Epitaxial structure and growth method thereof

Abstract

The present invention provides an epitaxial structure and a growth method thereof. The epitaxial structure comprises, from bottom to top, a composite patterned substrate, a buffer layer, a GaN nucleation layer, an n-type GaN layer, a multi-quantum well layer, an electron blocking layer, and a p-type GaN layer. A preparatory layer is provided between the composite patterned substrate and the buffer layer. The preparatory layer comprises a first sublayer and a second sublayer. The first sublayer comprises an Al atomic deposition layer, and the second sublayer comprises an aluminum nitride amorphous layer. The present invention utilizes the high-energy active state of H2 at high temperature to perform reduction pretreatment on each surface of the composite patterned substrate. Al atoms sputtered by magnetron sputtering are effectively deposited to prepare for subsequent buffer layer deposition and improve the deposition effect of aluminum nitride. During the growth process of an amorphous aluminum nitride thin film layer using N2 and Al as raw materials, a small amount of H2 is introduced to inhibit the reaction of N atoms with SiO2 to generate SiO2 without a crystalline direction. x N y , improve the purity, quality and epitaxial crystal quality of aluminum nitride films, and reduce the defect density of subsequent epitaxial layers.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to an epitaxial structure and a growth method thereof. Background Art

[0002] Compared to traditional LEDs, patterned sapphire substrates, due to their unique geometric structure, reduce total internal reflection in LEDs, significantly improving light extraction efficiency. In recent years, with the technological innovation of patterned sapphire substrates, heterogeneous composite substrates have been widely used, such as SiO2 PSS composite patterned sapphire substrates.

[0003] Advantages of PSS (Patterned Sapphire Substrate): Reduces total internal reflection (TIR) ​​and increases outgoing light; it also shifts epitaxial growth from longitudinal to lateral, reducing the dislocation density of the GaN epitaxial material and improving internal quantum efficiency. SiO2 PSS (Heterogeneous Composite Substrate): While retaining the advantages of PSS, the heterogeneous SiO2 material has a lower refractive index than sapphire, allowing for a greater shift in the angle of light prone to total internal reflection, thereby increasing light extraction efficiency.

[0004] However, the lattice mismatch rate between the heterogeneous substrate and GaN is large, and the difference in thermal expansion coefficient is too large. If GaN is directly grown on the heterogeneous substrate, the dislocation density will increase, affecting the crystal quality. The general solution is to grow an AlN buffer layer with a high lattice matching degree between the heterogeneous substrate and GaN.

[0005] In the prior art, N2 or NH3 is usually used as a nitrogen source, an AlN thin film is deposited by magnetron sputtering, and a buffer layer of an AlN nanocrystalline structure is formed by thermal annealing.

[0006] However, due to the special structure of the patterned substrate, the Al thin film and the subsequent AlN buffer layer crystal film cannot be effectively deposited on its sidewalls; at the same time, when N2 or NH3 gas is introduced, the heterogeneous substrate SiO2 easily reacts with N2 or NH3 to form SiO2 without crystallization direction. x N y This results in poor crystal quality and an increase in defect density compared to homogeneous composite substrates, affecting yield. Summary of the Invention

[0007] Based on this, an object of the present invention is to provide an epitaxial structure and a growth method thereof, so as to at least solve the deficiencies in the above-mentioned technology.

[0008] The present invention proposes an epitaxial structure, which includes, from bottom to top, a composite patterned substrate, a buffer layer, a GaN nucleation layer, an n-type GaN layer, a multi-quantum well layer, an electron blocking layer and a P-type GaN layer. A preliminary layer is provided between the composite patterned substrate and the buffer layer. The preliminary layer includes a first sublayer and a second sublayer. The first sublayer is provided on the composite patterned substrate, and the second sublayer is provided on the first sublayer. The first sublayer includes an Al atomic deposition layer, and the second sublayer includes an aluminum nitride amorphous layer.

[0009] Furthermore, the first sublayer is an Al atomic deposition layer formed by sputtering an Al target onto the composite patterned substrate using a magnetron sputtering method in a pure H2 atmosphere, wherein the growth temperature of the Al atomic deposition layer is 500-1000°C and the duration is 50-100s.

[0010] Furthermore, the second sub-layer is an aluminum nitride amorphous layer grown on the first sub-layer in a mixed atmosphere of H2 and N2, wherein the mixing ratio of H2 and N2 is 1:15 to 1:9.

[0011] Furthermore, the thickness of the first sub-layer is 5-10 nm, and the thickness of the second sub-layer is 15-20 nm.

[0012] The present invention further provides a method for growing an epitaxial structure, which is used to grow the above-mentioned epitaxial structure. The method for growing an epitaxial structure comprises:

[0013] Step 1: Select a composite patterned substrate and deposit a first sublayer on the composite patterned substrate using a magnetron sputtering method in a pure H2 atmosphere;

[0014] Step 2: introducing N2 to make the mixing ratio of H2 and N2 equal to a preset mixing ratio, and continuing to deposit the second sub-layer on the first sub-layer in the mixed atmosphere of H2 and N2;

[0015] Step 3: turning off the H2 input and continuing to deposit a buffer layer on the second sub-layer in the pure N2 atmosphere;

[0016] Step 4: Continue to grow a GaN nucleation layer, an n-type GaN layer, a multi-quantum well layer, an electron blocking layer and a p-type GaN layer from bottom to top on the buffer layer, wherein the buffer layer, the GaN nucleation layer, the n-type GaN layer, the multi-quantum well layer, the electron blocking layer and the p-type GaN layer are stacked.

[0017] Further, in the first step, the composite patterned substrate is any one of SiO2 patterned sapphire substrate and SiC patterned sapphire substrate, and the patterning of the composite patterned substrate is any one or a combination of a columnar shape with a slope surface, a triangular pyramid shape, and a semi-circular wrap shape.

[0018] Further, in the first step, the first sub-layer is an Al atomic thin film, and its growth temperature is 800 °C to 1200 °C and its growth thickness is 5 to 10 nm.

[0019] Further, in the second step, the preset mixing ratio is 1:15 to 1:9, and the second sub-layer is an amorphous aluminum nitride thin film layer, and its growth temperature is 200 to 500 °C and its growth thickness is 15 to 20 nm.

[0020] Further, in the third step, the buffer layer is an aluminum nitride layer, and its growth temperature is 200 to 500 °C and its growth thickness is 10 to 20 nm.

[0021] Further, in the fourth step, the growth temperature of the GaN nucleation layer gradually changes from 1050 °C to 1130 °C, the growth pressure gradually changes from 200 Torr to 100 Torr, and the V / III ratio is 500 to 1000;

[0022] The growth temperature of the n-type GaN layer is 1100 °C, the growth thickness is 2 to 3 μm, and the Si doping concentration is 1.6E19 to 5E19 Atom / cm3;

[0023] The multi-quantum well layer is an alternately stacked InGaN quantum well layer and an AlGaN quantum barrier layer, and the number of stacking periods is 6 to 12. Among them, the growth temperature of the InGaN quantum well layer is 790 to 810 °C, the growth thickness is 2 to 3.5 nm, the growth temperature of the AlGaN quantum barrier layer is 850 to 900 °C, the growth thickness is 9 to 12 nm, and the Al component is 0.1;

[0024] The electron blocking layer is Al x In y Ga 1-x-y N, its growth thickness is 10 to 40 nm, the growth temperature is 900 to 1000 °C, where the Al component is 0.005 < x < 0.1 and the In component concentration is 0.05 < y < 0.2;

[0025] The growth temperature of the p-type GaN layer is 900 to 1000 °C, the growth thickness is 10 to 50 nm, the growth pressure is 100 to 600 Torr, and the Mg doping concentration is 1E19 to 1E20 Atom / cm3.

[0026] Compared with the existing technology, the beneficial effects of the present invention are: utilizing the high energy active state of H2 at high temperature to perform in-situ etching on the composite patterned substrate, performing reduction pretreatment on each surface of the composite patterned substrate, and effectively depositing Al atoms generated by magnetron sputtering on the pretreated composite substrate surface, preparing for the subsequent deposition of the aluminum nitride buffer layer, and improving the deposition effect of aluminum nitride on the sidewalls of the patterned substrate. In addition, during the growth process of the amorphous aluminum nitride thin film layer using N2 and Al as raw materials, a small amount of H2 is introduced. The H atoms generated by the decomposition of H2 at high temperature will inhibit the reaction of N atoms with SiO2 to form SiO2 without crystallization direction. x N y , improve the purity and quality of aluminum nitride films, reduce the defect density of subsequent epitaxial layers, and improve the quality of epitaxial crystals. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic diagram of the overall structure of the epitaxial structure in the first embodiment of the present invention;

[0028] Figure 2 FIG. 4 is a flow chart of a method for growing an epitaxial structure according to a second embodiment of the present invention.

[0029] Description of main component symbols:

[0030] Composite patterned substrate 10 Multi-quantum well layer 60 Preparatory layer 20 electron blocking layer 70 buffer layer 30 P-type GaN layer 80 GaN nucleation layer 40 First sublayer 21 n-type GaN layer 50 Second sublayer 22

[0031] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0032] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The drawings illustrate several embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present invention.

[0033] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0035] Example 1

[0036] See also Figure 1 , shown is the epitaxial structure in the first embodiment of the present invention, which includes, from bottom to top, a composite patterned substrate 10, a buffer layer 30, a GaN nucleation layer 40, an n-type GaN layer 50, a multi-quantum well layer 60, an electron blocking layer 70, and a p-type GaN layer 80. A preliminary layer 20 is provided between the composite patterned substrate 10 and the buffer layer 30. The preliminary layer 20 includes a first sublayer 21 and a second sublayer 22. The first sublayer 21 is provided on the composite patterned substrate 10, and the second sublayer 22 is provided on the first sublayer 21. The first sublayer 21 includes an Al atomic deposition layer, and the second sublayer 22 includes an aluminum nitride amorphous layer.

[0037] It can be understood that by arranging an Al atomic deposition layer and an aluminum nitride amorphous layer between the composite patterned substrate 10 and the buffer layer 30, the ineffective buffer layer 30 deposition on the patterned heterogeneous substrate is improved, and the Si x N y The formation of ions reduces the defect density and improves the quality of the underlying crystal.

[0038] Specifically, the first sub-layer 21 is an Al atomic deposition layer formed by sputtering an Al target onto the composite patterned substrate 10 using a magnetron sputtering method in a pure hydrogen atmosphere, wherein the growth temperature of the Al atomic deposition layer is 500-1000° C. and the duration is 50-100 s.

[0039] It can be understood that the magnetron sputtering method can make Al atoms more fully combined with each surface of the patterned substrate, thereby achieving effective coverage of the Al atomic layer.

[0040] Furthermore, the second sub-layer 22 is an aluminum nitride amorphous layer grown on the first sub-layer 21 in a mixed atmosphere of H2 and N2, wherein the mixing ratio of H2 and N2 is 1:15 to 1:9.

[0041] It should be noted that in this embodiment, the ratio of the mixed gas of H2 and N2 introduced is 1:9. N2 is used as a nitrogen source to combine with Al atoms to form an amorphous structure Al x N yThe film covers the Al atomic layer of the first sub-layer 21. At the same time, a small amount of H2 can inhibit the N atoms from combining with the Si of the composite substrate to form Si without crystal direction. x N y layer, reducing the defect density during subsequent epitaxial growth and improving crystal quality.

[0042] In this embodiment, the thickness of the first sublayer 21 is 5-10 nm, and the thickness of the second sublayer 22 is 15-20 nm. The thickness of the entire preliminary layer 20 directly affects the deposition of the subsequent AlN buffer layer 30. If the thickness is too thin, the buffer layer 30 may be unevenly distributed, which in turn affects the island nucleation density of the subsequent epitaxial GaN.

[0043] In summary, the epitaxial structure in the above embodiment of the present invention utilizes the high energy active state of H2 at high temperature to perform in-situ etching on the composite patterned substrate, and performs reduction pretreatment on each surface of the composite patterned substrate. The Al atoms generated by magnetron sputtering can be effectively deposited on the pretreated composite substrate surface, preparing for the subsequent deposition of the aluminum nitride buffer layer, and improving the deposition effect of aluminum nitride on the sidewalls of the patterned substrate. In addition, during the growth process of the amorphous aluminum nitride thin film layer using N2 and Al as raw materials, a small amount of H2 is introduced. The H atoms generated by the decomposition of H2 at high temperature will inhibit the reaction of N atoms with SiO2 to generate SiO2 without crystallization direction. x N y , improve the purity and quality of aluminum nitride films, reduce the defect density of subsequent epitaxial layers, and improve the quality of epitaxial crystals.

[0044] Example 2

[0045] The present invention also proposes a method for growing an epitaxial structure, see Figure 2 , which shows a method for growing an epitaxial structure in a second embodiment of the present invention, and is used to grow the epitaxial structure in the first embodiment. The method for growing an epitaxial structure specifically includes steps S101 to S104:

[0046] S101: selecting a composite patterned substrate, and depositing a first sublayer on the composite patterned substrate by a magnetron sputtering method in a pure H2 atmosphere;

[0047] In the specific implementation, in this embodiment, an A7 MOCVD (Metal-organic Chemical Vapor Deposition, MOCVD for short) device is used to implement the epitaxial structure growth method. Of course, in some optional embodiments, other epitaxial devices can also be used.

[0048] Specifically, in step S101, the composite patterned substrate is a SiO2 patterned sapphire substrate, and the patterning of the composite patterned substrate is a columnar shape with a sloped surface.

[0049] It should be noted that, in other embodiments, the composite patterned substrate may also be a SiC patterned sapphire substrate, and the patterning of the composite patterned substrate may also be any one or more combinations of a triangular pyramid with a sloped surface and a semicircular package.

[0050] Furthermore, in the step S101, the first sub-layer is an Al atomic thin film, the growth temperature of which is 800° C. to 1200° C., and the growth thickness is 5 to 10 nm.

[0051] It should be noted that, in this embodiment, preferably, the growth temperature of the first sub-layer is 1000° C., and an Al atomic film is deposited on the above substrate by magnetron sputtering in an H 2 atmosphere, with a growth thickness of 5 nm.

[0052] S102: introducing N2 to make the mixing ratio of H2 and N2 equal to a preset mixing ratio, and continuing to deposit a second sub-layer on the first sub-layer in the mixed atmosphere of H2 and N2;

[0053] Furthermore, in step S102, the preset mixing ratio is 1:15 to 1:9, the second sub-layer is an amorphous aluminum nitride thin film layer, the growth temperature thereof is 200 to 500°C, and the growth thickness is 15 to 20 nm.

[0054] It should be noted that, in this embodiment, preferably, the preset mixing ratio is 1:9, the growth temperature of the second sub-layer is 500° C., and the growth thickness is 15 nm.

[0055] S103: turning off the H2 input and continuing to deposit a buffer layer on the second sub-layer in the pure N2 atmosphere;

[0056] Furthermore, in step S103, the buffer layer is an aluminum nitride layer, the growth temperature of which is 200-500° C., and the growth thickness is 10-20 nm.

[0057] It should be noted that, in this embodiment, preferably, the growth temperature of the buffer layer is 500° C. and the growth thickness is 15 nm.

[0058] S104: Continue to grow a GaN nucleation layer, an n-type GaN layer, a multi-quantum well layer, an electron blocking layer, and a p-type GaN layer on the buffer layer from bottom to top, wherein the buffer layer, the GaN nucleation layer, the n-type GaN layer, the multi-quantum well layer, the electron blocking layer, and the p-type GaN layer are stacked.

[0059] Further, in the step S104, the growth temperature of the GaN nucleation layer gradually changes from 1050 °C to 1130 °C, the growth pressure gradually changes from 200 Torr to 100 Torr, and the V / III ratio is 500 - 1000;

[0060] In this embodiment, preferably, the V / III ratio of the GaN nucleation layer is 800.

[0061] The growth temperature of the n-type GaN layer is 1100 °C, the growth thickness is 2 - 3 μm, and the Si doping concentration is 1.6E19 - 5E19 Atom / cm3;

[0062] In this embodiment, preferably, the growth thickness of the n-type GaN layer is 3 μm and the Si doping concentration is 5E19 Atom / cm3.

[0063] The multiple quantum well layer is an alternately stacked InGaN quantum well layer and an AlGaN quantum barrier layer, and the number of stacking periods is 6 - 12. Among them, the growth temperature of the InGaN quantum well layer is 790 - 810 °C, the growth thickness is 2 - 3.5 nm, the growth temperature of the AlGaN quantum barrier layer is 850 - 900 °C, the growth thickness is 9 - 12 nm, and the Al component is 0.1;

[0064] In this embodiment, preferably, the number of stacking periods of the multiple quantum well layer is 12. Among them, the growth temperature of the InGaN quantum well layer is 800 °C, the growth thickness is 3.5 nm, the growth temperature of the AlGaN quantum barrier layer is 900 °C, and the growth thickness is 12 nm.

[0065] The electron blocking layer is Al x In y Ga 1-x-y N, its growth thickness is 10 - 40 nm, the growth temperature is 900 - 1000 °C, where 0.005 < x < 0.1 for the Al component and 0.05 < y < 0.2 for the In component concentration;

[0066] In this embodiment, preferably, the growth thickness of the electron blocking layer is 40 nm, the growth temperature is 1000 °C, where the Al component is 0.05 and the In component concentration is 0.1.

[0067] ]>The growth temperature of the P-type GaN layer is 900 - 1000 °C, the growth thickness is 10 - 50 nm, the growth pressure is 10 '0 - 600 Torr, and the Mg doping concentration is 1E19 - 1E20 Atom / cm3.

[0068] In this embodiment, preferably, the growth temperature of the P-type GaN layer is 1000° C., the growth thickness is 50 nm, the growth pressure is 600 Torr, and the Mg doping concentration is 1E20 Atom / cm 3 .

[0069] Epitaxial wafer characterization measurements were performed on sample A obtained according to the above steps, along with sample B obtained using the prior art method. As shown in the table below, XRD rocking curves were measured along the (XRD 002) and (XRD102) planes of both samples, and the mean of the sample data for each group was calculated. The results show that the full width at half maximum (FWHM) of sample A on the (XRD 002) plane was 100 (arcsec), and the FWHM of the (XRD 102) plane was 164 (arcsec); while the FWHM of sample B on the (XRD 002) plane was 194 (arcsec), and the FWHM of the (XRD102) plane was 215 (arcsec). The measurement results indicate that the defect density of sample A is significantly lower than that of sample B, indicating that the above method can be beneficial for improving epitaxial crystal quality.

[0070] Sampl XRD 002 XRD 102 A 99.85 169.19 A 96.04 164.40 A 104.12 159.14 B 210.55 220.00 B 162.29 210.00 B 207.56 215.00

[0071] In summary, the epitaxial structure growth method in the above embodiment of the present invention utilizes the high energy active state of H2 at high temperature to perform in-situ etching on the composite patterned substrate, and performs reduction pretreatment on each surface of the composite patterned substrate. The Al atoms generated by magnetron sputtering can be effectively deposited on the pretreated composite substrate surface, preparing for the subsequent deposition of the aluminum nitride buffer layer, and improving the deposition effect of aluminum nitride on the sidewalls of the patterned substrate. In addition, during the growth process of the amorphous aluminum nitride thin film layer using N2 and Al as raw materials, a small amount of H2 is introduced. The H atoms generated by the decomposition of H2 at high temperature will inhibit the reaction of N atoms with SiO2 to generate SiO2 without crystallization direction. x N y , improve the purity and quality of aluminum nitride films, reduce the defect density of subsequent epitaxial layers, and improve the quality of epitaxial crystals.

[0072] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0073] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. An epitaxial structure, characterized in that From bottom to top, it includes a composite patterned substrate, a buffer layer, a GaN nucleation layer, an n-type GaN layer, a multi-quantum well layer, an electron blocking layer and a P-type GaN layer. A preparatory layer is provided between the composite patterned substrate and the buffer layer. The preparatory layer includes a first sublayer and a second sublayer. The first sublayer is provided on the composite patterned substrate, and the second sublayer is provided on the first sublayer. The first sublayer includes an Al atomic deposition layer, and the second sublayer includes an aluminum nitride amorphous layer. The thickness of the first sublayer is 5~10nm, and the thickness of the second sublayer is 15~20nm.

2. The epitaxial structure according to claim 1, wherein: The first sublayer is an Al atomic deposition layer formed by sputtering an Al target onto the composite patterned substrate using a magnetron sputtering method in a pure H2 atmosphere, wherein the growth temperature of the Al atomic deposition layer is 500-1000°C and the duration is 50-100s.

3. The epitaxial structure according to claim 1, wherein: The second sub-layer is an aluminum nitride amorphous layer grown on the first sub-layer in a mixed atmosphere of H2 and N2, wherein the mixing ratio of H2 and N2 is 1:15 to 1:

9.

4. A method for growing an epitaxial structure, for growing the epitaxial structure according to any one of claims 1 to 3, characterized in that: The method for growing the epitaxial structure comprises: Step 1: Select a composite patterned substrate and deposit a first sublayer on the composite patterned substrate using a magnetron sputtering method in a pure H2 atmosphere; Step 2: introducing N2 to make the mixing ratio of H2 and N2 equal to a preset mixing ratio, and continuing to deposit the second sub-layer on the first sub-layer in the mixed atmosphere of H2 and N2; Step 3: Turn off the H2 input and continue to deposit a buffer layer on the second sub-layer in a pure N2 atmosphere; Step 4: Continue to grow a GaN nucleation layer, an n-type GaN layer, a multi-quantum well layer, an electron blocking layer and a p-type GaN layer from bottom to top on the buffer layer, wherein the buffer layer, the GaN nucleation layer, the n-type GaN layer, the multi-quantum well layer, the electron blocking layer and the p-type GaN layer are stacked.

5. The method for growing an epitaxial structure according to claim 4, wherein: In the step 1, the composite patterned substrate is any one of a SiO2 patterned sapphire substrate and a SiC patterned sapphire substrate, and the patterning of the composite patterned substrate is any one or more combinations of a column with a sloped surface, a triangular pyramid, and a semicircular package.

6. The epitaxial structure growth method according to claim 4, characterized in that: In the step 1, the first sub-layer is an Al atomic thin film, the growth temperature of which is 800° C. to 1200° C., and the growth thickness is 5 to 10 nm.

7. The epitaxial structure growth method according to claim 4, characterized in that: In the step 2, the preset mixing ratio is 1:15-1:9, the second sub-layer is an amorphous aluminum nitride thin film layer, the growth temperature thereof is 200-500° C., and the growth thickness is 15-20 nm.

8. The epitaxial structure growth method according to claim 4, characterized in that: In the step three, the buffer layer is an aluminum nitride layer, the growth temperature of which is 200-500° C. and the growth thickness is 10-20 nm.

9. The epitaxial structure growth method according to claim 4, characterized in that: In the step 4, the growth temperature of the GaN nucleation layer is gradually changed from 1050° C. to 1130° C., the growth pressure is gradually changed from 200 Torr to 100 Torr, and the VIII ratio is 500-1000; The n-type GaN layer has a growth temperature of 1100°C, a growth thickness of 2-3 μm, and a Si doping concentration of 1.6E19-5E19 Atom / cm3; The multi-quantum well layer is an alternately stacked InGaN quantum well layer and an AlGaN quantum barrier layer, with a stacking period of 6 to 12. The InGaN quantum well layer is grown at a temperature of 790 to 810° C. and a thickness of 2 to 3.5 nm. The AlGaN quantum barrier layer is grown at a temperature of 850 to 900° C. and a thickness of 9 to 12 nm, and has an Al composition of 0.

1. The electron blocking layer is Al x In y Ga 1-x-y N, with a growth thickness of 10 to 40 nm and a growth temperature of 900 to 1000 °C, where the Al component is 0.005 < x < 0.1 and the In component concentration is 0.05 < y < 0.2; The growth temperature of the P-type GaN layer is 900-1000° C., the growth thickness is 10-50 nm, the growth pressure is 100-600 Torr, and the Mg doping concentration is 1E19-1E20 Atom / cm 3 .

Images