A method for growing GaN-based epitaxial layer for improving reverse voltage of LED chip

Abstract

The application relates to the technical field of LED chips, in particular to a GaN-based epitaxial layer growth method for improving the reverse voltage of an LED chip, which comprises the following steps: S3: setting the reaction cavity temperature to 750-850 degrees, the pressure to 150-350 mbar, inputting 60000-75000 sccm of NH3, 5000-20000 sccm of H2 and 60000-80000 sccm of N2, inputting 500-1500 sccm of TeGa, and intermittently inputting 100-500 sccm of TMIn, so as to grow a stress release layer on the N-type GaN layer. The S3 makes the stress release layer of the LED chip, the In content is changed and a small amount of H2 is inputted, the interface treatment of the stress release layer is improved, the stress and defect density of the multi-quantum well active region layer are improved, and therefore the reverse voltage of the LED chip is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of LED chip, and particularly relates to a GaN-based epitaxial layer growth method for improving reverse voltage of LED chip. BACKGROUND

[0002] As a high-efficiency, environmentally friendly, green new type of solid-state lighting source, GaN-based light-emitting diode (LED) has the advantages of low voltage, low power consumption, small size, light weight, long service life, high reliability, etc., and is rapidly being widely used in traffic signal lights, mobile phone backlights, outdoor full-color display screens, urban landscape lighting, car interior and exterior lights, tunnel lights and other fields. Therefore, the improvement of various performances of LED is focused by the industry.

[0003] In the preparation of GaN-based LED epitaxial layer, the characteristics of the stress release layer (SRL) are an important factor affecting the electrical properties of the LED. In the technical scheme for growing the stress release layer in the growth of LED epitaxial layer in the reaction chamber of the domestic MOCVD, in order to avoid the reaction of TMIn gas and hydrogen to generate complex during the growth of the stress release layer, hydrogen is not introduced into the reaction chamber during the above process, which leads to the phenomenon of low reverse voltage of the LED chip.

[0004] In order to solve the above problems, the publication number CN104362233 "GAN-based light-emitting diode epitaxial wafer and preparation method thereof" discloses that a stress release layer with variable temperature and In content is used, a stress release layer with higher temperature and lower In content is grown on the side close to the N-type layer, the lattice quality of the stress release layer is relatively high, thereby effectively reducing the number of V-type defects in the stress release layer, improving the crystal quality of the multi-quantum well layer, and further improving the internal quantum efficiency and anti-static capability of the GaN-based light-emitting diode device, which helps to improve the reverse voltage of the LED chip. However, the improvement range of the reverse voltage of the LED chip by the above scheme still cannot meet the expectations of the person skilled in the art. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a GaN-based epitaxial layer growth method for improving the reverse voltage of the LED chip.

[0006] In order to solve the above technical problem, a technical scheme adopted by the present application is as follows: a GaN-based epitaxial layer growth method for improving the reverse voltage of the LED chip, comprising the following steps:

[0007] S1: placing a substrate into a reaction chamber of a metal organic chemical vapor deposition device;

[0008] S2: growing an N-type GaN layer on the substrate;

[0009] S3: setting the temperature of the reaction cavity to 750-850 degrees, the pressure to 150-350 mbar, and introducing 60000-75000 sccm of NH3, 5000-20000 sccm of H2 and 60000-80000 sccm of N2, intermittently introducing 100-500 sccm of TMIn, and growing a stress release layer on the N-type GaN layer;

[0010] S4: growing a multi-quantum well active region layer on the stress release layer;

[0011] S5: growing a P-type GaN layer on the multi-quantum well active region layer; and completing the growth of the GaN-based epitaxial layer.

[0012] The GaN-based epitaxial layer growth method for improving the reverse voltage of an LED chip provided by the application has the advantages that the stress release layer of the LED chip is grown by changing the In content and introducing a small amount of H2, which improves the interface processing of the stress release layer, improves the stress and defect density of the multi-quantum well active region layer, and thus improves the reverse voltage of the LED chip. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 FIG. 1 is a schematic diagram of the overall structure of an LED chip formed by the GaN-based epitaxial layer growth method for improving the reverse voltage of an LED chip according to the application;

[0014] Label explanation:

[0015] 1, substrate; 2, buffer layer; 3, U-shaped GaN layer; 4, N-type GaN layer; 5, stress release layer; 6, multi-quantum well active region layer; 7, low-temperature P-type GaN layer; 8, superlattice layer; 9, high-temperature P-type GaN layer. DETAILED DESCRIPTION

[0016] To better illustrate the technical content, purposes and effects of the application, the following will be described in conjunction with the embodiments and the accompanying drawings.

[0017] Please refer to Figure 1 A GaN-based epitaxial layer growth method for improving the reverse voltage of an LED chip, comprising the following steps:

[0018] S1: placing the substrate 1 into the reaction cavity of a metal organic chemical vapor deposition device;

[0019] S2: growing an N-type GaN layer 4 on the substrate;

[0020] S3: set the temperature of the reaction cavity to 750-850 degrees, the pressure to 150-350 mbar, and introduce 60000-75000 sccm of NH3, 5000-20000 sccm of H2 and 60000-80000 sccm of N2, intermittently introduce 100-500 sccm of TMIn, and grow a stress release layer 5 on the N-type GaN layer;

[0021] S4: grow a multi-quantum well active region layer 6 on the stress release layer;

[0022] S5: grow a P-type GaN layer on the multi-quantum well active region layer; and complete the growth of the GaN-based epitaxial layer.

[0023] As can be seen from the above description, the GaN-based epitaxial layer growth method for improving the reverse voltage of an LED chip provided by the application has the stress release layer of the LED chip, and the In content is changed and a small amount of H2 is introduced, which improves the interface processing of the stress release layer, improves the stress and defect density of the multi-quantum well active region layer, and thus improves the reverse voltage of the LED chip.

[0024] Further, the "intermittently introducing 100-500 sccm of TMIn" of S3 specifically means that 100-500 sccm of TMIn is introduced multiple times, each time for 10-30 s, and the interval between two times of introducing TMIn is 50-90 s, until a 0.1-0.5 micron stress release layer is grown on the N-type GaN layer.

[0025] As can be seen from the above description, the above setting provides a simple and efficient method of intermittently introducing TMIn into the reaction cavity, which further improves the reverse voltage of the formed GaN-based epitaxial layer.

[0026] Further, steps S1.1 and S1.2 are further included between S1 and S2.

[0027] S1.1: grow a buffer layer 2 on the substrate;

[0028] S1.2: grow a U-type GaN layer 3 on the buffer layer;

[0029] S2 specifically means growing an N-type GaN layer 4 on the U-type GaN layer.

[0030] As can be seen from the above description, the buffer layer and the U-type GaN layer generated by the above setting will improve the performance of the GaN-based epitaxial layer.

[0031] Further, the S1.1 is specifically setting the temperature of the reaction cavity to 800-900 degrees, the pressure to 100-200 mbar, and introducing ammonia, nitrogen, 60-80 sccm of TMGa2 and 25-45 sccm of TMAl, and maintaining for 4-6 minutes; and growing a 0.1-0.2 micron buffer layer on the substrate.

[0032] From the above description, it can be seen that the above setting provides a simple and efficient method for growing a buffer layer.

[0033] Further, the S2 is specifically setting the pressure of the reaction cavity to 500-1000 mbar, the temperature to 1100-1100 degrees, and introducing nitrogen, hydrogen, ammonia and TMGa2; and growing a 2-3 micron N-type GaN layer on the U-shaped GaN layer.

[0034] From the above description, it can be seen that the above setting provides a simple and efficient method for growing a U-shaped GaN layer.

[0035] Further, the S4 is specifically introducing ammonia, hydrogen, nitrogen and TMGa2 into the reaction cavity while intermittently introducing TMIn, so as to grow a periodic InGaN / GaN multi-quantum well active region layer on the stress release layer.

[0036] From the above description, it can be seen that the above setting provides a simple and efficient method for growing a multi-quantum well active region layer.

[0037] Further, the S4 is specifically setting the pressure of the reaction cavity to 500-1000 mbar, the temperature to 700-800 degrees, and introducing ammonia, hydrogen, nitrogen and 25-40 sccm of TMGa2 while intermittently introducing 1200-1500 sccm of TMIn, so as to grow a periodic InGaN / GaN multi-quantum well active region layer on the stress release layer, the period number of InGaN / GaN being 10-16; the thickness of the multi-quantum well active region layer being 0.15-0.2 microns, and the doping concentration of In being 1E+20-2E+20 atom / cm 3 .

[0038] From the above description, it can be seen that the above setting provides a simple and efficient method for growing a multi-quantum well active region layer.

[0039] Further, the S5 is specifically:

[0040] growing a low-temperature P-type GaN layer 7 with a thickness of 60-90 nanometers on the multi-quantum well active region layer;

[0041] growing a periodic AlGaN / GaN superlattice layer 8 on the low-temperature P-type GaN layer;

[0042] growing a doped high-temperature P-type GaN layer 9 on the superlattice layer;

[0043] The growth of the GaN-based epitaxial layer is completed.

[0044] As described above, the P-type GaN layer comprises a low-temperature P-type GaN layer, a superlattice layer and a high-temperature P-type GaN layer, which improves the performance of the GaN-based epitaxial layer.

[0045] Further, the "growing a periodic AlGaN / GaN superlattice layer on the low-temperature P-type GaN layer" of S5 specifically refers to: setting the reaction cavity temperature to 700-950 degrees, the pressure to 300-800 mbar, and introducing 30000-60000 sccm of NH3, 30-50 sccm of TMGa2, 1500-2000 sccm of Cp2Mg and 150-200 sccm of TMAl, so as to grow a periodic AlGaN / GaN superlattice layer on the low-temperature P-type GaN layer; the period of AlGaN / GaN is 5-10, the single-layer thickness of AlGaN is 4-6 nanometers, and the thickness ratio of AlGaN and GaN layers in a single period is 1:1-3:1; the thickness of the superlattice layer is 50-70 nanometers, the doping concentration of Mg is 1E+18-1E+19 atom / cm 3 , and the doping concentration of Al is 1E+17-1E+18 atom / cm 3 .

[0046] As described above, the above setting provides a simple and efficient growth method of the superlattice layer.

[0047] Further, the "growing a doped high-temperature P-type GaN layer on the superlattice layer" of S5 specifically refers to:

[0048] setting the reaction cavity temperature to 900-1050 degrees, the pressure to 600-1000 mbar, and introducing 60000-75000 sccm of NH3, 25-50 sccm of TMGa2 and 2000-3000 sccm of Cp2Mg, so as to grow a doped high-temperature P-type GaN layer on the superlattice layer; the thickness of the high-temperature P-type GaN layer is 60-90 nanometers, and the doping concentration of Mg is 1E+20-3E+20 atom / cm 3 .

[0049] As described above, the above setting provides a simple and efficient growth method of the high-temperature P-type GaN layer.

[0050] Embodiment one

[0051] The embodiment provides a GaN-based epitaxial layer growth method for improving the reverse voltage of an LED chip, comprising the following steps:

[0052] S1: Put the substrate into the reaction cavity of the metal organic chemical vapor deposition equipment;

[0053] S2: Set the reaction cavity temperature to 800 degrees, the pressure to 100 mbar, and introduce ammonia, nitrogen, 60 sccm of TMGa2 and 25 sccm of TMAl, and maintain for 4-6 minutes; grow a 0.1-0.2 micron buffer layer on the substrate;

[0054] S3: Set the reaction cavity pressure to 250 mbar and the temperature to 1100 degrees, and introduce ammonia, nitrogen and TMGa2; maintain for 11-13 minutes; grow a 2-3 micron U-shaped GaN layer on the buffer layer;

[0055] S4: Set the reaction cavity pressure to 500 mbar and the temperature to 1100 degrees, and introduce nitrogen, hydrogen, ammonia and TMGa2; grow a 2 micron N-type GaN layer on the U-shaped GaN layer;

[0056] S5: Set the reaction cavity temperature to 750 degrees and the pressure to 150 mbar, and introduce 70000 sccm of NH3, 5000 sccm of H2 and 60000 sccm of N2, and intermittently introduce 100 sccm of TMIn, specifically, introduce TMIn for 10-30 s each time, and interval between two times of introducing TMIn is 50-90 s, and grow a 0.1-0.5 micron stress release layer on the N-type GaN layer;

[0057] S6: Set the reaction cavity pressure to 500 mbar and the temperature to 700 degrees, and intermittently introduce 1200 sccm of TMIn while introducing ammonia, hydrogen, nitrogen and 25-40 sccm of TMGa2, so as to grow a periodic InGaN / GaN multi-quantum well active region layer on the stress release layer, the period number of InGaN / GaN is 10; the thickness of the multi-quantum well active region layer is 0.15-0.2 micron, and the doping concentration of In is 1E+20-2E+20 atom / cm2. 3 ;

[0058] S7: Set the reaction cavity temperature to 600 degrees and the pressure to 300-800 mbar, and introduce 55000 sccm of NH3 and 25 sccm of TMGa2, so as to grow a 60-90 nanometer low-temperature P-type GaN layer on the multi-quantum well active region layer;

[0059] S8: set the reaction cavity temperature to 700 degrees, the pressure to 300-800 mbar, and introduce 30000-60000 sccm of NH3, 30-50 sccm of TMGa2, 1500 sccm of Cp2Mg and 150 sccm of TMAl, so as to grow a periodic AlGaN / GaN superlattice layer on the low-temperature P-type GaN layer; the period of the AlGaN / GaN is 5-10, the single-layer thickness of the AlGaN is 4 nanometers, and the thickness ratio of the AlGaN and GaN layers in a single period is 1:1-3:1; the thickness of the superlattice layer is 50-70 nanometers, the doping concentration of Mg is 1E+18-1E+19 atom / cm2, the doping concentration of Al is 1E+17-1E+18 atom / cm2. 3 3

[0060] S9: set the reaction cavity temperature to 900 degrees, the pressure to 600-1000 mbar, and introduce 60000 sccm of NH3, 25-50 sccm of TMGa2 and 2000 sccm of Cp2Mg, so as to grow a doped high-temperature P-type GaN layer on the superlattice layer; the thickness of the high-temperature P-type GaN layer is 60-90 nanometers, and the doping concentration of Mg is 1E+20-3E+20 atom / cm2. 3

[0061] S10: complete the growth of the GaN-based epitaxial layer.

[0062] Example Two

[0063] The embodiment provides a GaN-based epitaxial layer growth method for improving the reverse voltage of an LED chip, which comprises the following steps:

[0064] S1: place a substrate into a reaction cavity of a metal organic chemical vapor deposition device;

[0065] S2: set the reaction cavity temperature to 900 degrees, the pressure to 200 mbar, and introduce ammonia, nitrogen, 80 sccm of TMGa2 and 45 sccm of TMAl for 4 minutes; so as to grow a 0.1-0.2 micrometer buffer layer on the substrate;

[0066] S3: set the reaction cavity pressure to 350 mbar and the temperature to 1300 degrees, and introduce ammonia, nitrogen and TMGa2; continue for 11 minutes; so as to grow a 2-3 micrometer U-shaped GaN layer on the buffer layer;

[0067] S4: set the reaction cavity pressure to 1000 mbar and the temperature to 1100 degrees, and introduce nitrogen, hydrogen, ammonia and TMGa2; so as to grow a 2-3 micrometer N-type GaN layer on the U-shaped GaN layer;

[0068] ​​​S5: set the temperature of the reaction cavity to 850 degrees, the pressure to 350 mbar, and introduce 75000 sccm of NH3, 5000 sccm of H2, and 80000 sccm of N2, and intermittently introduce 500-1500 sccm of TeGa, and specifically, introduce 500 sccm of TMIn each time for 10-30 s, and the interval between two times of introducing TMIn is 50-90 s, and grow a stress release layer of 0.1-0.5 microns on the N-type GaN layer;

[0069] S6: set the pressure of the reaction cavity to 1000 mbar and the temperature to 800 degrees, and while introducing ammonia, hydrogen, nitrogen, and 25-40 sccm of TMGa2, intermittently introduce 1200-1500 sccm of TMIn, so as to grow a periodic InGaN / GaN multi-quantum well active region layer on the stress release layer, and the period number of InGaN / GaN is 10-16; the thickness of the multi-quantum well active region layer is 0.15-0.2 microns, and the doping concentration of In is 1E+20-2E+20 atom / cm 3 ;

[0070] S7: set the temperature of the reaction cavity to 700 degrees and the pressure to 800 mbar, and introduce 65000 sccm of NH3 and 50 sccm of TMGa2, so as to grow a low-temperature P-type GaN layer with a thickness of 60-90 nanometers on the multi-quantum well active region layer;

[0071] S8: set the temperature of the reaction cavity to 950 degrees and the pressure to 800 mbar, and introduce 60000 sccm of NH3, 50 sccm of TMGa2, 2000 sccm of Cp2Mg, and 200 sccm of TMAl, so as to grow a periodic AlGaN / GaN superlattice layer on the low-temperature P-type GaN layer; the period number of AlGaN / GaN is 5-10, the single-layer thickness of AlGaN is 4-6 nanometers, and the thickness ratio of AlGaN and GaN layers in a single period is 1:1-3:1; the thickness of the superlattice layer is 50-70 nanometers, the doping concentration of Mg is 1E+18-1E+19 atom / cm 3 , and the doping concentration of Al is 1E+17-1E+18 atom / cm 3 ;

[0072] S9: set the temperature of the reaction cavity to 1050 degrees and the pressure to 1000 mbar, and introduce 75000 sccm of NH3, 50 sccm of TMGa2, and 3000 sccm of Cp2Mg, so as to grow a doped high-temperature P-type GaN layer on the superlattice layer; the thickness of the high-temperature P-type GaN layer is 60-90 nanometers, and the doping concentration of Mg is 1E+20-3E+20 atom / cm 3 ;

[0073] S10: completing the growth of the GaN-based epitaxial layer.

[0074] Embodiment Three

[0075] The embodiment provides a GaN-based epitaxial layer growth method for improving reverse voltage of an LED chip, comprising the following steps:

[0076] S1: placing a substrate into a reaction cavity of a metal organic chemical vapor deposition device;

[0077] S2: setting the temperature of the reaction cavity to 850 degrees, the pressure to 150 mbar, and inputting ammonia, nitrogen, 70 sccm of TMGa2 and 35 sccm of TMAl, and maintaining for 4-6 minutes; and growing a 0.1-0.2 micron buffer layer on the substrate;

[0078] S3: setting the pressure of the reaction cavity to 300 mbar and the temperature to 1200 degrees, and inputting ammonia, nitrogen and TMGa2; and maintaining for 11-13 minutes; and growing a 2.5 micron U-shaped GaN layer on the buffer layer;

[0079] S4: setting the pressure of the reaction cavity to 500-1000 mbar and the temperature to 1100-1100 degrees, and inputting nitrogen, hydrogen, ammonia and TMGa2; and growing a 2-3 micron N-type GaN layer on the U-shaped GaN layer;

[0080] S5: setting the temperature of the reaction cavity to 750-850 degrees and the pressure to 150-350 mbar, and inputting 68000 sccm of NH3, 12000 sccm of H2 and 70000 sccm of N2, and inputting 1000 sccm of TeGa, and intermittently inputting 300 sccm of TMIn, specifically, inputting TMIn for 20 s each time, and the interval between the two times of inputting TMIn is 70 s; and growing a 0.3 micron stress release layer on the N-type GaN layer;

[0081] S6: setting the pressure of the reaction cavity to 750 mbar and the temperature to 700-800 degrees, and inputting ammonia, hydrogen, nitrogen and 25-40 sccm of TMGa2, and intermittently inputting 1200-1500 sccm of TMIn, so that a periodic InGaN / GaN multi-quantum well active region layer is grown on the stress release layer, the period number of InGaN / GaN is 13; the thickness of the multi-quantum well active region layer is 0.15-0.2 microns, and the doping concentration of In is 1.5E+20 atom / cm 3 ;

[0082] S7: set the reaction cavity temperature to 600-700 degrees, the pressure to 300-800 mbar, input 55000-65000 sccm of NH3 and 25-50 sccm of TMGa2, and grow a low-temperature P-type GaN layer with a thickness of 75 nanometers on the multi-quantum well active region layer;

[0083] S8: set the reaction cavity temperature to 700-950 degrees, the pressure to 300-800 mbar, input 30000-60000 sccm of NH3, 30-50 sccm of TMGa2, 1500-2000 sccm of Cp2Mg, and 150-200 sccm of TMAl, and grow a periodic AlGaN / GaN superlattice layer on the low-temperature P-type GaN layer; the period of the AlGaN / GaN is 7, the single-layer thickness of the AlGaN is 5 nanometers, and the thickness ratio of the AlGaN and GaN layers in a single period is 1:1-3:1; the thickness of the superlattice layer is 50-70 nanometers, the doping concentration of Mg is 1E+18-1E+19 atom / cm 3 , and the doping concentration of Al is 1E+17-1E+18 atom / cm 3 ;

[0084] S9: set the reaction cavity temperature to 900-1050 degrees, the pressure to 600-1000 mbar, input 60000-75000 sccm of NH3, 25-50 sccm of TMGa2, and 2000-3000 sccm of Cp2Mg, and grow a doped high-temperature P-type GaN layer on the superlattice layer; the thickness of the high-temperature P-type GaN layer is 60-90 nanometers, and the doping concentration of Mg is 1E+20-3E+20 atom / cm 3 ;

[0085] S10: complete the growth of the GaN-based epitaxial layer.

[0086] Comparative Example

[0087] This comparative example is a comparison of the data of photoelectric tests of LED chips produced using the scheme of Example Three of the present application with the data of photoelectric tests of LEDs produced using a conventional scheme.

[0088] Table 1

[0089]

[0090] In Table 1, Sample 1 is a plurality of LED chips formed using the scheme of Example Three of the present application.

[0091] Sample 2 is a plurality of LED chips produced by using a conventional method. The conventional method is different from that of Example 3 only in that step S5 is replaced by setting the temperature of the reaction cavity to 750-850 degrees, the pressure to 150-350 mbar, and flowing in 68,000 sccm of NH3, 70,000 sccm of N2, 1,000 sccm of TeGa, and 90 sccm of TMIn, and growing a stress release layer on the N-type GaN without H2.

[0092] Each parameter in Table 1 is the average of the parameters of the plurality of LED chips of Sample 1 or the average of the parameters of the plurality of LED chips of Sample 2.

[0093] As can be seen from Table 1, the reverse voltage of the LED chips produced by using the GaN-based epitaxial layer growth method for improving the reverse voltage of LED chips provided by the present application is increased by 16.6 V, or 49.2%.

[0094] The above description is only examples of the present application and does not limit the patent scope of the present application. Any equivalent transformation or direct or indirect application in related technical fields using the content of the specification and drawings of the present application are also included in the patent protection scope of the present application.

Claims

1. A method for growing a GaN-based epitaxial layer to improve the reverse voltage of an LED chip, characterized in that, Includes the following steps: S1: Place the substrate into the reaction chamber of the metal-organic chemical vapor deposition equipment; S2: An N-type GaN layer is grown on the substrate; S3: Set the reaction chamber temperature to 750-850 degrees Celsius and the pressure to 150-350 mbar. Introduce 60,000-75,000 sccm of NH3, 5,000-20,000 sccm of H2 and 60,000-80,000 sccm of N2, introduce 500-1,500 sccm of TeGa, and intermittently introduce 100-500 sccm of TMIn to grow a stress-relief layer on the N-type GaN layer. S4: Growth of a multi-quantum-well active region layer on the stress-relief layer; S5: Grow a P-type GaN layer on the multi-quantum-well active region layer; complete the growth of the GaN-based epitaxial layer.

2. The method for growing a GaN-based epitaxial layer to improve the reverse voltage of an LED chip according to claim 1, characterized in that, The "intermittently introducing 100-500 sccm of TMIn" in S3 specifically means: introducing 100-500 sccm of TMIn multiple times, with each introduction lasting 10-30 seconds and an interval of 50-90 seconds between two introductions, until a stress-relieving layer of 0.1-0.5 micrometers is grown on the N-type GaN layer.

3. The method for growing a GaN-based epitaxial layer to improve the reverse voltage of an LED chip according to claim 1, characterized in that, It also includes S1 and S2, specifically: S1: Place the substrate into the reaction chamber of the metal-organic chemical vapor deposition equipment; S1.1: Grow a buffer layer on the substrate; S1.2: Grow a U-shaped GaN layer on the buffer layer; S2: An N-type GaN layer is grown on the U-type GaN layer of the substrate.

4. The method for growing a GaN-based epitaxial layer to improve the reverse voltage of an LED chip according to claim 3, characterized in that, Specifically, S1.1 involves setting the reaction chamber temperature to 800-900 degrees Celsius and the pressure to 100-200 mbar, and introducing ammonia, nitrogen, 60-80 sccm of TMGa2 and 25-45 sccm of TMAl for 4-6 minutes to grow a 0.1-0.2 micrometer buffer layer on the substrate.

5. The method for growing a GaN-based epitaxial layer to improve the reverse voltage of an LED chip according to claim 3, characterized in that, Specifically, S2 involves setting the reaction chamber pressure to 500-1000 mbar and the temperature to 1100-1100 degrees Celsius, and introducing nitrogen, hydrogen, ammonia, and TMGa2; and growing a 2-3 micrometer N-type GaN layer on the U-type GaN layer.

6. The method for growing a GaN-based epitaxial layer to improve the reverse voltage of an LED chip according to claim 1, characterized in that, Specifically, S4 involves introducing ammonia, hydrogen, nitrogen, and TMGa2 into the reaction chamber while intermittently introducing TMIn, thereby growing a periodic InGaN / GaN multi-quantum-well active region layer on the stress-relief layer.

7. The method for growing a GaN-based epitaxial layer to improve the reverse voltage of an LED chip according to claim 6, characterized in that, Specifically, S4 involves setting the reaction chamber pressure to 500-1000 mbar and the temperature to 700-800 degrees Celsius. While introducing ammonia, hydrogen, nitrogen, and 25-40 sccm of TMGa2, 1200-1500 sccm of TMIn is intermittently introduced to grow periodic InGaN / GaN multi-quantum-well active regions on the stress-relief layer. The InGaN / GaN period number is 10-16. The thickness of the multi-quantum-well active region is 0.15-0.2 micrometers, and the In doping concentration is 1E+20-2E+20 atom / cm². 3 .

8. The method for growing a GaN-based epitaxial layer to improve the reverse voltage of an LED chip according to claim 1, characterized in that, S5 specifically refers to: Low-temperature P-type GaN layers with a thickness of 60-90 nanometers are grown on the active region layer of the multi-quantum well; This allows for the growth of periodic AlGaN / GaN superlattice layers on low-temperature P-type GaN layers. High-temperature doped P-type GaN layers are grown on superlattice layers; Complete the growth of GaN-based epitaxial layers.

9. The method for growing a GaN-based epitaxial layer to improve the reverse voltage of an LED chip according to claim 8, characterized in that, The specific steps of S5, "growing a periodic AlGaN / GaN superlattice layer on a low-temperature P-type GaN layer," involve: setting the reaction chamber temperature to 700-950 degrees Celsius and the pressure to 300-800 mbar; introducing 30,000-60,000 sccm of NH3, 30-50 sccm of TMGa2, 1500-2000 sccm of Cp2Mg, and 150-200 sccm of TMAl to grow a periodic AlGaN / GaN superlattice layer on the low-temperature P-type GaN layer; the period of AlGaN / GaN is 5-10, the thickness of a single AlGaN layer is 4-6 nanometers, and the thickness ratio of the AlGaN to GaN layer in a single period is 1:1-3:1; the thickness of the superlattice layer is 50-70 nanometers, and the doping concentration of Mg is 1E+18-1E+19 atom / cm³. 3 The doping concentration of Al is 1E+17-1E+18 atoms / cm³ 3 .

10. The method for growing a GaN-based epitaxial layer to improve the reverse voltage of an LED chip according to claim 8, characterized in that, Specifically, S5's "growing a doped high-temperature P-type GaN layer on a superlattice layer;" refers to: The reaction chamber temperature is set to 900-1050 degrees Celsius, and the pressure to 600-1000 mbar. NH3 is introduced at 60000-75000 sccm, TMGa2 at 25-50 sccm, and Cp2Mg at 2000-3000 sccm. A high-temperature doped p-type GaN layer is grown on the superlattice layer. The thickness of the high-temperature p-type GaN layer is 60-90 nanometers, and the Mg doping concentration is 1E+20-3E+20 atom / cm³. 3 .

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