the opening 23 a of the mask 23 was dry-etched to form a bonding recess 109 a having a depth of 10 nm on the upper surface 109 c of the translucent electrode 109.
　次に、スパッタ法により、透光性電極１０９の接合凹部１０９ａを覆うように、最大膜厚１０ÅのＣｒからなる接合層１１０を形成した。次に、スパッタ法により、接合層１１０を覆い、外側に向けて膜厚が漸次薄くなる傾斜面１１７ｃを外周部に有する最大膜厚１００ｎｍのＰｔからなる金属反射層１１７を形成した。続いて、スパッタ法により、マスク２３の開口部２３ａの内壁形状に沿って外周部の形状が形成され、金属反射層１１７を覆い、外側に向けて膜厚が漸次薄くなる傾斜面１１９ｃを外周部１２０ｄに有する最大膜厚１１００ｎｍのＡｕからなるボンディング層１１９を形成した。このことにより、金属反射層１１７とボンディング層１１９とからなるボンディングパッド電極１２０を形成した。 Next, a bonding layer 110 made of Cr having a maximum thickness of 10 mm was formed by sputtering so as to cover the bonding recess 109a of the translucent electrode 109. Next, a metal reflective layer 117 made of Pt having a maximum film thickness of 100 nm was formed by sputtering, covering the bonding layer 110 and having an inclined surface 117c that gradually decreases in thickness toward the outside at the outer periphery. Subsequently, by the sputtering method, the shape of the outer peripheral portion is formed along the inner wall shape of the opening 23a of the mask 23, covers the metal reflection layer 117, and the inclined surface 119c whose thickness gradually decreases toward the outer portion is formed on the outer peripheral portion. A bonding layer 119 made of Au having a maximum thickness of 1100 nm at 120d was formed. As a result, the bonding pad electrode 120 composed of the metal reflection layer 117 and the bonding layer 119 was formed.
　その後、レジスト剥離液に浸漬することにより、マスク２３を剥離した。次に、平面視したときに、ボンディングパッド電極１２０の中央部を露出させる略ドーナッツ状の形状であって、ボンディングパッド電極１２０の外縁部（輪郭線）と透明保護膜１０ａとの継ぎ目となる部分に跨ってボンディングパッド電極１２０の外縁部を覆う幅５μｍ、最大厚さ１００ｎｍのＳｉＯ２からなる縁部保護膜１０ｂを形成した。このようにして、図１４～図１６に示すｐ型電極１１１を備える実施例２１の半導体発光素子１を得た。 Then, the mask 23 was peeled by being immersed in a resist stripping solution. Next, when viewed in a plan view, it is a substantially donut-shaped shape that exposes the central portion of the bonding pad electrode 120, and is a portion that becomes a joint between the outer edge portion (contour line) of the bonding pad electrode 120 and the transparent protective film 10 a An edge protective film 10b made of SiO 2 having a width of 5 μm and a maximum thickness of 100 nm was formed to cover the outer edge of the bonding pad electrode 120. In this way, the semiconductor light emitting device 1 of Example 21 including the p-type electrode 111 shown in FIGS. 14 to 16 was obtained.
（比較例４）
　縁部保護膜１０ｂが形成されていないことと、透光性電極１０９の上面１０９ｃに接合凹部１０９ａが形成されていないことと、接合層２１０、ボンディングパッド電極２２０を構成する金属反射層２１７およびボンディング層２１９の側面が透光性電極１０９の上面１０９ｃに対してほぼ垂直に形成されていること以外は、実施例２１の半導体発光素子１と同様である図２５に示す半導体発光素子を製造した。 (Comparative Example 4)
The edge protection film 10b is not formed, the bonding recess 109a is not formed on the upper surface 109c of the translucent electrode 109, the metal reflection layer 217 constituting the bonding layer 210, the bonding pad electrode 220, and bonding A semiconductor light emitting device shown in FIG. 25 similar to the semiconductor light emitting device 1 of Example 21 was manufactured except that the side surface of the layer 219 was formed substantially perpendicular to the upper surface 109c of the translucent electrode 109.
＜半導体発光素子の評価＞
　実施例２１および比較例４の半導体発光素子について、順方向電圧を測定した。その結果、実施例２１および比較例４ともにプローブ針による通電で電流印加値２０ｍＡにおける順方向電圧が３．０Ｖであった。
　その後、実施例２１および比較例４の半導体発光素子をＴＯ－１８缶パッケージに実装してテスターによって発光出力を計測した。その結果、実施例２１および比較例４ともに印加電流２０ｍＡにおける発光出力は２０ｍＷを示した。また、実施例２１および比較例４ともに、発光面の発光分布は正極下の全面で発光しているのが確認できた。 <Evaluation of semiconductor light emitting device>
For the semiconductor light emitting devices of Example 21 and Comparative Example 4, the forward voltage was measured. As a result, in Example 21 and Comparative Example 4, the forward voltage at a current application value of 20 mA was 3.0 V when energized by the probe needle.
Thereafter, the semiconductor light emitting devices of Example 21 and Comparative Example 4 were mounted in a TO-18 can package, and the light emission output was measured by a tester. As a result, in both Example 21 and Comparative Example 4, the light emission output at an applied current of 20 mA was 20 mW. Further, in both Example 21 and Comparative Example 4, it was confirmed that the light emission distribution on the light emitting surface emitted light on the entire surface under the positive electrode.
　更に、実施例２１および比較例４において作製したボンディングパッド電極の反射率を測定したところ、４６０ｎｍの波長領域で８０％であった。反射率の測定は、ボンディングパッド電極を形成する時にチャンバに入れたガラス製のダミー基板に形成されたボンディングパッド電極と同じ薄膜について、分光光度計を用いて測定した。
　また、実施例２１１および比較例４の半導体発光素子（チップ）について、ボンディングテストを行った。その結果、実施例２１では、１００，０００チップ中、パッド剥れ（ボンディング不良）は１チップもなかった。これに対し、比較例４では、１００，０００チップ中、パッド剥れ（ボンディング不良）は３チップであった。 Furthermore, when the reflectance of the bonding pad electrode produced in Example 21 and Comparative Example 4 was measured, it was 80% in the wavelength region of 460 nm. The reflectance was measured using a spectrophotometer for the same thin film as the bonding pad electrode formed on the glass dummy substrate placed in the chamber when the bonding pad electrode was formed.
Further, a bonding test was performed on the semiconductor light emitting elements (chips) of Example 211 and Comparative Example 4. As a result, in Example 21, no pad peeling (bonding failure) was found in one chip among 100,000 chips. On the other hand, in Comparative Example 4, pad peeling (bonding failure) was 3 chips out of 100,000 chips.
＜チップの高温高湿度試験＞
　実施例２１および比較例４の半導体発光素子（チップ）を高温高湿器（いすゞ製作所、μーＳＥＲＩＥＳ）内に入れ、温度８５℃、相対湿度８５ＲＨ％の環境下で１００個のチップに対して発光試験（チップへの通電量５ｍＡ、２０００時間）を行った。その結果、実施例２１の不良数は０個であったが、比較例４の不良数は２０個であった。 <Chip high temperature and high humidity test>
The semiconductor light emitting devices (chips) of Example 21 and Comparative Example 4 were placed in a high-temperature and high-humidifier (Isuzu Seisakusho, μ-SERIES), and 100 chips under an environment of a temperature of 85 ° C. and a relative humidity of 85 RH%. A light emission test (amount of current applied to the chip: 5 mA, 2000 hours) was performed. As a result, the number of defects in Example 21 was 0, but the number of defects in Comparative Example 4 was 20.
＜耐食性試験＞
　電流印加値２０ｍＡ、順方向電圧３．０Ｖ、発光出力２０ｍＷの発光させた状態で、実施例２１および比較例４の半導体発光素子を水槽の水中に沈めた。
　実施例２１では、半導体発光素子を水槽の水中に沈めた状態のまま１０分間保持した後、水中から引き上げて、再び発光特性を測定した。その結果、実施例２１では、水中に沈める前と水中に沈める後とで発光特性はほとんど変わらなかった。
　これに対し、比較例４では、半導体発光素子を水槽の水中に沈めた状態のまま数秒間保持しただけで光らなくなった。 <Corrosion resistance test>
The semiconductor light-emitting elements of Example 21 and Comparative Example 4 were submerged in water in a state where light was emitted with a current application value of 20 mA, a forward voltage of 3.0 V, and a light emission output of 20 mW.
In Example 21, the semiconductor light emitting device was held for 10 minutes while being submerged in water in a water tank, then pulled up from the water, and light emission characteristics were measured again. As a result, in Example 21, the light emission characteristics hardly changed before and after being submerged in water.
On the other hand, in Comparative Example 4, the semiconductor light-emitting element did not shine only by being held for several seconds while being submerged in the water of the water tank.
（実施例２２～４１）
　表３に示す材料及び厚さでｐ型電極を形成した他は実施例２１と同様にして、実施例２２～４１の半導体発光素子を製造した。
　実施例２１と同様に評価を行い、表４に示す評価結果が得られた。 (Examples 22 to 41)
Semiconductor light emitting devices of Examples 22 to 41 were manufactured in the same manner as Example 21 except that the p-type electrode was formed with the material and thickness shown in Table 3.
Evaluation was performed in the same manner as in Example 21, and the evaluation results shown in Table 4 were obtained.
（比較例５～７）
　表３に示す材料及び厚さでｐ型電極を形成した他は比較例４と同様にして、比較例５～７の半導体発光素子を製造した。
　比較例４と同様に評価を行い、表４に示す評価結果が得られた。 (Comparative Examples 5 to 7)
Semiconductor light emitting devices of Comparative Examples 5 to 7 were manufactured in the same manner as Comparative Example 4 except that p-type electrodes were formed with the materials and thicknesses shown in Table 3.
Evaluation was performed in the same manner as in Comparative Example 4, and the evaluation results shown in Table 4 were obtained.
 
Figure JPOXMLDOC01-appb-T000003
  
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
（実施形態１２乃至実施形態１４に係る実施例）
（実施例４２）
　ｐ型電極（オーミック接合層、接合層、ボンディングパッド電極（金属反射層、バリア層、ボンディング層）およびｎ型電極が表５に示す構成である図２６～図２８に示す窒化ガリウム系化合物半導体からなる半導体発光素子を次のようにして製造した。 (Examples according to Embodiments 12 to 14)
(Example 42)
The p-type electrode (ohmic junction layer, junction layer, bonding pad electrode (metal reflection layer, barrier layer, bonding layer)) and n-type electrode have the configurations shown in Table 5 to the gallium nitride compound semiconductor shown in FIGS. A semiconductor light emitting device was manufactured as follows.
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
「積層半導体層の形成」
　まず、サファイアからなる基板１０１上に、ＡｌＮからなるバッファ層１０２を介して、厚さ８μｍのアンドープＧａＮからなる下地層１０３を形成した。次に、厚さ２μｍのＳｉドープｎ型ＧａＮからなるｎコンタクト層１０４ａ、厚さ２５０ｎｍのｎ型Ｉｎ０．１Ｇａ０．９Ｎからなるｎクラッド層１０４ｂを形成した。その後、厚さ１６ｎｍのＳｉドープＧａＮ障壁層および厚さ２．５ｎｍのＩｎ０．２Ｇａ０．８Ｎ井戸層を５回積層し、最後に障壁層を設けた多重量子井戸構造の発光層１０５を形成した。さらに、厚さ１０ｎｍのＭｇドープｐ型Ａｌ０．０７Ｇａ０．９３Ｎからなるｐクラッド層１０６ａ、厚さ１５０ｎｍのＭｇドープｐ型ＧａＮからなるｐコンタクト層１０６ｂを順に形成した。なお、積層半導体層２０の形成は、ＭＯＣＶＤ法により、当該技術分野においてよく知られた通常の条件で行なった。 "Formation of laminated semiconductor layers"
First, an underlayer 103 made of undoped GaN having a thickness of 8 μm was formed on a substrate 101 made of sapphire via a buffer layer 102 made of AlN. Next, an n-contact layer 104a made of Si-doped n-type GaN having a thickness of 2 μm and an n-cladding layer 104b made of n-type In 0.1 Ga 0.9 N having a thickness of 250 nm were formed. Thereafter, a light-emitting layer 105 having a multiple quantum well structure in which a Si-doped GaN barrier layer having a thickness of 16 nm and an In 0.2 Ga 0.8 N well layer having a thickness of 2.5 nm are stacked five times and finally a barrier layer is provided. Formed. Further, a p-cladding layer 106a made of Mg-doped p-type Al 0.07 Ga 0.93 N having a thickness of 10 nm and a p-contact layer 106b made of Mg-doped p-type GaN having a thickness of 150 nm were sequentially formed. The stacked semiconductor layer 20 was formed by MOCVD under normal conditions well known in the technical field.
「電極の形成」
　このようにして積層半導体層２０を形成した後、フォトリソグラフィーの手法によってパターニングし、所定の領域の積層半導体層２０の一部をエッチングしてｎコンタクト層１０４ａの一部を露出させた。
　次に、ｐ型ＧａＮコンタクト層１０６ｂ上に、厚さ２５０ｎｍのＩＺＯからなる透光性電極１０９を形成し、透光性電極１０９上およびｎコンタクト層１０４ａの露出面１０４ｃ上に厚さ１００ｎｍのＳｉＯ２からなる保護膜１０ａを形成した。 "Formation of electrodes"
After forming the laminated semiconductor layer 20 in this manner, patterning was performed by a photolithography technique, and a part of the laminated semiconductor layer 20 in a predetermined region was etched to expose a part of the n contact layer 104a.
Next, a light-transmitting electrode 109 made of IZO having a thickness of 250 nm is formed on the p-type GaN contact layer 106b, and SiO nm having a thickness of 100 nm is formed on the light-transmitting electrode 109 and the exposed surface 104c of the n-contact layer 104a. A protective film 10a made of 2 was formed.
　続いて、保護膜１０ａを、透光性電極１０９の上面１０９ｃに垂直な方向からＲＩＥ（反応性イオンエッチング）することにより除去して開口部１０ｄを形成し、開口部１０ｄから透光性電極１０９の上面１０９ｃおよびｎコンタクト層１０４ａの露出面１０４ｃを露出させた。
　次に、透光性電極１０９をドライエッチングすることにより、穴部１０９ａを形成した。その後、窒素雰囲気中、６５０℃の温度で熱処理を行ない、透光性電極１０９を構成するアモルファス状態のＩＺＯ膜を結晶化させた。 Subsequently, the protective film 10a is removed by RIE (reactive ion etching) from a direction perpendicular to the upper surface 109c of the translucent electrode 109 to form an opening 10d, and the translucent electrode 109 is formed from the opening 10d. The upper surface 109c and the exposed surface 104c of the n contact layer 104a were exposed.
Next, the hole 109a was formed by dry etching the translucent electrode 109. Thereafter, heat treatment was performed at a temperature of 650 ° C. in a nitrogen atmosphere to crystallize the amorphous IZO film constituting the translucent electrode 109.
　次に、イメージ反転型フォトレジストとしてＡＺ５２００ＮＪ（製品名：ＡＺエレクトロニックマテリアルズ株式会社製）を用いて、保護膜１０ａの形成された透光性電極１０９の上面およびｎコンタクト層１０４ａの露出面１０４ｃ上に、底面に向かって断面積が徐々に広くなる内壁形状を有する開口部２３ａを備えた逆テーパー型のマスク２３を形成した。このとき、透光性電極１０９上に形成したマスク２３の開口部２３は、透光性電極１０９の穴部１０９ａが開口部２３から露出される位置に形成した。 Next, AZ5200NJ (product name: manufactured by AZ Electronic Materials Co., Ltd.) is used as an image reversal type photoresist, and the upper surface of the translucent electrode 109 on which the protective film 10a is formed and the exposed surface 104c of the n contact layer 104a. Then, a reverse taper type mask 23 having an opening 23a having an inner wall shape whose cross-sectional area gradually increases toward the bottom surface was formed. At this time, the opening 23 of the mask 23 formed on the translucent electrode 109 was formed at a position where the hole 109 a of the translucent electrode 109 was exposed from the opening 23.
　「パッド形成工程」
　次に、スパッタ法により、透光性電極１０９の穴部１０９ａの底面１０９ｂ上またはｎコンタクト層１０４ａの露出面１０４ｃ上と、透光性電極１０９の穴部１０９ａの内壁１０９ｄと保護膜１０ａの開口部１０ｄの端部１０ｃとを連続して覆うように、膜厚１００ｎｍのＩＺＯからなるオーミック接合層９を形成した。次に、オーミック接合層９上と保護膜１０ａの開口部１０ｄの端部１０ｃとを連続して覆うように、最大膜厚１０ｎｍのＣｒからなる接合層１１０を形成した。次に、スパッタ法により、接合層１１０を覆い、外側に向けて膜厚が漸次薄くなる傾斜面１１７ｃを外周部に有する最大膜厚１００ｎｍのＰｔからなる金属反射層１１７を形成した。続いて、スパッタ法により、マスク２３の開口部２３ａの内壁形状に沿って外周部の形状が形成され、金属反射層１１７を覆い、外側に向けて膜厚が漸次薄くなる傾斜面１１９ｃを外周部１２０ｄに有する最大膜厚１１００ｎｍのＡｕからなるボンディング層１１９を形成した。このことにより、金属反射層１１７とボンディング層１１９とからなるボンディングパッド電極１２０を形成した。
　その後、レジスト剥離液に浸漬することにより、マスク２３を剥離した。 "Pad formation process"
Next, openings of the hole 109a of the translucent electrode 109 or the exposed surface 104c of the n-contact layer 104a, the inner wall 109d of the hole 109a of the translucent electrode 109, and the protective film 10a are formed by sputtering. An ohmic junction layer 9 made of IZO having a thickness of 100 nm was formed so as to continuously cover the end 10c of the portion 10d. Next, a bonding layer 110 made of Cr having a maximum film thickness of 10 nm was formed so as to continuously cover the ohmic bonding layer 9 and the end 10c of the opening 10d of the protective film 10a. Next, a metal reflective layer 117 made of Pt having a maximum film thickness of 100 nm was formed by sputtering, covering the bonding layer 110 and having an inclined surface 117c that gradually decreases in thickness toward the outside at the outer periphery. Subsequently, by the sputtering method, the shape of the outer peripheral portion is formed along the inner wall shape of the opening 23a of the mask 23, covers the metal reflection layer 117, and the inclined surface 119c whose thickness gradually decreases toward the outer portion is formed on the outer peripheral portion. A bonding layer 119 made of Au having a maximum thickness of 1100 nm at 120d was formed. As a result, the bonding pad electrode 120 composed of the metal reflection layer 117 and the bonding layer 119 was formed.
Then, the mask 23 was peeled by being immersed in a resist stripping solution.
　「熱処理工程」
　続いて、オーミック接合層９と接合層１１０との密着性を向上させるために、窒素雰囲気中、３６０℃の温度で熱処理を行なった。
　また、この熱処理工程を入れなくともオーミック接合層９と接合層１１０との密着性を向上させることもできる。 "Heat treatment process"
Subsequently, in order to improve the adhesion between the ohmic bonding layer 9 and the bonding layer 110, heat treatment was performed at a temperature of 360 ° C. in a nitrogen atmosphere.
In addition, the adhesion between the ohmic bonding layer 9 and the bonding layer 110 can be improved without the heat treatment step.
　次に、平面視したときに、平面視したときにボンディングパッド電極１２０の中央部を露出させる領域を除く全域に最大厚さ２５０ｎｍのＳｉＯ２からなる縁部保護膜１０ｂを形成した。
　このようにして、図２６～図２８に示すｐ型電極１１１を備える実施例４２の半導体発光素子１を得た。 Next, when viewed in plan, the edge protective film 10b made of SiO 2 having a maximum thickness of 250 nm was formed over the entire region excluding the region exposing the central portion of the bonding pad electrode 120 when viewed in plan.
In this way, the semiconductor light emitting device 1 of Example 42 including the p-type electrode 111 shown in FIGS. 26 to 28 was obtained.
（実施例４３～５９）
　ｐ型電極（オーミック接合層、接合層、ボンディングパッド電極（金属反射層、バリア層、ボンディング層）およびｎ型電極を表５に示す構成のものとしたこと以外は、実施例４２の半導体発光素子１と同様である実施例４３～５９の半導体発光素子を製造した。 (Examples 43 to 59)
The semiconductor light emitting device of Example 42, except that the p-type electrode (ohmic junction layer, junction layer, bonding pad electrode (metal reflective layer, barrier layer, bonding layer)) and n-type electrode have the configurations shown in Table 5 The semiconductor light emitting devices of Examples 43 to 59 which are the same as 1 were manufactured.
（比較例８）
　透光性電極１０９を形成する前に、スパッタ法によりｎコンタクト層１０４ａの露出面１０４ｃに当該面よりＴｉ／Ａｕからなるｎ型電極１０８を形成したことと、ｐ型電極１１１に（１）開口部を持たない（透光性電極の上面が平坦である）こと、（２）オーミック接合層を有さないこと、（３）接合層１１０、ボンディングパッド電極１２０の側面が透光性電極１０９の上面１０９ｃに対してほぼ垂直に形成されており、熱処理温度を２７５℃としたこと、（４）絶縁保護膜１０ｂが形成されていないこと以外は、実施例４２の半導体発光素子１と同様にして比較例８の半導体発光素子を製造した。 (Comparative Example 8)
Before forming the translucent electrode 109, the n-type electrode 108 made of Ti / Au was formed on the exposed surface 104c of the n-contact layer 104a by sputtering, and (1) openings were formed in the p-type electrode 111. (2) not having an ohmic bonding layer, (3) the side surfaces of the bonding layer 110 and the bonding pad electrode 120 of the light transmitting electrode 109. It is formed substantially perpendicular to the upper surface 109c, and the heat treatment temperature is 275 ° C. (4) The semiconductor light emitting element 1 of Example 42 is the same except that the insulating protective film 10b is not formed. The semiconductor light emitting device of Comparative Example 8 was manufactured.
＜半導体発光素子の評価＞
　実施例４２～５９および比較例８の半導体発光素子について、プローブ針による通電で電流印加値２０ｍＡにおける順方向電圧を測定した。その結果を表６に示す。
　表６に示すように、実施例４２～５９の順方向電圧は３．０Ｖまたは３．１Ｖであり、比較例８の順方向電圧は３．０Ｖであった。 <Evaluation of semiconductor light emitting device>
For the semiconductor light emitting devices of Examples 42 to 59 and Comparative Example 8, the forward voltage at a current applied value of 20 mA was measured by energization with a probe needle. The results are shown in Table 6.
As shown in Table 6, the forward voltage of Examples 42 to 59 was 3.0V or 3.1V, and the forward voltage of Comparative Example 8 was 3.0V.
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
　その後、実施例４２～５９および比較例８の半導体発光素子をＴＯ－１８缶パッケージに実装してテスターによって発光出力を計測し、その結果を表６に示す。
　表６に示すように、実施例４２～５９の発光出力は１９．５～２３ｍＷの範囲であり、比較例８の発光出力は、発光出力は２１ｍＷを示した。 Thereafter, the semiconductor light emitting devices of Examples 42 to 59 and Comparative Example 8 were mounted in a TO-18 can package, and the light emission output was measured by a tester. The results are shown in Table 6.
As shown in Table 6, the light emission outputs of Examples 42 to 59 were in the range of 19.5 to 23 mW, and the light emission output of Comparative Example 8 was 21 mW.
　更に、実施例４２～５９および比較例８において作製したボンディングパッド電極の反射率を測定した。反射率の測定は、ボンディングパッド電極を形成する時にチャンバに入れたガラス製のダミー基板に形成されたボンディングパッド電極と同じ薄膜について、分光光度計を用いて４６０ｎｍの波長領域で測定した。その結果を表６に示す。 Furthermore, the reflectance of the bonding pad electrodes produced in Examples 42 to 59 and Comparative Example 8 was measured. The reflectance was measured in the wavelength region of 460 nm using a spectrophotometer for the same thin film as the bonding pad electrode formed on the glass dummy substrate placed in the chamber when the bonding pad electrode was formed. The results are shown in Table 6.
　また、実施例４２～５９および比較例８の半導体発光素子（チップ）について、ボンディングテストを行った。その結果を表２に示す。
　表６に示すように、実施例４２，４４，４７，５１～５９では、１００，０００チップ中、パッド剥れ（ボンディング不良数）は０であった。また、その他の実施例についてもボンディング不良数は５以下であり、非常に少なかった。これに対し、比較例８では、１００，０００チップ中、ボンディング不良数は３０であった。 Also, bonding tests were performed on the semiconductor light emitting devices (chips) of Examples 42 to 59 and Comparative Example 8. The results are shown in Table 2.
As shown in Table 6, in Examples 42, 44, 47, 51 to 59, pad peeling (number of bonding failures) was 0 in 100,000 chips. In other examples, the number of bonding defects was 5 or less, which was very small. On the other hand, in Comparative Example 8, the number of bonding failures was 30 out of 100,000 chips.
　＜チップの高温高湿度試験＞
　実施例４２～５９および比較例８の半導体発光素子（チップ）を高温高湿器（いすゞ製作所、μーＳＥＲＩＥＳ）内に入れ、温度８５℃、相対湿度８５ＲＨ％の環境下で１００個のチップに対して発光試験（チップへの通電量５ｍＡ、２０００時間）を行った。その結果を表６に示す。
　表６に示すように、実施例４８，４９，５３～５９では、１００個の不良数は０であった。また、その他の実施例についても不良数は５以下であり、非常に少なかった。これに対し、比較例８では、１００個のチップ中、不良数は２０であった。 <Chip high temperature and high humidity test>
The semiconductor light emitting devices (chips) of Examples 42 to 59 and Comparative Example 8 are placed in a high-temperature and high-humidity device (Isuzu Seisakusho, μ-SERIES), and are formed into 100 chips in an environment of a temperature of 85 ° C. and a relative humidity of 85 RH%. On the other hand, a light emission test (amount of current to the chip of 5 mA, 2000 hours) was performed. The results are shown in Table 6.
As shown in Table 6, in Examples 48, 49, and 53 to 59, the number of 100 defects was 0. Also, in other examples, the number of defects was 5 or less, which was very small. On the other hand, in Comparative Example 8, the number of defects was 20 out of 100 chips.
＜耐食性試験＞
　電流印加値２０ｍＡ、順方向電圧３．０Ｖ、発光出力２０ｍＷの発光させた状態で、実施例４２～５９および比較例８の半導体発光素子を水槽の水中に沈め、半導体発光素子を水槽の水中に沈めた状態のまま１０分間保持した後、水中から引き上げて、再び発光特性を測定した。その結果を表６に示す。
　表６に示すように、実施例４８，４９，５３～５９では、１００個のチップ中の不良数は０であった。また、その他の実施例についても不良数は１０以下であり、非常に少なかった。これに対し、比較例８では、１００個のチップ中の不良数は４０であった。
（実施例６０）
　実施例１～５９で製造した半導体発光素子を特開２００７－１９４４０１号公報の記載と同じ方法に準じて、前記半導体発光素子を搭載したランプ（パッケージ）を作製することができた。また、電子機器や機械装置の一例として、そのランプを組み込んだバックライトを作製することができた。 <Corrosion resistance test>
The semiconductor light emitting devices of Examples 42 to 59 and Comparative Example 8 were submerged in water in the water tank with the current applied value of 20 mA, the forward voltage of 3.0 V, and the light emission output of 20 mW, and the semiconductor light emitting elements were submerged in the water of the water tank. After holding for 10 minutes in the submerged state, it was pulled up from the water, and the light emission characteristics were measured again. The results are shown in Table 6.
As shown in Table 6, in Examples 48, 49, and 53 to 59, the number of defects in 100 chips was 0. Also, in other examples, the number of defects was 10 or less, which was very small. On the other hand, in Comparative Example 8, the number of defects in 100 chips was 40.
(Example 60)
A lamp (package) in which the semiconductor light-emitting element manufactured in Examples 1 to 59 was mounted according to the same method as described in JP-A-2007-194401 could be produced. In addition, as an example of an electronic device or a mechanical device, a backlight incorporating the lamp could be manufactured.
　本発明は、半導体発光素子、その電極並びに製造方法及びランプに関するものであって、特に、接合性及び耐食性を向上させた電極を備えた半導体発光素子、その電極並びに製造方法及びランプを製造・利用する産業において利用可能性がある。 The present invention relates to a semiconductor light emitting device, an electrode thereof, a manufacturing method, and a lamp, and more particularly, to manufacture and use a semiconductor light emitting device including an electrode with improved bonding properties and corrosion resistance, the electrode, the manufacturing method, and the lamp. It can be used in the industry.
１、２、１ａ、１ｂ…半導体発光素子、３…ランプ、９…オーミック接合層、１０、１０ａ…保護膜（透明保護膜）、１０ｂ…縁部保護膜、１０ｃ…端部、１０ｄ…開口部、１１…保護膜、２０…積層半導体層、２１…不溶性レジスト部（レジスト部）、２２…可溶性レジスト部（可溶部）、２３…架橋高分子からなる硬化部（マスク）、２３ａ…開口部、２５…マスク、３１、３２…フレーム、３３、３４…ボンディングワイヤ（ワイヤ）、３５…モールド、１０１…基板、１０２…バッファ層、１０３…下地層、１０４…ｎ型半導体層、１０４ａ…ｎコンタクト層、１０４ｂ…ｎクラッド層、１０４ｃ…露出面（半導体層露出面）、１０５…発光層、１０５ａ…障壁層、１０５ｂ…井戸層、１０６…ｐ型半導体層、１０６ａ…ｐクラッド層、１０６ｂ…ｐコンタクト層、１０６ｃ…上面、１０８，１１８、１２８…ｎ型電極（他方の電極）、１０８ｃ…傾斜面、１０８ｄ…外周部、１０９…透光性電極、１０９ａ…接合凹部（穴部）、１０９ｂ…底面、１０９ｃ…上面、１０９ｄ…内壁、１１０…接合層、１１０ｃ…傾斜面、１１０ｄ…外周部、１１１、１１１ａ、１１１ｂ、１１２…ｐ型電極（一方の電極）、１１７…金属反射層、１１７ｃ…傾斜面、１１９…ボンディング層、１１９ｃ…傾斜面、１２０…ボンディングパッド電極、１２０ｄ…外周部、１３０…接合層、１３０ｃ…傾斜面、１３０ｄ…外周部、２０１…ｐ型電極、２１７…金属反射層、２１９…ボンディング層、２２０…ボンディングパッド電極。 1, 2, 1 a, 1 b... Semiconductor light emitting device, 3. Lamp, 9... Ohmic junction layer, 10, 10 a, protective film (transparent protective film), 10 b, edge protective film, 10 c, end, 10 d, opening DESCRIPTION OF SYMBOLS 11 ... Protective film, 20 ... Laminated semiconductor layer, 21 ... Insoluble resist part (resist part), 22 ... Soluble resist part (soluble part), 23 ... Curing part (mask) which consists of crosslinked polymer, 23a ... Opening part , 25 ... Mask, 31, 32 ... Frame, 33, 34 ... Bonding wire (wire), 35 ... Mold, 101 ... Substrate, 102 ... Buffer layer, 103 ... Underlayer, 104 ... N-type semiconductor layer, 104a ... n contact Layer 104b ... n clad layer 104c exposed surface (semiconductor layer exposed surface) 105 light emitting layer 105a barrier layer 105b well layer 106 p semiconductor layer 106a p clad 106b ... p contact layer, 106c ... upper surface, 108, 118, 128 ... n-type electrode (the other electrode), 108c ... inclined surface, 108d ... outer periphery, 109 ... translucent electrode, 109a ... joining recess (hole) 109b ... bottom surface, 109c ... upper surface, 109d ... inner wall, 110 ... bonding layer, 110c ... inclined surface, 110d ... outer peripheral part, 111, 111a, 111b, 112 ... p-type electrode (one electrode), 117 ... metal reflection Layer, 117c ... inclined surface, 119 ... bonding layer, 119c ... inclined surface, 120 ... bonding pad electrode, 120d ... outer periphery, 130 ... bonding layer, 130c ... inclined surface, 130d ... outer periphery, 201 ... p-type electrode, 217 ... metal reflective layer, 219 ... bonding layer, 220 ... bonding pad electrode.

Claims (33)

  1. 　基板と、前記基板上に形成されてなる発光層を含む積層半導体層と、前記積層半導体層の上面に形成された一方の電極と、前記積層半導体層の一部が切り欠けられてなる半導体層露出面上に形成された他方の電極と、を具備する半導体発光素子であって、
    　前記一方の電極または前記他方の電極の少なくともいずれか一方が、接合層と前記接合層を覆うように形成されたボンディングパッド電極とからなり、
    　前記ボンディングパッド電極の最大厚みが、前記接合層の最大厚みに比べて厚く形成され、かつ、１または２以上の層からなり、
    　前記接合層および前記ボンディングパッド電極の外周部にそれぞれ、外周側に向けて膜厚が漸次薄くなるような傾斜面が形成されていることを特徴とする半導体発光素子。     A substrate, a laminated semiconductor layer including a light emitting layer formed on the substrate, one electrode formed on an upper surface of the laminated semiconductor layer, and a semiconductor layer formed by partially cutting off the laminated semiconductor layer A semiconductor light emitting device comprising the other electrode formed on the exposed surface,
    At least one of the one electrode or the other electrode is composed of a bonding layer and a bonding pad electrode formed so as to cover the bonding layer,
    The maximum thickness of the bonding pad electrode is formed thicker than the maximum thickness of the bonding layer, and consists of one or more layers,
    A semiconductor light emitting element, wherein inclined surfaces are formed on the outer peripheral portions of the bonding layer and the bonding pad electrode so that the film thickness gradually decreases toward the outer peripheral side.
  2. 　前記一方の電極と前記積層半導体層の上面との間または前記他方の電極と前記半導体層露出面との間に透光性電極が形成されている請求項１記載の半導体発光素子。 2. The semiconductor light emitting element according to claim 1, wherein a translucent electrode is formed between the one electrode and the upper surface of the laminated semiconductor layer or between the other electrode and the exposed surface of the semiconductor layer.
  3. 　前記透光電極の上面に接合凹部をさらに有し、前記接合層が前記接合凹部を覆うように形成されたことを特徴とする請求項２に記載の半導体発光素子。 3. The semiconductor light emitting device according to claim 2, further comprising a bonding recess on an upper surface of the translucent electrode, wherein the bonding layer is formed to cover the bonding recess.
  4. 　前記積層半導体層の上面または前記半導体層露出面上に形成されたオーミック接合層をさらに有し、前記接合層が前記オーミック接合層上に形成されたことを特徴とする請求項１に記載の半導体発光素子。 The semiconductor according to claim 1, further comprising an ohmic junction layer formed on an upper surface of the laminated semiconductor layer or the exposed surface of the semiconductor layer, wherein the junction layer is formed on the ohmic junction layer. Light emitting element.
  5. 　前記接合層が、Ａｌ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｃｏ、Ｚｎ、Ｇｅ、Ｚｒ、Ｎｂ、Ｍｏ、Ｒｕ、Ｈｆ、Ｔａ、Ｗ、Ｒｅ、Ｒｈ、Ｉｒ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなるものであることを特徴とする請求項１乃至４のいずれか１項に記載の半導体発光素子。 The bonding layer is at least selected from the group consisting of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh, Ir, and Ni. The semiconductor light-emitting element according to claim 1, wherein the semiconductor light-emitting element is made of one kind of element.
  6. 　前記接合層の最大厚みが１０Å以上１０００Å以下の範囲の薄膜であることを特徴とする請求項５に記載の半導体発光素子。 6. The semiconductor light-emitting element according to claim 5, wherein the bonding layer is a thin film having a maximum thickness in a range of 10 to 1000 mm.
  7. 　前記接合層の最大厚みが１０Å以上４００Å以下の範囲の薄膜であることを特徴とする請求項６に記載の半導体発光素子。 The semiconductor light-emitting element according to claim 6, wherein the bonding layer is a thin film having a maximum thickness in a range of 10 to 400 mm.
  8. 　ボンディングパッド電極が、Ａｕ、Ａｌまたはこれらの金属の何れかを含む合金からなるボンディング層からなることを特徴とする請求項１乃至７のいずれか１項に記載の半導体発光素子。 The semiconductor light-emitting element according to claim 1, wherein the bonding pad electrode is made of a bonding layer made of Au, Al, or an alloy containing any of these metals.
  9. 　前記ボンディングパッド電極層の最大厚みが５０ｎｍ以上２０００ｎｍ以下の範囲の薄膜であることを特徴とする請求項８に記載の半導体発光素子。 9. The semiconductor light emitting element according to claim 8, wherein the bonding pad electrode layer is a thin film having a maximum thickness in a range of 50 nm to 2000 nm.
  10. 　ボンディングパッド電極が、前記接合層を覆うように形成された金属反射層と、前記金属反射層を覆うように形成されたボンディング層とからなり、
    　前記金属反射層が、Ａｇ、Ａｌ、Ｒｕ、Ｒｈ、Ｐｄ、Ｏｓ、Ｉｒ、Ｐｔ、Ｔｉのうちの何れかまたはこれら金属の何れかを含む合金からなるものであることを特徴とする請求項１乃至８のいずれか１項に記載の半導体発光素子。     The bonding pad electrode includes a metal reflective layer formed so as to cover the bonding layer, and a bonding layer formed so as to cover the metal reflective layer,
    2. The metal reflective layer is made of any one of Ag, Al, Ru, Rh, Pd, Os, Ir, Pt, and Ti or an alloy containing any of these metals. 9. The semiconductor light emitting device according to any one of 1 to 8.
  11. 　前記金属反射層の最大厚みが２０ｎｍ以上３０００ｎｍ以下の範囲の薄膜であることを特徴とする請求項１０に記載の半導体発光素子。 The semiconductor light emitting device according to claim 10, wherein the metal reflective layer is a thin film having a maximum thickness in a range of 20 nm to 3000 nm.
  12. 　前記透光性電極が、Ｉｎ、Ｚｎ、Ａｌ、Ｇａ、Ｔｉ、Ｂｉ、Ｍｇ、Ｗ、Ｃｅ、Ｓｎ、Ｎｉのいずれか一種を含む導電性の酸化物、硫化亜鉛または硫化クロムのうちいずれか一種からなる群より選ばれる透光性の導電性材料から構成されることを特徴とする請求項２、３、５乃至１１のいずれか１項に記載の半導体発光素子。 The translucent electrode is a conductive oxide containing any one of In, Zn, Al, Ga, Ti, Bi, Mg, W, Ce, Sn, and Ni, and any one of zinc sulfide and chromium sulfide. The semiconductor light-emitting element according to claim 2, comprising a translucent conductive material selected from the group consisting of:
  13. 　前記オーミック接合層が、Ｉｎ、Ｚｎ、Ａｌ、Ｇａ、Ｔｉ、Ｂｉ、Ｍｇ、Ｗ、Ｃｅ、Ｓｎ、Ｎｉのいずれか一種を含む導電性の酸化物、硫化亜鉛または硫化クロムのうちいずれか一種からなる群より選ばれる透光性の導電性材料から構成されることを特徴とする請求項４乃至１１のいずれか１項に記載の半導体発光素子。 The ohmic junction layer is made of any one of conductive oxides including any one of In, Zn, Al, Ga, Ti, Bi, Mg, W, Ce, Sn, and Ni, zinc sulfide, or chromium sulfide. The semiconductor light-emitting element according to claim 4, comprising a light-transmitting conductive material selected from the group consisting of:
  14. 　前記ボンディングパッド電極の外縁部を覆い、前記ボンディングパッド電極上の一部を露出させる縁部保護膜が形成されていることを特徴とする請求項３または請求項５乃至１２のいずれか１項に記載の半導体発光素子。 13. The edge protection film is formed to cover an outer edge portion of the bonding pad electrode and expose a part of the bonding pad electrode. 13. The semiconductor light emitting element as described.
  15. 　前記透光性電極の上面における前記接合凹部の形成されていない領域を覆うように透明保護膜が形成されており、
    　前記接合層の外縁部および前記ボンディングパッド電極の外縁部が、前記透明保護膜上に配置されていることを特徴とする請求項５乃至１２のいずれか１項に記載の半導体発光素子。     A transparent protective film is formed so as to cover a region where the bonding recess is not formed on the upper surface of the translucent electrode,
    13. The semiconductor light emitting element according to claim 5, wherein an outer edge portion of the bonding layer and an outer edge portion of the bonding pad electrode are disposed on the transparent protective film.
  16. 　前記積層半導体層が、前記基板側からｎ型半導体層、発光層、ｐ型半導体層の順に積層されてなり、前記発光層が多重量子井戸構造であることを特徴とする請求項１乃至１５のいずれか１項に記載の半導体発光素子。 The laminated semiconductor layer is formed by laminating an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer in this order from the substrate side, and the light emitting layer has a multiple quantum well structure. The semiconductor light emitting element of any one of Claims.
  17. 　前記積層半導体層が、窒化ガリウム系半導体を主体として構成されていることを特徴とする請求項１乃至１６のいずれか１項に記載の半導体発光素子。 The semiconductor light-emitting device according to claim 1, wherein the stacked semiconductor layer is mainly composed of a gallium nitride-based semiconductor.
  18. 　請求項１乃至１７のいずれか１項に記載の半導体発光素子と、前記半導体発光素子が配置されるとともに前記半導体発光素子の一方の電極とワイヤボンディングされる第１フレームと、前記半導体発光素子の他方の電極とワイヤボンディングされる第２フレームと、前記半導体発光素子を取り囲んで形成されるモールドと、を備えたことを特徴とするランプ。 18. The semiconductor light emitting device according to claim 1, a first frame in which the semiconductor light emitting device is disposed and wire-bonded to one electrode of the semiconductor light emitting device, and the semiconductor light emitting device. A lamp comprising: a second frame wire-bonded to the other electrode; and a mold formed to surround the semiconductor light emitting element.
  19. 　基板と、前記基板上に形成されてなる発光層を含む積層半導体層と、前記積層半導体層の上面に形成された一方の電極と、前記積層半導体層の一部が切り欠けられてなる半導体層露出面上に形成された他方の電極と、を具備する半導体発光素子用の電極であって、
    　前記一方の電極または前記他方の電極の少なくともいずれか一方が、接合層と前記接合層を覆うように形成されたボンディングパッド電極とからなり、
    　前記ボンディングパッド電極の最大厚みが、前記接合層の最大厚みに比べて厚く形成され、かつ、１または２以上の層からなり、
    　前記接合層および前記ボンディングパッド電極の外周部にそれぞれ、外周側に向けて膜厚が漸次薄くなるような傾斜面が形成されていることを特徴とする半導体発光素子用の電極。     A substrate, a laminated semiconductor layer including a light emitting layer formed on the substrate, one electrode formed on an upper surface of the laminated semiconductor layer, and a semiconductor layer formed by partially cutting off the laminated semiconductor layer An electrode for a semiconductor light emitting device comprising the other electrode formed on the exposed surface,
    At least one of the one electrode or the other electrode is composed of a bonding layer and a bonding pad electrode formed so as to cover the bonding layer,
    The maximum thickness of the bonding pad electrode is formed thicker than the maximum thickness of the bonding layer, and consists of one or more layers,
    An electrode for a semiconductor light-emitting element, wherein inclined surfaces are formed on the outer peripheral portions of the bonding layer and the bonding pad electrode so that the film thickness gradually decreases toward the outer peripheral side.
  20. 　前記接合層が、Ａｌ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｃｏ、Ｚｎ、Ｇｅ、Ｚｒ、Ｎｂ、Ｍｏ、Ｒｕ、Ｈｆ、Ｔａ、Ｗ、Ｒｅ、Ｒｈ、Ｉｒ、Ｎｉからなる群より選ばれた少なくとも一種の元素からなるものであり、最大厚みが１０Å以上１０００Å以下の範囲の薄膜であることを特徴とする請求項１９に記載の半導体発光素子用の電極。 The bonding layer is at least selected from the group consisting of Al, Ti, V, Cr, Mn, Co, Zn, Ge, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Rh, Ir, and Ni. The electrode for a semiconductor light-emitting element according to claim 19, wherein the electrode is for a semiconductor light-emitting element, comprising a kind of element and having a maximum thickness in a range of 10 to 1000 mm.
  21. 　前記ボンディングパッド電極が、Ａｕ、Ａｌまたはこれらの金属の何れかを含む合金からなるボンディング層からなり、前記ボンディング層の最大厚みが５０ｎｍ以上２０００ｎｍ以下の範囲の薄膜であることを特徴とする請求項９または請求項２０に記載の半導体発光素子用の電極。 The bonding pad electrode is made of a bonding layer made of Au, Al, or an alloy containing any of these metals, and the bonding layer is a thin film having a maximum thickness in a range of 50 nm to 2000 nm. The electrode for semiconductor light emitting elements of Claim 9 or Claim 20.
  22. 　前記ボンディングパッド電極が、前記接合層を覆うように形成された金属反射層と、前記金属反射層を覆うように形成されたボンディング層とからなり、
    　前記金属反射層が、Ａｇ、Ａｌ、Ｒｕ、Ｒｈ、Ｐｄ、Ｏｓ、Ｉｒ、Ｐｔ、Ｔｉのうちの何れかまたはこれら金属の何れかを含む合金からなるものであり、最大厚みが２０ｎｍ以上３０００ｎｍ以下の範囲の薄膜であることを特徴とする請求項１９乃至２１のいずれか１項に記載の半導体発光素子用の電極。     The bonding pad electrode comprises a metal reflective layer formed so as to cover the bonding layer, and a bonding layer formed so as to cover the metal reflective layer,
    The metal reflective layer is made of Ag, Al, Ru, Rh, Pd, Os, Ir, Pt, Ti or an alloy containing any of these metals, and has a maximum thickness of 20 nm to 3000 nm. The electrode for a semiconductor light-emitting element according to any one of claims 19 to 21, wherein the electrode is a thin film in a range of (1).
  23. 　前記一方の電極と前記積層半導体層の上面との間または前記他方の電極と前記半導体層露出面との間に透光性電極が形成されており、
    　前記透光性電極が、Ｉｎ、Ｚｎ、Ａｌ、Ｇａ、Ｔｉ、Ｂｉ、Ｍｇ、Ｗ、Ｃｅ、Ｓｎ、Ｎｉのいずれか一種を含む導電性の酸化物、硫化亜鉛または硫化クロムのうちいずれか一種からなる群より選ばれる透光性の導電性材料から構成されることを特徴とする請求項１９乃至２１のいずれか１項に記載の半導体発光素子用の電極。     A translucent electrode is formed between the one electrode and the upper surface of the laminated semiconductor layer or between the other electrode and the exposed surface of the semiconductor layer,
    The translucent electrode is a conductive oxide containing any one of In, Zn, Al, Ga, Ti, Bi, Mg, W, Ce, Sn, and Ni, and any one of zinc sulfide and chromium sulfide. The electrode for a semiconductor light emitting element according to any one of claims 19 to 21, wherein the electrode is made of a translucent conductive material selected from the group consisting of:
  24. 　基板上に、発光層を含む積層半導体層を形成する工程と、
    　前記積層半導体層の一部を切り欠けて半導体層露出面を形成する工程と、
    　前記積層半導体層の上面および前記半導体層露出面に一方の電極および他方の電極を形成する電極形成工程と、を有する半導体発光素子の製造方法であって、
    　前記電極形成工程が、前記積層半導体層の上面または前記半導体層露出面の少なくともいずれか一方の面上に逆テーパー型マスクを形成するマスク形成工程の後、前記積層半導体層の上面または前記半導体層露出面上に接合層を形成し、その後、前記接合層を覆うように前記接合層の最大厚みに比べて最大厚みの厚いボンディングパッド電極を形成して、一方の電極または他方の電極を形成する工程であることを特徴とする半導体発光素子の製造方法。     Forming a laminated semiconductor layer including a light emitting layer on a substrate;
    Forming a semiconductor layer exposed surface by cutting a part of the laminated semiconductor layer;
    An electrode forming step of forming one electrode and the other electrode on the upper surface of the laminated semiconductor layer and the exposed surface of the semiconductor layer, and a method for manufacturing a semiconductor light emitting device,
    In the electrode forming step, after the mask forming step of forming a reverse tapered mask on at least one of the upper surface of the stacked semiconductor layer and the exposed surface of the semiconductor layer, the upper surface of the stacked semiconductor layer or the semiconductor layer A bonding layer is formed on the exposed surface, and then a bonding pad electrode having a maximum thickness compared to the maximum thickness of the bonding layer is formed so as to cover the bonding layer, thereby forming one electrode or the other electrode. A method of manufacturing a semiconductor light emitting device, which is a process.
  25. 　前記電極形成工程の前に前記積層半導体層の上面または前記半導体層露出面に透光性電極を形成する工程を有することを特徴とする請求項２４に記載の半導体発光素子の製造方法。 The method for manufacturing a semiconductor light emitting element according to claim 24, further comprising a step of forming a translucent electrode on the upper surface of the stacked semiconductor layer or the exposed surface of the semiconductor layer before the electrode forming step.
  26. 　前記電極形成工程が、前記逆テーパー型マスクおよび前記接合層を形成した後、前記接合層を覆うように前記接合層の最大厚みに比べて最大厚みの厚い金属反射層を形成し、その後、前記金属反射層を覆うように前記金属反射層の最大厚みに比べて最大厚みの厚いボンディング層を形成して、一方の電極または他方の電極を形成する工程であることを特徴とする請求項２４または請求項２５に記載の半導体発光素子の製造方法。 After forming the reverse taper mask and the bonding layer, the electrode forming step forms a metal reflective layer having a maximum thickness compared to the maximum thickness of the bonding layer so as to cover the bonding layer, and then 25. The step of forming one electrode or the other electrode by forming a bonding layer having a maximum thickness compared to the maximum thickness of the metal reflection layer so as to cover the metal reflection layer. The method for manufacturing a semiconductor light emitting device according to claim 25.
  27. 　前記電極形成工程における前記接合層、前記金属反射層および前記ボンディング層の形成が、スパッタ法により行われることを特徴とする請求項２４乃至２６のいずれか１項に記載の半導体発光素子の製造方法。 27. The method of manufacturing a semiconductor light emitting element according to claim 24, wherein the bonding layer, the metal reflective layer, and the bonding layer in the electrode forming step are formed by a sputtering method. .
  28. 　前記マスク形成工程の前に、前記透光性電極の上面および前記積層半導体層の上面または前記半導体層露出面上に保護膜を形成する工程を備えたことを特徴とする請求項２４乃至２７のいずれか１項に記載の半導体発光素子の製造方法。 28. The method according to claim 24, further comprising a step of forming a protective film on the upper surface of the translucent electrode and the upper surface of the laminated semiconductor layer or on the exposed surface of the semiconductor layer before the mask forming step. The manufacturing method of the semiconductor light-emitting device of any one of Claims 1.
  29. 　基板と、前記基板上に形成された発光層を含む積層半導体層と、
    　前記積層半導体層の上面に形成された一方の電極と、前記積層半導体層の一部が切り欠けられてなる半導体層露出面上に形成された他方の電極とを具備する半導体発光素子の製造方法であって、前記一方の電極または前記他方の電極の少なくともいずれか一方を製造する工程が、透光性電極を形成する工程と、
    　前記透光性電極の上面に、底面に向かって断面積が徐々に広くなる内壁形状を有する開口部を備えたマスクを形成する工程と、
    　前記開口部から露出する前記透光性電極の上面をエッチングすることにより接合凹部を形成する工程と、
    　前記接合凹部を覆うように接合層を形成する工程と、
    　前記開口部の内壁形状に沿って外周部の形状を形成することにより、前記接合層を覆い、外側に向けて膜厚が漸次薄くなる傾斜面を外周部に有するボンディングパッド電極を形成する工程と、
    　前記マスクを除去する工程と
    　を備えることを特徴とする半導体発光素子の製造方法。     A substrate, and a laminated semiconductor layer including a light emitting layer formed on the substrate;
    A method for manufacturing a semiconductor light emitting device, comprising: one electrode formed on an upper surface of the laminated semiconductor layer; and the other electrode formed on an exposed surface of the semiconductor layer formed by partially cutting the laminated semiconductor layer And the step of producing at least one of the one electrode or the other electrode comprises forming a translucent electrode;
    Forming a mask having an opening having an inner wall shape whose cross-sectional area gradually increases toward the bottom surface on the top surface of the translucent electrode;
    Forming a bonding recess by etching an upper surface of the translucent electrode exposed from the opening;
    Forming a bonding layer so as to cover the bonding recess;
    Forming an outer peripheral shape along the inner wall shape of the opening, thereby forming a bonding pad electrode that covers the bonding layer and has an inclined surface that gradually decreases in thickness toward the outer periphery. ,
    And a step of removing the mask. A method of manufacturing a semiconductor light emitting device.
  30. 　基板上に発光層を含む積層半導体層を形成する工程と、
    　前記積層半導体層の上面に一方の電極を形成する工程と、
    　前記積層半導体層の一部を切り欠いて半導体層露出面を形成し、前記半導体層露出面上に他方の電極を形成する工程とを具備する半導体発光素子の製造方法において、
    　前記一方の電極を製造する工程と前記他方の電極を製造する工程の両方が、前記積層半導体層の上面または前記半導体層露出面上にオーミック接合層を形成し、前記オーミック接合層上に接合層を形成し、前記接合層を覆うようにボンディングパッド電極を形成するパッド形成工程と、
    　前記オーミック接合層と前記接合層との密着性を高める熱処理を８０℃～７００℃の温度で行う熱処理工程とを含むことを特徴とする半導体発光素子の製造方法。     Forming a laminated semiconductor layer including a light emitting layer on a substrate;
    Forming one electrode on the top surface of the laminated semiconductor layer;
    Forming a semiconductor layer exposed surface by cutting out part of the laminated semiconductor layer, and forming the other electrode on the semiconductor layer exposed surface.
    Both the step of manufacturing the one electrode and the step of manufacturing the other electrode form an ohmic junction layer on the upper surface of the stacked semiconductor layer or the exposed surface of the semiconductor layer, and the bonding layer on the ohmic junction layer Forming a bonding pad electrode so as to cover the bonding layer; and
    A method of manufacturing a semiconductor light emitting device, comprising: a heat treatment step of performing a heat treatment for improving adhesion between the ohmic bonding layer and the bonding layer at a temperature of 80 ° C. to 700 ° C.
  31. 　前記一方の電極を製造する工程と前記他方の電極を製造する工程とにおける前記パッド形成工程および前記熱処理工程を同時に行うことを特徴とする請求項３０に記載の半導体発光素子の製造方法。 31. The method of manufacturing a semiconductor light emitting element according to claim 30, wherein the pad forming step and the heat treatment step in the step of manufacturing the one electrode and the step of manufacturing the other electrode are simultaneously performed.
  32. 　請求項１８に記載のランプが組み込まれている電子機器。 An electronic device in which the lamp according to claim 18 is incorporated.
  33. 　請求項３１に記載の電子機器が組み込まれている機械装置。 A mechanical device in which the electronic device according to claim 31 is incorporated.
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