Flip light-emitting diode chip with high crystal quality and high luminous efficiency and preparation method of flip light-emitting diode chip

Abstract

The invention discloses a flip light-emitting diode chip with high crystal quality and high luminous efficiency and a preparation method thereof. The chip structurally comprises a sapphire patterned substrate, a buffer layer, a stress gradient layer, an n-type gallium nitride layer, a current expansion layer, a quantum well light-emitting layer, a P-type electron barrier layer, a P-type gallium nitride layer, a transparent conductive layer, a first electrode layer, a high-reflectivity DBR layer and a second electrode layer from bottom to top. Wherein the buffer layer and the stress gradient layer are of doped gradient composite structures, so that the defect density of the gallium nitride material can be effectively reduced. By adopting the buffer layer structure and the stress gradient layer structure, the LED epitaxial wafer with high crystal quality is obtained, and the probability of scattering and defect absorption of light in an LED material is reduced, so that the luminous efficiency of a flip LED chip is effectively improved.

Description

Technical Field

[0001] The invention relates to the field of LED chips, in particular to a flip-chip light emitting diode chip with high crystal quality and high light efficiency and a preparation method thereof. Background Art

[0002] At present, the mainstream growth substrate of light-emitting diodes is still sapphire substrate. The three major LED structures are: upright LED structure, flip-chip LED structure, and vertical LED structure. Among them, the technology and yield of upright and flip-chip are better than those of vertical structure LED, so the LED products on the market are mainly upright and flip-chip structure LED. The heat of the PN junction of the upright structure LED chip is conducted out through the sapphire substrate, and the heat conduction path is longer. In addition, the thermal conductivity of sapphire is lower than that of metal, so the thermal resistance of the upright structure LED chip will be relatively large; on the other hand, the P electrode and finger line of the upright structure LED chip will also block the output of part of the light. Therefore, the device power, light output efficiency and thermal performance of the upright LED chip are limited to a certain extent. The light of the flip-chip structure LED chip is extracted from the sapphire direction, so the light under the P electrode and finger can be reflected back to the substrate direction by the reflective layer, and the current expansion layer on the P-type gallium nitride can be thickened accordingly, which can be applied to high-efficiency and high-power devices; in addition, the heat of the PN junction of the flip-chip structure LED chip can be directly conducted to the silicon substrate with a higher thermal conductivity through the metal bump, which has a better heat dissipation effect. Therefore, flip-chip LED chips have a wide range of applications. Summary of the invention

[0003] Purpose of the invention: In order to solve the problems existing in the prior art, the present invention provides a flip-chip light-emitting diode chip with high crystal quality and high light efficiency and a preparation method thereof, which adopts a composite buffer layer and a stress gradient layer to obtain a high crystal quality LED epitaxial wafer, reduces the probability of light scattering and defect absorption inside the LED material, and effectively improves the light output efficiency of the flip-chip LED chip.

[0004] Technical solution: The present invention discloses a flip-chip light-emitting diode chip with high crystal quality and high light efficiency, which includes the following structures from bottom to top: a sapphire graphic substrate, a buffer layer, a stress gradient layer, an n-type gallium nitride layer, a current expansion layer, a quantum well light-emitting layer, a P-type electron blocking layer, a P-type gallium nitride layer, a transparent conductive layer, an electrode layer one, a high reflectivity DBR layer, and an electrode layer two.

[0005] Furthermore, the buffer layer is AlN, In x Al 1-x The composite structure of N (x = 0 ~ 0.18), GaN (two-dimensional growth mode), AlN layer is deposited by sputtering, In x Al 1-xN (x = 0 ~ 0.18) where the In content is gradually doped from 0 to 18%, and then a layer of GaN material is grown in two dimensions.

[0006] Furthermore, the stress gradient layer structure is GaN (two-dimensional growth mode), GaN (three-dimensional growth mode), Al y Ga 1-y N (y = 0 ~ 0.15), GaN layer is grown from intrinsic GaN material, Al y Ga 1-y The Al doping of the N layer is graded from 0 to 15%.

[0007] The present invention also discloses a method for preparing the above-mentioned flip-chip light-emitting diode chip with high crystal quality and high light efficiency, which specifically comprises first growing it in a metal-organic chemical vapor deposition device MOCVD to obtain an epitaxial wafer with a complete epitaxial structure, and then preparing the flip-chip LED chip on the epitaxial wafer.

[0008] Furthermore, the steps for preparing the light emitting diode epitaxial wafer are as follows:

[0009] 1) using a sputtering technique to evaporate AlN material on a sapphire pattern substrate, wherein the AlN material is also a part of the composite buffer layer;

[0010] 2) placing the sapphire pattern substrate coated with AlN material into MOCVD for high temperature treatment to clean the substrate surface;

[0011] 3) In the MOCVD device, In is then grown on the cleaned substrate. x Al 1-x N (x = 0 ~ 0.18), GaN (two-dimensional growth mode) buffer layer structure;

[0012] 4) Growing GaN (two-dimensional growth mode), GaN (three-dimensional growth mode), Al y Ga 1-y N (y = 0 ~ 0.15) composite stress gradient layer structure;

[0013] 5) growing Si-doped n-type gallium nitride material on the stress graded layer in an MOCVD device;

[0014] 6) growing a current spreading layer on the n-type gallium nitride in an MOCVD device, wherein the current spreading layer is a gallium nitride layer doped with low concentration Si;

[0015] 7) growing an InGaN / GaN multi-quantum well light-emitting layer on the current spreading layer in an MOCVD device;

[0016] 8) growing an electron blocking layer of p-type AlGaN material on the InGaN / GaN quantum well light-emitting layer in an MOCVD device;

[0017] 9) Growing a p-type gallium nitride material on the p-type AlGaN electron blocking layer in an MOCVD device.

[0018] Thus, a high-quality and high-light-efficiency flip-chip light-emitting diode epitaxial wafer with a complete structure is obtained. The epitaxial wafer is subjected to rapid thermal annealing, which can effectively improve the ohmic contact characteristics of the p-type gallium nitride material.

[0019] Furthermore, the specific method of growing the stress gradient layer structure in the MOCVD device is as follows:

[0020] 1) In MOCVD equipment, a composite buffer layer structure of InxAl1-xN (x=0-0.18) and GaN (two-dimensional growth mode) is continuously grown on a substrate coated with AlN material; the AlN material is grown by sputtering technology, and the thickness is In grown on the AlN material x Al 1-x N material, wherein the In doping content is gradually changed from 0 to 18%, the In x Al 1-x NMaterial thickness In the x Al 1-x Two-dimensional growth of GaN material on N material, with a thickness of The growth temperature of the above materials in the MOCVD chamber is 500-600°C;

[0021] 2) continuing to grow a two-dimensional GaN material at a high temperature on the composite buffer layer material in an MOCVD device, the growth temperature being 800-950° C. and the growth thickness being 0.5-1 μm; the two-dimensional GaN material grown at a high temperature serves as a nucleation layer, is a transition between two-dimensional GaN and three-dimensional GaN, and is part of a stress gradient layer;

[0022] 3) Continue to grow GaN, Al and other materials in three dimensions on the high temperature two-dimensional GaN material in the MOCVD device. y Ga 1-y N (y = 0 ~ 0.15) composite stress gradient layer structure; the growth temperature of the three-dimensional GaN material is 1000 ~ 1100 ℃, the growth thickness is 1 ~ 3μm; the Al y Ga 1-y The Al doping content of the N material gradually changes from 0 to 15%, the growth temperature is 1000~1100℃, and the growth thickness is

[0023] Furthermore, the preparation steps of the flip-chip LED chip are as follows:

[0024] 1) Depositing a transparent conductive layer on the prepared epitaxial wafer, wherein the transparent conductive layer is made of indium tin oxide (ITO) material with a thickness of The ITO transparent conductive film can be grown by using E-beam electron beam evaporation method, sputter magnetron sputtering method, or RPD reactive plasma deposition method;

[0025] 2) depositing an electrode layer 1 on the epitaxial wafer coated with the transparent conductive layer by an E-beam evaporation method, wherein the material of the electrode layer 1 is an alloy combination of Cr / Al / Ti / Pt / Au, and the electrode shape is designed according to the requirements;

[0026] 3) Depositing a DBR layer with high reflectivity on the epitaxial wafer forming the electrode layer 1, wherein the DBR layer structure is SiO2 / TiO2 periodically and alternately grown, the growth period is 20 to 50 periods, the total thickness is 1 um to 5 um, and the DBR layer wraps around the side wall of the LED core particle, and acts as a passivation protective layer while reflecting light;

[0027] 4) Electrode layer 2 is deposited on the epitaxial wafer with the high reflectivity DBR layer by E-bean evaporation method, wherein the material of electrode layer 2 is an alloy combination of Cr / Al / Ti / Pt / Au, and the area of ​​electrode layer 2 is large enough to facilitate the packaging operation of flip-chip LED; a reserved through hole is provided on the high reflectivity DBR layer to effectively connect electrode layer 2 and electrode layer 1; finally, a flip-chip light-emitting diode chip with high crystal quality and high light efficiency is obtained.

[0028] Beneficial effects: The present invention has the following advantages:

[0029] By using a composite buffer layer and a stress gradient layer, the internal defects of the gallium nitride material are reduced, a high-crystal quality LED epitaxial wafer is obtained, and the probability of light scattering and defect absorption inside the LED material is reduced, thereby effectively improving the light output efficiency of the flip-chip LED chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic structural diagram of a flip-chip light-emitting diode chip with high crystal quality and high light efficiency in an embodiment of the present invention;

[0031] Among them: 01-sapphire pattern substrate, 02-buffer layer, 03-stress gradient layer, 04-n-type gallium nitride layer, 05-current spreading layer, 06-quantum well light-emitting layer, 07-P-type electron blocking layer, 08-P-type gallium nitride layer, 09-transparent conductive layer, 10-electrode layer one (10-1 is P electrode one, 10-2 is n electrode one), 11-high reflectivity DBR layer, 12-electrode layer two (12-1 is P electrode two, 12-2 is n electrode two). DETAILED DESCRIPTION

[0032] Please refer to Figure 1 As shown, the present invention provides a high-light-efficiency flip-chip LED chip and a method for preparing the same. The chip structure is as follows Figure 1 As shown, from bottom to top, it includes: sapphire pattern substrate 01, buffer layer 02, stress gradient layer 03, n-type gallium nitride layer 04, current spreading layer 05, quantum well light emitting layer 06, P-type electron blocking layer 07, P-type gallium nitride layer 08, transparent conductive layer 09, electrode layer 1 10, high reflectivity DBR layer 11, electrode layer 2 12. The buffer layer is AlN, In x Al 1-x N (x = 0 ~ 0.18), GaN (two-dimensional growth mode) composite material structure; stress gradient layer is GaN (three-dimensional growth mode), Al y Ga 1-y The composite material structure is N (y=0-0.15), and the electrode layer 10 further includes a P electrode 1 10-1 and an n electrode 10-2, and the electrode layer 2 12 includes a P electrode 2 12-1 and an n electrode 2 12-2.

[0033] Specifically, the AlN material in the buffer layer 02 is deposited on the sapphire pattern substrate 01 by sputtering technology, and its thickness is Then, In was grown in the MOCVD equipment. x Al 1-x N (x = 0 ~ 0.18), GaN (two-dimensional growth mode), wherein the In doping content gradually changes from 0 to 18%, the In x Al 1-x NMaterial thickness When x = 0.18, In 0.18 Al 0.82 The lattice constant of N can be well matched with that of GaN; then 0.18 Al 0.82 Two-dimensional growth of GaN material on N material, with a thickness of The growth temperature of the above structures is 550°C; then the temperature of the MOCVD chamber is raised to 900°C, and the two-dimensional GaN material is grown at high temperature with a growth thickness of 0.5 to 1 μm.

[0034] In the MOCVD device, GaN (two-dimensional growth mode), GaN (three-dimensional growth mode), Al y Ga 1-y N (y = 0 ~ 0.15) composite stress gradient layer structure; the growth temperature of the two-dimensional GaN material is 900 ° C, the growth thickness is 0.5 ~ 1 μm; the growth temperature of the three-dimensional GaN material is 1050 ° C, the growth thickness is 1 ~ 3 μm; the Al y Ga 1-y The Al doping content of the N material changes from 0 to 15%, the growth temperature is 1050℃, and the growth thickness is

[0035] On the composite buffer layer and composite stress gradient layer described above, a material of an n-type gallium nitride layer 04 with a lower defect density can be obtained, which provides a good foundation for the growth of the quantum well light-emitting layer 06 and the p-type gallium nitride layer 08, thereby obtaining a high-crystal quality LED epitaxial wafer, reducing the probability of light scattering and defect absorption inside the LED material, and can effectively improve the light output efficiency of the flip-chip LED chip.

[0036] The present invention provides a method for preparing a high-quality and high-light-efficiency flip-chip light-emitting diode epitaxial wafer and chip. The specific process production process is as follows: First, a method for growing an epitaxial structure of a high-quality and high-light-efficiency flip-chip LED is performed, which is specifically as follows:

[0037] 1) Sputtering technology is used to evaporate AlN material on the sapphire pattern substrate 01. The thickness of the AlN layer is

[0038]

[0039] 2) The sapphire pattern substrate 01 coated with AlN material is placed in MOCVD for high temperature treatment to clean the substrate surface.

[0040] 3) In the MOCVD device, InxAl is then grown on the cleaned sapphire pattern substrate 01. 1-x N (x = 0 ~ 0.18), GaN (two-dimensional growth mode) composite buffer layer structure, wherein the In doping content gradually changes from 0 to 18%, the In x Al 1-x NMaterial thickness In the x Al 1-x Two-dimensional growth of GaN material on N material, with a thickness of The growth temperature of the above materials is 550°C; then the temperature of the MOCVD chamber is raised to 900°C, and the two-dimensional GaN material is grown at high temperature with a growth thickness of 0.5 to 1 μm. Thus, the composite buffer layer 02 is obtained.

[0041] 4) In the MOCVD device, GaN (two-dimensional growth mode), GaN (three-dimensional growth mode), Al y Ga 1-y N (y = 0 ~ 0.15) composite stress gradient layer 03; the growth temperature of the two-dimensional GaN material is 900 ° C, the growth thickness is 0.5 ~ 1 μm; the growth temperature of the three-dimensional GaN material is 1050 ° C, the growth thickness is 1 ~ 3 μm; the Al y Ga 1-y The Al doping content of the N material changes from 0 to 15%, the growth temperature is 1050℃, and the growth thickness is

[0042] 5) Growing Si-doped n-type gallium nitride material 04 on the stress gradient layer 03 in an MOCVD device; the growth temperature is 1050° C., the growth thickness is 1.5 to 3 μm, and the Si doping concentration is 5×10 18 cm -3 ~5×10 19 cm -3 .

[0043] 6) In the MOCVD device, a current spreading layer 05 is grown on the n-type GaN layer 04, which is a low-concentration Si-doped GaN layer; the growth temperature is 1050° C., the growth thickness is 150-300 nm, and the Si doping concentration is 5×10 16 cm -3 ~5×10 17 cm -3 .

[0044] 7) In a MOCVD device, an InGaN / GaN multi-quantum well light-emitting layer 06 is grown on the current spreading layer 05; the quantum well structure is a well layer InGaN and a barrier layer GaN grown alternately, with a growth cycle of 5 to 15 and a growth temperature of 800°C.

[0045] 8) In the MOCVD device, an electron blocking layer 07 of a P-type AlGaN material is grown on the InGaN / GaN quantum well light-emitting layer 06, and the thickness of the electron blocking layer 07 is The Mg doping concentration is 5×10 18 cm -3 ~5×10 19 cm -3 .

[0046] 9) growing a P-type gallium nitride layer 08 on the P-type electron blocking layer 07 in an MOCVD device; the thickness of the P-type gallium nitride layer 08 is The Mg doping concentration is 5×10 19 cm -3~5×10 20 cm -3 .

[0047] Next, the method for preparing a high-quality and high-light-efficiency flip-chip LED chip is as follows:

[0048] 1) The prepared epitaxial wafer is subjected to MESA etching to the n-GaN layer to etch out the mesa of the n-electrode. The specific method is to first clean the epitaxial wafer to remove surface dirt, then perform photoresist coating, exposure, and development in the yellow light area to obtain a MESA mask layer pattern on the surface of the epitaxial wafer, and then use an ICP device to perform dry etching to etch the area not covered by the mask layer to the n-GaN layer, thereby obtaining the mesa of the n-electrode and obtaining the cutting path between the core particles. After the etching is completed, the surface residual photoresist, i.e., the mask layer, is cleaned to remove.

[0049] 2) Depositing a transparent conductive layer 09 on the above epitaxial wafer, optionally, the transparent conductive layer is made of indium tin oxide ITO material with a thickness of The ITO transparent conductive film can be grown by E-beam electron beam evaporation, sputter magnetron sputtering coating, or RPD reactive plasma deposition; the present embodiment adopts sputter magnetron sputtering coating method to deposit indium tin oxide ITO material; then, the yellow light area is used for coating, exposure, and development to obtain the required pattern on the transparent conductive layer 09, and wet etching is used to remove the ITO layer on the mesa of the n-electrode and the core particle cutting path to expose the mesa of the n-electrode and the core particle cutting path, and then the residual mask layer on the surface is removed by cleaning. After the above steps, the p-electrode mesa of the core particle obtained is covered by the ITO layer.

[0050] 3) An electrode layer 10 (10-1 is a P electrode, 10-2 is an n electrode) is evaporated on the epitaxial wafer coated with a transparent conductive layer. Optionally, the material of the electrode layer 1 is an alloy combination of Cr / Al / Ti / Pt / Au, and the electrode finger shape that is conducive to current expansion is designed according to requirements. The specific method is to perform photoresist coating, exposure, and development in the yellow light area, form the required electrode pattern on the transparent conductive layer 09 and the n electrode platform, and then use electron beam evaporation equipment to evaporate the film of the electrode layer 1, and then peel off the gold and remove the glue to obtain the electrode layers 10-1 and 10-2 with preset patterns.

[0051] 4) Evaporate a DBR layer 11 with high reflectivity on the surface of the wafer obtained above. Optionally, the structure of the DBR layer 11 is that SiO2 / TiO2 materials grow alternately periodically, the growth period is 20 to 50 periods, and the total thickness is 1um to 5um. The specific method is to use vacuum equipment for LED multi-layer optical DBR film coating to evaporate the high reflectivity DBR layer 12; after coating the DBR film layer, perform coating, exposure, and development in the yellow light area, and use ICP for dry etching to obtain the DBR reflective layer. The DBR reflective layer also serves as a surface protection layer, and electrode interconnection through holes are reserved on the above-mentioned p-electrode 10-1 and n-electrode 10-2 to facilitate metal interconnection with the subsequent electrode layer 2 12;

[0052] 5) Electrode 2 12 (12-1 is p-pad, 12-2 is n-pad) is deposited on the epitaxial wafer with high reflectivity DBR layer 11, and the material of electrode layer 2 is an alloy combination of Cr / Al / Ti / Pt / Au; the specific method is to perform photoresist coating, exposure and development in the yellow light area, form the required electrode pattern on DBR layer 11, and still use electron beam evaporation equipment to perform film evaporation of electrode layer 2, and then peel off the gold and remove the photoresist to obtain electrode layer 2 12 (p-pad and n-pad respectively) of a preset pattern, and through the electrode interconnection through hole reserved on the above-mentioned high reflectivity DBR layer 11, electrode layer 2 12 and electrode layer 1 10 form a good metal interconnection. Finally, a flip-chip light-emitting diode chip with high crystal quality and high light efficiency is obtained.

[0053] The present invention can obtain n-type gallium nitride materials with lower defect density by using a composite buffer layer and a composite stress gradient layer, providing a good foundation for the growth of quantum well light-emitting layers and P-type doped gallium nitride layers, thereby obtaining LED epitaxial wafers with high crystal quality. Further, the internal defects of gallium nitride materials are reduced, and LED epitaxial wafers with high crystal quality are obtained, thereby reducing the probability of scattering and defect absorption of light emitted by the quantum well active region inside the LED structure, thereby effectively improving the light output efficiency of the flip-chip LED chip.

Claims

1. A flip-chip light-emitting diode chip with high crystal quality and high light efficiency, characterized in that From bottom to top, it includes the following structures: sapphire graphic substrate, buffer layer, stress gradient layer, n-type gallium nitride layer, current spreading layer, quantum well light-emitting layer, P-type electron blocking layer, P-type gallium nitride layer, transparent conductive layer, electrode layer 1, high reflectivity DBR layer, and electrode layer 2.

2. The flip-chip light emitting diode chip with high crystal quality and high light efficiency according to claim 1, characterized in that: The buffer layer is AlN, In x Al 1-x The composite structure of N (x = 0 ~ 0.18), GaN (two-dimensional growth mode), AlN layer is deposited by sputtering, In x Al 1-x N (x = 0 ~ 0.18) where the In content is gradually doped from 0 to 18%, and then a layer of GaN material is grown in two dimensions.

3. The flip-chip light emitting diode chip with high crystal quality and high light efficiency according to claim 1, characterized in that: The stress gradient layer structure is GaN (two-dimensional growth mode), GaN (three-dimensional growth mode), Al y Ga 1-y N (y = 0 ~ 0.15), GaN layer is grown from intrinsic GaN material, Al y Ga 1-y The Al doping of the N layer is gradually increased from 0 to 15%.

4. A method for preparing a flip-chip light-emitting diode chip with high crystal quality and high light efficiency as claimed in any one of claims 1 to 3, characterized in that First, it is grown in a metal-organic chemical vapor deposition device MOCVD to obtain an epitaxial wafer with a complete epitaxial structure, and then a flip-chip LED chip is prepared on the epitaxial wafer.

5. The method for preparing a flip-chip light-emitting diode chip with high crystal quality and high light efficiency according to claim 4, characterized in that The preparation steps of light-emitting diode epitaxial wafer are as follows: 1) using a sputtering technique to evaporate AlN material on a sapphire pattern substrate, wherein the AlN material is also a part of the buffer layer; 2) placing the sapphire pattern substrate coated with AlN material into MOCVD for high temperature treatment to clean the substrate surface; 3) In the MOCVD device, In is then grown on the cleaned substrate. x Al 1-x N (x = 0 ~ 0.18), GaN (two-dimensional growth mode) buffer layer structure; 4) Growing GaN (two-dimensional growth mode), GaN (three-dimensional growth mode), Al y Ga 1-y N (y = 0 ~ 0.15) composite stress gradient layer structure; 5) growing Si-doped n-type gallium nitride material on the stress graded layer in an MOCVD device; 6) growing a current spreading layer on the n-type gallium nitride in an MOCVD device, wherein the current spreading layer is a gallium nitride layer doped with low concentration Si; 7) growing an InGaN / GaN multi-quantum well light-emitting layer on the current spreading layer in an MOCVD device; 8) growing an electron blocking layer of a P-type AlGaN material on the InGaN / GaN quantum well light-emitting layer in an MOCVD device; 9) Growing a P-type gallium nitride material on the P-type AlGaN electron blocking layer in an MOCVD device.

6. The method for preparing a flip-chip light-emitting diode chip with high crystal quality and high light efficiency according to claim 5, characterized in that The specific method of growing a stress gradient layer structure in an MOCVD device is as follows: 1) In MOCVD equipment, a composite buffer layer structure of InxAl1-xN (x=0-0.18) and GaN (two-dimensional growth mode) is continuously grown on a substrate coated with AlN material; the AlN material is grown by sputtering technology, and the thickness is In grown on the AlN material x Al 1-x N material, wherein the In doping content is gradually changed from 0 to 18%, the In x Al 1-x NMaterial thickness In the x Al 1-x Two-dimensional growth of GaN material on N material, with a thickness of The growth temperature of the above materials in the MOCVD chamber is 500-600°C; 2) continuing to grow a two-dimensional GaN material at a high temperature on the composite buffer layer material in an MOCVD device, the growth temperature being 800-950° C. and the growth thickness being 0.5-1 μm; the two-dimensional GaN material grown at a high temperature serves as a nucleation layer, is a transition between two-dimensional GaN and three-dimensional GaN, and is part of a stress gradient layer; 3) Continue to grow GaN, Al and other materials in three dimensions on the high temperature two-dimensional GaN material in the MOCVD device. y Ga 1-y N (y = 0 ~ 0.15) composite stress gradient layer structure; the growth temperature of the three-dimensional GaN material is 1000 ~ 1100 ℃, the growth thickness is 1 ~ 3μm; the Al y Ga 1-y The Al doping content of the N material gradually changes from 0 to 15%, the growth temperature is 1000~1100℃, and the growth thickness is 7. The method for preparing a flip-chip light-emitting diode chip with high crystal quality and high light efficiency according to claim 4, characterized in that The preparation steps of flip-chip LED chip are as follows: 1) Depositing a transparent conductive layer on the prepared epitaxial wafer, wherein the transparent conductive layer is made of indium tin oxide (ITO) material with a thickness of Deposition growth can be carried out by using E-beam electron beam evaporation method, sputter magnetron sputtering method, or RPD reactive plasma deposition method; 2) depositing an electrode layer 1 on the epitaxial wafer coated with the transparent conductive layer by an E-beam evaporation method, wherein the material of the electrode layer 1 is an alloy combination of Cr / Al / Ti / Pt / Au, and the electrode shape is designed according to the requirements; 3) Depositing a DBR layer with high reflectivity on the epitaxial wafer forming the electrode layer 1, wherein the DBR layer structure is SiO2 / TiO2 periodically and alternately grown, the growth period is 20 to 50 periods, the total thickness is 1 um to 5 um, and the DBR layer wraps around the side wall of the LED core particle, and acts as a passivation protective layer while reflecting light; 4) Electrode layer 2 is deposited on the epitaxial wafer with the high reflectivity DBR layer by E-bean evaporation method, wherein the material of electrode layer 2 is an alloy combination of Cr / Al / Ti / Pt / Au, and the area of ​​electrode layer 2 is large enough to facilitate the packaging operation of flip-chip LED; a reserved through hole is provided on the high reflectivity DBR layer to effectively connect electrode layer 2 and electrode layer 1; finally, a flip-chip light-emitting diode chip with high crystal quality and high light efficiency is obtained.

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