JP2009231356A - Semiconductor light emitting device and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device which does not cause current leak from an electrode and element breakdown and moreover can control the degradation in element characteristics. <P>SOLUTION: The semiconductor device includes a semiconductor laminating part having a semiconductor layer of a first conductivity type and a semiconductor layer of a second conductivity type, a first conductor side electrode connected to the semiconductor layer of the first conductivity type, and a second conductor side electrode connected to the semiconductor layer of the second conductor type. The semiconductor device is characterized in that the second conductor side electrode and an insulating film covering the semiconductor laminating part are arranged separately via an isolating region, a first metal layer is provided on the surface of the insulating film, and a second metal layer formed of a material different from that of the first metal layer is provided on the surface of the second conductor side electrode. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a semiconductor element, and more particularly to a semiconductor element having an electrode and an insulating film on the same surface side.

  In a semiconductor element, an electrode for supplying a current to a semiconductor layer, and an insulating film for electrically insulating the electrode from the surroundings on a semiconductor stacked portion having a multilayer structure composed of a plurality of semiconductor layers May be provided respectively. In this case, for example, in the case of a semiconductor light emitting device, the electrode is formed of Ag, Al, or the like in order to reflect light from the light emitting layer and increase light extraction efficiency. And this semiconductor light-emitting device may be bonded to a bonding substrate or mounted on a support substrate.

And in this bonding or mounting, a metal layer is formed on the electrode or the insulating film and bonded to the bonding substrate or the support substrate, and heat treatment is performed (for example, see Patent Document 1). In addition, in the case where an electrode and an insulating film are provided on the semiconductor layer, the insulating film is formed so as to cover a part of the electrode, or the electrode is extended to a part of the insulating film. Or forming. In particular, since Ag and Al are materials that easily cause migration, an insulating film is often formed so as to cover a part of the electrode. For example, Patent Document 2 discloses a structure in which an insulating thin film is laminated so as to cover an electrode. Patent Document 3 discloses a structure having a protective film covering the Ag-containing first metal layer constituting the p-side electrode. Furthermore, Patent Document 4 discloses a structure in which electrodes are formed in close contact with the outer periphery of an insulating film.
WO2003 / 066544 JP 2000-36619 A JP 2003-168823 A Japanese Patent Laid-Open No. 5-110140

When bonding and mounting, sufficient adhesion can be obtained by heat treatment at a high temperature, but cracking or chipping that may be caused by thermal expansion may occur in the insulating film made of SiO ₂ or the like at a higher temperature. . In these structures, the electrode serves as a heat dissipation path during the operation light emission of the semiconductor light emitting device, and is necessarily a part that can be in a high temperature state. When cracks or chips occur, migration of Ag or Al constituting the electrode through this portion may occur, causing leakage or destruction of the element. In addition, when an element is separated from a wafer to form a chip, the insulating film may crack.

  Moreover, when forming a metal layer on an electrode or an insulating film, it is necessary to select a material in consideration of adhesion between the electrode and the insulating film, and the materials that can be selected are limited. Furthermore, when such a material is selected, the characteristics of the insulating film are not affected, but the characteristics of the electrode may be affected.

  Therefore, the present invention provides a semiconductor element that can select a suitable metal material for the electrode and the insulating film without causing current leakage from the electrode or destruction of the element.

  In order to solve the above-described problems, the invention according to claim 1 is directed to a semiconductor stacked portion having a first conductive type semiconductor layer and a second conductive type semiconductor layer, and a first conductive type connected to the first conductive type semiconductor layer. A semiconductor element comprising a side electrode and a second conductive side electrode connected to the second conductive type semiconductor layer, wherein the second conductive side electrode and the insulating film covering the semiconductor stacked portion are separated from each other A first metal layer is provided on the surface of the insulating film, and a second metal layer made of a material different from that of the first metal layer is provided on the surface of the second conductive side electrode. It is characterized by being.

  In this semiconductor element, the second conductive side electrode is disposed apart from the insulating film covering the semiconductor laminated portion via the separation region, so that the element does not leak or break down. Since different metal layers are provided on the electrode and the insulating film thus separated, the characteristics of only one of the electrode and the insulating film need only be taken into consideration when selecting the material. You can choose.

  The invention according to claim 2 is characterized in that the first metal layer is separated from the second conductive side electrode. In this semiconductor element, the first metal layer can be prevented from affecting the second conductive side electrode.

  The invention according to claim 3 is characterized in that the first metal layer includes one kind selected from Ti and Ni on the side in contact with the insulating film. According to a fourth aspect of the present invention, the second metal layer includes one type selected from Ru, Rh, Os, Ir, Pt, W, and Mo on the side in contact with the second conductive side electrode. Features.

  The invention according to claim 5 is characterized in that the second conductive side electrode side of the semiconductor stacked portion is bonded to a support substrate via the second metal layer. According to a sixth aspect of the present invention, in the semiconductor device, the second metal layer includes one type selected from Ti, Au, Sn, and Pd on the support substrate side, Two conductive side electrodes include one type selected from Ru, Rh, Os, Ir, Pt, W, and Mo. In this semiconductor element, the second metal layer containing one selected from Ti, Au, Sn, and Pd can be adhered to the support substrate, and further, diffusion of such a metal material to the second conductive side electrode can be performed. , Ru, Rh, Os, Ir, Pt, W, and Mo can be prevented by one type.

  According to a seventh aspect of the present invention, the second conductive side electrode includes one type selected from Ag and Al, and the second conductive side electrode is surrounded by the insulating film in a plan view of the semiconductor stacked portion. It is characterized by being. In this semiconductor element, the migration of Ag and Al in the electrode can be further suppressed by the insulating film surrounding the second conductive side electrode.

  According to an eighth aspect of the present invention, the second metal layer is a continuous layer that continues to the first metal layer, and a gap or the continuous layer is provided in the separation region. In this semiconductor element, the second conductive side electrode is separated from the insulating film by a gap region or a separated region formed of a continuous layer made of a metal layer provided on the second conductive side electrode, causing leakage or destruction of the element. There is nothing.

  According to a ninth aspect of the present invention, the first conductive side electrode and the second conductive side electrode are opposed to each other with the semiconductor stacked portion interposed therebetween, and the semiconductor stacked portion includes the first conductive type semiconductor layer and the A semiconductor light emitting unit having a light emitting layer interposed between second conductive type semiconductor layers.

  The semiconductor element of the present invention can suppress the occurrence of element leakage and destruction due to migration of Ag and Al constituting the electrode. In addition, a metal layer suitable for each of the electrode and the insulating film can be provided separately, and deterioration of the characteristics of the element due to the metal layer can be suppressed.

Hereinafter, the semiconductor device and the manufacturing method thereof of the present invention will be described in detail.
FIG. 1 is a schematic cross-sectional view showing the structure of a semiconductor element 1 according to an embodiment of the present invention.

  A semiconductor element 1 shown in FIG. 1 is a semiconductor light emitting element, and includes a first conductivity type semiconductor layer 2, a second conductivity type semiconductor layer 3, and between the first conductivity type semiconductor layer 2 and the second conductivity type semiconductor layer 3. A semiconductor laminated portion 5 which is a semiconductor light emitting portion having a light emitting layer 4 interposed between the first conductive side electrode 6 connected to the first conductive type semiconductor layer 2 and the second conductive type semiconductor layer 3. It has a structure provided with the 2nd electroconductive side electrode 7 connected. Further, the second conductive type semiconductor layer 3 is provided with an insulating film 11b spaced from the second conductive side electrode 7, and the lower surfaces of the insulating film 11b and the second conductive side electrode 7 are in contact with them. The first metal layer 8 and the second metal layer 9 which are different from each other are provided, and the substrate 10 and the back surface metallized layer 11 are provided on the lower surface. Reference numeral 12 a denotes an insulating film, which communicates with the insulating film 12 b on the side surface of the semiconductor stacked portion 5.

The first conductivity type semiconductor layer 2 and the second conductivity type semiconductor layer 3 constituting the semiconductor stacked portion are formed by doping a layer made of a semiconductor material with a dopant to form an n-type or p-type semiconductor layer. Specific examples of the semiconductor material constituting the first conductive type semiconductor layer 2 and the second conductive type semiconductor layer 3 include GaN, AlN, InN, or a III-V group nitride semiconductor (In _α Al _β Ga _1-α-β N, 0 ≦ α, 0 ≦ β, α + β ≦ 1), part or all of B is used as a group III element, or part of N is P as a group V element, Examples include mixed crystals substituted with As, Sb, etc., GaAs-based materials such as AlGaAs and InGaAs, InP-based materials such as AlGaInP, and other III-V group compound semiconductors such as InGaAsP which are mixed crystals thereof. In addition, dopants doped into semiconductor materials include n-type dopants such as Si, Ge, Sn, S, O, Ti, and Zr group IV or VI elements, and p-type dopants such as Be, Zn, and Mn. , Cr, Mg, Ca and the like. When the first conductive type semiconductor layer 2 and the second conductive type semiconductor layer 3 are made of a nitride semiconductor material, the contact resistance with the first conductive side electrode 6 or the second conductive side electrode 7 can be lowered. In view of the capability, GaN containing Si and GaN containing Mg are most preferable. Further, the film thickness of the first conductive semiconductor layer 2 and the second conductive semiconductor layer 3 is about 1000 nm to 5000 nm as the total film thickness of the semiconductor laminated portion including the light emitting layer 4.

  The first conductive semiconductor layer 2 and the second conductive semiconductor layer 3 may each be formed in a multilayer structure. For example, the first conductivity type semiconductor layer 2 may have a multilayer structure in which a contact layer and a cladding layer are laminated in this order from the first conductivity side electrode 6 side. The second conductivity type semiconductor layer 7 may have a multilayer structure in which a contact layer and a cladding layer are laminated in this order from the second conductivity side electrode side. In addition, when the first conductivity type semiconductor layer 2 and the second conductivity type semiconductor layer 3 have a multilayer structure, the multilayer structure is formed by alternately laminating an undoped semiconductor material or a layer formed of a doped semiconductor material. It may be configured.

  The light emitting layer 4 is energy generated by recombination of holes and electrons injected from the first conductive type semiconductor layer 2 and the second conductive type semiconductor layer 3 which are n-type or p-type semiconductor layers. Is emitted as light.

  The light emitting layer 4 preferably has a quantum well structure including a well layer and a barrier layer. The semiconductor material constituting the light emitting layer 4 may be any of non-doped, n-type impurity doped, and p-type impurity doped. Especially, it is preferable to form with a semiconductor material of non-doped or n-type impurity doping. Furthermore, for example, the well layer may be undoped and the barrier layer may be n-type impurity doped. Furthermore, the wavelength of light generated in the light emitting layer 4 can be adjusted according to the purpose and application of the semiconductor light emitting device by selecting the kind of dopant doped into the well layer and the doping amount. For example, the light emitting layer 4 made of a nitride semiconductor can emit light having a wavelength of about 60 nm to about 650 nm, preferably 380 nm to 560 nm. However, by containing Al in the well layer, a conventional InGaN well layer can be used. Then, it is possible to obtain a difficult wavelength range, specifically, a wavelength near 365 nm which is the band gap energy of GaN or shorter.

  The first metal layer 8 and the second metal layer 9 join the substrate 10 to the second conductive side electrode 7 and the insulating film 12b, and the second conductive side electrode 7 and the back metallization layer through the substrate 10. 11 for electrical connection. In FIG. 1, the first metal layer 8 is provided on the insulating film 12 b, and the second metal layer 9 is provided continuously so as to cover the second conductive side electrode 7 and the first metal layer 8. In particular, when the second conductive side electrode 7 is separated into a plurality of pieces in the plane, the second metal layer 9 is provided as a continuous layer in this way, so that the plurality of separated second conductive side electrodes 7 The two metal layers 9 can be electrically connected. The back metallized layer 11 is formed as a continuous layer made of a metal material or an alloy material.

  The first metal layer 8 and the second metal layer 9 constitute a bonding layer for bonding the second conductive side electrode 7 and the insulating film 12b to the substrate or the like when the substrate is bonded or mounted. . The material of the first metal layer 8 can be selected from materials suitable for the insulating film 12b, and those having good adhesion to the insulating film 12b are preferable. Specifically, it is formed of a metal material such as Ti or Ni and an alloy thereof. For example, the total film thickness is in the order of Ti / Pt, Ti / Rh, Ti / Ir, Ni / Pt, Ni / Rh, and Ni / Ir. A film can be formed with a thickness of about several tens to several hundreds of nanometers.

  The material of the second metal layer 9 is not only the adhesion to the second conductive side electrode 7 but also the ohmic characteristics between the second conductive side electrode 7 and the second conductive type semiconductor layer 3 and the second conductive side electrode 7. It is preferable to consider the influence on the resistance. That is, depending on the material of the second metal layer 9, the ohmic characteristics may be deteriorated or the resistance may be increased due to diffusion to the second conductive side electrode 7. For this reason, the second metal layer 9 can contain Ru, Rh, Os, Ir, Pt, W, Mo, or the like having a high melting point. In particular, when Ti, Au, Sn, Pd or the like having a melting point lower than these is included in the second metal layer 9, the Ru, Rh, Os, Ir, By disposing Pt, W, Mo, and the like, the influence on the second conductive side electrode 7 can be suppressed even under high temperature conditions such as bonding or bonding to a substrate or the like or driving an element. Thereby, the ohmic characteristic deterioration between the 2nd conductivity side electrode 7 and the 2nd conductivity type semiconductor layer 3 and resistance increase can be suppressed, and the raise of the forward voltage of an element can be suppressed.

  The first metal layer 8 and the second metal layer 9 function as a bonding layer in the case of an element bonded to a substrate or the like as shown in FIG. In the element shown in FIG. 1, the second metal layer 9 is used as a bonding layer. In this case, the second metal layer 9 includes at least a low melting point material such as Sn or Pb, and is made of a metal material such as Ti, Pt, Au, Sn, Au, Ag, Cu, Bi, Pb, Zn, or an alloy thereof. It is formed. For example, the second metal layer 9 is made of Pt / Ti / Pt / Au / Sn / Au, Pt / Au / Sn / Au, W / Pt / Au / Sn / Au, Mo / Pt / Au / Sn / Au, Ru. / Au / Sn / Au, Rh / Au / Sn / Au, and Ir / Au / Sn / Au in the order of a total film thickness of about 3000 nm to 4000 nm. Further, the back metallized layer 11 is formed with a film thickness of about 600 nm.

  The substrate 10 is made of, for example, silicon (Si). In addition to Si, a semiconductor substrate made of a semiconductor such as Ge, SiC, GaN, GaAs, GaP, InP, ZnSe, ZnS, and ZnO, a single metal substrate, or a small non-solid or semi-solid solubility limit 2 A metal substrate made of a composite of more than one kind of metal can be used. The single metal substrate is, for example, a Cu substrate, and the material of the metal substrate is, for example, at least one metal selected from highly conductive metals such as Ag, Cu, Au, Pt, and W, Mo, and the like. A material comprising at least one metal selected from metals with high hardness such as Cr, Ni, and the like can be used. In the case of using a substrate made of a semiconductor material, the substrate can be provided with an element function, for example, a Zener diode. Furthermore, a composite of Cu—W or Cu—Mo can also be used as the metal substrate. In addition to the first and second metal layers described above, a bonding layer on the substrate 10 side can be provided on the surface of the substrate 10 on the semiconductor laminated portion side.

  In the semiconductor element 1, the first conductive side electrode 6 is provided outside the first conductive type semiconductor layer 2, the second conductive side electrode 7 is provided outside the second conductive side semiconductor layer 3, The conductive side electrode 5 is spaced apart from the insulating film 12a via a separation region 13a made up of a gap. In addition, the second conductive side electrode 7 is interposed through a separation region 13b configured by filling a metal material or an alloy material forming the second metal layer 9 between the second conductive side electrode 7 and the insulating film 12b. And the insulating film 12b are spaced apart. In addition, the separation region 13b between the second conductive side electrode 7 and the insulating film 12b is a second metal layer (a continuous layer made of a metal material or an alloy material) 9 outside the second conductive side electrode 7 and the insulating film 12b. Is provided, and the separation region 13b is sealed by the second conductive semiconductor layer 3, the second conductive side electrode 7, the insulating film 12b, and the second metal layer 9, the metal material forming the second metal layer 9 Or you may be comprised by the space | gap which is not filled with alloy material.

  Thus, it is preferable to use a 2nd metal layer as a metal layer which fills or seals a separation area. In general, the electrode is more susceptible to the influence of the metal layer than the insulating film, and when the second metal layer provided on the second conductive side electrode is configured as described above in consideration of the influence on the electrode, a material different from that is used. This is because if the first metal layer is in contact with the second conductive side electrode, an unintended influence may occur on the second conductive side electrode. In addition to the first and second metal layers, a continuous layer made of a metal material or an alloy material may be further provided, thereby filling or sealing the separated region. When this continuous layer is in contact with the second conductive side electrode, it is preferable to select a material in consideration of the influence on the second conductive side electrode, similarly to the second metal layer.

  Further, in the semiconductor light emitting device, if the distance between the first conductive side electrode 5 and the insulating film 12a and the distance between the second conductive side electrode 7 and the insulating film 12b are too wide, the portion where the separation region is provided. Since the light extraction efficiency in the case becomes worse, it is separated by about 10 μm or less, and is separated by about 1 μm to 10 μm in that the effect of the separation can be stably obtained. The separation region is formed when the first conductive semiconductor layer 2 is formed of an n-type semiconductor and the second conductive semiconductor layer 3 is formed of a p-type semiconductor, that is, a p-side electrode (second conductive side). The electrode material such as Ag constituting the electrode 7) is transferred to the n-side electrode (first conductive side electrode 6) through the insulating film 12b and the insulating film 12c connecting the insulating film 12b and the insulating film 12a. From the viewpoint of preventing this, between the insulating film 12b disposed surrounded by the p-side electrode (second conductive side electrode 7) and the p-side electrode (second conductive side electrode 7) (FIG. 1 paper surface). It is not necessarily provided between the middle insulating film and the second conductive side electrode).

  The second conductive side electrode 7 is formed of Ag, Al, Ti, Pt, Rh or the like. In particular, in the light emitting element, it may be composed of a metal material that reflects light such as Ag, Al, Ag, Rh, This is effective for improving the light extraction efficiency. For example, the second conductive side electrode 7 has a total film thickness in the order of Ag layer (100 nm) / Ni layer (100 nm) / Ti layer (100 nm) / Pt layer (100 nm) from the second conductive type semiconductor layer 3 side. Is formed with a 400-layer four-layer structure. At this time, by providing the Ag layer in the second conductivity type semiconductor layer 3, the light emitted from the light emitting layer 4 can be efficiently reflected.

  As described above, when the second conductive side electrode 7 contains Ag, the second metal layer 9 has a higher melting point on the second conductive side electrode 7 side than Ti, Au, Sn, and Pd, and is stable. It is preferable to contain high Ru, Rh, Os, Ir, and Pt. In particular, when the second conductive side electrode 7 contains Ag, if Ti or W is contained on the side in contact with such an electrode, the second conductive side electrode 7 and the second conductive side electrode 7 may There is a tendency that the ohmic characteristics between the two-conductivity type semiconductor layer 3 deteriorate and the forward voltage of the element increases. For this reason, Ru, Rh, Os, Ir, Pt, and Mo are preferably disposed on the side in contact with the second conductive side electrode 7. Moreover, materials other than those described above may be included between such a material and the second conductive side electrode 7. Most preferably, the second metal layer 9 is made of Ru, Rh, Os, Ir, Pt, and Mo and is in contact with the second conductive side electrode 7.

  When the first conductive side electrode 6 and the second conductive side electrode 7 are formed of Ag, Al or the like, the second conductive side electrode 7 and the insulating film 12b are interposed via the separation regions 13a and 13b. Further, by separating the first conductive side electrode 6 and the insulating film 12a, it is possible to prevent element leakage and destruction due to migration of these metals, which is effective. In particular, when the second conductive side electrode 7 is formed of Ag having a high reflectance, it is effective because it can prevent element leakage and destruction due to migration.

  In addition, the first conductive side electrode 6 and the second conductive side electrode 7 include the first conductive side electrode and the second conductive side electrode in a plan view of the semiconductor stacked portion 5 with the semiconductor stacked portion 5 interposed therebetween. Are arranged so as not to overlap each other. That is, the first conductive side electrodes and the second conductive side electrodes are alternately arranged in a plan view of the semiconductor stacked portion 5. As described above, by arranging the first conductive side electrode 6 and the second conductive side electrode, the current flowing between the first conductive side electrode 6 and the second conductive side electrode 7 is transmitted in the semiconductor stacked portion 5. Can flow relatively uniformly in the semiconductor stacked portion 5, so that element destruction due to excessive current concentration can be prevented. In the light emitting device as shown in FIG. 1, the light emitting layer 4 emits light relatively uniformly, which is preferable in terms of light extraction efficiency. Further, the first conductive side electrode 6 and the second conductive side electrode 7 are configured such that the area of the second conductive side electrode is larger than the area of the first conductive side electrode when the semiconductor stacked portion 5 is viewed in plan view. Is formed. As a result, the area of the current injection region can be increased, the light emission efficiency of the light emitting element is improved, the heat dissipation of heat by driving the element is improved, and the heat dissipation of the semiconductor element 1 is improved. This is particularly effective when the second conductive side electrode is disposed on the mounting side.

Furthermore, the insulating films 12a and 12b are formed of an insulating material such as SiO ₂ , SiN, Al ₂ O ₃ , ZnO, or ZrO ₂ . Alternatively, an insulating film of niobium oxide, tantalum oxide, or titanium oxide can be used. Further, in the light emitting element, the insulating film 12b is composed of two or more kinds of multilayer films, and the film thickness of each film constituting the multilayer film is also reflected in the insulating film 12b so that the light from the light emitting layer 4 is reflected. May be set. The material of the first metal layer 8 provided on the insulating film 12b can be selected in consideration of the material of the insulating film 12b. For example, if the insulating film 12b is SiO ₂ , SiN, Nb ₂ O ₅ , if the first metal layer 8 is a metal layer containing Ti or Ni on the side in contact with the insulating film 12b, the adhesiveness is high and it is difficult to peel off. Can be. Further, the side of the first metal layer 8 in contact with the insulating film 12b may contain an element common to the insulating film 12b. For example, Nb when the insulating film 12b is niobium oxide and Ta when the insulating film 12b is tantalum oxide. Is preferably included on the insulating film 12b side.

  The insulating films 12a and 12b are preferably formed to have the same thickness as the second conductive side electrode 7, for example. In particular, the insulating film 12b is formed to have the same film thickness as the second conductive side electrode 7. When the insulating film 12b is bonded to the bonding substrate 10 via the bonding layer such as the second metal layer 9, the insulating film 12b is bonded to the insulating film 12b. Since it can suppress that a void (cavity) arises between a layer and between the 2nd electroconductive side electrode 7 and a joining layer, it is preferable. In the structure in which the second metal layer 9 covers the first metal layer 8 as shown in FIG. 1, the total film thickness of the insulating film 12 b and the first metal layer 8 is the same as the film thickness of the second conductive side electrode 7. If formed so as to have a degree, generation of cavities can be further suppressed.

  In the semiconductor element 1, the second conductive side electrode 7 is disposed so as to be separated from the insulating film 12 b via the separation region 13. As a result, from the electrode that is in a high temperature state during the operation light emission of the semiconductor light emitting element 1, through the crack or chip of the insulating film that is likely to be formed due to the thermal expansion due to the heat treatment at the high temperature at the time of bonding or mounting, Ag or Al Migration may be prevented, and element leakage and destruction may be prevented. In addition, since problems due to migration can be prevented, Ag, Al, or the like that easily causes migration can be used as the electrode material. In the light-emitting element, the electrode made of Ag, Al, or the like can be used as the electrode material. Therefore, high light extraction efficiency can be obtained. In particular, when the second conductivity type semiconductor layer 3 is composed of a p-type semiconductor, an electrode material constituting the second conductivity side electrode 7 serving as the p side electrode, for example, Ag is transferred via the insulating film 12b by migration. This is effective to prevent the element from leaking or being destroyed by shifting to the first conductive side electrode 6. Further, by providing such a separation structure on the side of the second conductive side electrode 7 having a large surface area, no leakage or destruction of the element is caused, and light is suitably reflected by the second conductive side electrode 7. Thus, a semiconductor light emitting device having excellent light extraction efficiency can be obtained, which is effective. Furthermore, since the area of the second conductive side electrode 7 is large, the area of the current injection region can be increased, heat dissipation due to driving of the element is improved, and light emission efficiency is improved in the light emitting element.

Next, the electrodes (first conductive side electrode 6, second conductive side electrode 7) 21, insulating film 22 (11a, 11b), first metal layer 24 (8), and second metal in the semiconductor element 1 An embodiment of the arrangement of the layer 25 (9) will be described.
2A and 2B are schematic plan views showing examples of arrangement of the electrode 21 and the insulating film 22, and FIGS. 3A to 3E show the electrode 21, the insulating film 22, the first metal layer 24, 3 is a schematic cross-sectional view showing an example of arrangement of a second metal layer 25. FIG.

  In the arrangement example shown in FIG. 2A, the electrode 21 and the insulating film 22 are disposed so as to surround the electrode 21, as shown in FIG. This is an example of being spaced apart via a spacing region 23. Further, in the arrangement example shown in FIG. 2B, the insulating film 22a is surrounded by the electrode 21 via the separation region 23a, and further, the outside is surrounded by the insulation film 22b via the separation region 23b. This is an example. In this arrangement example, the insulating film 22a and the electrode 21 are spaced apart via a separation region 23a, and the electrode 21 and the insulating film 22b are spaced apart via a separation region 23b. Corresponding to the insulating film 22b and the electrode 21, the first and second metal layers can be provided.

  In the arrangement example shown in FIG. 3A, the electrode 21 and the insulating film 22 are spaced apart from each other via the separation region 23 on the semiconductor stacked portion 26, and the first metal is disposed on the insulating film 22. In this example, the layer 24 is provided, and the separation region 23 is filled with the constituent material of the second metal layer 25 formed on the electrode 21 and the first metal layer 24.

  In the arrangement example shown in FIG. 3B, the electrode 21 and the insulating film 22 are spaced apart from each other via the separation region 23 on the semiconductor stacked portion 26, and the first metal is disposed on the insulating film 22. This is an example in which the layer 24 is provided and the gap region 23 is not filled with the constituent material of the second metal layer 25 formed on the electrode 21 and the first metal layer 24, and a gap is formed.

  In the arrangement example shown in FIGS. 3C and 3D, the electrodes 21 and the insulating layers 22 are alternately arranged on the semiconductor stacked portion 26, and there is no gap between the electrodes 21 and the insulating layers 22. This is an example in which a separation area 23 is provided. Further, in the arrangement example shown in FIG. 3C, the first metal layer 24 and the second metal layer 25 are separated from each other. In the arrangement example shown in FIG. The metal layer 25 is covered with a third metal layer 27. Thus, when the first metal layer 24 and the second metal layer 25 are provided apart from each other, the third metal layer 27 can be used as a bonding layer.

  In the arrangement example shown in FIG. 3 (e), the electrode 21 and the insulating film 22 are arranged on the semiconductor stacked portion 26 so as to be separated via a separation region 23, and the insulating film 22 is arranged on the insulating film 22. The first metal layer 24 is provided so as to cover the side surfaces of the first metal layer 24, and the separation region 23 is filled with the constituent material of the second metal layer 25 formed on the electrode 21 and the first metal layer 24. This is an example. Thus, since the electrode 21 and the insulating film 22 are spaced apart from each other, even if the first metal layer 24 is formed so as to cover not only the upper surface of the insulating film 22 but also the side surfaces, the first metal layer 24 is formed. Can be separated from the electrode 21.

  4A to 4C show an embodiment of an arrangement example of electrodes (first conductive side electrode 6 and second conductive side electrode 7) and insulating films (11a, 11b) in the semiconductor light emitting device. It is a plane schematic diagram to show. Corresponding to such insulating films and electrodes, the first and second metal layers can be provided.

The arrangement example shown in FIG. 4A includes insulating films 42a and 42b composed of circular circular head portions 43a and 43b and rectangular portions 44a and 44b connected to the circular head portions 43a and 43b, and insulation thereof. Membrane 42
In this example, an electrode 41 is provided so as to surround a and b, and an insulating film 46 is provided so as to surround the electrode 41. In the two insulating films 42a and 42b, circular head portions 43a and 43b and rectangular portions 44a and 44b are arranged in parallel on the same side. The insulating films 42a and 42b and the electrode 41 are provided apart via a separation region 45a, and the electrode 41 and the insulating film 46 are provided separately via a separation region 45b.

  In the arrangement example shown in FIG. 4B, the insulating films 42a and 42b including circular circular heads 43a and 43b and rectangular portions 44a and 44b connected to the circular heads 43a and 43b The portions 43a and 43b and the rectangular portions 44a and 44b are arranged so as to be opposite to each other, the electrode 41 is provided surrounding the insulating films 42a and 42b, and the insulating film 46 is provided surrounding the electrode 41. This is an example. The insulating films 42a and 42b are provided apart via a separation region 45a, and the electrode 41 and the insulating film 46 are provided separately via a separation region 45b.

The arrangement example shown in FIG. 4C includes insulating films 42a and 42b composed of circular circular head portions 43a and 43b and rectangular portions 44a and 44b connected to the circular head portions 43a and 43b, and insulation thereof. Membrane 42
In this example, an electrode 41 is provided so as to surround a and b, and an insulating film 464 is provided so as to surround the electrode 41. In the two insulating films 42a and 42b, the circular heads 43a and 43b and the rectangular parts 44a and 44b are arranged in parallel on the same side, and further, the circular head 43a of the insulating film 42a,
The circular head portion 43 b of the insulating film 42 b is in communication with the connecting portion 47. The insulating films 42a and 42b and the electrode 41 are provided apart via a separation region 45a, and the electrode 41 and the insulating film 46 are provided separately via a separation region 45b.

FIG. 5 is a schematic plan view showing another specific example of the arrangement of electrodes and insulating films in the semiconductor element of the present invention.
The semiconductor element 51 is a semiconductor light-emitting element, and is disposed so as to be opposed to the left and right with the second conductive side electrode 53 having a large area occupying the center of a rectangular plane and the second conductive side electrode 53 interposed therebetween. It has six first conductive side electrodes 52 and an insulating film 54 disposed between the second conductive side electrodes 52 and the second conductive side electrodes. In the semiconductor element 51, the second conductive side electrode 53 and the insulating film 54 are spaced apart via a separation region 55 formed of a gap. Such an insulating film 54 and the second conductive side electrode 53 are disposed. Corresponding to the first and second metal layers are provided.

  In the semiconductor element 51, when the electrodes are arranged and mounted on the mounting surface side (face-down mounting), the first and second electrodes are placed on the second conductive side electrode 53, the insulating film 54, and the first conductive side electrode 52. An element structure can be configured by laminating a metallized layer including a metal layer and bonding the metallized layer to the bonding substrate via the metallized layer. At this time, since the second conductive side electrode 53 and the insulating film 54 are spaced apart from each other through a separation region 55 formed of a gap, the second conductive side electrode 53 is formed by a heat treatment or the like during bonding. It is possible to prevent migration of Ag and Al constituting the layer, to prevent current leakage and destruction of the insulating film 54, and to reflect light from the semiconductor light-emitting portion satisfactorily by the electrode, so that high light extraction efficiency is achieved. It is effective to obtain. The first conductive side electrode 6 and the second conductive side electrode 7 are formed such that the area of the second conductive side electrode is larger than the area of the first conductive side electrode. As a result, the area of the current injection region can be increased, the light emission efficiency is improved, the heat dissipation of heat by light emission is also improved, and the heat dissipation of the semiconductor light emitting element 1 is improved. In face-down mounting, the semiconductor light-emitting element 51 is bonded to a bonding substrate, so that the first conductive side electrode 52, the insulating film 54, and the first conductive layer are formed by a metallized layer that is a continuous layer made of a metal material or an alloy material. The metallized layer is disposed on the second conductive side electrode, and the separation region 54 forms a sealed space between the insulating film 54 and the second conductive side electrode and the metallized layer.

Next, a method for manufacturing a semiconductor element of the present invention (hereinafter referred to as “method of the present invention”) will be described.
The semiconductor element of the present invention can be manufactured by a method including the following main steps 1 to 4.
(1) Step 1 of forming a semiconductor stacked portion having a first conductivity type semiconductor layer and a second conductivity type semiconductor layer
(2) Step 2 of forming a first conductive side electrode connected to the first conductive type semiconductor layer
(3) Step 3 of forming a second conductive side electrode connected to the second conductive type semiconductor layer
(4) Step 4 of forming an insulating film that is separated from at least one of the first conductive side electrode and the second conductive side electrode via a separation region and covers the semiconductor stacked portion.
(5) A first metal layer is formed on the insulating film, and at least one of the first conductive side electrode and the second conductive side electrode separated from the insulating film is different from the first metal layer. Step 5 of forming a second metal layer of material
The method for producing the element of the present invention is not limited to the above-described steps, and other steps can be performed as necessary. For example, in addition to these steps (1) to (5), a substrate cleaning step, a heat treatment step, and the like can be performed as the preceding step, the intermediate step, or the subsequent step of the above (1) to (5). Furthermore, in the method of the present invention, the order in which the steps 2, 3 and 4 are performed in the steps 1 to 4 is not particularly limited, and is appropriately selected according to the structure and mounting form of the semiconductor element to be manufactured.

6 (a) to 6 (f) and FIGS. 7 (a) to 7 (d) sequentially explain main steps 1 to 4 of the method for manufacturing a nitride semiconductor light emitting device as a method for manufacturing a semiconductor device of the present invention. It is a cross-sectional schematic diagram to do.
Step 1 of forming a semiconductor light emitting part having a first conductive type semiconductor layer, a second conductive type semiconductor layer, and a light emitting layer interposed between the first conductive type semiconductor layer and the second conductive type semiconductor layer includes: 6A, on the sapphire substrate 61, the first conductive type semiconductor layer, the light emitting layer, and the second conductive type semiconductor layer are formed in this order to form a semiconductor stacked portion 65 that is a semiconductor light emitting portion. Can be performed. The semiconductor laminated portion 65 is formed by supplying a gas containing a required semiconductor material, a dopant, and the like to the upper surface of the cleaned sapphire substrate 61 so that MOVPE (metal organic vapor phase epitaxy), HVPE (halide vapor phase) is supplied. (Growth method), MBE (molecular beam vapor phase epitaxy), MOMBE (organometallic molecular beam vapor phase epitaxy), and the like, can be performed by vapor phase growth. At this time, the gas to be supplied contains depending on the type of the conductive semiconductor layer to be formed, for example, the layer configuration and constituent materials of each layer of the n-type semiconductor layer, the p-type semiconductor layer, and the light-emitting layer, and the film thickness of the layer The semiconductor material and dopant component species, composition, and the like can be switched by supplying the sapphire substrate 61 using an inert gas such as nitrogen gas as a carrier gas.

Next, the step 3 of forming the second conductive side electrode 66 connected to the second conductive type semiconductor layer of the semiconductor light emitting unit 65 and the second conductive side electrode are separated from each other through the separation region, and the semiconductor light emitting unit 65 is covered. Step 4-1 for forming the insulating film 67 to be performed is performed. In Step 3 and Step 4-1, as shown in FIG. 6B, a photo corresponding to the second conductive side electrode 66 is formed on the upper surface of the second conductive type semiconductor layer of the semiconductor light emitting portion 65 using a resist. A second conductive side electrode 66 is formed by forming a mask and laminating an electrode material, for example, an electrode material containing Ag, by sputtering or the like. Thereafter, a photomask is formed on the second conductive side electrode 66 using a resist, and an insulating film material such as SiO ₂ is laminated by sputtering or the like, and then the resist is removed. As a result, as shown in FIG. 6C, a structure in which a gap 68 is disposed between the second conductive side electrode 66 and the insulating film 67 is formed.

In Step 3 and Step 4-1, an insulating film material such as SiO ₂ is stacked on the entire upper surface of the semiconductor light emitting portion 65, and then a photo corresponding to the insulating film 67 is formed on the insulating material film. It can also be performed by forming a mask, wet etching the portion corresponding to the second conductive side electrode 66, and laminating an electrode material on the etched portion by sputtering or the like to form the second conductive side electrode 66.

Next, as shown in FIG. 6D, a first metal layer 69 and a second metal layer 70 are formed on the insulating film 67 and the second conductive side electrode 66 as semiconductor side metallized layers, respectively. The second metal layer 70 is continuously formed up to the first metal layer 69, whereby the gap 68 between the insulating film 67 and the second conductive side electrode 66 is filled with the second metal layer 70, A separation region 71 that separates the insulating film 67 and the second conductive side electrode 66 is formed.
On the other hand, as shown in FIG. 6E, a Si substrate 72 is prepared, and a substrate-side metallized layer 73 is formed on the upper surface of the Si substrate 72. The substrate-side metallized layer 73 is a layer for bonding to the second metal layer 70.

  Next, as shown in FIG. 6F, the second metal layer 70, which is a semiconductor-side metallization layer, and the Si substrate-side metallization layer 73 are bonded together and heated at about 150 ° C. to 350 ° C. for bonding. As a result, a part of the second metal layer 70 and a part of the Si substrate-side metallized layer 73 form a eutectic, and the semiconductor laminate and the support substrate are bonded.

  Next, laser irradiation or polishing is performed from the side of the sapphire substrate 61 to remove the sapphire substrate 61 as shown in FIG. 6A and then expose the exposed semiconductor stack as shown in FIG. The portion 65 is chemically polished (CMP). Further, on the polished surface, the first conductive side electrode 73 and the second conductive side electrode 66 overlap each other in a plan view of the semiconductor stacked portion 65 at a portion facing the insulating film 67 across the semiconductor stacked portion 65. As shown in FIG. 6C, a mask is formed so that the first conductive side electrode 73 is formed, and electrode materials are laminated by sputtering or the like. Then, the first conductive side electrode 74 is formed. Here, the portion where the mask is provided, that is, the region where the first conductive side electrode 74 is not formed is drilled by RIE (reactive ion etching) to form a region where the first conductive side electrode 74 is not provided. By providing the region where the first conductive side electrode 74 is not provided, the light extraction is also improved. In particular, the light reflected by the second conductive side electrode 66 is efficiently extracted from this region. Furthermore, as shown in FIG. 6D, an insulating film 75 is formed on the surface of the first conductive side electrode 74 where the semiconductor laminated portion 65 is exposed, whereby the semiconductor element of the present invention can be obtained.

  Hereinafter, the present invention will be described in more detail by way of examples of the present invention, but the present invention is not limited to these examples.

Example 1
As Example 1, a semiconductor light emitting device having the structure shown in FIG. 1 is manufactured according to the following specifications.
Semiconductor laminated portion 5: Gallium nitride semiconductor p-electrode (second conductive side electrode 7): Ag (100 nm) / Ni (100 nm) / Ti (100 nm) / Pt (100 nm)
Insulating film 12b: SiO ₂ (300 nm) film Distance between p-electrode (second conductive side electrode 7) and insulating film 11b: 5 μm
Bonding substrate 10: Si substrate First metal layer 8: Ti (50 nm) / Pt (50 nm)
Second metal layer 9: Pt (100 nm) / Ti (100 nm) / Pt (300 nm) / Au (300 nm) / Sn (3000 nm) / Au (100 nm)
Back surface metallized layer 11: Pt (250 nm) / Au (500 nm)

  Here, as a comparative example 1, when a semiconductor light emitting device manufactured without providing a separation region between the second conductive side electrode and the insulating film is observed with an optical microscope, the semiconductor light emitting device of the comparative example 1 has a second conductive property. Cracks can be confirmed in the insulating film in contact with the side electrode. On the other hand, in the semiconductor light emitting device obtained in Example 1 of the present invention, there is no crack in the insulating film spaced apart from the second conductive side electrode.

  Further, as Comparative Example 2, instead of the first metal layer 8 and the second metal layer 9, a metallized layer made of Ti (100 nm) / Pt (300 nm) / Au (300 nm) / Sn (3000 nm) / Au (100 nm) Is produced in the same manner as in Example 1 except that the p-electrode and the insulating film are continuously provided. With respect to the semiconductor light emitting devices of Comparative Example 2 and Example 1, the forward voltage is compared between the low temperature condition and the high temperature condition by changing the temperature at which the semiconductor laminated portion and the Si substrate are bonded. When the temperature difference between the low temperature condition and the high temperature condition was 30 ° C., in Comparative Example 2, the temperature was increased by about 0.12 V by using the high temperature condition. On the other hand, in the semiconductor light emitting device of Example 1 in which the metal layers made of different materials are formed on the insulating film and the p electrode, the forward voltage rise is about 0.06 V, which is forward compared to Comparative Example 2. The voltage rise was reduced to half. Further, the current is continuously supplied to the element, and the forward voltage before energization is compared with the forward voltage after lapse of 10,000 hours from energization. As a result, the semiconductor light-emitting device obtained in Example 1 has a smaller increase in forward voltage after energization than the semiconductor light-emitting device obtained in Comparative Example 2, and when a current of 550 mA is kept flowing at room temperature, The same forward voltage was maintained before and after 10000 hours.

(Example 2)
As the semiconductor light emitting device of Example 2, the second metal layer 9 is manufactured in the same manner as in Example 1 except that Pt (300 nm) / Au (300 nm) / Sn (3000 nm) / Au (100 nm).

(Examples 3 to 7)
As the semiconductor light-emitting elements of Examples 3 to 7, the first metal layer 8 is made of Ti (50 nm) / Rh (50 nm), Ti (50 nm) / Ir (50 nm), Ni (50 nm) / Pt (50 nm), respectively. It is manufactured in the same manner as in Example 1 except that Ni (50 nm) / Rh (50 nm) and Ni (50 nm) / Ir (50 nm).

(Examples 8 to 11)
As the semiconductor light emitting devices of Examples 8 to 11, the second metal layer 9 was made of Rh (300 nm) / Au (300 nm) / Sn (3000 nm) / Au (100 nm), Ru (300 nm) / Au (300 nm) / Sn (3000 nm) / Au (100 nm), Ir (300 nm) / Au (300 nm) / Sn (3000 nm) / Au (100 nm), Mo (30 nm) / Pt (300 nm) / Au (300 nm) / Sn (3000 nm) / It is manufactured in the same manner as in Example 1 except that Au (100 nm) is used.

Example 12
As the semiconductor light emitting device of Example 12, the p electrode (second conductive side electrode 7) is an electrode containing Al, and the second metal layer 9 is W (30 nm) / Pt (300 nm) / Au (300 nm) / Sn. It is produced in the same manner as in Example 1 except that (3000 nm) / Au (100 nm).

(Example 13)
A semiconductor light emitting device of Example 13 is manufactured in the same manner as in Example 1 except that the insulating film 12b is a SiN (300 nm) film.

(Example 14)
As a semiconductor light emitting device of Example 14, the same as Example 1 except that the insulating film 12b is an Nb ₂ O ₅ (300 nm) film and the first metal layer 8 is Nb (50 nm) / Pt (50 nm). Make it.

(Example 15)
As a semiconductor light emitting device of Example 15, the same procedure as in Example 1 was performed except that the insulating film 12b was a Ta ₂ O ₅ (300 nm) film and the first metal layer 8 was Ta (50 nm) / Pt (50 nm). Make it.

  In the semiconductor light emitting devices of Examples 2 to 15 obtained in this way, the insulating film is not cracked, and the forward voltage increase range can be suppressed as compared with Comparative Example 2.

It is a schematic cross section which shows the structure of the semiconductor element which concerns on embodiment of this invention. (A) And (b) is a plane schematic diagram which shows the example of arrangement | positioning of the electrode and insulating film in the semiconductor element of this invention. FIGS. 3A to 3E are schematic cross-sectional views showing examples of arrangement of electrodes and insulating films in the semiconductor element of the present invention, respectively. (A)-(c) is a plane schematic diagram which shows the example of arrangement | positioning of the electrode and insulating film in the semiconductor element of this invention, respectively. It is a plane schematic diagram which shows the other specific example of arrangement | positioning of the electrode and insulating film in the semiconductor element of this invention. (A)-(f) is a schematic cross section explaining the main process of the manufacturing method of a nitride semiconductor light-emitting device in order. (A)-(d) is a schematic cross section explaining the main process of the manufacturing method of a nitride semiconductor light-emitting device later on.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor element 2 1st conductivity type semiconductor layer 3 2nd conductivity type semiconductor layer 4 Light emitting layer 5 Semiconductor laminated part 6 1st conductivity side electrode 7 2nd conductivity side electrode 8 1st metal layer 9 2nd metal layer 10 Substrate 11 Back surface Metallized layer 12a, 12b Insulating film 13 Spacing region 21 Electrode 22, 22a, 22b Insulating film 23, 23a, 23b Spacing region 24 First metal layer 25 Second metal layer 26 Semiconductor stacked portion 27 Third metal layer 41 Electrode 42a, 42b , 46 Insulating films 45a, 45b Spaced region 51 Semiconductor element 52 First conductive side electrode 53 Second conductive side electrode 54 Insulating film 55 Spaced region 61 Sapphire substrate 65 Semiconductor stacked portion 66 Second conductive side electrode 67, 75 Insulating film 68 Spaced Region 69 First metal layer 70 Second metal layer 71 Spacing region 72 Si substrate 73 Substrate side metallization layer 74 First conductive side electrode

Claims (9)

A semiconductor stacked portion having a first conductive type semiconductor layer and a second conductive type semiconductor layer, a first conductive side electrode connected to the first conductive type semiconductor layer, and a first connected to the second conductive type semiconductor layer. A semiconductor element comprising two conductive side electrodes,
The second conductive side electrode and the insulating film covering the semiconductor stacked portion are disposed apart via a separation region,
A semiconductor element, wherein a first metal layer is provided on a surface of the insulating film, and a second metal layer made of a material different from the first metal layer is provided on a surface of the second conductive side electrode.   The semiconductor element according to claim 1, wherein the first metal layer is separated from the second conductive side electrode.   3. The semiconductor device according to claim 1, wherein the first metal layer includes one selected from Ti and Ni on a side in contact with the insulating film.   The said 2nd metal layer contains 1 type chosen from Ru, Rh, Os, Ir, Pt, W, and Mo in the side which contact | connects the said 2nd electroconductive side electrode. The semiconductor element according to any one of the above.   The said 2nd electroconductive side electrode side of the said semiconductor laminated part is adhere | attached on the support substrate through the said 2nd metal layer, The any one of Claims 1-4 characterized by the above-mentioned. Semiconductor element.   The second metal layer includes at least one selected from Ti, Au, Sn, and Pd on the support substrate side, and more on the second conductive side electrode side than Ru, Rh, Os, Ir, Pt, The semiconductor element according to claim 5, comprising one type selected from W and Mo.   The second conductive side electrode includes one kind selected from Ag and Al, and the second conductive side electrode is surrounded by the insulating film in a plan view of the semiconductor stacked portion. The semiconductor device according to claim 1.   The said 2nd metal layer is a continuous layer which continues to the said 1st metal layer, The space | gap or the said continuous layer is provided in the said isolation | separation area | region, The any one of Claims 1-7 characterized by the above-mentioned. 2. The semiconductor element according to item 1.   The first conductive side electrode and the second conductive side electrode are opposed to each other with the semiconductor stacked portion interposed therebetween, and the semiconductor stacked portion is between the first conductive type semiconductor layer and the second conductive type semiconductor layer. The semiconductor element according to claim 1, wherein the semiconductor element has a light emitting layer interposed in the semiconductor light emitting portion.

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