CN106229389A - A method for preparing a light-emitting diode on a metal gallium nitride composite substrate - Google Patents

Abstract

A method for preparing LED on metal gallium nitride composite substrate includes following steps, firstly, N₂Extending a low-temperature N-type GaN stress release layer with the thickness of 200 nanometers on the metal GaN composite substrate in the atmosphere of 820-850 ℃ and the pressure of the reaction chamber of 300torr, and then carrying out epitaxial growth on the low-temperature N-type GaN stress release layer on the metal GaN composite substrate in the atmosphere of N₂Growing multi-period In under the atmosphere of 750-850 DEG C_xGa_1‑xN/GaN multiple quantum well active region; followed by reaction at H₂Growing p-type Al in the atmosphere at 850-95 DEG C_y1In_x1Ga_1‑y1‑x1A barrier layer for N electrons, then at H₂Growing a high-temperature p-type GaN layer under the atmosphere and at the temperature of 950-; then H₂Growing a p-type InGaN contact layer in an atmosphere at 650-750 ℃, and annealing to obtain the high-brightness metal gallium nitride composite substrate light-emitting diode. The invention improves the luminous efficiency of the metal gallium nitride composite substrate light-emitting diode.

Description

A method for preparing a light-emitting diode on a metal gallium nitride composite substrate

technical field

The invention relates to the technical field of semiconductor optoelectronics, and relates to a method for preparing a high-brightness light-emitting diode on a metal gallium nitride composite substrate.

Background technique

People are paying more and more attention to the heat dissipation of LEDs. This is because the light decay or life of LEDs is directly related to its junction temperature. If the heat dissipation is not good, the junction temperature will be high and the lifespan will be short. Lowering the life by 10°C will prolong the life by 2 times. According to the relationship between light decay and junction temperature, if the junction temperature can be controlled at 65°C, then the lifetime of light decay to 70% can be as high as 100,000 hours! However, limited to the heat dissipation performance of the actual LED lamp, the lifespan of the LED lamp has become a major issue affecting its performance. Moreover, the junction temperature not only affects the long-term lifetime, but also directly affects the short-term luminous efficiency. For example, when the junction temperature is 25 degrees, the luminescence is 100%, then when the junction temperature rises to 60 degrees, the luminescence is only 90%; when the junction temperature is 100 degrees, the luminescence drops to 80%; when the junction temperature rises to 140 When the temperature is high, the luminous amount is only 70%. It can be seen that it is very important to improve the heat dissipation of LED lamps and control the junction temperature. In addition, the heating of the LED will also cause its spectrum to shift, the color temperature will increase, the forward current will increase (when the power supply is constant), the reverse current will also increase, the thermal stress will increase, and the aging of the phosphor epoxy resin will be accelerated. and other issues. Therefore, the heat dissipation of LEDs is the most important issue in the design of LED lamps.

LED chips are characterized by extremely high heat generation in an extremely small volume. The heat capacity of the LED itself is very small, so the heat must be conducted out at the fastest speed, otherwise a high junction temperature will be generated. In order to draw the heat out of the chip as much as possible, many improvements have been made on the chip structure of the LED. In order to improve the heat dissipation of the LED chip itself, the main improvement is to use a substrate material with better thermal conductivity. Early LEDs just used Si (silicon) as the substrate. Later it was changed to sapphire as the substrate. But the thermal conductivity of sapphire substrate is not very good, about 25W/(m-K) at 100°C. Metal gallium nitride composite substrates can effectively solve the heat dissipation problem of LEDs. However, due to the large thermal mismatch between the metal substrate and the GaN epitaxial layer, light-emitting diodes are currently fabricated on metal gallium nitride composite substrates. Brightness is less than satisfactory.

Contents of the invention

The technical problem to be solved by the invention is to provide a method for preparing a light-emitting diode on a metal gallium nitride composite substrate with good heat dissipation and improved luminous efficiency.

In order to solve the problems of the technologies described above, the present invention takes the following solutions:

A method for preparing a light-emitting diode on a metal gallium nitride composite substrate, comprising the following steps:

Step 1, put the metal gallium nitride composite substrate into the MOCVD reaction chamber, raise the temperature of the MOCVD reaction chamber to 820-850°C under the _N2 atmosphere and the pressure of the MOCVD reaction chamber at 300torr, and then set the temperature at 820-850°C Annealing within the range of 55-65s, followed by MOCVD chamber pressure of 300torr, V/III molar ratio of 500-1300, growth rate of 0.2μm/hour-1μm/hour, and growth of low-temperature n-type GaN with a thickness of 200nm stress relief layer;

Step 2, grow 3-10 cycles of In _x Ga _1-x N/GaN multi-quantum in N ₂ atmosphere, 750-850 ° C, with V/III molar ratio of 5000-10000 and MOCVD reaction chamber pressure of 300 Torr Well active area, where 0<x≤0.3;

Step 3, grow p-type Al _y1 In _x1 Ga _1-y1 with a thickness of 30 nanometers under N ₂ atmosphere at 850-950°C, with a V/III molar ratio of 5000-10000 and an MOCVD reaction chamber pressure of 100-300torr _-x1 N electron blocking layer, Al composition 0≤y ₁ ≤0.2, In composition 0≤x ₁ ≤x;

Step 4, growing a high-temperature p-type GaN layer with a thickness of 100-300 nm in an _H2 atmosphere at 950-1050° C. with a V/III molar ratio of 2000-5000 and a MOCVD reaction chamber pressure of 100 torr;

Step 5, growing a p-type InGaN contact layer with a thickness of 2-4 nm in an _H2 atmosphere at 650-750° C., with a V/III molar ratio of 5000-10000 and an MOCVD reaction chamber pressure of 300 torr;

In step 6, the temperature of the MOCVD reaction chamber is lowered to 20-30° C., the growth is terminated, and the growth of the epitaxial layer of the metal gallium nitride composite substrate light-emitting diode is completed, and a high-brightness metal gallium nitride composite substrate light-emitting diode is prepared.

The Si doping concentration of the low-temperature n-type GaN stress release layer in the step 1 is 10 ¹⁸ -10 ¹⁹ cm ^-3 .

The step 2 of growing the In _x Ga _1-x N/GaN multi-quantum well active region specifically includes:

Step 2.1, in N ₂ atmosphere, 750-850°C, with the V/III molar ratio of 5000-10000, and the pressure of the MOCVD reaction chamber at 300torr, first grow the In _x Ga _1-x N/GaN multiple quantum wells for 3 cycles In the active region, where 0<x≤0.3, the thickness of the In _x Ga _1-x N well layer is 2-4nm, the thickness of the GaN barrier layer is 8-20nm, and the Si doping concentration of the GaN barrier layer is 10 ¹⁷ cm ^-3 ;

Step 2.2, and then continue to grow the In _x Ga _1-x N/GaN multi-quantum well active region for 7 cycles, wherein, 0<x≤0.3, the thickness of the In _x Ga _1-x N well layer is 2-4nm 1. The thickness of the GaN barrier layer is 8-20nm, wherein the GaN barrier layer is a non-doped layer.

The step 3 of growing the p-type Al _y1 In _x1 Ga _1-y1-x1 N electron blocking layer specifically includes:

Step 3.1, in a _N2 atmosphere at 850-950°C, with a V/III molar ratio of 5000-10000 and an MOCVD reaction chamber pressure of 100-300 torr, grow a p-type Al _y1 In _x1 Ga _{1- y1-x1} N electron blocking layer, the Mg doping concentration of the p-type Al _y1 In _x1 Ga _1-y1-x1 N electron blocking layer corresponds to a hole concentration of 1×10 ¹⁷ cm ^-3 , where the Al component is 0 ≤y ₁ ≤0.2, In composition 0≤x ₁ ≤x;

Step 3.2, and then continue to grow a p-type Al _y1 In _x1 Ga _1-y1-x1 N electron blocking layer with a thickness of 30 nm, the Mg doping of the p-type Al _y1 In _x1 Ga _1-y1-x1 N electron blocking layer The hole concentration corresponding to the concentration is 2×10 ¹⁷ cm ^-3 , wherein, the Al composition 0≤y ₁ ≤0.2, and the In composition 0≤x ₁ ≤x.

The Mg doping concentration of the high temperature p-type GaN layer in step 4 is 5×10 ¹⁷ cm ⁻³ .

The Mg doping concentration of the p-type InGaN contact layer in the step 5 is greater than 10 ¹⁸ cm ^-3 .

The step 6 specifically includes lowering the temperature of the MOCVD reaction chamber to 700-750° C., then performing annealing treatment in a pure nitrogen atmosphere for 5-20 minutes, and then lowering the temperature to 20-30° C.

The invention effectively alleviates the compressive stress of the active area and improves the crystal quality of the active area by epitaxially extending the low-temperature stress release layer between the metal gallium nitride composite substrate and the multi-quantum well active area. By adopting the Si step-doped quantum barrier layer and the electron blocking layer with a step-change Mg doping concentration, the distribution of electron holes in the active region is effectively improved, and the luminous efficiency of the metal gallium nitride composite substrate light-emitting diode is improved.

Description of drawings

Accompanying drawing 1 is the schematic cross-sectional structure diagram of the light-emitting diode prepared by the method of the present invention.

detailed description

In order to facilitate the understanding of those skilled in the art, the present invention will be further described below in conjunction with the drawings and specific embodiments.

The invention utilizes a close-coupled vertical reaction chamber MOCVD growth system to grow in a metal organic compound vapor phase epitaxy reaction chamber MOCVD reaction chamber to complete the growth of a light-emitting diode epitaxial layer on a metal gallium nitride composite substrate. As shown in Figure 1, the structure of the epitaxial layer of the light-emitting diode is, from bottom to top, metal gallium nitride composite substrate 101, low-temperature n-type GaN stress release layer 102, In _x Ga _1-x N/GaN multiple quantum wells Active region 103 , p-type Al _y1 In _x1 Ga _1-y1-x1 N electron blocking layer 104 , high-temperature p-type GaN layer 105 , and p-type InGaN contact layer 106 . During the growth process, trimethylgallium (TMGa), triethylgallium (TEGa), trimethylindium (TMIn), trimethylaluminum (TMAl) were used as Group III sources, and ammonia (NH ₃ ) was used as Ga, Al, In and N sources, silane (SiH ₄ ) as n-type dopant, and dimagnesocene (Cp ₂ Mg) as p-type dopant.

The present invention will be further elaborated below with specific examples.

Embodiment one

A method for preparing a light-emitting diode on a metal gallium nitride composite substrate, comprising the following steps:

Step 1, put the metal gallium nitride composite substrate 101 into the MOCVD reaction chamber, raise the temperature of the MOCVD reaction chamber to 820°C under the _N2 atmosphere and the pressure of the MOCVD reaction chamber at 300torr, and then carry out while maintaining the temperature at 820°C Annealing treatment for 55 seconds, followed by an MOCVD reaction chamber pressure of 300 torr, V/III molar ratio of 500, and a growth rate of 0.2 μm/hour to grow a low-temperature n-type GaN stress release layer 102 with a thickness of 200 nanometers. The low-temperature n-type GaN stress The Si doping concentration of the release layer is 10 ¹⁸ cm ^-3 .

Step 2, grow 3-10 cycles of In _x Ga _1-x N/GaN multi-quantum in N ₂ atmosphere, 750-850 ° C, with V/III molar ratio of 5000-10000 and MOCVD reaction chamber pressure of 300 Torr Well active region 103, where 0<x≤0.3.

This step 2 specifically includes: step 2.1, in a _N2 atmosphere at 750°C, with a V/III molar ratio of 5000 and an MOCVD reaction chamber pressure of 300 torr, the In _x Ga _1-x N/GaN poly In the quantum well active region, x is 0.1, the thickness of the In _x Ga _1-x N well layer is 2 nm, the thickness of the GaN barrier layer is 8 nm, and the Si doping concentration of the GaN barrier layer is 10 ¹⁷ cm ^-3 . Gtvb

Step 2.2, and then keep the _N2 atmosphere in step 2.1, at 750°C, with the V/III molar ratio of 5000, and the MOCVD reaction chamber pressure of 300torr, continue to grow In _x Ga _1-x N/ The GaN multi-quantum well active region, wherein x is 0.1, the thickness of the In _x Ga _1-x N well layer is 2nm, and the thickness of the GaN barrier layer is 8nm, wherein the GaN barrier layer is a non-doped layer. After the above growth, the In _x Ga _1-x N/GaN multi-quantum well active region in which the doping concentration of the barrier layer Si changes stepwise is obtained.

Step 3, grow p-type Al _y1 In _x1 Ga _1-y1 with a thickness of 30 nanometers under N ₂ atmosphere at 850-950°C, with a V/III molar ratio of 5000-10000 and an MOCVD reaction chamber pressure of 100-300torr _-x1 N electron blocking layer (104), Al composition 0≤y ₁ ≤0.2, In composition 0≤x ₁ ≤x.

This step 3 specifically includes: step 3.1, in a N ₂ atmosphere at 850°C, with a V/III molar ratio of 5000 and an MOCVD reaction chamber pressure of 100 torr, first grow p-type Al _y1 In _x1 Ga _{1- y1-x1} N electron blocking layer, the Mg doping concentration of the p-type Al _y1 In _x1 Ga _1-y1-x1 N electron blocking layer corresponds to a hole concentration of 1×10 ¹⁷ cm ^-3 , wherein the Al composition y ₁ is 0, In composition x ₁ is 0.

Step 3.2, and then keep the _N2 atmosphere in step 3.1, at 850°C, with the V/III molar ratio of 5000, and the pressure of the MOCVD reaction chamber at 100torr, continue to grow p-type Al _y1 In _x1 Ga with a thickness of 30 nanometers _1-y1-x1 N electron blocking layer, the Mg doping concentration of the p-type Al _y1 In _x1 Ga _1-y1-x1 N electron blocking layer corresponds to a hole concentration of 2×10 ¹⁷ cm ^-3 , where the Al group Component y ₁ is 0, In component x ₁ is 0. After the above growth, a p-type Al _y1 In _x1 Ga _{1-y1- x1} N electron blocking layer with a stepwise change in Mg doping concentration is obtained.

Step 4, grow a high-temperature p-type GaN layer 105 with a thickness of 100 nm in a _H2 atmosphere at 950° C. with a V/III molar ratio of 2000 and a MOCVD reaction chamber pressure of 100 torr. The high-temperature p-type GaN layer is doped with Mg The concentration is 5×10 ¹⁷ cm ^-3 .

Step 5, grow a p-type InGaN contact layer 106 with a thickness of 2nm in an _H2 atmosphere at 650°C, with a V/III molar ratio of 5000 and an MOCVD reaction chamber pressure of 300torr. The p-type InGaN contact layer has a Mg doping concentration of is larger than 10 ¹⁸ cm ^-3 .

Step 6, the temperature of the MOCVD reaction chamber is first lowered to 700°C, then annealed in a pure nitrogen atmosphere for 5 minutes, and then lowered to 20°C to complete the growth of the epitaxial layer of the light-emitting diode on the metal gallium nitride composite substrate, and prepare a high Brightness of Metal GaN Composite Substrate Light Emitting Diodes.

Embodiment two

A method for preparing a light-emitting diode on a metal gallium nitride composite substrate, comprising the following steps:

Step 1, put the metal gallium nitride composite substrate 101 into the MOCVD reaction chamber, raise the temperature of the MOCVD reaction chamber to 835° C. under the _N2 atmosphere and the pressure of the MOCVD reaction chamber at 300 torr, and then proceed while maintaining the temperature at 835° C. Annealing for 60 seconds, followed by MOCVD chamber pressure of 300 torr, V/III molar ratio of 900, and a growth rate of 0.6 μm/hour, to grow a low-temperature n-type GaN stress release layer 102 with a thickness of 200 nanometers. The low-temperature n-type GaN stress The Si doping concentration of the release layer is 10 ¹⁹ cm ^-3 .

Step 2, grow In _x Ga _1-x N/GaN multi-quantum for 3-10 cycles in _N2 atmosphere at 750-850°C, with V/III molar ratio of 5000-10000 and MOCVD reaction chamber pressure of 300torr Well active region 103, where 0<x≤0.3.

This step 2 specifically includes: step 2.1, in a _N2 atmosphere at 800°C, with a V/III molar ratio of 8000 and an MOCVD reaction chamber pressure of 300 torr, grow In _x Ga _1-x N/GaN poly In the quantum well active region, x is 0.2, the thickness of the In _x Ga _1-x N well layer is 3 nm, the thickness of the GaN barrier layer is 14 nm, and the Si doping concentration of the GaN barrier layer is 10 ¹⁷ cm ^-3 .

Step 2.2, and then continue to grow 7 cycles of In _x Ga _1-x N/GaN multiple quantum well active regions, where x is 0.2, the thickness of the In _x Ga _1-x N well layer is 3nm, and the GaN barrier layer The thickness is 14nm, and the GaN barrier layer is a non-doped layer. After the above growth, the In _x Ga _1-x N/GaN multi-quantum well active region in which the doping concentration of the barrier layer Si changes stepwise is obtained.

Step 3, grow p-type Al _y1 In _x1 Ga _1-y1 with a thickness of 30 nanometers under N ₂ atmosphere at 850-950°C, with a V/III molar ratio of 5000-10000 and an MOCVD reaction chamber pressure of 100-300torr _-x1 N electron blocking layer (104), Al composition 0≤y ₁ ≤0.2, In composition 0≤x ₁ ≤x.

This step 3 specifically includes: step 3.1, in a N ₂ atmosphere at 900°C, with a V/III molar ratio of 8000 and an MOCVD reaction chamber pressure of 200 torr, grow a p-type Al _y1 In _x1 Ga _{1- y1-x1} N electron blocking layer, the Mg doping concentration of the p-type Al _y1 In _x1 Ga _1-y1-x1 N electron blocking layer corresponds to a hole concentration of 1×10 ¹⁷ cm ^-3 , wherein the Al composition y ₁ is 0.1 and In composition x ₁ is 0.1.

Step 3.2, and then continue to grow a p-type Al _y1 In _x1 Ga _1-y1-x1 N electron blocking layer with a thickness of 30 nm, the Mg doping of the p-type Al _y1 In _x1 Ga _1-y1-x1 N electron blocking layer The hole concentration corresponding to the concentration is 2×10 ¹⁷ cm ^-3 , wherein the Al composition y ₁ is 0.1, and the In composition x ₁ is 0.1. After the above growth, a p-type Al _y1 In _x1 Ga _{1-y1- x1} N electron blocking layer with a stepwise change in Mg doping concentration is obtained.

Step 4, grow a high-temperature p-type GaN layer 105 with a thickness of 200 nm in an _H2 atmosphere at 1000° C., with a V/III molar ratio of 3500 and an MOCVD reaction chamber pressure of 100 torr. The high-temperature p-type GaN layer is doped with Mg The concentration is 5×10 ¹⁷ cm ^-3 .

Step 5, grow a p-type InGaN contact layer 106 with a thickness of 3nm in an _H2 atmosphere at 700°C, with a V/III molar ratio of 8000 and an MOCVD reaction chamber pressure of 300torr. The p-type InGaN contact layer has a Mg doping concentration of is larger than 10 ¹⁸ cm ^-3 .

Step 6, the temperature of the MOCVD reaction chamber is first lowered to 720°C, then annealed in a pure nitrogen atmosphere for 10 minutes, and then lowered to 25°C to complete the growth of the epitaxial layer of the metal gallium nitride composite substrate light-emitting diode, and prepare a high Brightness of Metal GaN Composite Substrate Light Emitting Diodes.

Embodiment Three

A method for preparing a light-emitting diode on a metal gallium nitride composite substrate, comprising the following steps:

Step 1, put the metal gallium nitride composite substrate 101 into the MOCVD reaction chamber, raise the temperature of the MOCVD reaction chamber to 850°C under the atmosphere of N ₂ and the pressure of the MOCVD reaction chamber at 300torr, and then keep the temperature at 850°C. Annealing for 65 seconds, followed by MOCVD chamber pressure of 300 torr, V/III molar ratio of 1300, and a growth rate of 1.0 μm/hour to grow a low-temperature n-type GaN stress release layer 102 with a thickness of 200 nanometers. The low-temperature n-type GaN stress The Si doping concentration of the release layer is 10 ¹⁹ cm ^-3 .

Step 2, grow 3-10 cycles of In _x Ga _1-x N/GaN multi-quantum in N ₂ atmosphere, 750-850 ° C, with V/III molar ratio of 5000-10000 and MOCVD reaction chamber pressure of 300 Torr Well active region 103, where 0<x≤0.3.

This step 2 specifically includes: step 2.1, in a _N2 atmosphere at 850°C, with a V/III molar ratio of 10,000 and an MOCVD reaction chamber pressure of 300 torr, the In _x Ga _1-x N/GaN poly In the quantum well active region, x is 0.3, the thickness of the In _x Ga _1-x N well layer is 4nm, the thickness of the GaN barrier layer is 20nm, and the Si doping concentration of the GaN barrier layer is 10 ¹⁷ cm ^-3 .

Step 2.2, and then continue to grow the In _x Ga _1-x N/GaN multi-quantum well active region for 7 cycles, where x is 0.3, the thickness of the In _x Ga _1-x N well layer is 4nm, and the GaN barrier layer The thickness is 20nm, and the GaN barrier layer is a non-doped layer. After the above growth, the In _x Ga _1-x N/GaN multi-quantum well active region in which the doping concentration of the quantum barrier layer Si changes stepwise is obtained.

Step 3, grow p-type Al _y1 In _x1 Ga _1-y1 with a thickness of 30 nanometers under N ₂ atmosphere at 850-950°C, with a V/III molar ratio of 5000-10000 and an MOCVD reaction chamber pressure of 100-300torr _-x1 N electron blocking layer (104), Al composition 0≤y ₁ ≤0.2, In composition 0≤x ₁ ≤x.

This step 3 specifically includes: step 3.1, in a N ₂ atmosphere at 950°C, with a V/III molar ratio of 10,000 and an MOCVD reaction chamber pressure of 300 torr, first grow p-type Al _y1 In _x1 Ga _{1- y1-x1} N electron blocking layer, the Mg doping concentration of the p-type Al _y1 In _x1 Ga _1-y1-x1 N electron blocking layer corresponds to a hole concentration of 1×10 ¹⁷ cm ^-3 , wherein the Al composition y ₁ is 0.2 and In composition x ₁ is 0.3.

Step 3.2, and then continue to grow a p-type Al _y1 In _x1 Ga _1-y1-x1 N electron blocking layer with a thickness of 30 nm, the Mg doping of the p-type Al _y1 In _x1 Ga _1-y1-x1 N electron blocking layer The hole concentration corresponding to the concentration is 2×10 ¹⁷ cm ^-3 , wherein the Al composition y ₁ is 0.2, and the In composition x ₁ is 0.3. After the above growth, a p-type Al _y1 In _x1 Ga _{1-y1- x1} N electron blocking layer with a stepwise change in Mg doping concentration is obtained.

Step 4, grow a high-temperature p-type GaN layer 105 with a thickness of 300 nm in an _H2 atmosphere at 1050° C. with a V/III molar ratio of 5000 and an MOCVD reaction chamber pressure of 100 torr. The high-temperature p-type GaN layer is doped with Mg The concentration is 5×10 ¹⁷ cm ^-3 .

Step 5, grow a p-type InGaN contact layer 106 with a thickness of 4 nm in an _H2 atmosphere at 750° C. with a V/III molar ratio of 10,000 and an MOCVD reaction chamber pressure of 300 torr. The p-type InGaN contact layer has a Mg doping concentration of is larger than 10 ¹⁸ cm ^-3 .

In step 6, the temperature of the MOCVD reaction chamber is first lowered to 750°C, then annealed in a pure nitrogen atmosphere for 20 minutes, and then lowered to 30°C to complete the growth of the epitaxial layer of the light-emitting diode on the metal gallium nitride composite substrate, and prepare a high Brightness of Metal GaN Composite Substrate Light Emitting Diodes.

The invention effectively alleviates the compressive stress of the active area and improves the crystal quality of the active area by epitaxially extending the low-temperature stress release layer between the metal gallium nitride composite substrate and the multi-quantum well active area. The In _x Ga _1-x N/GaN multi-quantum well active region with a stepwise change in the doping concentration of Si by growing multi-period quantum barrier layers, and the p-type Al _y1 In _x1 with a stepwise change in the Mg doping concentration The Ga _1-y1-x1 N electron blocking layer can effectively improve the distribution of electron holes in the active area, and improve the luminous efficiency of the metal gallium nitride composite substrate light-emitting diode.

The above-described embodiments are only to illustrate the technical ideas and characteristics of the present invention, and its description is more specific and detailed. Its purpose is to enable those of ordinary skill in the art to understand the content of the present invention and implement it accordingly. To limit the patent protection scope of the present invention, it should not be construed as limiting the scope of the present invention. It should be pointed out that for those skilled in the art, some modifications and improvements can be made without departing from the inventive concept of the present invention, that is, any changes made according to the spirit disclosed in the present invention should still be Covered within the scope of patent protection of the present invention.

Claims (7)

1. A method for preparing a light-emitting diode on a metal gallium nitride composite substrate, comprising the following steps: Step 1, put the metal gallium nitride composite substrate (101) into the MOCVD reaction chamber, raise the temperature of the MOCVD reaction chamber to 820-850°C under the atmosphere of N ₂ and the pressure of the MOCVD reaction chamber at 300torr, and then set the temperature at 820-850°C Annealing treatment in the temperature range of ℃ for 55-65s, followed by MOCVD reaction chamber pressure of 300torr, V/III molar ratio of 500-1300, growth rate of 0.2μm/hour-1μm/hour, growth thickness of 200nm at low temperature n-type GaN stress release layer (102); Step 2, grow 3-10 cycles of In _x Ga _1-x N/GaN multi-quantum in N ₂ atmosphere, 750-850 ° C, with V/III molar ratio of 5000-10000 and MOCVD reaction chamber pressure of 300 Torr Well active region (103), where 0<x≤0.3; Step 3, grow p-type Al _y1 In _x1 Ga _1-y1 with a thickness of 30 nanometers under N ₂ atmosphere at 850-950°C, with a V/III molar ratio of 5000-10000 and an MOCVD reaction chamber pressure of 100-300torr _-x1 N electron blocking layer (104), Al composition 0≤y ₁ ≤0.2, In composition 0≤x ₁ ≤x; Step 4, growing a high-temperature p-type GaN layer (105) with a thickness of 100-300nm in an _H2 atmosphere at 950-1050°C with a V/III molar ratio of 2000-5000 and a MOCVD reaction chamber pressure of 100 torr; Step 5, growing a p-type InGaN contact layer ( 106 ) with a thickness of 2-4 nm in H ₂ atmosphere at 650-750° C. with a V/III molar ratio of 5000-10000 and an MOCVD reaction chamber pressure of 300 torr; In step 6, the temperature of the MOCVD reaction chamber is lowered to 20-30° C., the growth is terminated, and the growth of the epitaxial layer of the metal gallium nitride composite substrate light-emitting diode is completed, and a high-brightness metal gallium nitride composite substrate light-emitting diode is prepared. 2. The method for preparing a light-emitting diode on a metal gallium nitride composite substrate according to claim 1, wherein the Si doping concentration of the low-temperature n-type GaN stress release layer in the step 1 is 10 ¹⁸ -10 ¹⁹ cm ^-3 . 3. the method for preparing light-emitting diode on metal gallium nitride composite substrate according to claim 2, is characterized in that, in described step 2, grow In _x Ga _1-x N/GaN multi-quantum well active region concrete include: Step 2.1, in N ₂ atmosphere, 750-850°C, with the V/III molar ratio of 5000-10000, and the pressure of the MOCVD reaction chamber at 300torr, first grow the In _x Ga _1-x N/GaN multiple quantum wells for 3 cycles In the active region, where 0<x≤0.3, the thickness of the In _x Ga _1-x N well layer is 2-4nm, the thickness of the GaN barrier layer is 8-20nm, and the Si doping concentration of the GaN barrier layer is 10 ¹⁷ cm ^-3 ; Step 2.2, and then continue to grow the In _x Ga _1-x N/GaN multi-quantum well active region for 7 cycles, wherein, 0<x≤0.3, the thickness of the In _x Ga _1-x N well layer is 2-4nm 1. The thickness of the GaN barrier layer is 8-20nm, wherein the GaN barrier layer is a non-doped layer. 4. The method for preparing a light-emitting diode on a metal gallium nitride composite substrate according to claim 3, wherein in the step 3, a p-type Al _y1 In _x1 Ga _1-y1-x1 N electron blocking layer is grown Specifically include: Step 3.1, in N ₂ atmosphere, at 850-950°C, with V/III molar ratio of 5000-10000, MOCVD reaction chamber pressure of 100-300torr, grow p-type Al _y1 In _x1 Ga _{1- y1-x1} N electron blocking layer, the Mg doping concentration of the p-type Al _y1 In _x1 Ga _1-y1-x1 N electron blocking layer corresponds to a hole concentration of 1×10 ¹⁷ cm ^-3 , where the Al component is 0 ≤y ₁ ≤0.2, In composition 0≤x ₁ ≤x; Step 3.2, and then continue to grow a p-type Al _y1 In _x1 Ga _1-y1-x1 N electron blocking layer with a thickness of 30 nm, the Mg doping of the p-type Al _y1 In _x1 Ga _1-y1-x1 N electron blocking layer The hole concentration corresponding to the concentration is 2×10 ¹⁷ cm ^-3 , wherein, the Al composition 0≤y ₁ ≤0.2, and the In composition 0≤x ₁ ≤x. 5. The method for preparing a light-emitting diode on a metal gallium nitride composite substrate according to claim 4, wherein the Mg doping concentration of the high-temperature p-type GaN layer in the step 4 is 5×10 ¹⁷ cm ^-3 . 6. The method for preparing a light-emitting diode on a metal gallium nitride composite substrate according to claim 5, wherein the Mg doping concentration of the p-type InGaN contact layer in the step 5 is greater than 10 ¹⁸ cm ^-3 . 7. The method for preparing a light-emitting diode on a metal gallium nitride composite substrate according to claim 6, wherein the step 6 is specifically reducing the temperature of the MOCVD reaction chamber to 700-750°C, and then using Anneal in pure nitrogen atmosphere for 5-20 minutes, then lower to 20-30°C.