Hydrolysis-resistant GaN epitaxial structure and its manufacturing method and chip

Abstract

The present invention discloses a hydrolysis-resistant GaN epitaxial structure and a manufacturing method and chip thereof, wherein the epitaxial structure comprises a substrate, a buffer layer arranged on the substrate, a 3D-Gr layer arranged on the buffer layer, a defect barrier layer arranged on the 3D-Gr layer, a first semiconductor layer arranged on the defect barrier layer, an active layer arranged on the first semiconductor layer, and a second semiconductor layer arranged on the active layer. The present invention effectively reduces the lattice defects of the epitaxial structure and improves the crystal quality of the epitaxial structure through the interaction of the buffer layer, the 3D-Gr layer and the defect barrier layer, while increasing the density of the buffer layer, the 3D-Gr layer and the defect barrier layer, slowing down the hydrolysis corrosion rate of the buffer layer, the 3D-Gr layer and the defect barrier layer, thereby improving the hydrolysis resistance of the epitaxial structure.

Description

Technical Field

[0001] The invention relates to the technical field of light emitting diodes, and in particular to a hydrolysis-resistant GaN epitaxial structure and a manufacturing method and chip thereof. Background Art

[0002] Most LED display products are used outdoors. In order to reduce costs, the packaging materials and packaging processes in the packaging stage have been continuously simplified, resulting in reduced airtightness of the packaged LED devices. Water vapor can easily enter the LED packaging devices, causing the LED chips in the devices to easily undergo hydrolysis corrosion and fail, thereby reducing the service life of the LED devices.

[0003] To this end, the present invention improves the epitaxial structure of the LED to enhance the hydrolysis resistance of the GaN epitaxial structure. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a hydrolysis-resistant GaN epitaxial structure with fewer lattice defects and strong hydrolysis resistance.

[0005] The technical problem that the present invention needs to solve is to provide a method for manufacturing a hydrolysis-resistant GaN epitaxial structure, where the GaN epitaxial structure has fewer lattice defects and a strong hydrolysis resistance.

[0006] Another technical problem to be solved by the present invention is to provide a hydrolysis-resistant LED chip with strong hydrolysis resistance.

[0007] In order to solve the above problems, the present invention provides a hydrolysis-resistant GaN epitaxial structure, comprising a substrate, a buffer layer disposed on the substrate, a 3D-Gr layer disposed on the buffer layer, a defect barrier layer disposed on the 3D-Gr layer, a first semiconductor layer disposed on the defect barrier layer, an active layer disposed on the first semiconductor layer, and a second semiconductor layer disposed on the active layer;

[0008] The buffer layer is made of GaN doped with Si, the 3D-Gr layer is made of GaN doped with Si, and the defect barrier layer is made of Al x Ga 1-x N, x=0.01-0.05, wherein the doping concentration of Si in the 3D-Gr layer is greater than the doping concentration of Si in the buffer layer, and the growth rate of the 3D-Gr layer is greater than the growth rate of the buffer layer.

[0009] As an improvement of the above solution, the thickness of the 3D-Gr layer is greater than the thickness of the buffer layer, and the 3D-Gr layer forms a mirror structure on the buffer layer.

[0010] As an improvement of the above solution, the doping concentration of Si in the buffer layer is 1*10 16~1*10 17 The doping concentration of Si in the 3D-Gr layer is 1*10 17 ~1*10 18 ; The thickness of the buffer layer is 10 to 50 nm, and the thickness of the 3D-Gr layer is 1.5 to 3.0 μm.

[0011] As an improvement of the above solution, the buffer layer is prepared by the following method:

[0012] Using MOCVD process, TMGa, NH 3 、SiH 4 The gas flow rate is 20-30 sccm, 5-6 L, and 4.5-6 sccm to form the buffer layer.

[0013] As an improvement of the above solution, the 3D-Gr layer is prepared by the following method:

[0014] Using MOCVD process, TMGa, NH 3 、N 2 , H 2 、SiH 4 The gas flow rate is 40-60 sccm, 70-90 L, 25-35 L, 130-160 L, 140-165 sccm to form the 3D-Gr layer.

[0015] Accordingly, the present invention also provides a method for manufacturing a hydrolysis-resistant GaN epitaxial structure, comprising:

[0016] 1. forming a buffer layer on a substrate, wherein the buffer layer is made of GaN doped with Si;

[0017] 2. forming a 3D-Gr layer on the buffer layer, wherein the 3D-Gr layer is made of GaN doped with Si, wherein the doping concentration of Si in the 3D-Gr layer is greater than the doping concentration of Si in the buffer layer, and the growth rate of the 3D-Gr layer is greater than the growth rate of the buffer layer;

[0018] 3. Forming a defect barrier layer on the 3D-Gr layer, wherein the defect barrier layer is composed of Al x Ga 1-x N is made of

[0019] 4. A first semiconductor layer, an active layer and a second semiconductor layer are sequentially formed on the defect barrier layer.

[0020] As an improvement of the above solution, in step (i), the growth rate of the buffer layer is less than 0.5 μm / HR, and the growth rate of the 3D-Gr layer is less than 2 μm / HR.

[0021] As an improvement of the above scheme, in step (i), the buffer layer is formed by using a MOCVD process at a pressure of 200 to 300 torr, a temperature of 500 to 600° C., and a growth rate of 0.1 to 0.5 μm / HR;

[0022] In step (ii), the 3D-Gr layer is formed under the conditions of a pressure of 500 to 600 torr, a temperature of 900 to 1100° C., and a growth rate of 1.0 to 2.0 μm / HR;

[0023] In step (iii), a defect barrier layer is formed under the conditions of a pressure of 70 to 90 torr and a temperature of 1100 to 1300°C.

[0024] As an improvement of the above scheme, in step (a), an MOCVD process is used to introduce TMGa and NH 3 、SiH 4 gas, with flow rates of 20 to 30 sccm, 5 to 6 L, and 4.5 to 6 sccm, forming a buffer layer with a thickness of 10 to 50 nm;

[0025] In step (ii), TMGa and NH 3 、N 2 , H 2 、SiH 4 Gas, with flow rates of 40-60 sccm, 70-90 L, 25-35 L, 130-160 L, 140-165 sccm, formed a 3D-Gr layer with a thickness of 1.5-3.0 μm;

[0026] In step (iii), TMGa, TMAl, N 2 NH 3 , H 2 The gas flow rate was 80-110 sccm, 180-220 sccm, 20-30 L, 28-42 L, and 70-90 L, forming a defect barrier layer with a thickness of 100-300 nm.

[0027] Correspondingly, the present invention further provides a hydrolysis-resistant LED chip, which comprises the hydrolysis-resistant GaN epitaxial structure as claimed in any one of claims 1 to 5.

[0028] Correspondingly, the present invention also provides a hydrolysis-resistant LED chip, which includes the hydrolysis-resistant GaN epitaxial structure described above.

[0029] The implementation of the present invention has the following beneficial effects:

[0030] The buffer layer of the present invention is arranged on the substrate to form a seed crystal, so that the subsequent GaN can be smoothly formed on the sapphire substrate. Specifically, the buffer layer of the present invention dopes a certain amount of Si in GaN to form a small amount of SiH 4 , among which a small amount of SiH 4 It can be used to shield some areas, reduce lattice defects, and improve the hydrolysis resistance of the epitaxial structure.

[0031] The 3D-Gr layer of the present invention is arranged on the buffer layer, so that the bottom particles of the epitaxial structure become smaller, forming a mirror structure, and further improving the hydrolysis resistance of the epitaxial structure; in addition, the 3D-Gr layer of the present invention is 4 To fill the gaps, reduce epitaxial lateral defects, and improve the overall quality of the epitaxial structure.

[0032] The present invention controls the Al content in the defect barrier layer, thereby not only reducing the lattice defects of the epitaxial structure, but also improving the hydrolysis resistance of the epitaxial structure.

[0033] The present invention effectively reduces the lattice defects of the epitaxial structure and improves the crystal quality of the epitaxial structure through the interaction of the buffer layer, the 3D-Gr layer and the defect barrier layer, while increasing the density of the buffer layer, the 3D-Gr layer and the defect barrier layer, slowing down the hydrolysis corrosion rate of the buffer layer, the 3D-Gr layer and the defect barrier layer, thereby improving the hydrolysis resistance of the epitaxial structure.

[0034] The present invention adopts a low-speed and low-temperature method to form a buffer layer, which can not only reduce the doping concentration of Si, but also make Si easier to dope into GaN, thereby increasing the density of the buffer layer, and further improving the hydrolysis resistance of the buffer layer. In addition, the present invention adopts a low-pressure method to form a buffer layer, which can make the seed distribution of the buffer layer more uniform, thereby improving the crystal quality of the epitaxial layer.

[0035] The present invention adopts a high-speed method to form a 3D-Gr layer, quickly transforming the seed from a point to a surface, thereby forming a mirror structure on the surface of the buffer layer, and improving the hydrolysis resistance of the structure. In addition, the present invention adopts a high-temperature and high-pressure method to form a 3D-Gr layer, which can not only increase the doping concentration of Si, but also quickly transform the seed from a point to a surface, so that the 3D-Gr layer is produced horizontally, reducing epitaxial lateral defects, and improving the hydrolysis resistance of the epitaxial structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic structural diagram of the hydrolysis-resistant GaN epitaxial structure of the present invention. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings.

[0038] The present invention provides a hydrolysis-resistant GaN epitaxial structure, comprising a substrate 10, a buffer layer 20 disposed on the substrate 10, a 3D-Gr layer 30 disposed on the buffer layer 20, a defect barrier layer 40 disposed on the 3D-Gr layer 30, a first semiconductor layer 50 disposed on the defect barrier layer 40, an active layer 60 disposed on the first semiconductor layer 50, and a second semiconductor layer 70 disposed on the active layer 60.

[0039] The substrate 10 of the present invention is a silicon substrate 10, a silicon nitride substrate or a sapphire substrate, but is not limited thereto. Preferably, the substrate 10 of the present invention is a sapphire substrate. In addition, the substrate 10 of the present invention is a patterned substrate or a non-patterned substrate.

[0040] In the present invention, the first semiconductor layer 50 is an N-type GaN layer, the second semiconductor layer 70 is a P-type GaN layer, and the active layer 60 is a multi-quantum well layer.

[0041] Since defects are generated between the substrate 10 and the first semiconductor layer 50, the active layer 60 and the second semiconductor layer 70 due to lattice differences, thereby affecting the crystal quality of the epitaxial structure, the present invention arranges a buffer layer 20, a 3D-Gr layer 30 and a defect barrier layer 40 between the substrate 10 and the first semiconductor layer 50 to reduce the lattice defects of the epitaxial structure, and at the same time utilizes the characteristics of the buffer layer 20, the 3D-Gr layer 30 and the defect barrier layer 40 themselves to slow down hydrolysis corrosion, thereby improving the hydrolysis resistance of the epitaxial structure.

[0042] Different from the existing buffer layer, the buffer layer 20 of the present invention dopes a small amount of Si in GaN to form a seed crystal on the substrate, so that the subsequent GaN can be smoothly formed on the sapphire substrate 10. Specifically, the buffer layer 20 of the present invention dopes a small amount of Si in GaN to form a small amount of SiH 4, among which a small amount of SiH 4 It can be used to shield some areas, reduce lattice defects, and improve the hydrolysis resistance of the epitaxial structure.

[0043] Preferably, the doping concentration of Si in the buffer layer 20 is 1*10 16 ~1*10 17 If the Si doping concentration of the buffer layer 20 is less than 1*10 16 , the concentration is too small to form the preset SiH 4 , thus failing to reduce lattice defects; if the Si doping concentration of the buffer layer 20 is greater than 1*10 17 , the concentration is too high and the SiN x If the content is too high, the growth of the first semiconductor layer 50 , the active layer 60 and the second semiconductor layer 70 will be affected.

[0044] More preferably, the doping concentration of Si in the buffer layer 20 is 2*10 16 ~8*10 16 .

[0045] More preferably, the doping concentration of Si in the buffer layer 20 is 4*10 16 ~6*10 16 .

[0046] In addition, the thickness of the buffer layer 20 also has a certain influence on the performance of the buffer layer 20. Preferably, the thickness of the buffer layer 20 is 10-50 nm. If the thickness of the buffer layer 20 is less than 10 nm, it is too thin to play a buffering role and is easily baked off at high temperature; if the thickness of the buffer layer 20 is greater than 50 nm, it is too thick, which will affect the crystal quality of the epitaxial structure.

[0047] The full name of the 3D-Gr in the 3D-Gr layer of the present invention is 3D Grown, and its function is to make the bottom particles of the epitaxial structure smaller, form a mirror structure, and further improve the hydrolysis resistance of the epitaxial structure. Therefore, the 3D-Gr layer of the present invention is different from the existing GaN epitaxial structure. Specifically, the 3D-Gr layer 30 of the present invention is made of GaN doped with Si. The present invention reduces the lattice defects of the epitaxial layer structure by controlling the Si doping concentration in the 3D-Gr layer.

[0048] In addition, the present invention controls the growth rate of the 3D-Gr layer by using SiH 4 To fill the lattice defects; further, the present invention adopts a high temperature and high pressure method to form a 3D-Gr layer to increase the doping concentration of Si, quickly transform the seed from a point to a surface, enable the 3D-Gr layer to be produced laterally, reduce epitaxial lateral defects, and improve the hydrolysis resistance of the epitaxial structure.

[0049] Preferably, the Si doping concentration of the 3D-Gr layer 30 is 1*10 17 ~1*10 18 If the Si doping concentration of the 3D-Gr layer 30 is less than 1*10 17 , the concentration is too small to form the preset SiH 4 , thus failing to reduce lattice defects; if the Si doping concentration of the 3D-Gr layer 30 is greater than 1*10 18 , the concentration is too high and the SiN x If the content is too high, the growth of the first semiconductor layer 50 , the active layer 60 and the second semiconductor layer 70 will be affected.

[0050] More preferably, the doping concentration of Si in the 3D-Gr layer 30 is 2*10 17 ~8*10 17 .

[0051] Optimally, the doping concentration of Si in the 3D-Gr layer 30 is 4*10 17 ~6*10 17 .

[0052] In addition, the thickness of the 3D-Gr layer 30 also has a certain influence on the performance of the 3D-Gr layer 30. Preferably, the thickness of the 3D-Gr layer 30 is 1.5-3.0 μm.

[0053] If the thickness of the 3D-Gr layer 30 is less than 1.5 μm, it is too thin to cover the patterned substrate 10, thus affecting the formation of the first semiconductor layer 50 ; if the thickness of the 3D-Gr layer 30 is greater than 3.0 μm, it is too thick and is prone to cracking due to internal stress, thus affecting the crystal quality of the epitaxial structure.

[0054] The defect barrier layer 40 of the present invention is made of Al x Ga 1-x N, which further reduces the lattice defects of the epitaxial structure and improves the hydrolysis resistance of the epitaxial structure.

[0055] Preferably, x=0.01-0.05. If x in the defect barrier layer 40 is less than 0.01, the Al content is too low and the defect barrier layer 40 cannot block defects; if x is greater than 0.05, the Al content is too high and the defect barrier layer 40 is easily corroded by hydrolysis.

[0056] More preferably, x=0.02~0.04.

[0057] Optimal, x = 0.03 ~ 0.04

[0058] The epitaxial structure is affected by hydrolysis, H 2 O decomposes into H +and OH - , where GaN becomes Ga(OH) 3 , while Al with high Al content x Ga 1-x N undergoes hydrolysis faster and becomes Al(OH) 3 and AlO x .

[0059] The present invention effectively reduces the lattice defects of the epitaxial structure and improves the crystal quality of the epitaxial structure through the interaction of the buffer layer 20, the 3D-Gr layer 30 and the defect barrier layer 40, while increasing the density of the buffer layer 20, the 3D-Gr layer 30 and the defect barrier layer 40, slowing down the hydrolysis corrosion rate of the buffer layer 20, the 3D-Gr layer 30 and the defect barrier layer 40, thereby improving the hydrolysis resistance of the epitaxial structure.

[0060] Accordingly, the present invention also provides a method for manufacturing a hydrolysis-resistant GaN epitaxial structure, comprising the following steps:

[0061] 1. forming a buffer layer on a substrate;

[0062] The buffer layer is formed by adopting the MOCVD process under the condition that the growth rate is less than 0.5 μm / HR, and the buffer layer is made of GaN doped with Si.

[0063] It should be noted that the growth rate of the buffer layer plays an important role in the hydrolysis resistance and lattice defect reduction performance of the buffer layer. If the growth rate of the buffer layer is greater than 0.5 μm / HR, the growth rate of the buffer layer is too fast and the preset content of SiH 4 , then it cannot pass SiH 4 to fill the lattice defects.

[0064] Preferably, the buffer layer is formed by an MOCVD process at a pressure of 200-300 torr, a temperature of 500-600° C., and a growth rate of 0.1-0.5 μm / HR, and the buffer layer is made of GaN doped with Si.

[0065] It should be noted that the present invention adopts a low-temperature method to form a buffer layer, which can not only reduce the doping concentration of Si, but also make it easier for Si to be doped into GaN, thereby increasing the density of the buffer layer, and further improving the hydrolysis resistance of the buffer layer. In addition, the present invention adopts a low-pressure method to form a buffer layer, which can make the seed distribution of the buffer layer more uniform, thereby improving the crystal quality of the epitaxial layer.

[0066] More preferably, the MOCVD process is used to introduce TMGa and NH 3 、SiH 4 The gas flow rate was 20-30 sccm, 5-6 L, and 4.5-6 sccm, forming a buffer layer with a thickness of 10-50 nm.

[0067] 2. forming a 3D-Gr layer on the buffer layer;

[0068] The 3D-Gr layer is formed by adopting the MOCVD process at a growth rate of 0.5 to 2 μm / HR. The 3D-Gr layer is made of GaN doped with Si.

[0069] It should be noted that the growth rate of the 3D-Gr layer plays an important role in the hydrolysis resistance and lattice defect reduction performance of the 3D-Gr layer. Since the growth temperature of the buffer layer is only 500-600°C, it is easily baked off by the high temperature (above 1100°C) of the subsequent process and cannot form a mirror structure. Therefore, the 3D-Gr layer of the present invention is formed on the buffer layer at a faster growth rate, and a mirror structure is formed on the surface of the buffer layer to protect the buffer layer. Specifically, if the growth rate of the 3D-Gr layer is greater than 2μm / HR, the growth rate of the 3D-Gr layer is too fast to form a preset content of SiH 4 , then it cannot pass SiH 4 To fill the lattice defects; if the growth rate of the 3D-Gr layer is less than 0.5μm / HR, the surface flattening speed of the 3D-Gr layer is too slow, affecting the production efficiency, and the single-point particle size of the 3D-Gr layer is too large, which is prone to defects, resulting in an uneven surface of the 3D-Gr layer.

[0070] Preferably, the 3D-Gr layer is formed by an MOCVD process at a pressure of 500-600 torr, a temperature of 900-1100° C., and a growth rate of 1.0-2.0 μm / HR, and the 3D-Gr layer is made of GaN doped with Si.

[0071] The present invention adopts a high temperature and high pressure method to form a 3D-Gr layer, which can not only increase the doping concentration of Si, but also quickly transform the seed from a point to a surface, so that the 3D-Gr layer can be produced laterally, reduce epitaxial lateral defects, and improve the hydrolysis resistance of the epitaxial structure.

[0072] More preferably, the MOCVD process is used to introduce TMGa and NH 3 、N2 , H 2 、SiH 4 The gas flow rate was 40-60 sccm, 70-90 L, 25-35 L, 130-160 L, and 140-165 sccm, forming a 3D-Gr layer with a thickness of 1.5-3.0 μm.

[0073] 3. forming a defect barrier layer on the 3D-Gr layer;

[0074] Specifically, the MOCVD process is used to introduce TMGa, TMAl, N 2 NH 3 , H 2 The gas flow rate was 80-110 sccm, 180-220 sccm, 20-30 L, 28-42 L, and 70-90 L, forming a defect barrier layer with a thickness of 100-300 nm.

[0075] 4. forming a first semiconductor layer, an active layer and a second semiconductor layer in sequence on the defect barrier layer;

[0076] Specifically, the MOCVD process is used to introduce TMGa and NH 3 、N 2 , H 2 、SiH 4 Gas, with flow rates of 130-180 sccm, 70-90 L, 20-40 L, 130-160 L, 140-160 sccm, etc., to form a first semiconductor layer;

[0077] Under the conditions of pressure of 180-220 torr and temperature of 700-800°C, TEGa, TMIn, NH 3 、N 2 Gas, with flow rates of 160-180 sccm, 440-470 sccm, 70-90 L, 80-100 L, to form an active layer;

[0078] Under the conditions of pressure of 180-220 torr and temperature of 900-1000℃, TMGa and CP are introduced. 2 Mg, NH 3 , H 2 、N 2 The gas flow rate is 40-50 sccm, 190-220 sccm, 60-70 L, 140-170 L, and 10-30 L to form the second semiconductor layer.

[0079] Correspondingly, the present invention also provides a hydrolysis-resistant LED chip, which includes the hydrolysis-resistant GaN epitaxial structure described above.

[0080] The present invention will be further described below with specific embodiments.

[0081] Example 1

[0082] A hydrolysis-resistant GaN epitaxial structure includes a substrate, a buffer layer disposed on the substrate, a 3D-Gr layer disposed on the buffer layer, a defect barrier layer disposed on the 3D-Gr layer, a first semiconductor layer disposed on the defect barrier layer, an active layer disposed on the first semiconductor layer, and a second semiconductor layer disposed on the active layer;

[0083] Using MOCVD process, TMGa, NH 3 、SiH 4 Gas, flow rate is 20-30sccm, 5-6L, 4.5-6sccm, to form the buffer layer, the buffer layer is made of GaN doped with Si, the doping concentration of Si is 7*10 16 ;

[0084] Using MOCVD process, TMGa, NH 3 、N 2 , H 2 、SiH 4 The gas flow rate is 40-60 sccm, 70-90 L, 25-35 L, 130-160 L, 140-165 sccm to form the 3D-Gr layer, which is made of GaN doped with Si, and the doping concentration of Si is 7*10 17 ;

[0085] The defect barrier layer is made of Al 0.2 Ga 0.8 Made of N.

[0086] Comparative Example 1

[0087] A hydrolysis-resistant GaN epitaxial structure includes a substrate, a buffer layer disposed on the substrate, a 3D-Gr layer disposed on the buffer layer, a defect barrier layer disposed on the 3D-Gr layer, a first semiconductor layer disposed on the defect barrier layer, an active layer disposed on the first semiconductor layer, and a second semiconductor layer disposed on the active layer;

[0088] Using MOCVD process, TMGa, NH 3 Gas, with a flow rate of 20-30 sccm, 5-6 L, to form the buffer layer, wherein the buffer layer is made of GaN;

[0089] Using MOCVD process, TMGa, NH 3 Gas, with a flow rate of 40 to 50 sccm and 30 to 40 L, forms the 3D-Gr layer, wherein the 3D-Gr layer is made of GaN;

[0090] The defect barrier layer is made of Al 0.6 Ga 0.4 Made of N.

[0091] Comparative Example 2

[0092] A hydrolysis-resistant GaN epitaxial structure includes a substrate, a buffer layer disposed on the substrate, a 3D-Gr layer disposed on the buffer layer, a defect barrier layer disposed on the 3D-Gr layer, a first semiconductor layer disposed on the defect barrier layer, an active layer disposed on the first semiconductor layer, and a second semiconductor layer disposed on the active layer;

[0093] Using MOCVD process, TMGa, NH 3 、SiH 4 The gas has a flow rate of 20 to 30 sccm, 5 to 6 L, and 4.5 to 6 sccm to form the buffer layer, which is made of GaN doped with Si, and the doping concentration of Si is 2*10 15 ;

[0094] Using MOCVD process, TMGa, NH 3 Gas, with a flow rate of 40-60 sccm and 70-90 L, forms the 3D-Gr layer, wherein the 3D-Gr layer is made of GaN;

[0095] The defect barrier layer is made of Al 0.2 Ga 0.8 Made of N.

[0096] Comparative Example 3

[0097] A hydrolysis-resistant GaN epitaxial structure includes a substrate, a buffer layer disposed on the substrate, a 3D-Gr layer disposed on the buffer layer, a defect barrier layer disposed on the 3D-Gr layer, a first semiconductor layer disposed on the defect barrier layer, an active layer disposed on the first semiconductor layer, and a second semiconductor layer disposed on the active layer;

[0098] Using MOCVD process, TMGa, NH 3 、SiH 4 Gas, flow rate is 20-30sccm, 5-6L, 4.5-6sccm, to form the buffer layer, the buffer layer is made of GaN doped with Si, the doping concentration of Si is 5*10 16 ;

[0099] Using MOCVD process, TMGa, NH 3 、SiH 4 The gas flow rate is 40-60 sccm, 70-90 L, 10-20 sccm, forming the 3D-Gr layer, the 3D-Gr layer is made of GaN doped with Si, and the doping concentration of Si is 8*10 16 ;

[0100] The defect barrier layer is made of Al 0.2 Ga 0.8 Made of N.

[0101] The epitaxial structures of Example 1 and Comparative Examples 1-3 were applied to RGB small pitch packaging, and then subjected to a hydrolysis resistance test (high temperature and high humidity, dual 85, reverse -10V), and the results were as follows:

[0102] The hydrolysis resistance of the epitaxial structure of Example 1 reaches 500 hours; the hydrolysis resistance of the epitaxial structure of Comparative Example 1 is only 168 hours; the hydrolysis resistance of Comparative Example 2 is only 200 hours; and the hydrolysis resistance of Comparative Example 3 is only 220 hours.

[0103] Since the epitaxial structure of comparative example 1 does not incorporate Si into the buffer layer and 3D-Gr layer to fill defects, and the Al content in the barrier layer is too high and the growth rate is too fast, many lateral defects are caused. Therefore, when encountering hydrolysis, it will be quickly corroded by the side.

[0104] Although a small amount of Si is doped into GaN in the buffer layer in Comparative Example 2, a good seed crystal cannot be formed due to the excessively fast growth rate, and a predetermined content of SiH4 , so it cannot pass SiH 4 To fill the lattice defects, and there is no Si doped in the 3D-Gr layer, so the epitaxial structure has poor resistance to hydrolysis.

[0105] Although a small amount of Si is doped into GaN in the 3D-Gr layer in Comparative Example 3, due to the slow growth rate and low growth temperature, a good mirror structure cannot be formed in the buffer layer, and a preset content of SiH 4 , so the epitaxial structure has poor resistance to hydrolysis.

[0106] The above disclosure is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A hydrolysis-resistant GaN epitaxial structure, characterized in that: The invention comprises a substrate, a buffer layer disposed on the substrate, a 3D-Gr layer disposed on the buffer layer, a defect barrier layer disposed on the 3D-Gr layer, a first semiconductor layer disposed on the defect barrier layer, an active layer disposed on the first semiconductor layer, and a second semiconductor layer disposed on the active layer; The buffer layer is made of GaN doped with Si, the 3D-Gr layer is made of GaN doped with Si, and the defect barrier layer is made of Al x Ga 1-x N, x=0.01-0.05, wherein the doping concentration of Si in the 3D-Gr layer is greater than the doping concentration of Si in the buffer layer, and the growth rate of the 3D-Gr layer is greater than the growth rate of the buffer layer; The 3D-Gr layer forms a mirror structure on the buffer layer.

2. The hydrolysis-resistant GaN epitaxial structure according to claim 1, characterized in that: The thickness of the 3D-Gr layer is greater than that of the buffer layer.

3. The hydrolysis-resistant GaN epitaxial structure according to claim 1, characterized in that: The doping concentration of Si in the buffer layer is 1*10 16 ~1*10 17 The doping concentration of Si in the 3D-Gr layer is 1*10 17 ~1*10 18 ; The thickness of the buffer layer is 10 to 50 nm, and the thickness of the 3D-Gr layer is 1.5 to 3.0 μm.

4. The hydrolysis-resistant GaN epitaxial structure according to claim 1, characterized in that: The buffer layer is prepared by the following method: The buffer layer is formed by adopting MOCVD process, under the conditions of pressure of 200-300 torr, temperature of 500-600°C, growth rate of 0.3-0.5 μm / HR, introducing TMGa, NH3, SiH4 gases with flow rates of 20-30 sccm, 5-6 L, and 4.5-6 sccm.

5. The hydrolysis-resistant GaN epitaxial structure according to claim 1, characterized in that: The 3D-Gr layer is prepared by the following method: The MOCVD process is adopted, under the conditions of pressure of 500-600 torr, temperature of 900-1100°C, and growth rate of 1.0-1.5 μm / HR, TMGa, NH3, N2, H2, and SiH4 gases are introduced with flow rates of 40-60 sccm, 70-90 L, 25-35 L, 130-160 L, and 140-165 sccm to form the 3D-Gr layer.

6. A method for producing a hydrolysis-resistant GaN epitaxial structure, comprising:

1. forming a buffer layer on a substrate, wherein the buffer layer is made of GaN doped with Si; 2. forming a 3D-Gr layer on the buffer layer, wherein the 3D-Gr layer is made of GaN doped with Si, wherein the doping concentration of Si in the 3D-Gr layer is greater than the doping concentration of Si in the buffer layer, and the growth rate of the 3D-Gr layer is greater than the growth rate of the buffer layer; 3. Forming a defect barrier layer on the 3D-Gr layer, wherein the defect barrier layer is composed of Al x Ga 1-x N is made of 4. Forming a first semiconductor layer, an active layer and a second semiconductor layer in sequence on the defect barrier layer.

7. The method for manufacturing a hydrolysis-resistant GaN epitaxial structure according to claim 6, characterized in that: In step (i), the growth rate of the buffer layer is less than 0.5 μm / HR, and the growth rate of the 3D-Gr layer is less than 2 μm / HR.

8. The method for manufacturing a hydrolysis-resistant GaN epitaxial structure according to claim 7, characterized in that: In step (i), the buffer layer is formed by MOCVD process at a pressure of 200 to 300 torr, a temperature of 500 to 600° C., and a growth rate of 0.1 to 0.5 μm / hr; In step (ii), the 3D-Gr layer is formed under the conditions of a pressure of 500 to 600 torr, a temperature of 900 to 1100° C., and a growth rate of 1.0 to 2.0 μm / HR; In step (iii), a defect barrier layer is formed under the conditions of a pressure of 70 to 90 torr and a temperature of 1100 to 1300°C.

9. The method for manufacturing a hydrolysis-resistant GaN epitaxial structure according to claim 7, characterized in that: In step (a), a MOCVD process is used, under the conditions of a pressure of 200 to 300 torr, a temperature of 500 to 600°C, and a growth rate of 0.3 to 0.5 μm / HR, TMGa, NH3, and SiH4 gases are introduced at flow rates of 20 to 30 sccm, 5 to 6 L, and 4.5 to 6 sccm, to form a buffer layer with a thickness of 10 to 50 nm; In step (ii), under the conditions of a pressure of 500-600 torr, a temperature of 900-1100°C, and a growth rate of 1.0-1.5 μm / HR, TMGa, NH3, N2, H2, and SiH4 gases are introduced at flow rates of 40-60 sccm, 70-90 L, 25-35 L, 130-160 L, and 140-165 sccm to form a 3D-Gr layer with a thickness of 1.5-3.0 μm; In step (iii), under the conditions of pressure of 70-90 torr, temperature of 1100-1300°C and growth rate of 0.1-0.8 μm / HR, TMGa, TMAl, N2, NH3 and H2 gases are introduced with flow rates of 80-110 sccm, 180-220 sccm, 20-30 L, 28-42 L and 70-90 L to form a defect barrier layer with a thickness of 100-300 nm.

10. A hydrolysis-resistant LED chip, comprising the hydrolysis-resistant GaN epitaxial structure according to any one of claims 1 to 5.

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