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CN-115911201-B - Light-emitting diode epitaxial wafer, preparation method thereof and light-emitting diode

CN115911201BCN 115911201 BCN115911201 BCN 115911201BCN-115911201-B

Abstract

The invention discloses a light-emitting diode epitaxial wafer and a preparation method thereof, and a light-emitting diode, wherein the light-emitting diode epitaxial wafer comprises a substrate, and a buffer layer, an N-type GaN layer, a stress compensation layer, a stress release layer, a multiple quantum well layer and a P-type GaN layer which are sequentially laminated on the substrate, wherein the stress compensation layer comprises an AlGaN layer, a first GaN layer, an InGaN/GaN superlattice layer and a second GaN layer which are sequentially laminated on the N-type GaN layer. The LED epitaxial wafer provided by the invention has high yield and can effectively improve the luminous brightness of the chip.

Inventors

  • GAO HONG
  • Jin Conglong
  • CHENG LONG
  • ZHENG WENJIE
  • SHU JUN
  • ZHANG CAIXIA
  • CHENG JINLIAN
  • YIN CONGFEI
  • LIU CHUNYANG
  • HU JIAHUI

Assignees

  • 江西兆驰半导体有限公司

Dates

Publication Date
20260512
Application Date
20221121

Claims (10)

  1. 1. The light-emitting diode epitaxial wafer is characterized by comprising a substrate, and a buffer layer, an N-type GaN layer, a stress compensation layer, a stress release layer, a multiple quantum well layer and a P-type GaN layer which are sequentially laminated on the substrate; The stress compensation layer consists of an AlGaN layer, a first GaN layer, an InGaN/GaN superlattice layer and a second GaN layer which are sequentially laminated on the N-type GaN layer; The first GaN layer is a heavily-doped Si GaN layer, and the Si doping concentration of the first GaN layer is 9 x 10 18 atoms/cm 3 -9.5*10 18 atoms/cm 3 ; The second GaN layer is a GaN layer with low Si doping concentration of 1 x 10 17 atoms/cm 3 -1*10 18 atoms/cm 3 , and the Si doping concentration of the second GaN layer gradually changes from low to high from the InGaN/GaN superlattice layer to the stress release layer; The InGaN/GaN superlattice layer comprises an InGaN layer and a GaN layer which are overlapped, wherein the overlapping period number is 20-30, and the thickness ratio of the InGaN layer to the GaN layer is less than 1.5; The InGaN/GaN superlattice layer is an InGaN/GaN superlattice layer with low Si doping concentration of 5 x 10 17 atoms/cm 3 -1*10 18 atoms/cm 3 ; The Si doping concentration of the stress compensation layer is gradually reduced from the first GaN layer to the InGaN/GaN superlattice layer.
  2. 2. The light-emitting diode epitaxial wafer of claim 1, wherein the concentration of Al component in the AlGaN layer is 0.01 to 0.1.
  3. 3. The light-emitting diode epitaxial wafer of claim 1, wherein the concentration of the In component In the InGaN layer is 0.01-0.1.
  4. 4. The light-emitting diode epitaxial wafer of claim 1, wherein the stress compensation layer has a thickness of 300nm to 500nm; The thickness of the AlGaN layer is 20nm-30nm; The thickness of the InGaN/GaN superlattice layer is 100nm-150nm; the thickness of the first GaN layer is 2.5-4 times that of the second GaN layer.
  5. 5. A method for preparing the light-emitting diode epitaxial wafer according to any one of claims 1 to 4, comprising the steps of: preparing a substrate; sequentially depositing a buffer layer, an N-type GaN layer, a stress compensation layer, a stress release layer, a multiple quantum well layer and a P-type GaN layer on the substrate; The stress compensation layer comprises an AlGaN layer, a first GaN layer, an InGaN/GaN superlattice layer and a second GaN layer which are sequentially laminated on the N-type GaN layer.
  6. 6. The method of manufacturing a light emitting diode epitaxial wafer of claim 5, wherein depositing the AlGaN layer on the N-type GaN layer comprises the steps of: The temperature of the reaction chamber is controlled between 950 ℃ and 1200 ℃, and an N source, a Ga source and an Al source are introduced to finish the deposition.
  7. 7. The method of manufacturing a light emitting diode epitaxial wafer of claim 5, wherein depositing the first GaN layer on the AlGaN layer comprises the steps of: Firstly controlling the temperature of a reaction chamber to be 800-980 ℃, introducing N 2 and H 2 as carrier gases, and introducing an N source, a Ga source and a Si source to finish deposition; Wherein the atmosphere ratio of N 2 ：H 2 is (3-4): 1.
  8. 8. The method of fabricating a light emitting diode epitaxial wafer of claim 5, wherein depositing the InGaN/GaN superlattice layer on the first GaN layer comprises the steps of: Controlling the temperature of the reaction chamber at 900-1050 ℃, introducing N 2 and H 2 as carrier gas, firstly introducing a Ga source, an In source, an N source and a Si source to finish InGaN layer deposition, then introducing the Ga source, the N source and the Si source to finish GaN layer deposition, and overlapping deposition for 20-30 periods; Wherein the atmosphere ratio of N 2 ：H 2 is (2-3): 1.
  9. 9. The method of fabricating a light emitting diode epitaxial wafer of claim 5, wherein depositing the second GaN layer on the InGaN/GaN superlattice layer comprises the steps of: controlling the temperature of the reaction chamber at 900-1050 ℃, introducing N 2 and H 2 as carrier gases, and introducing a Ga source, an N source and a Si source to finish deposition; Wherein the atmosphere ratio of N 2 ：H 2 is 1 (1-2).
  10. 10. A light emitting diode, characterized in that the light emitting diode comprises a light emitting diode epitaxial wafer according to any one of claims 1-4.

Description

Light-emitting diode epitaxial wafer, preparation method thereof and light-emitting diode Technical Field The invention relates to the technical field of photoelectricity, in particular to a light-emitting diode epitaxial wafer, a preparation method thereof and a light-emitting diode. Background A GaN-based light emitting diode using a multiple quantum well structure as a main light emitting layer has high radiation recombination efficiency, and is a core technology in the field of semiconductors in recent years. The growth mode is mainly formed by alternately growing InGaN/GaN materials with two different forbidden bandwidths, the forbidden bandwidth of the InGaN is smaller than that of the GaN, and electrons are more easily limited in a quantum well layer with a small forbidden bandwidth to be subjected to radiation recombination with holes in the process of transmitting electrons from an N-type semiconductor to a P-type semiconductor. Therefore, the InGaN/GaN multiple quantum well structure plays a role in limiting carriers to improve radiation recombination efficiency. However, due to poor lattice constant matching of InGaN and GaN, a larger strain polarization electric field is generated, so that the energy band is severely inclined, carriers cannot be effectively limited, more carriers are overflowed, and light efficiency attenuation is aggravated. In order to reduce piezoelectric polarization effect caused by lattice mismatch, stress of the quantum well region is effectively released, and a section of InGaN/GaN quantum well preparation layer with low In composition or InGaN/GaN superlattice preparation layer is usually grown before the quantum well layer. The simple InGaN/GaN quantum well preparation layer or InGaN/GaN superlattice preparation layer is subjected to factors such as bottom defect extension or growth temperature mismatch, so that In segregation phenomenon is serious, crystal quality is poor, stacking faults are increased, V-shaped defects with smaller size are easier to open between stress release layers or active layers which grow subsequently, the small-size V-shaped defects are easier to become leakage channels to influence the final product yield, meanwhile, the uneven stress release layers enable the crystal quality of the quantum well layers which grow subsequently to be poor, the defects penetrate into the active layers, non-radiation recombination probability of the active layers is increased, and finally internal quantum efficiency is reduced. Disclosure of Invention The invention aims to solve the technical problem of providing the light-emitting diode epitaxial wafer which has high yield and can effectively improve the light-emitting brightness of a chip. The invention also aims to solve the technical problem of providing a preparation method of the light-emitting diode epitaxial wafer, which has simple process and can stably prepare the light-emitting diode epitaxial wafer with good performance. In order to solve the technical problems, the invention provides a light-emitting diode epitaxial wafer, which comprises a substrate, and a buffer layer, an N-type GaN layer, a stress compensation layer, a stress release layer, a multiple quantum well layer and a P-type GaN layer which are sequentially laminated on the substrate; The stress compensation layer comprises an AlGaN layer, a first GaN layer, an InGaN/GaN superlattice layer and a second GaN layer which are sequentially laminated on the N-type GaN layer. In one embodiment, the Al component concentration in the AlGaN layer is 0.01-0.1; The first GaN layer is a heavily-doped Si GaN layer, and the Si doping concentration of the first GaN layer is 9 x 10 18atoms/cm3-9.5*1018atoms/cm3; The second GaN layer is a GaN layer with low Si doping concentration of 1 x 10 17atoms/cm3-1*1018atoms/cm3, and the stress release layer is gradually changed from low to high from the InGaN/GaN superlattice layer. In one embodiment, the InGaN/GaN superlattice layer comprises an InGaN layer and a GaN layer which are overlapped, wherein the overlapping period number is 20-30; The InGaN/GaN superlattice layer is an InGaN/GaN superlattice layer with low Si doping concentration of 5 x 10 17atoms/cm3-1*1018atoms/cm3; the concentration of the In component In the InGaN layer is 0.01-0.1; the thickness ratio of the InGaN layer to the GaN layer is <1.5. In one embodiment, the stress compensation layer has a thickness of 300nm to 500nm; The thickness of the AlGaN layer is 20nm-30nm; The thickness of the InGaN/GaN superlattice layer is 100nm-150nm; the thickness of the first GaN layer is 2.5-4 times that of the second GaN layer. In order to solve the problems, the invention provides a preparation method of a light-emitting diode epitaxial wafer, which comprises the following steps: preparing a substrate; sequentially depositing a buffer layer, an N-type GaN layer, a stress compensation layer, a stress release layer, a multiple quantum well layer and a P-type