A p-ebd layer, its gan-based epitaxial structure and growth method

Abstract

The application relates to the technical field of LED chips, in particular to a P-EBL layer, an epitaxial structure thereof and a growth method. The GaN-based epitaxial structure comprises a buffer layer, a UGaN layer, an NGaN layer, a stress release layer and a multi-quantum-step active region layer which are sequentially grown on a substrate, and the multi-quantum-step active region layer further has a low-temperature P-type GaN layer, a P-EBL layer and a high-temperature P-type GaN layer which are sequentially grown. The application inserts a stage P-EBL layer with different sources and different concentrations of doping into the low-temperature P-type GaN layer, can greatly improve the electron concentration and the hole concentration of the LED, and the distribution is uniform, can effectively inhibit the electron leakage current, slow down the efficiency decay, and thus the brightness is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of LED chip, in particular to a P-EBL layer, a GaN-based epitaxial structure and a growth method thereof. BACKGROUND

[0002] With the continuous progress of LED (light emitting diode) material technology, LED has begun to gradually replace incandescent lamps, fluorescent lamps, mercury lamps and other low energy efficiency and high pollution light emitting materials, and has realized comprehensive dominance in lighting, curing, sterilization and disinfection and many other fields. In recent years, the LED luminous efficiency has been rapidly improved. In order to obtain a more efficient and higher brightness LED chip, the main method is to optimize the epitaxial structure.

[0003] P-EBL is an electron blocking layer, which is part of the LED epitaxial structure. The Chinese invention patent with publication number CN104134730B discloses an epitaxial wafer of Mg-doped electron blocking layer, which comprises, from bottom to top, a substrate, a low-temperature GaN buffer layer, a high-temperature GaN buffer layer, an N-GaN layer, an N-type AlGaN layer, an N-type contact layer, a multi-quantum well layer, a GaN barrier layer, an AlGaN / GaN electron blocking layer, a low-temperature P-type GaN layer, a high-concentration AlGaN / INGaN electron blocking layer doped with Mg, and a high-temperature P-type GaN layer. The electron blocking layer uses a higher potential barrier to limit the leakage of electrons to the P-type layer, thereby reducing the non-radiative recombination caused by electron leakage and effectively improving the brightness.

[0004] However, the traditional P-EBL layer has poor electron blocking effect, and electrons can easily pass through the blocking layer to reach the P region and recombine with holes to form electron leakage current, causing the GaN-based LED to suffer from efficiency decay. Moreover, the activation energy of Mg in the traditional P-EBL layer is very high, and the activation energy increases rapidly with the increase of Al content. In P-AlN, it is more likely to form a P-type compensation center of nitrogen vacancy, which reduces the LED luminous efficiency. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a P-EBL layer with good electron blocking effect, a GaN-based epitaxial structure and a growth method thereof.

[0006] In order to solve the above technical problems, the technical scheme adopted by the present application is as follows: a GaN-based epitaxial structure, comprising a buffer layer, a UGaN layer, an N-GaN layer, a stress release layer and a multi-quantum step active region layer grown on a substrate in sequence, and the multi-quantum step active region layer further has a low-temperature P-type GaN layer, a P-EBL layer and a high-temperature P-type GaN layer grown in sequence thereon.

[0007] Another technical solution of the present application is the growth method of the P-EBL layer of the GaN-based epitaxial structure, which comprises three stages.

[0008] The first stage is to input 80-100sccm of TMAl source;

[0009] The second stage is to simultaneously input 150-200sccm of TMIN source, 80-100sccm of TMAl source and 1300-1500sccm of TEGa source, and the input time of the TMIN source, TMAl source and TEGa source is equal;

[0010] The third stage is to simultaneously input 60-80sccm of TMIN source, 30-50sccm of TMAl source and 400-500sccm of TEGa source, and the input time of the TMIN source, TMAl source and TEGa source is equal.

[0011] Still another technical solution of the present application is the growth method of the GaN-based epitaxial structure, wherein the growth of the stress release layer is performed in a reaction chamber, and the temperature of the reaction chamber is set to 750-850℃ and the pressure is set to 150-350mbar.

[0012] The GaN-based epitaxial structure of the present application inserts a P-EBL layer with different source and different concentration doping between the low-temperature P-type GaN layer, and the stage-type TMAl source / TMIN source / TEGa source process is performed on the P-EBL layer, different amounts of Al source, IN source and Ga source are input into the reaction chamber, the stage-type current blocking layer with different concentration contents is formed, the stage-type electron blocking layer blocks the electrons from the cathode at the interface of the light-emitting layer, the concentration of the electrons at the interface of the light-emitting layer is increased, the electron potential barrier of the conduction band bottom is improved, thereby effectively limiting the leakage of the electrons to the P-type GaN layer and inhibiting the electron leakage current, the hole potential barrier of the valence band top is reduced, the injection efficiency of the holes of the P-type GaN layer to the active region is enhanced, and the purpose of improving the brightness is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 FIG. 1 is a structural schematic diagram of the GaN-based epitaxial structure in the embodiment of the present application;

[0014] Figure 2 FIG. 4 is a brightness comparison diagram of Example 1 and Comparative Example 1. DETAILED DESCRIPTION

[0015] The technical content, purposes and effects of the present application are described in detail below by combining the embodiments with the drawings.

[0016] Please refer to Figure 1The application discloses a GaN-based epitaxial structure, which comprises a buffer layer, a UGaN layer, a NGaN layer, a stress release layer and a multi-quantum-step active region layer which are sequentially grown on a substrate, and the multi-quantum-step active region layer further comprises a low-temperature P-type GaN layer, a P-EBL layer and a high-temperature P-type GaN layer which are sequentially grown.

[0017] From the above description, the application has the advantages that: the application inserts a stage P-EBL layer with different sources and different concentrations of doping into the low-temperature P-type GaN layer, which can greatly improve the electron concentration and hole concentration of the LED and make the distribution uniform, effectively suppresses the electron leakage current, slows down the efficiency decay, and achieves the purpose of improving the brightness.

[0018] Another technical scheme of the application is a growth method of the P-EBL layer of the GaN-based epitaxial structure, which comprises three stages.

[0019] The first stage is to input 80-100sccm of TMAl source;

[0020] The second stage is to simultaneously input 150-200sccm of TMIN source, 80-100sccm of TMAl source and 1300-1500sccm of TEGa source, and the input time of the TMIN source, the TMAl source and the TEGa source is equal;

[0021] The third stage is to simultaneously input 60-80sccm of TMIN source, 30-50sccm of TMAl source and 400-500sccm of TEGa source, and the input time of the TMIN source, the TMAl source and the TEGa source is equal.

[0022] From the above description, the stage TMAl source / TMIN source / TEGa source process is performed on the P-EBL layer, different amounts of Al source, IN source and Ga source are input into the reaction chamber, the stage current blocking layer with different concentration contents is formed, the stage electron blocking layer blocks the electrons from the cathode at the light-emitting layer interface, increases the concentration of the electrons at the light-emitting layer interface, improves the electron potential barrier of the conduction band, effectively limits the leakage of the electrons to the P-type GaN layer, effectively suppresses the electron leakage current, reduces the hole potential barrier of the valence band, enhances the injection efficiency of the holes of the P-type GaN layer to the active region, and achieves the purpose of improving the brightness.

[0023] The first stage only passes 80-100 sccm TMAl source to form a thin pure AlN layer for interface treatment; the second stage passes TMIN source and TMAl source and 1300-1500 sccm TEGa source to prepare a main EBL layer for carrier limitation; the third stage passes TMIN source, TMAl source and 400-500 sccm TEGa source to process the potential barrier gently and the interface flatly, which plays a role of connection for the subsequent high-temperature P-type GaN layer, wherein the flux of TEGa source and TMIN source is lower than that in the second stage because the second layer is the main EBL layer and needs more TEGa to maintain a certain thickness. The order among the three stages cannot be changed, otherwise the EBL effect will be reduced.

[0024] Further, the duration of the first stage is 50-80 s, the duration of the second stage is 200-260 s, and the duration of the third stage is 80-120 s.

[0025] As can be seen from the above description, the three stages control the thickness of the growth, and each layer has a corresponding thickness range; if not within the thickness range, the Al doping ratio of the EBL will be incorrect, the light efficiency will be reduced, and the brightness will be reduced.

[0026] Further, the P-EBL layer is grown in a reaction chamber, and the temperature of the reaction chamber is set to 900-1000℃ and the pressure is set to 200-300 mbar.

[0027] As can be seen from the above description, the temperature and pressure are too high, which will cause the layer structure to grow too fast, and vice versa, which will cause the layer structure to grow too slowly, both of which will affect the crystal quality of the grown layer.

[0028] Further, when the P-EBL layer is grown, N2 is continuously passed into the reaction chamber.

[0029] As can be seen from the above description, N2 plays a role of protective gas.

[0030] Another technical solution adopted by the application is that the growth method of the GaN-based epitaxial structure, the stress release layer is grown in a reaction chamber, and the temperature of the reaction chamber is set to 750-850℃ and the pressure is set to 150-350 mbar.

[0031] As can be seen from the above description, the stress release layer is used to release the stress in the epitaxial layer, which plays a role of reducing defects in the epitaxial layer.

[0032] Further, when growing the stress release layer, 60000-75000sccm of NH3, 5000-20000sccm of H2, 60000-80000sccm of N2 and 500-1500sccm of TEGa are simultaneously introduced, and the introduction time of NH3, H2, N2 and TEGa is the same, and 100-500sccm of TMIN is introduced.

[0033] As can be seen from the above description, the stress release layer is a periodic structure of INGaN / GaN, which can reduce defects in the epitaxial layer.

[0034] Further, the low-temperature P-type GaN layer is grown in a reaction chamber, the temperature of the reaction chamber is set to 600-700℃, the pressure is 300-800mbar, 55000-65000sccm of NH3 and 25-50sccm of TMGa source are simultaneously introduced, and the introduction time of NH3 and TMGa is the same.

[0035] Please refer to Figure 1 Embodiment 1 of the present application is a GaN-based epitaxial structure, which comprises a buffer layer, a UGaN layer, an NGaN layer, a stress release layer and a multi-quantum step active region layer grown on a substrate in sequence, and the multi-quantum step active region layer further has a low-temperature P-type GaN layer, a P-EBL layer and a high-temperature P-type GaN layer grown in sequence.

[0036] Embodiment 2 of the present application is a growth method of a GaN-based epitaxial structure, which comprises the following steps:

[0037] S1: A sapphire substrate is put into a reaction chamber of a metal organic chemical vapor deposition device, the pressure of the reaction chamber is 550mbar, the temperature is 1100℃, H2 is used as a carrier gas to treat the surface of the substrate, and the process lasts for 11min.

[0038] S2: The pressure of the reaction chamber is reduced to 150mbar, the temperature is 850℃, H2 and NH3 are used as carriers, 110sccm of TMGa source and 90sccm of TMAl source are introduced, TMIN source is simultaneously introduced, the time is 45s, and a buffer layer with a thickness of 0.15μm is grown on the substrate.

[0039] S3: The temperature is raised to 1100℃, the pressure of the reaction chamber is adjusted to 200mbar, 800sccm of TMGa source is introduced, the process lasts for 8min, and a UGaN layer with a thickness of 3μm is formed on the buffer layer.

[0040] S4: The pressure of the reaction cavity is increased to 700 mbar, the temperature is set to 1100 °C, 50000 sccm of NH3, 15000 sccm of H2, and 50000 sccm of N2 and 1000 sccm of TMGa source are introduced, and a 2.5 μm thick NGaN layer is grown on the UGaN layer.

[0041] S5: The temperature of the reaction cavity is set to 800 °C, the pressure is 200 mbar, 70000 sccm of NH3, 10000 sccm of H2, and 70000 sccm of N2 are introduced, 1000 sccm of TEGa (triethyl gallium) source is introduced every 30 s, and 300 sccm of TMIN source is intermittently introduced, and a 200 nm thick stress release layer is grown on the NGaN layer.

[0042] S6: The pressure of the reaction cavity is set to 800 mbar, the temperature is 750 °C, 40000 sccm of NH3, 15000 sccm of H2, and 40000 sccm of N2 and 30 sccm of TMGa source are introduced, and 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 0.18 μm, and the doping concentration of IN is 1.5E+20 atom / cm 3 , wherein 1300 sccm of TMIN source is introduced when the INGaN / GaN is grown.

[0043] S7: The pressure of the reaction cavity is set to 600 mbar, the temperature is 650 °C, 60000 sccm of NH3, and 40 sccm of TMGa source are introduced, and a 70 nm thick low-temperature P-type GaN layer is formed on the multi-quantum well active region layer.

[0044] S8: The pressure of the reaction cavity is lowered to 250 mbar, the temperature is raised to 950 °C, the CP2Mg source is turned off, 60000 sccm of N2 is introduced, and a P-EBL layer is grown on the low-temperature P-type GaN layer by segmented doping;

[0045] , wherein the segmented doping is specifically that different concentrations of TMIN source, TMAl source, and TEGa source are introduced in three stages;

[0046] In the first stage, no TMIN source and TEGa source are introduced, 90 sccm of TMAl source is introduced, and the duration is 70 s;

[0047] In the second stage, 160 sccm of TMIN source is introduced, 90 sccm of TMAl source and 1400 sccm of TEGa source are introduced at the same time, and the duration is 230 s;

[0048] The third step is to input 70sccm of TMIN source, 40sccm of TMAl source and 450sccm of TEGa source, and the process lasts for 80-120s.

[0049] S9: Finally, the temperature of the reaction cavity is increased to 1000℃, the pressure is 800mbar, 65000sccm of NH3, 40sccm of TMGa source and 2500sccm of CP2Mg source are inputted, and a high-temperature P-type GaN layer with a thickness of 80Nm is formed on the current blocking layer, and the doping concentration of Mg in the high-temperature P-type GaN layer is 1E+20atom / cm 3 .

[0050] S10: The temperature of the reaction cavity is decreased, and annealing treatment is performed in a N2 atmosphere, the annealing temperature is 700℃, the annealing treatment lasts for 10min, and then the temperature is decreased to room temperature, and the epitaxial growth is completed.

[0051] Embodiment 3 of the present application is a growth method of GaN-based epitaxial structure, comprising the following steps:

[0052] S1: A sapphire substrate is used, the substrate is put into a reaction cavity of a metal organic chemical vapor deposition device, the pressure of the reaction cavity is 500mbar, the temperature is 1200℃, H2 is used as a carrier gas to perform substrate surface treatment, and the process lasts for 10min.

[0053] S2: The pressure of the reaction cavity is decreased to 100mbar, the temperature is 900℃, H2 and NH3 are used as carriers, 100sccm of TMGa source and 80sccm of TMAl source are inputted, a TMIN source is inputted at the same time, the time length is 30s, and a buffer layer with a thickness of 0.1μm is grown on the substrate.

[0054] S3: The temperature is increased to 1000℃, the pressure of the reaction cavity is adjusted to 250mbar, 650sccm of TMGa source is inputted, and the process lasts for 6min, so as to form a UGaN layer with a thickness of 2μm on the buffer layer.

[0055] S4: The pressure of the reaction cavity is increased to 500mbar, the temperature is set to 1100℃, 50000sccm of NH3, 15000sccm of H2, 50000sccm of N2 and 1000sccm of TMGa source are inputted, and a NGaN layer with a thickness of 2μm is grown on the UGaN layer.

[0056] S5: set the temperature of the reaction cavity to 750°C, the pressure to 350 mbar, introduce 60000 sccm of NH3, 5000 sccm of H2 and 60000 sccm of N2, introduce 500 sccm of TEGa source, introduce 100 sccm of TMIN source intermittently every 1 min, and grow a stress release layer with a thickness of 200 nm on the NGaN layer.

[0057] S6: set the pressure of the reaction cavity to 500 mbar and the temperature to 800°C, introduce 40000 sccm of NH3, 15000 sccm of H2, 40000 sccm of N2 and 25 sccm of TMGa source, and grow a periodic INGaN / GaN multi-quantum well active region layer on the stress release layer, the period number of INGaN / GaN being 10; the thickness of the multi-quantum well active region layer is 0.15 μm, and the doping concentration of IN is 1E+20 atom / cm 3 wherein 1200 sccm of TMIN source is introduced when growing INGaN / GaN.

[0058] S7: set the pressure of the reaction cavity to 300 mbar and the temperature to 700°C, introduce 55000 sccm of NH3 and 25 sccm of TMGa source, and form a low-temperature P-type GaN layer with a thickness of 60 nm on the multi-quantum well active region layer.

[0059] S8: set the pressure of the reaction cavity to 200 mbar and the temperature to 1000°C, close the CP2Mg source, introduce 60000 sccm of N2, and grow a P-EBL layer on the low-temperature P-type GaN layer by segmented doping;

[0060] wherein the segmented doping is specifically that different concentrations of TMIN source, TMAl source and TEGa source are introduced in three stages;

[0061] In the first stage, no TMIN source and TEGa source are introduced, and 80 sccm of TMAl source is introduced, which lasts for 50 s;

[0062] In the second stage, 150 sccm of TMIN source is introduced, and 80 sccm of TMAl source and 1300 sccm of TEGa source are introduced, which lasts for 200 s;

[0063] In the third stage, 60 sccm of TMIN source, 30 sccm of TMAl source and 400 sccm of TEGa source are introduced, which lasts for 80 s.

[0064] S9: finally, the temperature of the reaction cavity is increased to 900 DEG C, the pressure is 1000 mbar, 60000 sccm of NH3, 25 sccm of TMGa source and 2000 sccm of CP2Mg source are introduced, a high-temperature P-type GaN layer with a thickness of 60 Nm is formed on the current blocking layer, the doping concentration of Mg in the high-temperature P-type GaN layer is 1E+20 atom / cm 3 .

[0065] S10: the temperature of the reaction cavity is decreased, annealing treatment is carried out in a N2 atmosphere, the annealing temperature is 650 DEG C, the annealing treatment is carried out for 15 min, and then the temperature is decreased to room temperature, and the epitaxial growth is completed.

[0066] Embodiment 4 of the application is a growth method of a GaN-based epitaxial structure, comprising the following steps:

[0067] S1: a sapphire substrate is used, the substrate is placed into a reaction cavity of a metal organic chemical vapor deposition device, the pressure of the reaction cavity is 600 mbar, the temperature is 1000 DEG C, H2 is used as a carrier gas to carry out substrate surface treatment, and the duration of the process is 12 min.

[0068] S2: the pressure of the reaction cavity is decreased to 200 mbar, the temperature is 800 DEG C, H2 and NH3 are used as carriers, 120 sccm of TMGa source and 100 sccm of TMAl source are introduced, at the same time, TMIn source is introduced, the duration is 60 s, and a buffer layer with a thickness of 0.2 um is grown on the substrate.

[0069] S3: the temperature is increased to 1150 DEG C, the pressure of the reaction cavity is adjusted to 120 mbar, 1200 sccm of TMGa source is introduced, the process lasts for 9 min, and a UGaN layer with a thickness of 4 um is formed on the buffer layer.

[0070] S4: the pressure of the reaction cavity is increased to 1000 mbar, the temperature is set to 1100 DEG C, 50000 sccm of NH3, 15000 sccm of H2, 50000 sccm of N2 and 1000 sccm of TMGa source are introduced, and a NGaN layer with a thickness of 3 um is grown on the UGaN layer.

[0071] S5: the temperature of the reaction cavity is set to 850 DEG C, the pressure is 150 mbar, 75000 sccm of NH3, 20000 sccm of H2 and 80000 sccm of N2 are introduced, 1500 sccm of TEGa source is introduced, and 500 sccm of TMIn source is intermittently introduced every 15 s, and a stress release layer with a thickness of 200 nm is grown on the NGaN layer.

[0072] S6: Set the reaction cavity pressure to 1000 mbar and the temperature to 700°C, and introduce 40000 sccm of NH3, 15000 sccm of H2, 40000 sccm of N2, and 40 sccm of TMGa source, so that a periodic INGaN / GaN multi-quantum well active region layer is grown on the stress release layer, and the period number of INGaN / GaN is 16; the thickness of the multi-quantum well active region layer is 0.2 μm, and the doping concentration of IN is 12E+20 atom / cm 3 , wherein when the INGaN / GaN is grown, the INGaN layer is also introduced with 1500 sccm of TMIN source.

[0073] S7: Set the reaction cavity pressure to 800 mbar and the temperature to 600°C, and introduce 65000 sccm of NH3 and 50 sccm of TMGa source, so that a low-temperature P-type GaN layer with a thickness of 90 Nm is formed on the multi-quantum well active region layer.

[0074] S8: Set the reaction cavity pressure to be lowered to 300 mbar and the temperature to be raised to 900°C, and close the CP2Mg source, introduce 60000 sccm of N2, and simultaneously perform segmented doping, so that a P-EBL layer is grown on the low-temperature P-type GaN layer;

[0075] , wherein the segmented doping is specifically that different concentrations of TMIN source, TMAl source, and TEGa source are introduced in three stages;

[0076] In the first stage, no TMIN source and TEGa source are introduced, and 100 sccm of TMAl source is introduced, and the process lasts for 80 s;

[0077] In the second stage, 200 sccm of TMIN source is introduced, and 100 sccm of TMAl source and 1500 sccm of TEGa source are introduced simultaneously, and the process lasts for 260 s;

[0078] In the third stage, 80 sccm of TMIN source, 50 sccm of TMAl source, and 500 sccm of TEGa source are introduced, and the process lasts for 120 s.

[0079] S9: Finally, the temperature of the reaction cavity is raised to 1050°C, the pressure is 600 mbar, 75000 sccm of NH3, 0 sccm of TMGa source, and 3000 sccm of CP2Mg source are introduced, so that a high-temperature P-type GaN layer with a thickness of 90 Nm is formed on the current blocking layer, and the doping concentration of Mg in the high-temperature P-type GaN layer is 1E+20 atom / cm 3 .

[0080] S10: reducing the temperature of the reaction cavity, annealing in N2 atmosphere, annealing temperature is 850 DEG C, annealing for 5 min, then reducing to room temperature, and the epitaxial growth is finished.

[0081] The comparative example 1 of the present application is:

[0082] The comparative example 1 and the example 2 only differ in that: no step S8, no current blocking layer.

[0083] The comparative example 2 of the present application is: a growth method of an epitaxial wafer containing a conventional current blocking layer

[0084] The comparative example 2 and the example 2 only differ in that: S8: setting the pressure of the reaction cavity to 300 mbar, the temperature to 900 DEG C, closing the CP2Mg source, inputting 40000 sccm of NH3, 15000 sccm of H2, 40000 sccm of N2, 100 sccm of TMAl source and 1000 sccm of TEGa source, and growing a P-EBL layer on the low-temperature P-type GaN layer for 6 min.

[0085] The epitaxial wafers grown in the example 2, the comparative example 1 and the comparative example 2 are prepared into chips, and the chips are electrically tested, and the test results are shown in Table 1 (the data in Table 1 is the average value of multiple chips); the brightness contrast results of the example 2 and the comparative example 1 are shown in Figure 2 .

[0086] Note: Figure 2 The horizontal coordinate in the table represents the number of chips, and the vertical coordinate represents the brightness (unit: MW).

[0087] Table 1

[0088]

[0089] From Figure 2 and Table 1, under the condition of equivalent electrical properties, the electrical properties of the example 2 are not different from those of the comparative example 1, but the brightness of the example 2 is obviously improved compared with the comparative example 1, and is also improved compared with the comparative example 2.

[0090] In summary, the GaN-based epitaxial structure provided by the present application can greatly improve the electron concentration and the hole concentration of the LED by inserting a P-EBL layer between the low-temperature P-type GaN layer and the high-temperature P-type GaN layer, and the distribution is uniform, so that the purpose of improving the brightness is achieved.

[0091] Specifically, when growing the P-EBL layer, different amounts of TMAl source, TMIN source and TEGa source are introduced into the reaction chamber in stages to form a stage current blocking layer with different concentration contents and thicknesses. The stage electron blocking layer blocks the electrons from the cathode at the interface of the light-emitting layer, increases the concentration of the electrons at the interface of the light-emitting layer, and can improve the electron potential barrier of the conduction band, thereby effectively limiting the leakage of the electrons to the P-type GaN layer and effectively inhibiting the electron leakage current. In addition, the stage electron blocking layer can reduce the hole potential barrier of the valence band, enhance the injection efficiency of the holes in the P-type GaN layer to the active region, and achieve the purpose of improving the brightness.

[0092] The above description is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent transformation or direct or indirect application in the related technical field based on the content of the specification and drawings is also included in the patent protection scope of the present application.

Claims

1. A GaN-based epitaxial structure comprising, in order, a buffer layer, a UGaN layer, an NGaN layer, a stress release layer, and a multiple quantum step active region layer grown on a substrate, characterized in that, The multi-quantum-step active region layer further has a low-temperature P-type GaN layer, a P-EBL layer and a high-temperature P-type GaN layer grown in sequence.

2. A method of growing a P-EBL layer of a GaN-based epitaxial structure according to claim 1, characterized in that, The method comprises three stages; The first stage is to introduce 80-100 sccm of TMAl source; The second stage is to simultaneously introduce 150-200 sccm of TMIN source, 80-100 sccm of TMAl source and 1300-1500 sccm of TEGa source, and the time length of the TMIN source, TMAl source and TEGa source is equal; The third stage is to simultaneously introduce 60-80 sccm of TMIN source, 30-50 sccm of TMAl source and 400-500 sccm of TEGa source, and the time length of the TMIN source, TMAl source and TEGa source is equal.

3. The method of growing a P-EBL layer of a GaN-based epitaxial structure according to claim 2, wherein The duration of the first stage is 50-80 s, the duration of the second stage is 200-260 s, and the duration of the third stage is 80-120 s.

4. The method of growing a P-EBL layer of a GaN-based epitaxial structure according to claim 2, wherein The P-EBL layer is grown in a reaction chamber, and the temperature of the reaction chamber is set to 900-1000 ℃ and the pressure is set to 200-300 mbar.

5. The method of growing a P-EBL layer of a GaN-based epitaxial structure according to claim 4, wherein When the P-EBL layer is grown, N2 is continuously introduced into the reaction chamber.

6. A method for growing a GaN-based epitaxial structure as claimed in claim 1, characterized by, The stress release layer is grown in a reaction chamber, and the temperature of the reaction chamber is set to 750-850 ℃ and the pressure is set to 150-350 mbar.

7. The method of growing a GaN-based epitaxial structure according to claim 6, wherein When the stress release layer is grown, 60000-75000 sccm of NH3, 5000-20000 sccm of H2, 60000-80000 sccm of N2 and 500-1500 sccm of TEGa are simultaneously introduced, and the time length of the NH3, H2, N2 and TEGa is equal, and 100-500 sccm of TMIN is introduced.

8. The method of growing a GaN-based epitaxial structure according to claim 6, wherein The low-temperature P-type GaN layer is grown in a reaction chamber, and the temperature of the reaction chamber is set to 600-700 ℃ and the pressure is set to 300-800 mbar, 55000-65000 sccm of NH3 and 25-50 sccm of TMGa source are simultaneously introduced, and the time length of the NH3 and TMGa is equal.

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