WO2014107955A1 - 一种发光二极管及其制造方法 - Google Patents
一种发光二极管及其制造方法 Download PDFInfo
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- WO2014107955A1 WO2014107955A1 PCT/CN2013/081145 CN2013081145W WO2014107955A1 WO 2014107955 A1 WO2014107955 A1 WO 2014107955A1 CN 2013081145 W CN2013081145 W CN 2013081145W WO 2014107955 A1 WO2014107955 A1 WO 2014107955A1
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- electrode
- layer
- light emitting
- sapphire substrate
- emitting diode
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Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers 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 having potential barriers 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 having potential barriers 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
- H01L33/382—Semiconductor devices having potential barriers 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 the electrode extending partially in or entirely through the semiconductor body
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/005—Processes
- H01L33/0093—Wafer bonding; Removal of the growth substrate
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/48—Semiconductor devices having potential barriers 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 body packages
- H01L33/64—Heat extraction or cooling elements
- H01L33/647—Heat extraction or cooling elements the elements conducting electric current to or from the semiconductor body
-
- 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 having potential barriers 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 having potential barriers 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
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/44—Semiconductor devices having potential barriers 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 coatings, e.g. passivation layer or anti-reflective coating
Definitions
- the invention belongs to the field of semiconductor illumination, and in particular relates to a light emitting diode and a manufacturing method thereof. Background technique
- semiconductor lighting As a new high-efficiency solid-state light source, semiconductor lighting has significant advantages such as long life, energy saving, environmental protection and safety. It will become another leap after the incandescent lamp and fluorescent lamp in the history of human lighting. Its application field is rapidly expanding, which is driving traditional lighting and display. The upgrading of the industry and other industries has huge economic and social benefits. For this reason, semiconductor lighting is widely regarded as one of the most promising emerging industries in the 21st century, and one of the most important commanding heights in the field of optoelectronics in the next few years.
- LEDs are made of III-IV compounds, such as GaAs (gallium arsenide), GaP (gallium phosphide), GaAsP (phosphorus gallium arsenide), and their core is the PN junction. Therefore, it has the I-N characteristics of a general P-N junction, that is, forward conduction, reverse cutoff, and breakdown characteristics. In addition, it has luminescent properties under certain conditions. At the forward voltage, electrons are injected into the P region from the N region, and holes are injected into the N region from the P region. A minority carrier (small child) entering the other region is combined with a majority carrier (multiple) to emit light.
- III-IV compounds such as GaAs (gallium arsenide), GaP (gallium phosphide), GaAsP (phosphorus gallium arsenide)
- GaN-based LED packages mainly include three types: a front-mounted structure, a flip-chip structure, and a vertical structure.
- the more mature one is the III-type nitride gallium nitride sapphire material as the substrate. Due to the insulation of the sapphire substrate, the common GaN-based LED adopts a formal structure. Light emitted from the active region of the positive structure is emitted through the P-type GaN region and the transparent electrode. The structure is simple and the production process is relatively mature.
- the LED of the formal structure has two obvious disadvantages. First, the LEDs of the positive-fit structure are placed on the same side of the LED. The current must flow laterally through the n-GaN layer, causing current crowding and high local heat generation, which limits the driving current. Due to the poor thermal conductivity of the sapphire substrate, the heat loss is seriously hindered.
- Lumileds Lighting Company of the United States invented Flipchip technology.
- a large-sized LED chip having a suitable eutectic soldering is first prepared, and a silicon substrate of a corresponding size is prepared, and a gold conductive layer of the eutectic soldering electrode and a conductive layer (ultrasonic gold ball solder joint) are formed thereon.
- the large-sized LED chip is soldered to the silicon substrate using a eutectic soldering apparatus.
- the installation structure has greatly improved the heat dissipation effect.
- the existing flip-chip structure is usually fixed in a silicon substrate by soldering, which tends to introduce more thermal resistance and reduce the heat dissipation efficiency of the LED chip.
- the P electrode and the N electrode are usually prepared on the same side of the LED chip, which tends to increase the difficulty of the flip-chip bonding process and the lead process, and it is difficult to achieve wafer level manufacturing, which is likely to cause product yield. reduce.
- the invention provides a novel wafer-level flip-chip LED chip structure, which can effectively improve the heat dissipation efficiency of the LED chip, simultaneously reduce the difficulty of the process and improve the yield of the product. Summary of the invention
- an object of the present invention is to provide a light emitting diode and a manufacturing method thereof for solving the problem that the flip chip LED chip in the prior art is difficult to realize wafer level manufacturing, and the heat dissipation efficiency is not high enough. More complex, costly, and lower yields.
- the present invention provides a light emitting diode, the light emitting diode comprising at least:
- thermally conductive substrate having a P electrode bonded to the lower surface and a bonding layer bonded to the upper surface;
- a light emitting epitaxial structure coupled to the mirror, comprising a P-type layer, a quantum well layer and an N-type layer which are sequentially stacked;
- An N electrode electrically connecting the N-type layer to the surface of the sapphire substrate by the contact region; and a passivation layer filling between the N electrode and the bonding layer in the contact region.
- the contact region is a hole-like structure or a groove-like structure.
- a portion of the P-type layer, the quantum well layer and the N-type layer are removed from the contact region to form an N-electrode preparation platform.
- connection surface of the N electrode preparation platform and the sapphire substrate is perpendicular to the surface of the sapphire substrate.
- a portion of the contact region in the sapphire substrate is a tapered hole or a V-shaped groove, and a connection surface of the N electrode preparation platform and the sapphire substrate is used. It is a bevel.
- the N electrode includes a surface of the N-electrode preparation platform, covering the oblique surface And a first electrode covering the surface of the tapered hole or the V-shaped groove and a second electrode coupled to the light-emitting surface of the sapphire substrate and connected to the first electrode.
- connection surface of the N electrode preparation platform and the sapphire substrate is a slope.
- the N electrode includes a first electrode bonded to the surface of the N electrode preparation platform and spanning the contact region, and filled in the sapphire substrate and The first electrode is coupled to a second electrode of the light exiting surface of the sapphire substrate.
- the P-type layer surface is further combined with a current spreading layer.
- the light exiting surface of the sapphire substrate has a roughened microstructure.
- the invention also provides a method for manufacturing a light emitting diode, comprising the following steps:
- a light-emitting epitaxial structure including at least an N-type layer, a quantum well layer, and a P-type layer on the surface of the sapphire substrate;
- thermally conductive substrate having a P electrode on the surface, and bonding the thermally conductive conductive substrate and the mirror and the passivation layer through a bonding layer;
- the step 4 ) further includes the step of forming a current spreading layer on the surface of the P-type layer.
- the groove structure is tapered Hole, or V-groove.
- step 3) further comprises the step of etching the connecting surface of the N electrode preparation platform and the sapphire substrate into a slope.
- the step 5) further includes the step of forming a plurality of apertured structures in the mirror.
- the step 8) further comprises the step of roughening the surface of the sapphire substrate to form a roughened microstructure.
- the invention also provides a method for manufacturing a light emitting diode, comprising the following steps:
- a light-emitting epitaxial structure including at least an N-type layer, a quantum well layer, and a P-type layer on the surface of the sapphire substrate;
- the step 5) further includes the step of forming a current spreading layer on the surface of the P-type layer.
- the groove structure is a tapered hole or a V-shaped groove.
- the step 3 ) further comprises the step of etching the connection surface of the N electrode preparation platform and the sapphire substrate into a slope.
- the present invention provides a light emitting diode and a method of fabricating the same, comprising: a thermally conductive conductive substrate having upper and lower surfaces respectively having a bonding layer and a P electrode; a mirror; an epitaxial structure comprising a stacked P-type layer and a quantum well a layer and an N-type layer; a sapphire substrate bonded to the light-emitting epitaxial structure; a contact region penetrating from the sapphire substrate to the bonding layer; an N electrode, the N-type layer being formed by the contact region Electrically connected to the surface of the sapphire substrate; a passivation layer filled in the contact region.
- the invention provides a novel flip-chip LED structure, which realizes the manufacture of a flip-chip LED chip by a wafer level bonding process, and directly bonds the LED chip to the heat conductive conductive substrate, thereby greatly improving the LED chip.
- Heat dissipation efficiency; the groove structure is formed in the sapphire substrate, and then the N electrode is exposed by thinning to avoid defects such as debris in subsequent processing, which reduces the difficulty of the process and effectively improves the yield of the product.
- Fig. 1 is a view showing the structure of a light emitting diode according to a first embodiment of the present invention.
- FIGS. 2 to 15 are views showing the structure of each step of the method for fabricating a light emitting diode according to Embodiment 2 of the present invention.
- Fig. 16 is a view showing the structure of a light emitting diode in Embodiment 3 of the present invention.
- Figure 17 is a diagram showing the structure of a light emitting diode in Embodiment 5 of the present invention.
- 18 to 33 are views showing the structure of each step of the method of manufacturing the light emitting diode according to Embodiment 6 of the present invention.
- Figure 34 is a view showing the structure of a light-emitting diode in Embodiment 7 of the present invention. Component label description
- the embodiment provides a light emitting diode
- the light emitting diode includes at least: a thermally conductive conductive substrate 112, a lower surface of which is coupled with a P electrode 113, and an upper surface is bonded with a bonding layer 111; a mirror 108, Bonded to the bonding layer 111;
- the light emitting epitaxial structure is coupled to the mirror 108, and includes a P-type layer 105, a quantum well layer 104 and an N-type layer 103 which are sequentially stacked;
- a sapphire substrate 101 coupled to the light emitting epitaxial structure
- the N electrodes 109 and 115 electrically connect the N-type layer 103 to the surface of the sapphire substrate 101 by the contact region;
- the passivation layer 110 is filled between the N electrode and the bonding layer 111 in the contact region.
- the thermally conductive conductive substrate 112 may be a silicon substrate, a metal substrate, a composite substrate of silicon and metal, and the metal substrate includes Al, Cu, Ti, Sn, Ni, or the like, or an alloy thereof.
- the thermally conductive substrate 112 is a silicon substrate.
- the thermally conductive substrate 112 can be any desired substrate material that ensures good thermal and electrical conductivity.
- the contact region is a hole-like structure or a groove-like structure.
- the contact region includes a tapered hole or a V-shaped groove penetrating through the sapphire substrate 101, and is located in the tapered hole or An electrode preparation region portion under the V-shaped groove, the electrode preparation region portion generally including a through hole up to the bonding layer 111 and an N electrode preparation platform 106 on both sides of the via hole, that is, the portion in the contact region is removed
- the N-electrode preparation platform 106 formed by the P-type layer 105, the quantum well layer 104, and the N-type layer 103.
- connection surface of the N electrode preparation platform 106 and the sapphire substrate 101 is a slope, and the angle between the slope and the surface of the sapphire substrate 101 is greater than 0° and less than 90°, in the embodiment, the angle between the slope and the surface of the sapphire substrate 101 is 30° to 60°.
- the main function of the contact region is to form an N electrode, that is, the N-type layer 103 is electrically connected to the surface of the sapphire substrate 101.
- the N electrode includes a bonding to the N electrode. Forming a surface of the platform 106, covering the inclined surface, and covering the tapered electrode or the V-groove surface of the sapphire substrate 101, and bonding to the light-emitting surface of the sapphire substrate 101 and connecting to the surface
- the second electrode 115 of the first electrode 109 is described.
- the passivation layer 110 is used for filling.
- the passivation layer 110 is insulated by silicon oxide, titanium oxide or titanium nitride. material.
- the first function of the passivation layer 110 is to insulate the first electrode 109 on the N electrode preparation platform 106 from other luminescent epitaxial layers (the quantum well and the P-type layer 105).
- the second function is The first electrode 109 and the second electrode 115 function as supports to ensure the stability of the electrode and prevent it from falling off or breaking, which can greatly improve the stability and life of the LED chip.
- the surface of the P-type layer 105 is further combined with a current spreading layer 107.
- the current spreading layer 107 includes ITO, A TO, and FTO. Or AZO's transparent conductive layer.
- the current spreading layer 107 is located on the other side of the light emitting surface, so it is not limited to a transparent material, and metal materials such as Pt, Au, Ag, Ti, and W may also be used. It is not limited to the ones listed here.
- the mirror 108 can be designed as a planar mirror 108 or a mirror 108 having a hole-like structure as required.
- the square structure may be, for example, a square matrix Column holes, hexagonal arrays, or other arrangements of circular holes, elliptical holes, polygonal holes, or rounded polygonal holes.
- the mirror is a conductive mirror, and includes a Bragg mirror, an Ag mirror, an A1 mirror, and an ITO/Ag composite mirror;
- the mirror is not required to be electrically conductive, and the mirror may include a Bragg mirror, an Ag mirror, an A1 mirror, an ITO/Ag composite mirror, and a dielectric/metal composite mirror.
- the mirror may include a Bragg mirror, an Ag mirror, an A1 mirror, an ITO/Ag composite mirror, and a dielectric/metal composite mirror.
- mirrors listed herein are only preferred, and in other embodiments, all contemplated reflective materials may be employed as the mirrors of the present invention.
- the N-type layer 103 is an N-GaN layer
- the quantum well layer 104 is an InGaN/G aN multiple quantum well layer
- the P-type layer 105 is a P-GaN layer.
- the light-emitting epitaxial structure may employ a light-emitting epitaxial structure such as a GaAs-based or GaP-based structure, and is not limited to the ones listed herein.
- the bonding layer 111 is an Au or Au/Sn alloy.
- the light-emitting surface of the sapphire substrate 101 has a roughened microstructure 114.
- the roughened microstructures 114 include triangular pyramidal projections, quadrangular pyramidal projections, conical projections, rounded projections, and the like arranged in an ordered or disordered manner.
- the light-emitting diode provided in this embodiment has a simple structure, and only needs to bond the light-emitting structure to the heat-conductive conductive substrate through a bonding layer, thereby improving the heat dissipation efficiency of the chip, and the invention can improve the light-emitting efficiency of the light-emitting diode. Improve product life, reduce production costs, and increase product yield.
- Example 2
- This embodiment provides a method for manufacturing a light emitting diode, including the following steps:
- step 1) is first performed to provide a sapphire substrate 101, and a plurality of light emitting unit regions are defined, and at least one groove structure 102 is etched in each of the light emitting unit regions.
- a plurality of light-emitting units are defined in the wafer-level sapphire substrate 101, and then a photoresist pattern is formed on the surface thereof, and then the surface of the sapphire substrate 101 is engraved by inductively coupled plasma ICP etching.
- the groove structure 102 is etched out.
- the groove structure 102 is a tapered hole or a V-shaped groove.
- the groove structure 102 may also be a cylindrical hole structure, a circle.
- the stage structure, the groove-like structure having a trapezoidal cross section, the groove-like structure having a rectangular cross section, and the like are not limited to the ones listed herein.
- the manufacturing process of one light-emitting unit will be described below as an example.
- step 2) is followed to form a light-emitting epitaxial structure including at least an N-type layer 103, a quantum well layer 104, and a P-type layer 105 on the surface of the sapphire substrate 101;
- the N-type layer 103, the quantum well layer 104, and the P-type layer 105 are formed by a chemical vapor deposition method, wherein the N-type layer 103 is an N-GaN layer, and the quantum well layer 104 is An InGaN/GaN multiple quantum well layer, the P-type layer 105 being a P-GaN layer.
- the light-emitting epitaxial structure may employ a light-emitting epitaxial structure such as a GaAs-based or GaP-based structure, and is not limited to the ones listed herein.
- step 3 is then performed to etch the P-type layer 105, the quantum well layer 104, and a portion of the N-type layer 103 on both sides of the recess structure 102 to form an N-electrode preparation platform 106.
- the N-electrode preparation platform 106 and the groove structure 102 are simultaneously etched while the N-type preparation stage 106 is etched.
- the connecting surface 117 is etched into a bevel, which can greatly improve the reliability of the subsequent electrode preparation and the integrity of the electrode.
- a current spreading layer 107 is then formed on the surface of the P-type layer 105, and the current spreading layer 107 is a transparent conductive layer including ITO, ATO, FTO or AZO.
- the current spreading layer 107 is located on the other side of the light-emitting surface, so it is not limited to a transparent material, and metals such as Pt, Au, Ag, Ti, and W may also be used. The materials are not limited to the ones listed here.
- step 4) to make a mirror 108
- the mirror 108 can be designed as a planar mirror or a mirror having a hole-like structure as required.
- the hole-like structure may be a circular hole, an elliptical hole, a polygonal hole or a rounded polygonal hole arranged in a square array arrangement, a hexagonal array arrangement or the like.
- the mirror is a conductive mirror, and includes a Bragg mirror, an Ag mirror, an A1 mirror, and an ITO/Ag composite mirror;
- the mirror is not required to be electrically conductive, and the mirror may include a Bragg mirror, an Ag mirror, an A1 mirror, an ITO/Ag composite mirror, and a dielectric/metal composite mirror.
- the mirror may include a Bragg mirror, an Ag mirror, an A1 mirror, an ITO/Ag composite mirror, and a dielectric/metal composite mirror.
- mirrors listed here are only preferred, and in other embodiments, All contemplated reflective materials are used as mirrors of the present invention.
- step 5 forming a first electrode 109 in the N electrode preparation platform 106 and the recess structure 102;
- the groove structure 102 is a tapered hole or a V-shaped groove
- the connecting surface 117 of the N-electrode preparation platform 106 and the groove structure 102 is a sloped surface, and is deposited by plating or deposition.
- the first electrode 109 is formed in the N electrode preparation platform 106, the bevel and the groove structure 102.
- the material of the first electrode 109 may be Ti, Al, Ag, Pt, Au, W, Ni or the like.
- step 6 is performed to form a passivation layer 110 in the N electrode preparation platform 106 and the recess structure 102;
- the method includes the following steps: 6-1) depositing the passivation layer 110 by vapor phase epitaxy; 6-2) removing passivation of the surface of the mirror by mechanical chemical polishing, wet etching or dry etching Layer 110.
- the passivation layer 110 is an insulating material such as silicon oxide, titanium oxide or titanium nitride, and the first function of the passivation layer 110 is to be the first on the N electrode preparation platform 106.
- the electrode 109 is insulated from other luminescent epitaxial layers (quantum well and P-type layer 105), the second function is to ensure the stability of the subsequent bonding process, and the passivation layer 110 can also ensure the stability of the electrode and avoid it. Dropping or breaking can greatly improve the stability and life of the LED chip.
- step 7) is then performed to provide a thermally conductive conductive substrate 112 having a P electrode 113 on the surface, and bonding the thermally conductive conductive substrate 112 and the mirror through the bonding layer 111.
- Passivation layer 110 is then performed to provide a thermally conductive conductive substrate 112 having a P electrode 113 on the surface, and bonding the thermally conductive conductive substrate 112 and the mirror through the bonding layer 111.
- the method includes the following steps: 7-1) forming a first bonding layer on the surface of the reflective layer and the passivation layer 110; 7-2) forming a second bonding layer on the upper surface of the thermally conductive conductive substrate 112. 8-3) bonding the first bonding layer and the second bonding layer.
- the thermally conductive conductive substrate 112 has a conductive function at the same time, and may be a silicon substrate, a metal substrate, a composite substrate of silicon and metal, and the metal substrate includes Al, Cu, Ti, Sn, Ni, or the like, or an alloy thereof. .
- the thermally conductive substrate 112 is a silicon substrate.
- the thermally conductive electrically conductive substrate 112 can be any desired substrate material that ensures good thermal and electrical conductivity.
- step 8 is performed to thin the sapphire substrate 101 until the first electrode 109 is exposed;
- the sapphire substrate 101 is thinned by a grinding or wet etching process until the first electrode 109 is exposed.
- the embodiment further includes the step of roughening the surface of the sapphire substrate 101 to form the roughened microstructures 114.
- the surface of the sapphire substrate 101 is roughened by a process such as wet etching or ICP etching, and the roughened microstructures 114 include triangular pyramidal protrusions and square pyramids arranged in an ordered or disordered manner. Protrusions, conical protrusions, rounded protrusions, and the like.
- step 9 is performed, and a second electrode 115 connected to the first electrode 109 is formed on the surface of the sapphire substrate 101 to complete the preparation of the N electrode.
- the material of the second electrode 115 is the same as that of the first electrode 109, and may be Ti, Al, Ag, Pt, Au, W, Ni or the like.
- the embodiment provides a light emitting diode having a basic structure as in Embodiment 1, wherein a connection surface of the N electrode preparation platform 106 and the sapphire substrate 101 is the same as the sapphire substrate 101. Vertical vertical plane.
- Example 4
- the embodiment provides a method for manufacturing a light emitting diode, the basic steps of which are as in Embodiment 2, wherein the N electrode preparation platform 106 and the concave are omitted in the step 3) of the embodiment.
- the connecting surface 117 of the trench structure 102 is etched into a bevel, that is, the connecting surface 117 of the N electrode preparation platform 106 and the recess structure 102 is perpendicular to the surface of the sapphire substrate 101.
- the embodiment provides a light emitting diode.
- the light emitting diode includes at least: a thermally conductive conductive substrate 112, a lower surface of which is coupled with a P electrode 113, and an upper surface is bonded with a bonding layer 111; a mirror 108, Bonded to the bonding layer 111;
- the light emitting epitaxial structure is coupled to the mirror 108, and includes a P-type layer 105, a quantum well layer 104 and an N-type layer 103 which are sequentially stacked;
- a sapphire substrate 101 coupled to the light emitting epitaxial structure
- N electrodes 109 and 115 electrically connecting the N-type layer 103 to the sapphire by the contact region The surface of the substrate 101;
- the passivation layer 110 is filled between the N electrode and the bonding layer 111 in the contact region.
- the thermally conductive substrate 112 may be a silicon substrate, a metal substrate, a composite substrate of silicon and a metal, and the metal substrate includes Al, Cu, Ti, Sn, Ni, or the like, or an alloy thereof.
- the thermally conductive conductive substrate 112 is a silicon substrate.
- the thermally conductive substrate 112 can be any desired substrate material that ensures good thermal and electrical conductivity.
- the contact region is a hole-like structure or a groove-like structure.
- the contact region includes a tapered hole or a V-shaped groove penetrating through the sapphire substrate 101, and is located in the tapered hole or An electrode preparation region portion under the V-shaped groove, the electrode preparation region portion generally including a through hole up to the bonding layer 111 and an N electrode preparation platform 106 on both sides of the via hole, that is, the portion in the contact region is removed
- the N-electrode preparation platform 106 formed by the P-type layer 105, the quantum well layer 104, and the N-type layer 103.
- connection surface of the N electrode preparation platform 106 and the sapphire substrate 101 is perpendicular to the surface of the sapphire substrate 101.
- the main function of the contact region is to form an N electrode, that is, the N-type layer 103 is electrically connected to the surface of the sapphire substrate 101.
- the N electrode includes a bonding to the N electrode.
- the passivation layer 110 is used for filling.
- the passivation layer 110 is insulated by silicon oxide, titanium oxide or titanium nitride. material.
- the first function of the passivation layer 110 is to insulate the first electrode 109 on the N electrode preparation platform 106 from other luminescent epitaxial layers (the quantum well and the P-type layer 105).
- the second function is The first electrode 109 and the second electrode 115 function as supports to ensure the stability of the electrode and prevent it from falling off or breaking, which can greatly improve the stability and life of the LED chip.
- the surface of the P-type layer 105 is further combined with a current spreading layer 107.
- the current spreading layer 107 includes ITO, A TO, and FTO. Or AZO's transparent conductive layer.
- the current spreading layer 107 is located on the other side of the light emitting surface, so it is not limited to a transparent material, and metal materials such as Pt, Au, Ag, Ti, and W may also be used. It is not limited to the ones listed here.
- the mirror 108 can be designed as a planar mirror 108 or a mirror 108 having a hole-like structure as required.
- the square structure may be, for example, a square matrix Column holes, hexagonal arrays, or other arrangements of circular holes, elliptical holes, polygonal holes, or rounded polygonal holes.
- the mirror is a conductive mirror, and includes a Bragg mirror, an Ag mirror, an A1 mirror, and an ITO/Ag composite mirror;
- the mirror is not required to be electrically conductive, and the mirror may include a Bragg mirror, an Ag mirror, an A1 mirror, an ITO/Ag composite mirror, and a dielectric/metal composite mirror.
- the mirror may include a Bragg mirror, an Ag mirror, an A1 mirror, an ITO/Ag composite mirror, and a dielectric/metal composite mirror.
- mirrors listed herein are only preferred, and in other embodiments, all contemplated reflective materials may be employed as the mirrors of the present invention.
- the N-type layer 103 is an N-GaN layer
- the quantum well layer 104 is an InGaN/G aN multiple quantum well layer
- the P-type layer 105 is a P-GaN layer.
- the light-emitting epitaxial structure may employ a light-emitting epitaxial structure such as a GaAs-based or GaP-based structure, and is not limited to the ones listed herein.
- the bonding layer 111 is an Au or Au/Sn alloy.
- the light-emitting surface of the sapphire substrate 101 has a roughened microstructure 114.
- the roughened microstructures 114 include triangular pyramidal projections, quadrangular pyramidal projections, conical projections, rounded projections, and the like arranged in an ordered or disordered manner.
- the light-emitting diode provided in this embodiment has a simple structure, and only needs to bond the light-emitting structure to the heat-conductive conductive substrate through a bonding layer, thereby improving the heat dissipation efficiency of the chip, and the invention can improve the light-emitting efficiency of the light-emitting diode. Improve product life, reduce production costs, and increase product yield.
- Example 6
- the embodiment provides a method for manufacturing a light emitting diode, which includes the following steps:
- step 1) is first performed to provide a sapphire substrate 101, and a plurality of light emitting unit regions are defined, and at least one groove structure 102 is etched in each of the light emitting unit regions.
- a plurality of light-emitting units are defined in the wafer-level sapphire substrate 101, and then a photoresist pattern is formed on the surface thereof, and then the surface of the sapphire substrate 101 is engraved by inductively coupled plasma ICP etching.
- the groove structure 102 is etched out.
- the groove structure 102 is a tapered hole, or V. Shaped groove.
- the groove structure 102 may also be a cylindrical hole structure, a truncated cone structure, a trough-like structure having a trapezoidal cross section, a trough-like structure having a rectangular cross section, and the like, and is not limited thereto. Listed several. In order to better illustrate the specific manufacturing process of the present invention, the manufacturing process of one light-emitting unit will be described below as an example.
- step 2) is followed to form a light-emitting epitaxial structure including at least an N-type layer 103, a quantum well layer 104, and a P-type layer 105 on the surface of the sapphire substrate 101;
- the N-type layer 103, the quantum well layer 104, and the P-type layer 105 are formed by a chemical vapor deposition method, wherein the N-type layer 103 is an N-GaN layer, and the quantum well layer 104 is An InGaN/GaN multiple quantum well layer, the P-type layer 105 being a P-GaN layer.
- the light-emitting epitaxial structure may employ a light-emitting epitaxial structure such as a GaAs-based or GaP-based structure, and is not limited to the ones listed herein.
- step 3 is then performed to etch the P-type layer 105, the quantum well layer 104, and a portion of the N-type layer 103 on both sides of the recess structure 102 to form an N-electrode preparation platform 106.
- step 4) is then performed to form a fill layer 116 in the recess structure 102.
- the filling layer 116 is an insulator, specifically silicon oxide.
- a current spreading layer 107 is then formed on the surface of the P-type layer 105, and the current spreading layer 107 is a transparent conductive layer including ITO, ATO, FTO or AZO.
- the current spreading layer 107 is located on the other side of the light-emitting surface, so it is not limited to a transparent material, and metals such as Pt, Au, Ag, Ti, and W may also be used. The materials are not limited to the ones listed here.
- step 5 proceed to step 5 to make a mirror 108;
- the mirror 108 can be designed as a planar mirror or a mirror having a hole-like structure as required.
- the hole-like structure may be a circular hole, an elliptical hole, a polygonal hole or a rounded polygonal hole arranged in a square array arrangement, a hexagonal array arrangement or the like.
- the mirror is a conductive mirror, and includes a Bragg mirror, an Ag mirror, an A1 mirror, and an ITO/Ag composite mirror;
- the mirror is not required to be electrically conductive, and the mirror may include a Bragg mirror, an Ag mirror, an A1 mirror, an ITO/Ag composite mirror, and a dielectric/metal composite mirror.
- the mirror may include a Bragg mirror, an Ag mirror, an A1 mirror, an ITO/Ag composite mirror, and a dielectric/metal composite mirror.
- mirrors listed here are only preferred, and in other embodiments, All contemplated reflective materials are used as mirrors of the present invention.
- step 6 is then performed to form a first electrode 109 on the surface of the N electrode preparation platform 106 and the filling layer 116.
- the first electrode 109 is prepared by a method of electroplating or deposition, and the material of the first electrode 109 may be Ti, Al, Ag, Pt, Au, W, Ni or the like.
- a passivation layer 110 is formed on the surface of the N electrode preparation platform 106 and the filling layer 116.
- the method includes the following steps: 7-1) depositing the passivation layer 110 by vapor phase epitaxy; 7-2) removing passivation of the mirror surface by mechanical chemical polishing, wet etching, or dry etching Layer 110.
- the passivation layer 110 is an insulating material such as silicon oxide, titanium oxide or titanium nitride, and the first function of the passivation layer 110 is to be the first on the N electrode preparation platform 106.
- the electrode 109 is insulated from other luminescent epitaxial layers (quantum well and P-type layer 105), the second function is to ensure the stability of the subsequent bonding process, and the passivation layer 110 can also ensure the stability of the electrode and avoid it. Dropping or breaking can greatly improve the stability and life of the LED chip.
- step 8 is then performed to provide a thermally conductive conductive substrate 112 having a P electrode 113 on the surface, and bonding the thermally conductive conductive substrate 112 and the mirror through the bonding layer 111. Passivation layer 110.
- the method includes the following steps: 8-1) forming a first bonding layer on the surface of the reflective layer and the passivation layer 110; 8-2) forming a second bonding layer on the upper surface of the thermally conductive conductive substrate 112. 8-3) bonding the first bonding layer and the second bonding layer.
- the thermally conductive conductive substrate 112 has a conductive function at the same time, and may be a silicon substrate, a metal substrate, a composite substrate of silicon and metal, and the metal substrate includes Al, Cu, Ti, Sn, Ni, or the like, or an alloy thereof. .
- the thermally conductive substrate 112 is a silicon substrate.
- the thermally conductive electrically conductive substrate 112 can be any desired substrate material that ensures good thermal and electrical conductivity.
- step 9 is then performed to thin the sapphire substrate 101 until the recess structure 102 is exposed.
- the sapphire substrate 101 is thinned by a grinding or wet etching process until the recess structure 102 is exposed.
- the embodiment further includes the step of roughening the surface of the sapphire substrate 101 to form a roughened microstructure 114.
- the roughened microstructures 114 include triangular pyramidal protrusions, quadrangular pyramidal protrusions, and conical protrusions arranged in an ordered or disordered manner. Rounded protrusions, etc.
- step 10 is then performed to remove the filler in the recess structure 102 to expose the first electrode 109.
- the filler is silica, which may be removed using an HF solution.
- step 11) is then performed to form a second electrode 115 connected to the first electrode 109 in the recess structure 102 and the surface of the sapphire substrate 101 to complete the preparation of the N electrode.
- the material of the second electrode 115 is the same as that of the first electrode 109, and may be Ti, Al, Ag, Pt, Au, W, Ni or the like.
- the invention provides a novel flip-chip LED structure, which realizes the manufacture of a flip-chip LED chip by a wafer level bonding process, and directly bonds the LED chip to the thermally conductive conductive substrate, thereby greatly improving the LED chip.
- Heat dissipation efficiency firstly process the sapphire substrate and then perform epitaxy, and then expose the N electrode by thinning, so that the N electrode and the P electrode are respectively located on both sides of the LED chip, thereby avoiding defects such as debris and subsequent processes, and reducing the process. The difficulty, and effectively improve the yield of the product.
- Example 7 Example 7
- the present embodiment provides a light emitting diode having a basic structure as in Embodiment 5, wherein the N electrode preparation platform 106 and the sapphire substrate 01 are used to ensure effective growth of the electrode during preparation.
- the connecting surface is a bevel, and the angle between the inclined surface and the surface of the sapphire substrate 101 is greater than 0° and less than 90°. In this embodiment, the angle between the inclined surface and the surface of the sapphire substrate 101 is 30° ⁇ 60°.
- the embodiment provides a method for manufacturing a light emitting diode, the basic steps of which are as in Embodiment 6, wherein, in order to ensure effective growth of the electrode during preparation, the step 3) further includes preparing the N electrode preparation platform.
- the step 106 is etched into a bevel with the connection surface 117 of the sapphire substrate 101.
- the angle between the slope and the surface of the sapphire substrate 101 is greater than 0° and less than 90°. In the embodiment, the angle between the slope and the surface of the sapphire substrate 101 is 30° to 60°.
- the present invention provides a light emitting diode and a method of fabricating the same, including: a thermally conductive conductive substrate, The upper and lower surfaces respectively have a bonding layer and a P electrode; a mirror; a light emitting epitaxial structure comprising a laminated P-type layer, a quantum well layer and an N-type layer; a sapphire substrate bonded to the light-emitting epitaxial structure; a contact region, a sapphire substrate penetrating the bonding layer; an N electrode electrically connecting the N-type layer to the surface of the sapphire substrate by the contact region; and a passivation layer filling the contact region.
- the invention provides a novel flip-chip LED structure, which realizes the manufacture of a flip-chip LED chip by a wafer level bonding process, and directly bonds the LED chip to the heat conductive conductive substrate, thereby greatly improving the LED chip.
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Abstract
提供了一种发光二极管及其制造方法,包括:导热导电衬底(112),上下表面分别具有键合层(111)与P电极(113);反射镜(108);发光外延结构,包括层叠的P型层(105)、量子阱层(104)及N型层(103);蓝宝石衬底(101),结合于所述发光外延结构;接触区,由所述蓝宝石衬底(101)贯穿至所述键合层(111);N电极(109,115),藉由所述接触区将所述N型层(103)电性连接至所述蓝宝石衬底(101)表面;钝化层(110),填充于所述接触区内。提供了一种新型的倒装LED结构,通过晶圆级的键合工艺实现了倒装LED芯片的制造,将LED芯片直接键合于导热导电衬底中,大大地提高了LED芯片的散热效率;先于蓝宝石衬底中形成凹槽结构后进行外延,最后通过减薄将N电极露出,避免后续加工容易出现碎片等缺陷,降低了工艺的难度,并有效提高了产品的良率。
Description
一种发光二极管及其制造方法
技术领域
本发明属于半导体照明领域, 特别是涉及一种发光二极管及其制造方法。 背景技术
半导体照明作为新型高效固体光源, 具有寿命长、 节能、 环保、 安全等显著优 点, 将成为人类照明史上继白炽灯、 荧光灯之后的又一次飞跃, 其应用领域正在迅 速扩大, 正带动传统照明、 显示等行业的升级换代, 其经济效益和社会效益巨大。 正因如此, 半导体照明被普遍看作是 21世纪最具发展前景的新兴产业之一, 也是 未来几年光电子领域最重要的制高点之一。 发光二极管 LED是由 III-IV族化合物, 如 GaAs (砷化镓)、 GaP (磷化镓)、 GaAsP (磷砷化镓)等半导体制成的, 其核心 是 PN结。 因此它具有一般 P-N结的 I-N特性, 即正向导通, 反向截止、击穿特性。 此外, 在一定条件下, 它还具有发光特性。 在正向电压下, 电子由 N区注入 P区, 空穴由 P区注入 N区。 进入对方区域的少数载流子 (少子) 一部分与多数载流子 (多子) 复合而发光。
随着 LED灯市场爆发的日益临近, LED封装技术的研发竞争也十分激烈。 目 前 GaN基 LED封装主要有正装结构、 倒装结构和垂直结构三种。 当前较为成熟的 是 III族氮化物氮化镓用蓝宝石材料作为衬底, 由于蓝宝石衬底的绝缘性, 所以普 通的 GaN 基 LED 采用正装结构。正装结构有源区发出的光经由 P型 GaN区和透 明电极出射。 该结构简单, 制作工艺相对成熟。 然而正装结构 LED有两个明显的 缺点, 首先正装结构 LED p、 n 电极在 LED 的同一侧, 电流须横向流过 n-GaN 层, 导致电流拥挤, 局部发热量高, 限制了驱动电流; 其次, 由于蓝宝石衬底的导 热性差, 严重的阻碍了热量的散失。
为了解决散热问题, 美国 Lumileds Lighting 公司发明了倒装芯片 (Flipchip) 技术。 这种方法首先制备具有适合共晶焊接的大尺寸 LED芯片, 同时制备相应尺 寸的硅底板, 并在其上制作共晶焊接电极的金导电层和引出导电层(超声波金丝球 焊点)。 然后, 利用共晶焊接设备将大尺寸 LED芯片与硅底板焊在一起。 到装结构 在散热效果上有了很大的改善。但现有的倒装结构通常是通过焊接的方法固定于硅 衬底中, 这样的做法往往会引入较多的热阻而且降低 LED芯片的散热效率。而且,
这中结构的 LED芯片, P电极与 N电极通常制备于 LED芯片的同一侧, 往往会增 加倒装键合工艺和引线工艺的难度, 较难实现晶圆级的制造, 容易造成产品良率的 降低。
本发明提供一种新型的晶圆级的倒装 LED芯片结构,可以有效的提高 LED芯 片的散热效率, 同时降低工艺的难度, 提高产品的良率。 发明内容
鉴于以上所述现有技术的缺点,本发明的目的在于提供一种发光二极管及其制 造方法, 用于解决现有技术中倒装 LED芯片较难实现晶圆级制造、 散热效率不够 高、 工艺较复杂、 成本过高且良率较低等问题。
为实现上述目的及其他相关目的, 本发明提供一种发光二极管, 所述发光二极 管至少包括:
导热导电衬底, 其下表面结合有 P电极, 上表面结合有键合层;
反射镜, 结合于所述键合层;
发光外延结构, 结合于所述反射镜, 包括依次层叠的 P型层、 量子阱层及 N 型层;
蓝宝石衬底, 结合于所述发光外延结构;
接触区, 由所述蓝宝石衬底贯穿至所述键合层;
N电极, 藉由所述接触区将所述 N型层电性连接至所述蓝宝石衬底表面; 钝化层, 填充所述接触区内的 N电极与键合层之间。
作为本实施例的发光二极管的一种优选方案,所述接触区为孔状结构或槽状结 构。
作为本实施例的发光二极管的一种优选方案,所述接触区内去除了部分的 P型 层、 量子阱层及 N型层形成 N电极制备平台。
作为本实施例的发光二极管的一种优选方案, 所述 N 电极制备平台与所述蓝 宝石衬底的连接面垂直于所述蓝宝石衬底表面。
作为本实施例的发光二极管的一种优选方案,所述接触区于所述蓝宝石衬底内 的部分为锥形孔或 V型槽, 所述 N电极制备平台与所述蓝宝石衬底的连接面为斜 面。
进一步地, 所述 N电极包括结合于所述 N电极制备平台表面、 覆盖于所述斜
面、 并覆盖于所述锥形孔或 V型槽表面的第一电极以及结合于所述蓝宝石衬底出 光面并连接于所述第一电极的第二电极。
作为本实施例的发光二极管的一种优选方案, 所述 N 电极制备平台与所述蓝 宝石衬底的连接面为斜面。
作为本实施例的发光二极管的一种优选方案, 所述 N 电极包括结合于所述 N 电极制备平台表面并横跨所述接触区的第一电极、以及填充于所述蓝宝石衬底内并 将所述第一电极连接至所述蓝宝石衬底出光面的第二电极。 作为本实施例的发光二极管的一种优选方案,所述 P型层表面还结合有电流扩 展层。
作为本实施例的发光二极管的一种优选方案,所述蓝宝石衬底的出光面具有粗 化微结构。
本发明还提供一种发光二极管的制造方法, 包括以下步骤:
1 ) 提供一蓝宝石衬底, 并定义出多个发光单元区域, 于每个发光单元区域中 刻蚀出至少一个凹槽结构;
2)于所述蓝宝石衬底表面依次形成至少包括 N型层、 量子阱层及 P型层的发 光外延结构;
3)刻蚀所述凹槽结构两侧的 P型层、量子阱层及部分的 N型层形成 N电极制 备平台;
4) 制作反射镜;
5) 于所述 N电极制备平台及凹槽结构内形成第一电极;
6) 于所述 N电极制备平台及所述凹槽结构内形成钝化层;
7) 提供一下表面具有 P电极的导热导电衬底, 并通过键合层键合所述导热导 电衬底及所述反射镜与钝化层;
8) 减薄所述蓝宝石衬底直至露出所述第一电极;
9) 于所述蓝宝石衬底表面形成连接于所述第一电极的第二电极, 以完成 N电 极的制备。
作为本发明的发光二极管的制造方法的一种优选方案, 步骤 4)之前还包括于 所述 P型层表面制作电流扩展层的步骤。
作为本发明的发光二极管的制造方法的一种优选方案, 所述凹槽结构为锥形
孔、 或 V形槽。
进一步地, 步骤 3)还包括将所述 N电极制备平台与所述蓝宝石衬底的连接面 刻蚀成斜面的步骤。
作为本发明的发光二极管的制造方法的一种优选方案, 步骤 5)还包括于所述 反射镜中形成多个孔状结构的步骤。
作为本发明的发光二极管的制造方法的一种优选方案, 步骤 8)还包括对所述 蓝宝石衬底表面进行粗化形成粗化微结构的步骤。
本发明还提供一种发光二极管的制造方法, 包括以下步骤:
1 ) 提供一蓝宝石衬底, 并定义出多个发光单元区域, 于每个发光单元区域中 刻蚀出至少一个凹槽结构;
2)于所述蓝宝石衬底表面依次形成至少包括 N型层、 量子阱层及 P型层的发 光外延结构;
3)刻蚀所述凹槽结构两侧的 P型层、量子阱层及部分的 N型层形成 N电极制 备平台;
4) 于所述凹槽结构内形成填充层;
5) 制作反射镜;
6) 于所述 N电极制备平台及所述填充层表面形成第一电极;
7) 于所述 N电极制备平台及填充层表面形成钝化层;
8) 提供一下表面具有 P电极的导热导电衬底, 并通过键合层键合所述导热导 电衬底及所述反射镜与钝化层;
9) 减薄所述蓝宝石衬底直至露出所述凹槽结构;
10) 去除所述凹槽结构内的填充物以露出所述第一电极;
11 )于所述凹槽结构内及所述蓝宝石衬底表面形成连接于所述第一电极的第二 电极, 以完成 N电极的制备。
作为本发明的发光二极管的制造方法的一种优选方案, 步骤 5)之前还包括于 所述 P型层表面制作电流扩展层的步骤。
作为本发明的发光二极管的制造方法的一种优选方案, 所述凹槽结构为锥形 孔、 或 V形槽。
作为本发明的发光二极管的制造方法的一种优选方案, 步骤 3)还包括将所述 N电极制备平台与所述蓝宝石衬底的连接面刻蚀成斜面的步骤。
如上所述, 本发明提供一种发光二极管及其制造方法, 包括: 导热导电衬底, 上下表面分别具有键合层与 P电极; 反射镜; 发光外延结构, 包括层叠的 P型层、 量子阱层及 N型层; 蓝宝石衬底, 结合于所述发光外延结构; 接触区, 由所述蓝 宝石衬底贯穿至所述键合层; N 电极, 藉由所述接触区将所述 N型层电性连接至 所述蓝宝石衬底表面; 钝化层, 填充于所述接触区内。本发明提供了一种新型的倒 装 LED结构, 通过晶圆级的键合工艺实现了倒装 LED芯片的制造, 将 LED芯片 直接键合于导热导电衬底中, 大大地提高了 LED芯片的散热效率; 先于蓝宝石衬 底中形成凹槽结构后进行外延, 最后通过减薄将 N 电极露出, 避免后续加工容易 出现碎片等缺陷, 降低了工艺的难度, 并有效提高了产品的良率。 附图说明
图 1显示为本发明实施 1中的发光二极管的结构示意图。
图 2〜图 15显示为本发明实施例 2中的发光二极管的制造方法各步骤所呈现的 结构示意图。
图 16显示为本发明实施例 3中的发光二极管的结构示意图。
图 17显示为本发明实施例 5中的发光二极管的结构示意图。
图 18〜图 33显示为本发明实施例 6中的发光二极管的制造方法各步骤所呈现 的结构示意图。
图 34显示为本发明实施例 7中的发光二极管的结构示意图。 元件标号说明
101 蓝宝石衬底
102 凹槽结构
103 N型层
104 量子阱层
105 P型层
106 N电极制备平台
107 电流扩展层
108 反射镜
109 第一电极
no 钝化层
in 键合层
112 导热导电衬底
113 P电极
114 粗化微结构
115 第二电极
116 填充层
117 连接面 具体实施方式
以下通过特定的具体实例说明本发明的实施方式,本领域技术人员可由本说明 书所揭露的内容轻易地了解本发明的其他优点与功效。本发明还可以通过另外不同 的具体实施方式加以实施或应用,本说明书中的各项细节也可以基于不同观点与应 用, 在没有背离本发明的精神下进行各种修饰或改变。
请参阅图 1~图 34。 需要说明的是, 本实施例中所提供的图示仅以示意方式说 明本发明的基本构想,遂图式中仅显示与本发明中有关的组件而非按照实际实施时 的组件数目、 形状及尺寸绘制, 其实际实施时各组件的型态、数量及比例可为一种 随意的改变, 且其组件布局型态也可能更为复杂。 实施例 1
如图 1所示, 本实施例提供一种发光二极管, 所述发光二极管至少包括: 导热导电衬底 112, 其下表面结合有 P电极 113, 上表面结合有键合层 111 ; 反射镜 108, 结合于所述键合层 111 ;
发光外延结构, 结合于所述反射镜 108, 包括依次层叠的 P型层 105、 量子阱 层 104及 N型层 103;
蓝宝石衬底 101, 结合于所述发光外延结构;
接触区, 由所述蓝宝石衬底 101贯穿至所述键合层 111 ;
N电极 109及 115,藉由所述接触区将所述 N型层 103电性连接至所述蓝宝石 衬底 101表面;
钝化层 110, 填充于所述接触区内的 N电极与键合层 111之间。
所述导热导电衬底 112可以为硅衬底、 金属衬底、 硅和金属的复合衬底, 所述 金属衬底包括 Al、 Cu、 Ti、 Sn、 Ni等或其合金等。 在本实施例中, 所述导热导电 衬底 112为硅衬底。 当然, 在其它的实施例中, 所述导热导电衬底 112可以是能保 证良好导热性能和导电性能的一切预期的衬底材料。
在本实施例中, 所述接触区为孔状结构或槽状结构, 具体地, 所述接触区包括 贯穿所述蓝宝石衬底 101的锥形孔或 V型槽, 以及位于该锥形孔或 V型槽下方的 电极制备区域部分,该电极制备区域部分通常包括直至所述键合层 111的通孔以及 所述通孔两侧的 N电极制备平台 106, 即所述接触区内去除了部分的 P型层 105、 量子阱层 104及 N型层 103形成的 N电极制备平台 106。 为了保证电极在制备时 的有效生长, 所述 N电极制备平台 106与所述蓝宝石衬底 101的连接面为斜面, 该斜面与所述蓝宝石衬底 101表面的夹角范围为大于 0°且小于 90°,在本实施例中, 所述斜面与所述蓝宝石衬底 101表面的夹角为 30°~60°。
所述接触区主要的作用是用于形成 N电极, 即将所述 N型层 103电性连接至 所述蓝宝石衬底 101表面, 在本实施例中, 所述 N电极包括结合于所述 N电极制 备平台 106表面、覆盖于所述斜面、并覆盖于所述蓝宝石衬底 101内的锥形孔或 V 型槽表面的第一电极 109以及结合于所述蓝宝石衬底 101出光面并连接于所述第一 电极 109的第二电极 115。
对于所述 N电极和所述键合层 111之间的空隙, 则采用钝化层 110进行填充, 在本实施例中, 所述钝化层 110为氧化硅、 氧化钛或氮化钛等绝缘材料。所述钝化 层 110的第一个作用是将所述 N电极制备平台 106上的第一电极 109与其它的发 光外延层 (量子阱和 P型层 105)进行绝缘, 第二个作用是对所述第一电极 109及 第二电极 115起支撑的作用, 可以保证电极的稳定性, 避免其脱落或者折断, 可以 大大地提高 LED芯片的稳定性和寿命。
为了增加 LED芯片的电流使用效率和发光效率, 在本实施例中, 所述 P型层 105表面还结合有电流扩展层 107, 一般地, 所述电流扩展层 107为包括 ITO 、 A TO、 FTO或 AZO的透明导电层。 当然, 在本发明的 LED中, 该电流扩展层 107 位于出光面的另一侧, 故其并不限定为透明材料, 其也可以采用如 Pt、 Au、 Ag、 T i、 W等金属材料, 且并不限定于此处所列举的几种。
为了提高反射镜 108的反射效率,所述反射镜 108可以根据需求设计为平面型 的反射镜 108或者是具有孔状结构的反射镜 108。 所述孔状结构可以是以如四方阵
列排列、六方阵列排列或其它方式排列的圆孔、 椭圆孔、 多边形孔或圆角多边形孔 等。 若采用平面型的反射镜, 所述反射镜为导电反射镜, 包括布拉格反射镜、 Ag 反射镜、 A1反射镜、 ITO/Ag复合反射镜的一种;
若采用具有孔状结构的反射镜, 则不要求所述反射镜导电, 所述反射镜可以包 括布拉格反射镜、 Ag反射镜、 A1反射镜、 ITO/Ag复合反射镜、 介质 /金属复合反 射镜的一种。
当然, 此处所列举的反射镜种类仅为优选方案, 在其它的实施例中, 可以采用 一切预期的反射材料作为本发明的反射镜。
在本实施例中, 所述 N型层 103为 N-GaN层, 所述量子阱层 104为 InGaN/G aN多量子阱层, 所述 P型层 105为 P-GaN层。 当然在其它的实施例中, 所述发光 外延结构可以采用如 GaAs基、 GaP基等发光外延结构, 且不限于此处所列举的几 种。
为了提高 LED芯片的散热效率, 降低热阻, 在本实施例中, 所述键合层 111 为 Au或 Au/Sn合金。
为了进一步提供 LED芯片的出光效率, 所述蓝宝石衬底 101的出光面具有粗 化微结构 114。 所述粗化微结构 114包括以有序或无序方式排列的三角锥状突起、 四方锥状突起、 圆锥状突起、 圆包状突起等。
本实施例提供的发光二极管, 结构简单, 只需通过一层键合层将发光结构键合 于导热导电衬底, 提高了芯片的散热效率, 本发明可以提高芯片可以有效提高发光 二极管的出光效率, 提高产品的寿命, 降低生产成本, 提高产品的良率。 实施例 2
本实施例提供一种发光二极管的制造方法, 包括以下步骤:
如图 2~图3所示, 首先进行步骤 1 ) , 提供一蓝宝石衬底 101, 并定义出多个 发光单元区域, 于每个发光单元区域中刻蚀出至少一个凹槽结构 102。
具体地, 先于晶圆级的蓝宝石衬底 101中定义出多个发光单元, 然后于其表面 制作光刻胶图形, 接着采用电感耦合等离子体 ICP刻蚀法于所述蓝宝石衬底 101 表面刻蚀出所述凹槽结构 102, 在本实施例中, 所述凹槽结构 102为锥形孔、 或 V 形槽。 当然, 在其它的实施例中, 所述凹槽结构 102也可以是如圆柱状孔结构、 圆
台结构、截面为梯形的槽状结构、 截面为矩形的槽状结构等, 且并不限于此处所列 举的几种。为了更好说明本发明的具体制造过程, 以下以一个发光单元的制造过程 为例进行说明。
如图 4〜图 5所示, 然后进行步骤 2), 于所述蓝宝石衬底 101表面依次形成至 少包括 N型层 103、 量子阱层 104及 P型层 105的发光外延结构;
在本实施例中, 采用化学气相沉积法形成所述 N型层 103、 量子阱层 104及 P 型层 105, 其中, 所述 N型层 103为 N-GaN层, 所述量子阱层 104为 InGaN/GaN 多量子阱层, 所述 P型层 105为 P-GaN层。
当然在其它的实施例中, 所述发光外延结构可以采用如 GaAs基、 GaP基等发 光外延结构, 且不限于此处所列举的几种。
如图 6所示, 然后进行步骤 3) , 刻蚀所述凹槽结构 102两侧的 P型层 105、 量子阱层 104及部分的 N型层 103形成 N电极制备平台 106。
在本实施例中, 在刻蚀出所述 N型制备平台 106的同时, 将所述 N电极制备 平台 106与所述凹槽结构 102 (在本实施例中为锥形孔或 V型槽)的连接面 117刻 蚀成斜面, 可以很大程度的提高后续电极制备的可靠性和电极的完整性。
如图 7所示, 然后于所述 P型层 105表面制作电流扩展层 107, 所述电流扩展 层 107为包括 ITO 、 ATO、 FTO或 AZO的透明导电层。
需要说明的是, 在本发明的 LED中, 该电流扩展层 107位于出光面的另一侧, 故其并不限定为透明材料, 其也可以采用如 Pt、 Au、 Ag、 Ti、 W等金属材料, 且 并不限定于此处所列举的几种。
如图 8所示, 然后进行步骤 4) , 制作反射镜 108;
为了提高反射镜 108的反射效率,所述反射镜 108可以根据需求设计为平面型 的反射镜或者是具有孔状结构的反射镜。 所述孔状结构可以是以如四方阵列排列、 六方阵列排列或其它方式排列的圆孔、 椭圆孔、 多边形孔或圆角多边形孔等。
若采用平面型的反射镜, 所述反射镜为导电反射镜, 包括布拉格反射镜、 Ag 反射镜、 A1反射镜、 ITO/Ag复合反射镜的一种;
若采用具有孔状结构的反射镜, 则不要求所述反射镜导电, 所述反射镜可以包 括布拉格反射镜、 Ag反射镜、 A1反射镜、 ITO/Ag复合反射镜、 介质 /金属复合反 射镜的一种。
当然, 此处所列举的反射镜种类仅为优选方案, 在其它的实施例中, 可以采用
一切预期的反射材料作为本发明的反射镜。
如图 9所示, 然后进行步骤 5) , 于所述 N电极制备平台 106及凹槽结构 102 内形成第一电极 109;
在本实施例中, 所述凹槽结构 102为锥形孔或 V型槽, 所述 N电极制备平台 106与所述凹槽结构 102的连接面 117为斜面,通过电镀或沉积的方法于所述 N电 极制备平台 106、 斜面及凹槽结构 102内形成第一电极 109, 所述第一电极 109的 材料可以为 Ti、 Al、 Ag、 Pt、 Au、 W、 Ni等材料。
如图 10所示, 然后进行步骤 6) , 于所述 N电极制备平台 106及所述凹槽结 构 102内形成钝化层 110;
具体地, 包括以下步骤: 6-1 ) 采用气相外延法沉积钝化层 110; 6-2) 采用机 械化学抛光法、 湿法腐蚀法或干法刻蚀法去除所述反射镜表面的钝化层 110。
在本实施例中, 所述钝化层 110为氧化硅、 氧化钛或氮化钛等绝缘材料, 所述 钝化层 110的第一个作用是将所述 N电极制备平台 106上的第一电极 109与其它 的发光外延层 (量子阱和 P型层 105)进行绝缘, 第二个作用是保证后续键合工艺 的稳定性, 所述钝化层 110还可以保证电极的稳定性, 避免其脱落或者折断, 可以 大大地提高 LED芯片的稳定性和寿命。
如图 11~图 12所示, 然后进行步骤 7), 提供一下表面具有 P电极 113的导热 导电衬底 112, 并通过键合层 111键合所述导热导电衬底 112及所述反射镜与钝化 层 110。
具体地, 包括以下步骤: 7-1 ) 于所述反射层及钝化层 110表面形成第一键合 层; 7-2) 于所述导热导电衬底 112的上表面形成第二键合层; 8-3) 键合所述第一 键合层及所述第二键合层。
所述导热导电衬底 112同时具有导电功能, 可以为硅衬底、 金属衬底、硅和金 属的复合衬底, 所述金属衬底包括 Al、 Cu、 Ti、 Sn、 Ni等或其合金等。 在本实施 例中, 所述导热导电衬底 112为硅衬底。 当然, 在其它的实施例中, 所述导热导电 衬底 112可以是能保证良好导热性能和导电性能的一切预期的衬底材料。
如图 13所示, 然后进行步骤 8) , 减薄所述蓝宝石衬底 101直至露出所述第 一电极 109;
在本实施例中, 采用研磨或湿法腐蚀工艺减薄所述蓝宝石衬底 101, 直至露出 所述第一电极 109。
为了进一步提供 LED芯片的出光效率, 如图 14所示, 本实施例还包括对所述 蓝宝石衬底 101表面进行粗化形成粗化微结构 114的步骤。具体地, 采用湿法腐蚀 或 ICP刻蚀等工艺对所述蓝宝石衬底 101表面进行粗化处理, 所述粗化微结构 114 包括以有序或无序方式排列的三角锥状突起、 四方锥状突起、 圆锥状突起、 圆包状 突起等。
如图 15所示, 最后进行步骤 9) , 于所述蓝宝石衬底 101表面形成连接于所 述第一电极 109的第二电极 115, 以完成 N电极的制备。
在本实施例中, 所述第二电极 115的材料与第一电极 109的材料相同, 可以为 Ti、 Al、 Ag、 Pt、 Au、 W、 Ni等材料。 实施例 3
如图 16所示, 本实施例提供一种发光二极管, 其基本结构如实施例 1, 其中, 所述 N电极制备平台 106与所述蓝宝石衬底 101的连接面为与所述蓝宝石 衬底 101垂直的垂直面。 实施例 4
如图 16所示, 本实施例提供一种发光二极管的制造方法, 其基本步骤如实施 例 2, 其中, 本实施例的步骤 3) 中省略了将所述 N电极制备平台 106与所述凹槽 结构 102的连接面 117刻蚀成斜面的步骤, 即所述 N电极制备平台 106与所述凹 槽结构 102的连接面 117垂直于所述蓝宝石衬底 101表面。 实施例 5
如图 17所示, 本实施例提供一种发光二极管, 所述发光二极管至少包括: 导热导电衬底 112, 其下表面结合有 P电极 113, 上表面结合有键合层 111 ; 反射镜 108, 结合于所述键合层 111 ;
发光外延结构, 结合于所述反射镜 108, 包括依次层叠的 P型层 105、 量子阱 层 104及 N型层 103;
蓝宝石衬底 101, 结合于所述发光外延结构;
接触区, 由所述蓝宝石衬底 101贯穿至所述键合层 111 ;
N电极 109及 115,藉由所述接触区将所述 N型层 103电性连接至所述蓝宝石
衬底 101表面;
钝化层 110, 填充于所述接触区内的 N电极与键合层 111之间。
所述导热导电衬底 112可以为硅衬底、 金属衬底、 硅和金属的复合衬底, 所述 金属衬底包括 Al、 Cu、 Ti、 Sn、 Ni等或其合金等。 在本实施例中, 所述导热导电 衬底 112为硅衬底。 当然, 在其它的实施例中, 所述导热导电衬底 112可以是能保 证良好导热性能和导电性能的一切预期的衬底材料。
在本实施例中, 所述接触区为孔状结构或槽状结构, 具体地, 所述接触区包括 贯穿所述蓝宝石衬底 101的锥形孔或 V型槽, 以及位于该锥形孔或 V型槽下方的 电极制备区域部分,该电极制备区域部分通常包括直至所述键合层 111的通孔以及 所述通孔两侧的 N电极制备平台 106, 即所述接触区内去除了部分的 P型层 105、 量子阱层 104及 N型层 103形成的 N电极制备平台 106。
在本实施例中, 所述 N电极制备平台 106与所述蓝宝石衬底 101的连接面垂 直于所述蓝宝石衬底 101表面。
所述接触区主要的作用是用于形成 N电极, 即将所述 N型层 103电性连接至 所述蓝宝石衬底 101表面, 在本实施例中, 所述 N电极包括结合于所述 N电极制 备平台 106表面并横跨所述接触区的第一电极 109、 以及填充于所述蓝宝石衬底 1 01内并将所述第一电极 109连接至所述蓝宝石衬底 101出光面的第二电极 115。
对于所述 N电极和所述键合层 111之间的空隙, 则采用钝化层 110进行填充, 在本实施例中, 所述钝化层 110为氧化硅、 氧化钛或氮化钛等绝缘材料。所述钝化 层 110的第一个作用是将所述 N电极制备平台 106上的第一电极 109与其它的发 光外延层 (量子阱和 P型层 105)进行绝缘, 第二个作用是对所述第一电极 109及 第二电极 115起支撑的作用, 可以保证电极的稳定性, 避免其脱落或者折断, 可以 大大地提高 LED芯片的稳定性和寿命。
为了增加 LED芯片的电流使用效率和发光效率, 在本实施例中, 所述 P型层 105表面还结合有电流扩展层 107, 一般地, 所述电流扩展层 107为包括 ITO 、 A TO、 FTO或 AZO的透明导电层。 当然, 在本发明的 LED中, 该电流扩展层 107 位于出光面的另一侧, 故其并不限定为透明材料, 其也可以采用如 Pt、 Au、 Ag、 T i、 W等金属材料, 且并不限定于此处所列举的几种。
为了提高反射镜 108的反射效率,所述反射镜 108可以根据需求设计为平面型 的反射镜 108或者是具有孔状结构的反射镜 108。 所述孔状结构可以是以如四方阵
列排列、六方阵列排列或其它方式排列的圆孔、 椭圆孔、 多边形孔或圆角多边形孔 等。 若采用平面型的反射镜, 所述反射镜为导电反射镜, 包括布拉格反射镜、 Ag 反射镜、 A1反射镜、 ITO/Ag复合反射镜的一种;
若采用具有孔状结构的反射镜, 则不要求所述反射镜导电, 所述反射镜可以包 括布拉格反射镜、 Ag反射镜、 A1反射镜、 ITO/Ag复合反射镜、 介质 /金属复合反 射镜的一种。
当然, 此处所列举的反射镜种类仅为优选方案, 在其它的实施例中, 可以采用 一切预期的反射材料作为本发明的反射镜。
在本实施例中, 所述 N型层 103为 N-GaN层, 所述量子阱层 104为 InGaN/G aN多量子阱层, 所述 P型层 105为 P-GaN层。 当然在其它的实施例中, 所述发光 外延结构可以采用如 GaAs基、 GaP基等发光外延结构, 且不限于此处所列举的几 种。
为了提高 LED芯片的散热效率, 降低热阻, 在本实施例中, 所述键合层 111 为 Au或 Au/Sn合金。
为了进一步提供 LED芯片的出光效率, 所述蓝宝石衬底 101的出光面具有粗 化微结构 114。 所述粗化微结构 114包括以有序或无序方式排列的三角锥状突起、 四方锥状突起、 圆锥状突起、 圆包状突起等。
本实施例提供的发光二极管, 结构简单, 只需通过一层键合层将发光结构键合 于导热导电衬底, 提高了芯片的散热效率, 本发明可以提高芯片可以有效提高发光 二极管的出光效率, 提高产品的寿命, 降低生产成本, 提高产品的良率。 实施例 6
如图 18~图 33所示, 本实施例提供一种发光二极管的制造方法, 包括以下步 骤:
如图 18~图 19所示, 首先进行步骤 1 ) , 提供一蓝宝石衬底 101, 并定义出多 个发光单元区域, 于每个发光单元区域中刻蚀出至少一个凹槽结构 102。
具体地, 先于晶圆级的蓝宝石衬底 101中定义出多个发光单元, 然后于其表面 制作光刻胶图形, 接着采用电感耦合等离子体 ICP刻蚀法于所述蓝宝石衬底 101 表面刻蚀出所述凹槽结构 102, 在本实施例中, 所述凹槽结构 102为锥形孔、 或 V
形槽。 当然, 在其它的实施例中, 所述凹槽结构 102也可以是如圆柱状孔结构、 圆 台结构、截面为梯形的槽状结构、 截面为矩形的槽状结构等, 且并不限于此处所列 举的几种。为了更好说明本发明的具体制造过程, 以下以一个发光单元的制造过程 为例进行说明。
如图 20〜图 21所示, 然后进行步骤 2), 于所述蓝宝石衬底 101表面依次形成 至少包括 N型层 103、 量子阱层 104及 P型层 105的发光外延结构;
在本实施例中, 采用化学气相沉积法形成所述 N型层 103、 量子阱层 104及 P 型层 105, 其中, 所述 N型层 103为 N-GaN层, 所述量子阱层 104为 InGaN/GaN 多量子阱层, 所述 P型层 105为 P-GaN层。
当然在其它的实施例中, 所述发光外延结构可以采用如 GaAs基、 GaP基等发 光外延结构, 且不限于此处所列举的几种。
如图 22所示, 然后进行步骤 3) , 刻蚀所述凹槽结构 102两侧的 P型层 105、 量子阱层 104及部分的 N型层 103形成 N电极制备平台 106。
如图 23所示, 然后进行步骤 4) , 于所述凹槽结构 102内形成填充层 116。 在本实施例中, 所述的填充层 116为绝缘物, 具体为氧化硅。
如图 24所示, 然后于所述 P型层 105表面制作电流扩展层 107, 所述电流扩 展层 107为包括 ITO 、 ATO、 FTO或 AZO的透明导电层。
需要说明的是, 在本发明的 LED中, 该电流扩展层 107位于出光面的另一侧, 故其并不限定为透明材料, 其也可以采用如 Pt、 Au、 Ag、 Ti、 W等金属材料, 且 并不限定于此处所列举的几种。
如图 25所示, 然后进行步骤 5) , 制作反射镜 108;
为了提高反射镜 108的反射效率,所述反射镜 108可以根据需求设计为平面型 的反射镜或者是具有孔状结构的反射镜。 所述孔状结构可以是以如四方阵列排列、 六方阵列排列或其它方式排列的圆孔、 椭圆孔、 多边形孔或圆角多边形孔等。
若采用平面型的反射镜, 所述反射镜为导电反射镜, 包括布拉格反射镜、 Ag 反射镜、 A1反射镜、 ITO/Ag复合反射镜的一种;
若采用具有孔状结构的反射镜, 则不要求所述反射镜导电, 所述反射镜可以包 括布拉格反射镜、 Ag反射镜、 A1反射镜、 ITO/Ag复合反射镜、 介质 /金属复合反 射镜的一种。
当然, 此处所列举的反射镜种类仅为优选方案, 在其它的实施例中, 可以采用
一切预期的反射材料作为本发明的反射镜。
如图 26所示, 然后进行步骤 6) , 于所述 N电极制备平台 106及所述填充层 116表面形成第一电极 109。
在本实施例中, 通过电镀或沉积的方法制备所述第一电极 109, 所述第一电极 109的材料可以为 Ti、 Al、 Ag、 Pt、 Au、 W、 Ni等材料。
如图 27所示, 然后进行 7) 于所述 N电极制备平台 106及填充层 116表面形 成钝化层 110。
具体地, 包括以下步骤: 7-1 ) 采用气相外延法沉积钝化层 110; 7-2) 采用机 械化学抛光法、 湿法腐蚀法或干法刻蚀法去除所述反射镜表面的钝化层 110。
在本实施例中, 所述钝化层 110为氧化硅、 氧化钛或氮化钛等绝缘材料, 所述 钝化层 110的第一个作用是将所述 N电极制备平台 106上的第一电极 109与其它 的发光外延层 (量子阱和 P型层 105)进行绝缘, 第二个作用是保证后续键合工艺 的稳定性, 所述钝化层 110还可以保证电极的稳定性, 避免其脱落或者折断, 可以 大大地提高 LED芯片的稳定性和寿命。
如图 28~图 29所示, 然后进行步骤 8), 提供一下表面具有 P电极 113的导热 导电衬底 112, 并通过键合层 111键合所述导热导电衬底 112及所述反射镜与钝化 层 110。
具体地, 包括以下步骤: 8-1 ) 于所述反射层及钝化层 110表面形成第一键合 层; 8-2) 于所述导热导电衬底 112的上表面形成第二键合层; 8-3) 键合所述第一 键合层及所述第二键合层。
所述导热导电衬底 112同时具有导电功能, 可以为硅衬底、 金属衬底、硅和金 属的复合衬底, 所述金属衬底包括 Al、 Cu、 Ti、 Sn、 Ni等或其合金等。 在本实施 例中, 所述导热导电衬底 112为硅衬底。 当然, 在其它的实施例中, 所述导热导电 衬底 112可以是能保证良好导热性能和导电性能的一切预期的衬底材料。
如图 30所示, 然后进行步骤 9) , 减薄所述蓝宝石衬底 101直至露出所述凹 槽结构 102。
在本实施例中, 采用研磨或湿法腐蚀工艺减薄所述蓝宝石衬底 101, 直至露出 所述凹槽结构 102。
为了进一步提供 LED芯片的出光效率, 如图 31所示, 本实施例还包括对所述 蓝宝石衬底 101表面进行粗化形成粗化微结构 114的步骤。具体地, 采用湿法腐蚀
或 ICP刻蚀等工艺对所述蓝宝石衬底 101表面进行粗化处理, 所述粗化微结构 114 包括以有序或无序方式排列的三角锥状突起、 四方锥状突起、 圆锥状突起、 圆包状 突起等。
如图 32所示, 然后进行步骤 10) , 去除所述凹槽结构 102内的填充物以露出 所述第一电极 109。
在本实施例中, 所述填充物为氧化硅, 可以采用 HF溶液将其去除。
如图 33所示, 然后进行步骤 11 ) , 于所述凹槽结构 102内及所述蓝宝石衬底 101表面形成连接于所述第一电极 109的第二电极 115, 以完成 N电极的制备。
在本实施例中, 所述第二电极 115的材料与第一电极 109的材料相同, 可以为 Ti、 Al、 Ag、 Pt、 Au、 W、 Ni等材料。
本发明提供了一种新型的倒装 LED结构, 通过晶圆级的键合工艺实现了倒装 LED芯片的制造,将 LED芯片直接键合于导热导电衬底中, 大大地提高了 LED芯 片的散热效率; 先对蓝宝石衬底进行加工后再进行外延, 然后通过减薄将 N 电极 露出, 使 N电极与 P电极分别位于 LED芯片的两侧, 避免后续加工容易出现碎片 等缺陷, 降低了工艺的难度, 并有效提高了产品的良率。 实施例 7
如图 34所示, 本实施例提供一种发光二极管, 其基本结构如实施例 5, 其中, 为了保证电极在制备时的有效生长,所述 N电极制备平台 106与所述蓝宝石衬底 1 01的连接面为斜面, 该斜面与所述蓝宝石衬底 101表面的夹角范围为大于 0°且小 于 90°, 在本实施例中, 所述斜面与所述蓝宝石衬底 101表面的夹角为 30°~60°。 实施例 8
如图 34所示, 本实施例提供一种发光二极管的制造方法, 其基本步骤如实施 例 6, 其中, 为了保证电极在制备时的有效生长, 步骤 3) 还包括将所述 N电极制 备平台 106与所述蓝宝石衬底 101的连接面 117刻蚀成斜面的步骤。该斜面与所述 蓝宝石衬底 101表面的夹角范围为大于 0°且小于 90°, 在本实施例中, 所述斜面与 所述蓝宝石衬底 101表面的夹角为 30°~60°。 综上所述, 本发明提供一种发光二极管及其制造方法, 包括: 导热导电衬底,
上下表面分别具有键合层与 P电极; 反射镜; 发光外延结构, 包括层叠的 P型层、 量子阱层及 N型层; 蓝宝石衬底, 结合于所述发光外延结构; 接触区, 由所述蓝 宝石衬底贯穿至所述键合层; N 电极, 藉由所述接触区将所述 N型层电性连接至 所述蓝宝石衬底表面; 钝化层, 填充于所述接触区内。本发明提供了一种新型的倒 装 LED结构, 通过晶圆级的键合工艺实现了倒装 LED芯片的制造, 将 LED芯片 直接键合于导热导电衬底中, 大大地提高了 LED芯片的散热效率; 先于蓝宝石衬 底中形成凹槽结构后进行外延, 最后通过减薄将 N 电极露出, 避免后续加工容易 出现碎片等缺陷, 降低了工艺的难度, 并有效提高了产品的良率。 所以, 本发明有 效克服了现有技术中的种种缺点而具高度产业利用价值。
上述实施例仅例示性说明本发明的原理及其功效, 而非用于限制本发明。任何 熟悉此技术的人士皆可在不违背本发明的精神及范畴下,对上述实施例进行修饰或 改变。 因此, 举凡所属技术领域中具有通常知识者在未脱离本发明所揭示的精神与 技术思想下所完成的一切等效修饰或改变, 仍应由本发明的权利要求所涵盖。
Claims
权利要求书 、 一种发光二极管, 其特征在于, 所述发光二极管至少包括:
导热导电衬底, 其下表面结合有 P电极, 上表面结合有键合层; 反射镜, 结合于所述键合层;
发光外延结构, 结合于所述反射镜, 包括依次层叠的 P型层、 量子阱层 及 N型层;
蓝宝石衬底, 结合于所述发光外延结构;
接触区, 由所述蓝宝石衬底贯穿至所述键合层;
N电极,藉由所述接触区将所述 N型层电性连接至所述蓝宝石衬底表面; 钝化层, 填充所述接触区内的 N电极与键合层之间。 、 根据权利要求 1所述的发光二极管, 其特征在于: 所述接触区为孔状结构或 槽状结构。 、 根据权利要求 1所述的发光二极管, 其特征在于: 所述接触区内去除了部分 的 P型层、 量子阱层及 N型层形成 N电极制备平台。 、 根据权利要求 3所述的发光二极管, 其特征在于: 所述 N电极制备平台与所 述蓝宝石衬底的连接面垂直于所述蓝宝石衬底表面。 、 根据权利要求 3所述的发光二极管, 其特征在于: 所述接触区于所述蓝宝石 衬底内的部分为锥形孔或 V型槽,所述 N电极制备平台与所述蓝宝石衬底的 连接面为斜面。 、 根据权利要求 5所述的发光二极管, 其特征在于: 所述 N电极包括结合于所 述 N电极制备平台表面、覆盖于所述斜面、并覆盖于所述锥形孔或 V型槽表 面的第一电极以及结合于所述蓝宝石衬底出光面并连接于所述第一电极的第 二电极。 、 根据权利要求 3所述的发光二极管, 其特征在于: 所述 N电极制备平台与所 述蓝宝石衬底的连接面为斜面。
、 根据权利要求 3所述的发光二极管, 其特征在于: 所述 N电极包括结合于所 述 N电极制备平台表面并横跨所述接触区的第一电极、 以及填充于所述蓝宝 石衬底内并将所述第一电极连接至所述蓝宝石衬底出光面的第二电极。
、 根据权利要求 1所述的发光二极管, 其特征在于: 所述 P型层表面还结合有 电流扩展层。 0、 根据权利要求 1所述的发光二极管, 其特征在于: 所述蓝宝石衬底的出 光面具有粗化微结构。 1、 一种发光二极管的制造方法, 其特征在于: 包括以下步骤:
1 )提供一蓝宝石衬底, 并定义出多个发光单元区域, 于每个发光单元区 域中刻蚀出至少一个凹槽结构;
2) 于所述蓝宝石衬底表面依次形成至少包括 N型层、 量子阱层及 P型 层的发光外延结构;
3) 刻蚀所述凹槽结构两侧的 P型层、 量子阱层及部分的 N型层形成 N 电极制备平台;
4) 制作反射镜;
5) 于所述 N电极制备平台及凹槽结构内形成第一电极;
6) 于所述 N电极制备平台及所述凹槽结构内形成钝化层;
7)提供一下表面具有 P电极的导热导电衬底,并通过键合层键合所述导 热导电衬底及所述反射镜与钝化层;
8) 减薄所述蓝宝石衬底直至露出所述第一电极;
9)于所述蓝宝石衬底表面形成连接于所述第一电极的第二电极, 以完成 N电极的制备。 、 根据权利要求 11所述的发光二极管的制造方法, 其特征在于: 步骤 4) 之 前还包括于所述 P型层表面制作电流扩展层的步骤。 3、 根据权利要求 11所述的发光二极管的制造方法, 其特征在于: 所述凹槽结
构为锥形孔、 或 V形槽。 、 根据权利要求 13所述的发光二极管的制造方法, 其特征在于: 步骤 3) 还 包括将所述 N电极制备平台与所述蓝宝石衬底的连接面刻蚀成斜面的步骤。 、 根据权利要求 11所述的发光二极管的制造方法, 其特征在于: 步骤 5) 还 包括于所述反射镜中形成多个孔状结构的步骤。 、 根据权利要求 11所述的发光二极管的制造方法, 其特征在于: 步骤 8) 还 包括对所述蓝宝石衬底表面进行粗化形成粗化微结构的步骤。 、 一种发光二极管的制造方法, 其特征在于: 包括以下步骤:
1 )提供一蓝宝石衬底, 并定义出多个发光单元区域, 于每个发光单元区 域中刻蚀出至少一个凹槽结构;
2) 于所述蓝宝石衬底表面依次形成至少包括 N型层、 量子阱层及 P型 层的发光外延结构;
3) 刻蚀所述凹槽结构两侧的 P型层、 量子阱层及部分的 N型层形成 N 电极制备平台;
4) 于所述凹槽结构内形成填充层;
5) 制作反射镜;
6) 于所述 N电极制备平台及所述填充层表面形成第一电极;
7) 于所述 N电极制备平台及填充层表面形成钝化层;
8)提供一下表面具有 P电极的导热导电衬底,并通过键合层键合所述导 热导电衬底及所述反射镜与钝化层;
9) 减薄所述蓝宝石衬底直至露出所述凹槽结构;
10) 去除所述凹槽结构内的填充物以露出所述第一电极;
11 ) 于所述凹槽结构内及所述蓝宝石衬底表面形成连接于所述第一电极 的第二电极, 以完成 N电极的制备。 、 根据权利要求 17所述的发光二极管的制造方法, 其特征在于: 步骤 5) 之 前还包括于所述 P型层表面制作电流扩展层的步骤。
、 根据权利要求 17所述的发光二极管的制造方法, 其特征在于: 所述凹槽结 构为锥形孔、 或 V形槽。 、 根据权利要求 17所述的发光二极管的制造方法, 其特征在于: 步骤 3) 还 包括将所述 N电极制备平台与所述蓝宝石衬底的连接面刻蚀成斜面的步骤。
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CN101604717A (zh) * | 2009-07-15 | 2009-12-16 | 山东华光光电子有限公司 | 一种垂直GaN基LED芯片及其制作方法 |
CN101847675A (zh) * | 2009-10-30 | 2010-09-29 | 武汉华灿光电有限公司 | 垂直结构发光二极管芯片结构及其制造方法 |
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CN101604717A (zh) * | 2009-07-15 | 2009-12-16 | 山东华光光电子有限公司 | 一种垂直GaN基LED芯片及其制作方法 |
CN101847675A (zh) * | 2009-10-30 | 2010-09-29 | 武汉华灿光电有限公司 | 垂直结构发光二极管芯片结构及其制造方法 |
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