A method for generating an epitaxial structure of a mini LED with high ESD

Abstract

The application relates to the technical field of LED chip, in particular to a high-ESD Mini LED epitaxial structure generation method, which comprises the following steps: S2: a first static electricity release layer is grown on a multi-quantum well active region layer, a second static electricity release layer is grown on the first static electricity release layer, and a third static electricity release layer is grown on the second static electricity release layer; the Mg doping concentration of the second static electricity release layer is 1.1-5E+16 atom / cm 3 , the Mg doping concentration of the first static electricity release layer is 1.1-5 times the Mg doping concentration of the third static electricity release layer, and the Mg doping concentration of the second static electricity release layer is 0.1%-2% of the Mg doping concentration of the first static electricity release layer; the principle or beneficial effect of the application is as follows: since the size of the Mini LED is reduced compared with a conventional LED, the ESD performance is particularly important, the high-ESD Mini LED epitaxial structure generation method provided by the application can significantly improve the ESD performance of the Mini LED.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of LED chip, and particularly relates to a high-ESD Mini LED epitaxial structure generation method. BACKGROUND

[0002] Compared with traditional LED, the volume of Mini LED is smaller, the display effect is more delicate, and the brightness, color saturation and contrast are higher. Modern society has entered the information age and is developing towards intelligence, and display is a key link to realize information exchange and intelligence. Among the current many display technologies, Mini LED display technology is regarded as the next generation of display technology and will inevitably occupy a dominant position.

[0003] Existing research shows that the quantum efficiency of Mini LED devices decreases significantly with the decrease of size, and the peak efficiency moves towards high current density. Due to the large lattice mismatch and thermal mismatch between gallium nitride material and sapphire substrate, there is a large stress in epitaxial growth, which produces a large number of defects, affecting the quality of the multi-quantum well layer. With the decrease of chip size, especially under high current density, the chip will bear more and more weak electrostatic discharge (ESD) performance, so how to improve the electrostatic discharge performance is of great importance to the efficiency of Mini LED devices.

[0004] In order to solve the above problems, researchers found (referring to Chinese patent with publication number CN104009136A) that doping Mg or Al elements in the epitaxial layer can help improve the ESD performance of LED chips, but the effect of improving the electrostatic discharge performance is not obvious. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a high-ESD Mini LED epitaxial structure generation method.

[0006] In order to solve the above technical problems, a technical solution adopted by the present application is as follows: a high-ESD Mini LED epitaxial structure generation method, comprising the following steps:

[0007] S1: placing a substrate into a reaction cavity of a metal organic chemical vapor deposition device, and growing a buffer layer, a U-shaped GaN layer, an N-type GaN layer and a multi-quantum well active region layer on the substrate in sequence;

[0008] S2: introducing NH3, TMGa and Cp2Mg into the reaction cavity;

[0009] The first static electricity release layer is grown on the multi-quantum well active region layer, the second static electricity release layer is grown on the first static electricity release layer, and the third static electricity release layer is grown on the second static electricity release layer, under the condition that the growth atmosphere is H2;

[0010] The Mg doping concentration of the second static electricity release layer is 1.1-5E+16 atom / cm 3 ,

[0011] The Mg doping concentration of the first static electricity release layer is 1.1-5 times the Mg doping concentration of the third static electricity release layer, and the Mg doping concentration of the second static electricity release layer is 0.1%-2% of the Mg doping concentration of the first static electricity release layer;

[0012] S3: sequentially growing a P-type electron blocking layer and a P-type GaN layer on the third static electricity release layer; and completing preparation of the high-ESD Mini LED.

[0013] The principle or beneficial effect of the present application is that in the first static electricity release layer, the second static electricity release layer and the third static electricity release layer in the present application, the doping concentration of the Mg element first decreases and then increases, and the quantity relationship of the doping concentration of the Mg element in the first static electricity release layer, the second static electricity release layer and the third static electricity release layer is that the Mg doping concentration of the second static electricity release layer is 1.1-5E+16 atom / cm 3 , the Mg doping concentration of the first static electricity release layer is 1.1-5 times the Mg doping concentration of the third static electricity release layer, and the Mg doping concentration of the second static electricity release layer is 0.1%-2% of the Mg doping concentration of the first static electricity release layer; which can maximize the ESD performance of the LED.

[0014] Therefore, due to the size reduction of the Mini LED compared with the conventional LED, the ESD performance is particularly important, and the epitaxial structure generation method of the high-ESD Mini LED provided by the present application can significantly improve the ESD performance of the Mini LED. DETAILED DESCRIPTION

[0015] To illustrate the technical content, purposes and effects of the present application, the following embodiments are described.

[0016] An epitaxial structure generation method of a high-ESD Mini LED, comprising the following steps:

[0017] S1: placing a substrate into a reaction cavity of a metal organic chemical vapor deposition device, and sequentially growing a buffer layer, a U-shaped GaN layer, an N-type GaN layer and a multi-quantum well active region layer on the substrate;

[0018] S2: introducing NH3, TMGa and Cp2Mg into the reaction cavity;

[0019] In the case that the growth atmospheres are both H2, the instant input amount of Cp2Mg is controlled, a first electrostatic discharge layer is grown on the multi-quantum well active region layer, a second electrostatic discharge layer is grown on the first electrostatic discharge layer, and a third electrostatic discharge layer is grown on the second electrostatic discharge layer;

[0020] The Mg doping concentration of the second electrostatic discharge layer is 1.1-5E+16 atom / cm 3 ,

[0021] The Mg doping concentration of the first electrostatic discharge layer is 1.1-5 times the Mg doping concentration of the third electrostatic discharge layer, and the Mg doping concentration of the second electrostatic discharge layer is 0.1%-2% of the Mg doping concentration of the first electrostatic discharge layer;

[0022] S3: sequentially growing a P-type electron blocking layer and a P-type GaN layer on the third electrostatic discharge layer; and completing the preparation of the Mini LED with high ESD.

[0023] The principle or beneficial effect of the present application is as follows: in the prior art, in order to improve the ESD performance of the Mini LED chip, an electrostatic layer is usually arranged between the P-type GaN layer and the multi-quantum well active region layer, and the electrostatic layer includes a Mg-doped body layer and an undoped body layer; in other words, the doping concentration of the Mg element in the electrostatic layer in the prior art is always increased or decreased in the direction away from the substrate.

[0024] The first electrostatic discharge layer, the second electrostatic discharge layer and the third electrostatic discharge layer in the present application correspond to the electrostatic layer in the prior art, and the inventors have found that the doping concentration of the Mg element in the electrostatic layer is first decreased and then increased or first increased and then decreased in the direction away from the substrate, which can further improve the ESD performance of the LED.

[0025] Specifically, in the first electrostatic discharge layer, the second electrostatic discharge layer and the third electrostatic discharge layer in the present application, the doping concentration of the Mg element is first decreased and then increased, and the quantity relationship of the doping concentration of the Mg element in the first electrostatic discharge layer, the second electrostatic discharge layer and the third electrostatic discharge layer is that the Mg doping concentration of the second electrostatic discharge layer is 1.1-5E+16 atom / cm 3 , the Mg doping concentration of the first electrostatic discharge layer is 1.1-5 times the Mg doping concentration of the third electrostatic discharge layer, and the Mg doping concentration of the second electrostatic discharge layer is 0.1%-2% of the Mg doping concentration of the first electrostatic discharge layer; which can maximize the ESD performance of the LED.

[0026] Therefore, due to the size reduction of Mini LED compared with the conventional LED, the ESD performance is particularly important, and the epitaxial structure generation method of the high ESD Mini LED provided by the application can significantly improve the ESD performance of the Mini LED.

[0027] Further, S1 is specifically:

[0028] Put the substrate into the reaction cavity of the metal organic chemical vapor deposition equipment, use hydrogen to purge the reaction cavity, and make the reaction cavity full of hydrogen;

[0029] Close the hydrogen purge; set the reaction cavity pressure to 500-600 mbar and the temperature to 1000-1200 DEG C, and continue for 7-10 minutes; use hydrogen and ammonia to purge the reaction cavity.

[0030] From the above description, the above method purges the reaction cavity of impurities, and introduces the gas required for subsequent reaction in advance, preheats and pressurizes the substrate to pretreat the reaction cavity, and improves the quality of the structure grown on the substrate in subsequent growth.

[0031] Further, the "growth buffer layer" of S1 is specifically:

[0032] Set the reaction cavity pressure to 100-200 mbar and the temperature to 800-900 DEG C, and simultaneously introduce 60-80 sccm of TMGa and 25-45 sccm of TMAl into the reaction cavity, and continue for 4-6 minutes, so that a buffer layer with a thickness of 0.01-0.02 um is grown on the substrate.

[0033] From the above description, the above setting provides a simple and efficient method for growing a buffer layer, and realizes the growth of a high-quality buffer layer.

[0034] Further, the "growth U-shaped GaN layer" of S1 is specifically:

[0035] Set the reaction cavity pressure to 150-500 mbar and the temperature to 900-1100 DEG C, and simultaneously introduce 300-400 sccm of TMGa into the reaction cavity, and continue for 6-30 minutes, so that a U-shaped GaN layer is formed on the buffer layer.

[0036] From the above description, the above setting provides a simple and efficient method for growing a U-shaped GaN layer, and realizes the generation of a high-quality U-shaped GaN layer.

[0037] Further, the "growth N-type GaN layer" of S1 is specifically:

[0038] The pressure of the reaction cavity is set to 500-1000 mbar, and the N-type GaN layer with a thickness of 2-3 μm is grown on the U-shaped GaN layer.

[0039] From the above description, the above setting provides a simple and efficient method for growing the N-type GaN layer, and a high-quality N-type GaN layer is generated.

[0040] Further, the "growing a multi-quantum well active region layer" of S1 is specifically:

[0041] The well layer and the barrier layer of the multi-quantum well active region layer are alternately grown on the N-type GaN, the thickness of the multi-quantum well active region layer is 0.15-0.2 μm, the well layer is InGaN, and the barrier layer is GaN. Each growth of the well layer and the barrier layer is one cycle, and the number of InGaN / GaN cycles is 10-16.

[0042] When growing the well layer, the temperature of the reaction cavity is set to 700-800 degrees, 1200-1500 sccm of TMIn and 25-400 sccm of TEGa are introduced into the reaction cavity, and the doping concentration of In in each well layer is 1E+20-2E+20 atom / cm 3 ;

[0043] When growing the barrier layer, the temperature of the reaction cavity is set to 800-950 degrees, and 300-1000 sccm of TEGa is introduced into the reaction cavity.

[0044] When growing the last barrier layer, TMAl is introduced into the reaction cavity, the flow rate of TMAl is linearly decreased from 180 sccm to 0 sccm, the molar number of Al in the last barrier layer is linearly decreased along the direction away from the substrate, and the ratio of the molar number of Al to the molar number of GaN is linearly decreased from 15% to 0%.

[0045] From the above description, the above setting provides a simple and efficient method for growing the multi-quantum well active region layer, and the ESD performance of the LED can be improved by doping Al elements in the last barrier layer of the multi-quantum well active region layer in combination with the first electrostatic discharge layer. Specifically, the molar number of Al in the last barrier layer is linearly decreased in the direction of the original substrate, which can maximize the ESD performance of the LED.

[0046] Further, S2 is specifically:

[0047] The temperature of the reaction cavity is set to 700-950 degrees, the pressure is 300-800 mbar, 55000-65000 sccm of NH3, 25-50 sccm of TMGa, and Cp2Mg are introduced into the reaction cavity.

[0048] In the case that the growth atmospheres are both H2, the instant input amount of Cp2Mg is controlled to grow a first static electricity release layer of 20-40 nm on the multi-quantum well active region layer, grow a second static electricity release layer of 10-30 nm on the first static electricity release layer, and grow a third static electricity release layer of 10-30 nm on the second static electricity release layer;

[0049] The Mg doping concentration of the second static electricity release layer is 1.1-5E+16 atom / cm 3 ,

[0050] The Mg doping concentration of the first static electricity release layer is 1.1-5 times the Mg doping concentration of the third static electricity release layer, and the Mg doping concentration of the second static electricity release layer is 0.1%-2% of the Mg doping concentration of the first static electricity release layer;

[0051] It can be seen from the above description that the above setting provides a simple and efficient method for generating the first static electricity release layer, the second static electricity release layer, and the third static electricity release layer, and improves the quality of the Mini LED with high ESD.

[0052] Further, the S2 further comprises:

[0053] When the second static electricity release layer is grown, TMAl is input into the reaction cavity, and the flow rate of TMAl is linearly increased, so that in the second static electricity release layer, the mole number of Al and the mole number of GaN linearly increase from 0% to 15% in the direction away from the substrate;

[0054] When the third static electricity release layer is grown, TMAl is input into the reaction cavity, and the flow rate of TMAl is linearly increased, so that in the third static electricity release layer, the mole number of Al and the mole number of GaN linearly increase from 0% to 15% in the direction away from the substrate.

[0055] It can be seen from the above description that doping Al elements in the second static electricity release layer and the third static electricity release layer can improve the ESD performance of the LED; and the setting is combined with the setting of doping Al elements in the last barrier layer of the multi-quantum well active region layer, and the effect is better.

[0056] Specifically, the mole number of Al doped in the second static electricity release layer and the third static electricity release layer is linearly increased in the direction away from the substrate, so that the ESD performance of the LED is maximally improved.

[0057] Further, the “growing a P-type electron blocking layer” of the S3 is specifically: setting the temperature of the reaction cavity to 700-950 ℃, inputting 30000-60000 sccm of NH3, 30-50 sccm of TMGa, 1500-2000 sccm of Cp2Mg, and 150-200 sccm of TMAl, and growing a P-type electron blocking layer of 50-70 nm on the third static electricity release layer;

[0058] The doping concentration of Mg in the P-type electron blocking layer is 0-1E+19 atom / cm 3 The doping concentration of Al is 1E+17-1E+18 atom / cm3.

[0059] From the above description, it can be seen that the above setting provides a simple and efficient method for growing a P-type electron blocking layer.

[0060] Further, the "growing a P-type GaN layer" of S3 is specifically: setting the reaction chamber temperature to 900-1050℃, the pressure to 600-1000mbar, introducing 60000-75000sccm of NH3, 25-50sccm of TMGa, and 2000-3000sccm of Cp2Mg into the reaction chamber, and forming a 60-90nm P-type GaN layer on the P-type electron blocking layer.

[0061] From the above description, it can be seen that the above setting provides a simple and efficient method for growing a P-type GaN layer, which reduces the operating voltage of the LED and improves the light-emitting efficiency of the LED.

[0062] Embodiment one

[0063] The embodiment provides a method for generating an epitaxial structure of a Mini LED with high ESD, including the following steps:

[0064] S1: Place the substrate into the reaction chamber of a metal organic chemical vapor deposition device, and use hydrogen to purge the reaction chamber;

[0065] S2: Set the pressure of the reaction chamber to 550mbar and the temperature to 1100℃, and maintain for 8.5 minutes; use hydrogen and ammonia to purge the reaction chamber;

[0066] S3: Set the pressure of the reaction chamber to 150mbar and the temperature to 850℃, and simultaneously introduce 70sccm of TMGa and 35sccm of TMAl into the reaction chamber, and maintain for 5 minutes, so that a buffer layer with a thickness of 0.015μm is grown on the substrate;

[0067] S4: Set the pressure of the reaction chamber to 325mbar and the temperature to 1000℃, and simultaneously introduce 350sccm of TMGa into the reaction chamber, and maintain for 18 minutes, so that a U-shaped GaN layer is formed on the buffer layer;

[0068] S5: Set the pressure of the reaction chamber to 750mbar, and grow a N-type GaN layer with a thickness of 2.5μm on the U-shaped GaN layer;

[0069] S6: alternately growing a well layer and a barrier layer of a multi-quantum well active region layer on the N-type GaN, the thickness of the multi-quantum well active region layer being 0.18 μm; the well layer being InGaN, and the barrier layer being GaN, one cycle being formed by growing one well layer and one barrier layer, and the number of cycles of InGaN / GaN being 13;

[0070] When the well layer is grown, the temperature of the reaction chamber is set to 750 degrees, 1300 sccm of TMIn and 210 sccm of TEGa are introduced into the reaction chamber; the doping concentration of In of each well layer is 1E+20-2E+20 atom / cm 3 ;

[0071] When the barrier layer is grown, the temperature of the reaction chamber is set to 800-950 degrees, 300-1000 sccm of TEGa is introduced into the reaction chamber;

[0072] When the last barrier layer is grown, TMAl is introduced into the reaction chamber, the flow rate of TMAl is linearly decreased from 180 sccm to 0 sccm, so that the mole number of Al in the last barrier layer is linearly decreased along the direction away from the substrate, and the ratio of the mole number of Al to the mole number of GaN is linearly decreased from 15% to 0%;

[0073] S7: setting the temperature of the reaction chamber to 850 degrees, the pressure to 550 mbar, introducing 60000 sccm of NH3, 35 sccm of TMGa and Cp2Mg into the reaction chamber;

[0074] In the case that the growth atmosphere is H2, the instantaneous introduction amount of Cp2Mg is controlled, so that a first electrostatic discharge layer with a thickness of 30 nm is grown on the multi-quantum well active region layer, a second electrostatic discharge layer with a thickness of 20 nm is grown on the first electrostatic discharge layer, and a third electrostatic discharge layer with a thickness of 20 nm is grown on the second electrostatic discharge layer;

[0075] The Mg doping concentration of the second electrostatic discharge layer is 1.1-5E+16 atom / cm 3 ,

[0076] The Mg doping concentration of the first electrostatic discharge layer is 3 times the Mg doping concentration of the third electrostatic discharge layer, and the Mg doping concentration of the second electrostatic discharge layer is 1% of the Mg doping concentration of the first electrostatic discharge layer;

[0077] When the second electrostatic discharge layer is grown, TMAl is introduced into the reaction chamber, and the flow rate of TMAl is linearly increased, so that in the second electrostatic discharge layer, the ratio of the mole number of Al to the mole number of GaN is linearly increased from 0% to 15% along the direction away from the substrate;

[0078] When the third static electricity release layer is grown, TMAl is introduced into the reaction cavity, the flow rate of TMAl is linearly increased, and in the third static electricity release layer, the mole number of Al is linearly increased from 0% to 15% in the direction away from the substrate relative to the mole number of GaN;

[0079] S8: set the temperature of the reaction cavity to 850 DEG C, introduce 40000 sccm of NH3, 40 sccm of TMGa, 1800 sccm of Cp2Mg and 170 sccm of TMAl, and grow a 60 nm P-type electron blocking layer on the third static electricity release layer;

[0080] In the P-type electron blocking layer, the doping concentration of Mg is 0-1E+19 atom / cm3 3 , and the doping concentration of Al is 1E+17-1E+18 atom / cm3;

[0081] S9: set the temperature of the reaction cavity to 955 DEG C and the pressure to 800 mbar, introduce 67500 sccm of NH3, 37.5 sccm of TMGa and 2500 sccm of Cp2Mg into the reaction cavity, and form a 75 nm P-type GaN layer on the P-type electron blocking layer; and the preparation of the high ESD Mini LED is completed.

[0082] Example two

[0083] The embodiment provides a high ESD Mini LED epitaxial structure generation method, which comprises the following steps:

[0084] S1: place the substrate into the reaction cavity of a metal organic chemical vapor deposition device, and use hydrogen to purge the reaction cavity;

[0085] S2: set the pressure of the reaction cavity to 500 mbar and the temperature to 1000 DEG C, and maintain for 7 minutes; use hydrogen and ammonia to purge the reaction cavity;

[0086] S3: set the pressure of the reaction cavity to 100 mbar and the temperature to 800 DEG C, and simultaneously introduce 60 sccm of TMGa and 25 sccm of TMAl into the reaction cavity, and maintain for 4 minutes, so that a buffer layer with a thickness of 0.01-0.02 mu m is grown on the substrate;

[0087] S4: set the pressure of the reaction cavity to 150 mbar and the temperature to 900 DEG C, and simultaneously introduce 300 sccm of TMGa into the reaction cavity, and maintain for 6 minutes, so that a U-shaped GaN layer is formed on the buffer layer;

[0088] S5: set the pressure of the reaction cavity to 500 mbar, and grow a N-type GaN layer with a thickness of 2 mu m-3 mu m on the U-shaped GaN layer;

[0089] S6: alternately growing a well layer and a barrier layer of a multi-quantum well active region layer on the N-type GaN, the thickness of the multi-quantum well active region layer being 0.15-0.2 μm; the well layer being InGaN and the barrier layer being GaN, one cycle being formed by growing one well layer and one barrier layer, and the number of cycles of InGaN / GaN being 10;

[0090] When the well layer is grown, the temperature of the reaction cavity is set to 700 degrees, 1200 sccm of TMIn and 25 sccm of TEGa are introduced into the reaction cavity; the In doping concentration of each well layer being 1E+20-2E+20 atom / cm 3 ;

[0091] When the barrier layer is grown, the temperature of the reaction cavity is set to 800 degrees, 300 sccm of TEGa is introduced into the reaction cavity;

[0092] When the last barrier layer is grown, TMAl is introduced into the reaction cavity, the flow rate of TMAl being linearly decreased from 180 sccm to 0 sccm, so that the mole number of Al in the last barrier layer is linearly decreased in the direction away from the substrate, and the ratio of the mole number of Al to the mole number of GaN is linearly decreased from 15% to 0%;

[0093] S7: setting the temperature of the reaction cavity to 700 degrees, the pressure to 300 mbar, introducing 55000 sccm of NH3, 25 sccm of TMGa and Cp2Mg into the reaction cavity;

[0094] In the case that the growth atmosphere is H2, the instantaneous introduction amount of Cp2Mg is controlled, so that a 20 nm first electrostatic discharge layer is grown on the multi-quantum well active region layer, a 10 nm second electrostatic discharge layer is grown on the first electrostatic discharge layer, and a 10 nm third electrostatic discharge layer is grown on the second electrostatic discharge layer;

[0095] The Mg doping concentration of the second electrostatic discharge layer is 1.1-5E+16 atom / cm 3 ,

[0096] The Mg doping concentration of the first electrostatic discharge layer is 1.1-5 times the Mg doping concentration of the third electrostatic discharge layer, and the Mg doping concentration of the second electrostatic discharge layer is 0.1%-2% of the Mg doping concentration of the first electrostatic discharge layer;

[0097] When the second electrostatic discharge layer is grown, TMAl is introduced into the reaction cavity, and the flow rate of TMAl is linearly increased, so that in the second electrostatic discharge layer, the ratio of the mole number of Al to the mole number of GaN is linearly increased from 0% to 15% in the direction away from the substrate;

[0098] In the growth of the third static electricity release layer, TMAl is introduced into the reaction cavity, and the flow of TMAl is linearly increased, so that in the third static electricity release layer, the mole number of Al is linearly increased from 0% to 15% in the direction away from the substrate relative to the mole number of GaN;

[0099] S8: set the temperature of the reaction cavity to 700-950 DEG C, introduce 30000-60000 sccm of NH3, 30-50 sccm of TMGa, 1500-2000 sccm of Cp2Mg and 150-200 sccm of TMAl, and grow a 50-70 nm P-type electron blocking layer on the third static electricity release layer;

[0100] In the P-type electron blocking layer, the doping concentration of Mg is 0-1E+19 atom / cm3 3 , and the doping concentration of Al is 1E+17-1E+18 atom / cm3;

[0101] S9: set the temperature of the reaction cavity to 900-1050 DEG C and the pressure to 1000 mbar, introduce 60000-75000 sccm of NH3, 25-50 sccm of TMGa and 3000 sccm of Cp2Mg into the reaction cavity, and form a 60-90 nm P-type GaN layer on the P-type electron blocking layer; and the preparation of the high ESD Mini LED is completed.

[0102] Example Three

[0103] The embodiment provides a high ESD Mini LED epitaxial structure generation method, which comprises the following steps:

[0104] S1: place the substrate into the reaction cavity of a metal organic chemical vapor deposition device, and use hydrogen to purge the reaction cavity;

[0105] S2: set the pressure of the reaction cavity to 600 mbar and the temperature to 1200 DEG C, and continue for 7-10 minutes; use hydrogen and ammonia to purge the reaction cavity;

[0106] S3: set the pressure of the reaction cavity to 100-200 mbar and the temperature to 800-900 DEG C, simultaneously introduce 60-80 sccm of TMGa and 25-45 sccm of TMAl into the reaction cavity, and continue for 4-6 minutes, so that a buffer layer with a thickness of 0.01-0.02 mu m is grown on the substrate;

[0107] S4: set the pressure of the reaction cavity to 500 mbar and the temperature to 900-1100 DEG C, simultaneously introduce 300-400 sccm of TMGa into the reaction cavity, and continue for 30 minutes, so that a U-shaped GaN layer is formed on the buffer layer;

[0108] S5: setting the pressure of the reaction chamber to 1000 mbar, and growing a N-type GaN layer with a thickness of 2-3 μm on the U-shaped GaN layer;

[0109] S6: alternately growing a well layer and a barrier layer of a multi-quantum well active region layer on the N-type GaN, the thickness of the multi-quantum well active region layer being 0.2 μm; the well layer being InGaN, and the barrier layer being GaN, one cycle being formed by growing one well layer and one barrier layer, and the number of cycles of InGaN / GaN being 16;

[0110] When growing the well layer, the temperature of the reaction chamber is set to 800 degrees, 1200-1500 sccm of TMIn and 400 sccm of TEGa are introduced into the reaction chamber; the doping concentration of In of each well layer being 1E+20-2E+20 atom / cm 3 ;

[0111] When growing the barrier layer, the temperature of the reaction chamber is set to 950 degrees, and 1000 sccm of TEGa is introduced into the reaction chamber;

[0112] When growing the last barrier layer, TMAl is introduced into the reaction chamber, the flow rate of TMAl being linearly decreased from 180 sccm to 0 sccm, so that the number of moles of Al in the last barrier layer is linearly decreased along the direction away from the substrate, and the ratio of the number of moles of Al to the number of moles of GaN is linearly decreased from 15% to 0%;

[0113] S7: setting the temperature of the reaction chamber to 950 degrees, and the pressure to 300-800 mbar, and introducing 65000 sccm of NH3, 25-50 sccm of TMGa and Cp2Mg into the reaction chamber;

[0114] In the case that the growth atmosphere is H2, the instantaneous introduction amount of Cp2Mg is controlled, so that a first electrostatic discharge layer with a thickness of 20-40 nm is grown on the multi-quantum well active region layer, a second electrostatic discharge layer with a thickness of 0 nm is grown on the first electrostatic discharge layer, and a third electrostatic discharge layer with a thickness of 30 nm is grown on the second electrostatic discharge layer;

[0115] The Mg doping concentration of the second electrostatic discharge layer is 1.1-5E+16 atom / cm 3 ,

[0116] The Mg doping concentration of the first electrostatic discharge layer is 1.1-5 times the Mg doping concentration of the third electrostatic discharge layer, and the Mg doping concentration of the second electrostatic discharge layer is 0.1%-2% of the Mg doping concentration of the first electrostatic discharge layer;

[0117] In the growth of the second static electricity release layer, TMAl is introduced into the reaction cavity, the flow of TMAl is linearly increased, so that in the second static electricity release layer, the mole number of Al and the mole number of GaN in the direction away from the substrate are linearly increased from 0% to 15%;

[0118] In the growth of the third static electricity release layer, TMAl is introduced into the reaction cavity, the flow of TMAl is linearly increased, so that in the third static electricity release layer, the mole number of Al and the mole number of GaN in the direction away from the substrate are linearly increased from 0% to 15%;

[0119] S8: Set the temperature of the reaction cavity to 950℃, introduce 30000-60000sccm of NH3, 30-50sccm of TMGa, 2000sccm of Cp2Mg and 200sccm of TMAl, and grow a 50-70nm P-type electron blocking layer on the third static electricity release layer;

[0120] In the P-type electron blocking layer, the doping concentration of Mg is 0-1E+19atom / cm 3 , and the doping concentration of Al is 1E+17-1E+18atom / cm3;

[0121] S9: Set the temperature of the reaction cavity to 1050℃ and the pressure to 1000mbar, introduce 60000-75000sccm of NH3, 50sccm of TMGa and 3000sccm of Cp2Mg into the reaction cavity, and form a 90nm P-type GaN layer on the P-type electron blocking layer; the preparation of the high ESD Mini LED is completed.

[0122] Examples 4-9

[0123] Examples 4-9, except that the Mg doping concentration of the second static electricity release layer is different from that of Example 1, the other steps are the same as Example 1;

[0124] Specifically, in Example 4-9, the Mg doping concentration of the first static electricity release layer is 4-5E+20atom / cm 3 ;

[0125] The Mg doping concentration of the second static electricity release layer is 1-5E+16atom / cm 3 ;

[0126] The Mg doping concentration of the third static electricity release layer is 1-5E+20atom / cm 3 .

[0127] Comparative Example

[0128] In Table 1, each wafer number represents an epitaxial layer structure, and each epitaxial layer structure has about 400,000 mini LED cores. The 9 wafer numbers of the implementation group represent 9 different epitaxial layer structures produced by the scheme of Example 1 of the present application.

[0129] In Table 1, the production schemes of the epitaxial layers of the control groups 1, 2 and 3 are different from Example 1 in that: in the control group 1, no first, second and third static electricity release layers are set. In the control group 2, only the first and second static electricity release layers with the same Mg doping concentration are set. In the control group 3, the first, second and third static electricity release layers are set, and the Mg doping concentration of the second static electricity release layer is higher than that of the first and third static electricity release layers.

[0130] Table 1

[0131]

[0132] Table 1 represents the yield or pass rate of mini LED cores passing the 5KV ESD test chip, for example, the pass rate of mini LED cores of wafer number 1 of the implementation group is 99.83%.

[0133] As can be seen from Table 1, the pass rate of mini LED in ESD test is significantly improved by using the method provided by the present application.

[0134] The above description is only an embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent transformation or direct or indirect application in related technical fields based on the content of the present application is also included in the patent protection scope of the present application.

Claims

1. A method for generating an epitaxial structure of a high ESD Mini LED, characterized in that, Comprising the following steps: S1: Put the substrate into the reaction cavity of the metal organic chemical vapor deposition device, and sequentially grow the buffer layer, U-shaped GaN layer, N-type GaN layer and multi-quantum well active region layer on the substrate; S2: Introduce NH3, TMGa and Cp2Mg into the reaction cavity; In the case that the growth atmosphere is all H2, the instantaneous introduction amount of Cp2Mg is controlled, so that the first electrostatic discharge layer is grown on the multi-quantum well active region layer, the second electrostatic discharge layer is grown on the first electrostatic discharge layer, and the third electrostatic discharge layer is grown on the second electrostatic discharge layer; The Mg doping concentration of the second static electricity release layer is 1.1-5E+16 atom / cm 3 , The Mg doping concentration of the first electrostatic discharge layer is 1.1-5 times the Mg doping concentration of the third electrostatic discharge layer, and the Mg doping concentration of the second electrostatic discharge layer is 0.1%-2% of the Mg doping concentration of the first electrostatic discharge layer; S3: Sequentially grow the P-type electron blocking layer and the P-type GaN layer on the third electrostatic discharge layer; and complete the preparation of the Mini LED with high ESD; The S2 is specifically: The temperature of the reaction cavity is set to 700-950℃, the pressure is set to 300-800mbar, 55000-65000sccm of NH3, 25-50sccm of TMGa and Cp2Mg are introduced into the reaction cavity; In the case that the growth atmosphere is all H2, the instantaneous introduction amount of Cp2Mg is controlled, so that the first electrostatic discharge layer is grown on the multi-quantum well active region layer, the second electrostatic discharge layer is grown on the first electrostatic discharge layer, and the third electrostatic discharge layer is grown on the second electrostatic discharge layer.

2. The method of claim 1, wherein the method further comprises: The S1 is specifically: Put the substrate into the reaction cavity of the metal organic chemical vapor deposition device, and use hydrogen to purge the reaction cavity so that the reaction cavity is filled with hydrogen; Close the purge of hydrogen; set the pressure of the reaction cavity to 500-600mbar and the temperature to 1000-1200℃, and continue for 7-10 minutes; use hydrogen and ammonia to purge the reaction cavity.

3. The method of claim 1, wherein the method further comprises: The "growth of the buffer layer" of the S1 is specifically: Set the pressure of the reaction cavity to 100-200mbar and the temperature to 800-900℃, and simultaneously introduce 60-80sccm of TMGa and 25-45sccm of TMAl into the reaction cavity, and continue for 4-6 minutes, so that a buffer layer with a thickness of 0.01-0.02μm is grown on the substrate.

4. The method of claim 1, wherein the method further comprises: The "growth of the U-shaped GaN layer" of the S1 is specifically: Set the pressure of the reaction cavity to 150-500mbar and the temperature to 900-1100℃, and simultaneously introduce 300-400sccm of TMGa into the reaction cavity, and continue for 6-30 minutes, so that a U-shaped GaN layer is formed on the buffer layer.

5. The method of claim 1, wherein the method further comprises: The "growth of the N-type GaN layer" of the S1 is specifically: Set the pressure of the reaction cavity to 500-1000mbar, and grow a N-type GaN layer with a thickness of 2μm-3μm on the U-shaped GaN layer.

6. The method of claim 1, wherein the method further comprises: The "growth of the multi-quantum well active region layer" of the S1 is specifically: The well layer and the barrier layer of the multi-quantum well active region layer are alternately grown on the N-type GaN, the thickness of the multi-quantum well active region layer is 0.15-0.2 μm; the well layer is InGaN, and the barrier layer is GaN, one cycle is formed by growing one well layer and one barrier layer, and the number of InGaN / GaN cycles is 10-16; When growing the well layer, the temperature of the reaction chamber is set to 700-800 degrees, 1200-1500 sccm of TMIn and 25-400 sccm of TEGa are introduced into the reaction chamber; the doping concentration of In of each well layer is 1E+20-2E+20 atom / cm 3 ; When the barrier layer is grown, the reaction cavity temperature is set to 800-950 degrees, and 300-1000 sccm of TEGa is introduced into the reaction cavity; When the last barrier layer is grown, TMAl is introduced into the reaction cavity, the flow rate of TMAl is linearly decreased from 180 sccm to 0 sccm, the molar number of Al in the last barrier layer is linearly decreased along the direction away from the substrate, and the ratio of the molar number of Al to the molar number of GaN is linearly decreased from 15% to 0%.

7. The method of claim 1 or 6, wherein the method further comprises: The S2 further comprises: When the second static electricity release layer is grown, TMAl is introduced into the reaction cavity, the flow rate of TMAl is linearly increased, and the molar number of Al to the molar number of GaN in the second static electricity release layer is linearly increased from 0% to 15% along the direction away from the substrate; When the third static electricity release layer is grown, TMAl is introduced into the reaction cavity, the flow rate of TMAl is linearly increased, and the molar number of Al to the molar number of GaN in the third static electricity release layer is linearly increased from 0% to 15% along the direction away from the substrate.

8. The method of claim 1, wherein the method further comprises: The "growing a P-type electron blocking layer" of the S3 is specifically: the temperature of the reaction cavity is set to 700-950 degrees, 30000-60000 sccm of NH3, 30-50 sccm of TMGa, 1500-2000 sccm of Cp2Mg and 150-200 sccm of TMAl are introduced, and a 50-70 nm P-type electron blocking layer is grown on the third static electricity release layer; The doping concentration of Mg in the P-type electron blocking layer is 0-1E+19 atom / cm 3 The doping concentration of Al is 1E+17-1E+18 atom / cm 3 .

9. The method of claim 1, wherein the method further comprises: The "growing a P-type GaN layer" of the S3 is specifically: the temperature of the reaction cavity is set to 900-1050 degrees, the pressure is 600-1000 mbar, 60000-75000 sccm of NH3, 25-50 sccm of TMGa and 2000-3000 sccm of Cp2Mg are introduced into the reaction cavity, and a 60-90 nm P-type GaN layer is formed on the P-type electron blocking layer.

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