A GaN-based HEMT device and a method of manufacturing the same

Abstract

Provided are a GaN-based HEMT device and a manufacturing method thereof, the manufacturing method comprising: forming an h-BN film on a substrate; forming a diamond film on the h-BN film; forming a GaN-based HEMT epitaxial structure on the diamond film; preparing an electrode on the GaN-based HEMT epitaxial structure; and mechanically peeling off the substrate to obtain the GaN-based HEMT device. The device structure of the h-BN film / diamond film / GaN-based HEMT epitaxial structure is formed in situ on a conventional substrate, and then the conventional substrate is peeled off by taking advantage of the peelable property of the h-BN film, so that the device can directly use the diamond film with high thermal conductivity as a heat sink substrate for heat dissipation, effectively reducing the device temperature and improving the reliability of the device; moreover, the conventional substrate is peeled off without causing damage to the device, which is conducive to improving the yield of the device; in addition, the manufacturing method is simple, convenient and low in cost.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of semiconductor devices, and particularly relates to a GaN-based HEMT device and a manufacturing method thereof. BACKGROUND

[0002] High electron mobility transistor (HEMT) is a kind of heterojunction field effect transistor, also known as modulation doped field effect transistor (MODFET), two-dimensional electron gas field effect transistor (2-DEGFET), and selectively doped heterojunction transistor (SDHT). It works by using a two-dimensional electron gas with very high mobility, so the device and its integrated circuit can be well applied to ultra-high frequency, millimeter wave, ultra-high speed and other fields. GaN HEMT (Gallium Nitride High Electron Mobility Transistor) device, as a typical power semiconductor device, is widely used in power electronic systems due to its high frequency, high power and high efficiency. However, when the GaN HEMT device works in high power / high frequency state, the thermal electron collision in the device channel is intensified, and the heat generated will increase sharply, resulting in a decrease in carrier mobility, a decrease in device output current, and a degradation of performance. By effectively improving the heat dissipation efficiency of the device and dissipating heat in time, the overall performance of the device can be greatly optimized, and its reliability and service life can be improved. Therefore, the heat dissipation problem of GaN HEMT device has become the focus of its application research.

[0003] The traditional method to solve the heat dissipation problem of GaN HEMT device is to prepare the device on a sapphire substrate or a SiC substrate, and use the sapphire substrate or the SiC substrate as a heat sink for heat dissipation. However, the thermal conductivity of sapphire substrate and SiC substrate (thermal conductivity of sapphire is 35 W / m.K, and thermal conductivity of SiC is 490 W / m.K) is relatively low, and the heat dissipation effect is poor, which is difficult to meet the heat dissipation demand of high frequency and high power application of the device. Diamond has extremely high thermal conductivity, which can reach 2000 W / m.K, and using diamond as a heat sink is an effective method to solve the heat dissipation problem of GaN HEMTs.

[0004] In the prior art, a GaN HEMT device based on a diamond heat sink substrate is prepared mainly by growing a GaN HEMT epitaxial structure on a sapphire substrate by MOCVD, then forming a Si support material layer on an AlGaN barrier layer of the epitaxial structure, then peeling off the sapphire substrate by using a laser peeling technology, then depositing a thin layer on a GaN bottom surface and a diamond heat sink piece surface, bonding an adhesive on the thin layer and performing low-temperature bonding and solidification, and finally removing the temporary Si support material, so as to realize the GaN HEMT device based on the diamond as the heat sink. However, in the process of laser peeling off the sapphire substrate, it is difficult to avoid damage to the GaN material. In addition, the heat conductivity of the substrate can also be improved by etching a groove on the substrate and then depositing a diamond film in the groove. However, due to the complicated groove process and small area of the diamond, the time and cost are high, which affects the practicability. SUMMARY

[0005] In order to solve the problems existing in the prior art, the application provides a GaN-based HEMT device and a manufacturing method thereof.

[0006] According to an aspect of the embodiment of the application, the manufacturing method of the GaN-based HEMT device is provided. The manufacturing method comprises the following steps: forming an h-BN thin film on a substrate; forming a diamond thin film on the h-BN thin film; forming a GaN-based HEMT epitaxial structure on the diamond thin film; preparing an electrode on the GaN-based HEMT epitaxial structure; and mechanically peeling off the substrate to obtain the GaN-based HEMT device.

[0007] In one example of the manufacturing method of the GaN-based HEMT device provided in an aspect of the above embodiment, the GaN-based HEMT epitaxial structure comprises a GaN nucleation layer, a GaN buffer layer, a GaN channel layer and an AlGaN barrier layer which are sequentially stacked.

[0008] In one example of the manufacturing method of the GaN-based HEMT device provided in an aspect of the above embodiment, the method of forming the GaN-based HEMT epitaxial structure on the diamond thin film specifically comprises the following steps:

[0009] The substrate is annealed at an annealing temperature of 900-1050℃ in an atmosphere of hydrogen and ammonia;

[0010] A GaN nucleation layer, a GaN buffer layer and a GaN channel layer which are sequentially stacked are grown on the surface of the diamond thin film away from the h-BN thin film by using a metal organic chemical vapor deposition process, with trimethylgallium and ammonia as gallium source and nitrogen source respectively, and nitrogen and hydrogen as carrier gas;

[0011] Aluminum source, gallium source and nitrogen source are respectively provided by trimethylaluminum, trimethylgallium and ammonia gas, and nitrogen gas and hydrogen gas are used as carrier gas, and the AlGaN barrier layer is formed by growing on the surface of the GaN channel layer opposite to the GaN buffer layer through metal organic chemical vapor deposition process.

[0012] In one example of the method for manufacturing GaN-based HEMT device provided in an aspect of the above embodiment, the GaN nucleation layer is grown at a temperature of 530-580℃ and has a thickness of 20-50nm; and / or the GaN buffer layer is grown at a temperature of 1050℃ and has a thickness of 3.5μm; and / or the GaN channel layer is grown at a temperature of 1100℃ and has a thickness of 100nm; and / or the AlGaN barrier layer is grown at a temperature of 1100℃ and has a thickness of 25nm.

[0013] In one example of the method for manufacturing GaN-based HEMT device provided in an aspect of the above embodiment, the method for manufacturing h-BN thin film on the substrate comprises:

[0014] The substrate is subjected to surface nitridation treatment to form an AlN layer on the surface of the substrate. x N y layer;

[0015] The h-BN thin film is formed by growing on the AlN layer through metal organic chemical vapor deposition process with triethylboron and ammonia gas as carrier gas. x N y

[0016] In one example of the method for manufacturing GaN-based HEMT device provided in an aspect of the above embodiment, the method for manufacturing diamond thin film on the h-BN thin film comprises:

[0017] The diamond thin film with a thickness of 100-200μm is formed by growing on the surface of the h-BN thin film opposite to the substrate through metal organic chemical vapor deposition process with methane and hydrogen gas as carrier gas.

[0018] In one example of the method for manufacturing GaN-based HEMT device provided in an aspect of the above embodiment, after the GaN-based HEMT epitaxial structure is manufactured on the diamond thin film, and before electrodes are prepared on the GaN-based HEMT epitaxial structure, the method further comprises: removing part of the GaN channel layer and part of the AlGaN barrier layer of the GaN-based HEMT epitaxial structure through inductively coupled plasma etching process to expose the GaN buffer layer. ​

[0019] The method for preparing electrodes on the GaN-based HEMT epitaxial structure includes: preparing electrodes on the AlGaN barrier layer which is not removed by etching.

[0020] In one example of the method for manufacturing GaN-based HEMT devices provided in an aspect of the above-mentioned embodiments, the method for preparing electrodes on the AlGaN barrier layer which is not removed by etching specifically includes:

[0021] A first composite metal layer is deposited in the first and second predetermined regions of the AlGaN barrier layer by a magnetron sputtering device, and an annealing process is performed to form an ohmic contact, so as to form a source electrode and a drain electrode, respectively; the first composite metal layer includes a composite metal layer of Ti metal layer / Al metal layer / Ni metal layer / Au metal layer;

[0022] A second composite metal layer is deposited in the third predetermined region of the AlGaN barrier layer by a magnetron sputtering device, and a Schottky contact is formed by an annealing process, so as to form a gate electrode; the second composite metal layer includes a composite metal layer of Ni metal layer / Au metal layer.

[0023] In one example of the method for manufacturing GaN-based HEMT devices provided in an aspect of the above-mentioned embodiments, after the electrodes are prepared on the GaN-based HEMT epitaxial structure, and before the substrate is mechanically exfoliated to obtain the GaN-based HEMT devices, the method further includes:

[0024] A silicon nitride passivation layer covering the AlGaN barrier layer and the exposed GaN buffer layer is prepared by a plasma-enhanced chemical vapor deposition method;

[0025] According to another aspect of the embodiments of the present application, a GaN-based HEMT device is provided, which is manufactured by the above-mentioned method.

[0026] Beneficial effects: the device structure of the h-BN film / diamond film / GaN-based HEMT epitaxial structure is formed by directly growing in situ on a traditional substrate, and then the traditional substrate is peeled off by using the peelable property of the h-BN film, so that the device can directly use the diamond film with high thermal conductivity as a heat sink substrate for heat dissipation, effectively utilizes the excellent thermal conductivity of the diamond film, is beneficial to reducing the overall thermal resistance of the device, further improves the overall heat dissipation capacity of the device, solves the heat dissipation problem of the high-power GaN-based HEMT device, reduces the device temperature, and further improves the reliability of the device; and in the process of peeling off the traditional substrate, damage to the GaN-based HEMT device is avoided, which is beneficial to improving the yield of the device. Moreover, the manufacturing method directly grows each device structure in situ on the substrate, effectively eliminates the secondary interface contamination caused in the growth process, avoids oxidation in the atmospheric environment, and is beneficial to reducing the interface thermal resistance. In addition, the manufacturing method is simple and convenient, and can effectively reduce the manufacturing cost of the device. BRIEF DESCRIPTION OF DRAWINGS

[0027] The above and other aspects, features and advantages of embodiments of the present application will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0028] Figure 1 is a flowchart of a manufacturing method of a GaN-based HEMT device according to an embodiment of the present application;

[0029] Figures 2A to 2G is a process diagram of a GaN-based HEMT device according to an embodiment of the present application;

[0030] Figure 3 is a structure schematic diagram of a GaN-based HEMT device manufactured by the manufacturing method according to an embodiment of the present application. Figure 1 DETAILED DESCRIPTION

[0031] Hereinafter, specific embodiments of the present application will be described in detail with reference to the accompanying drawings. However, the present application can be implemented in many different forms, and should not be construed as being limited to the specific embodiments set forth herein. Rather, these embodiments are provided so that the principles of the present application can be understood and the various embodiments and modifications suitable for a specific intended application can be understood by those skilled in the art.

[0032] ​As used herein, the terms "includes," "including," "has," "having," "contains," "containing," "comprises," "comprising," "may" and other similar terminology are open-ended, and mean "including but not limited to." The term "based on" or "based upon" means "based at least in part on." The terms "one embodiment," "an embodiment," "one example," and "an example" mean "at least one embodiment" or "at least one example." The terms "another embodiment" and "another example" mean "at least one additional embodiment" or "at least one additional example." The terms "first," "second," "third," "fourth," etc. can refer to different or identical objects. Other definitions can be found throughout this description. Unless the context clearly indicates otherwise, the definition of a term throughout this description is consistent throughout the description.

[0033] As described in the background, due to the prior art of preparing GaN-based HEMT devices based on diamond heat sink substrates, it is difficult to avoid damage to the device caused by laser stripping in the process of stripping the sapphire substrate, or the preparation cost is high due to the complicated process. Therefore, in order to solve the many technical problems existing in the prior art related to GaN-based HEMT devices, according to the embodiments of the present application, a GaN-based HEMT device and a manufacturing method thereof are provided.

[0034] The manufacturing method directly grows an h-BN film / diamond film / GaN-based HEMT epitaxial structure device structure on a conventional substrate in situ, and then uses the strippable characteristics of the h-BN film to strip off the conventional substrate, so that the device can directly use diamond with high thermal conductivity as a heat sink substrate for heat dissipation, thereby effectively solving the heat dissipation problem of high-power GaN-based HEMT devices. In addition, the manufacturing method also effectively avoids damage to the device in the process of stripping the substrate.

[0035] The GaN-based HEMT device and the manufacturing method thereof according to the embodiments of the present application will be described in detail below with reference to the accompanying drawings. Figure 1 is a flowchart of the manufacturing method of the GaN-based HEMT device according to the embodiments of the present application, with reference to Figure 1 The manufacturing method of the GaN-based HEMT device according to the embodiments of the present application includes steps S110, S120, S130, S140 and S150.

[0036] Figures 2A to 2G is a process diagram for manufacturing a GaN-based HEMT device according to the embodiments of the present application.

[0037] Specifically, in step S110, an h-BN film 20 is manufactured on a substrate 10.

[0038] Specifically, with reference to Figure 2A The substrate 10 is subjected to surface nitriding treatment at 850-950°C to form amorphous AlN on the surface of the substrate 10. x Ny Layer; then, under conditions of triethylboron and ammonia as carrier gases, a temperature of 850℃~950℃, a V / III ratio of 600~1500, and atmospheric pressure, organometallic chemical vapor deposition is used to deposit the Al layer. x N y The h-BN thin film 20 is grown on the layer. Here, the substrate 10 is a sapphire substrate, and the thickness of the h-BN thin film 20 is 1.5 nm.

[0039] Continue to refer to Figure 1 In step S120, a diamond film 30 is formed on the h-BN film 20.

[0040] Specifically, refer to Figure 2B Under conditions of methane and hydrogen as carrier gases, a methane-to-hydrogen gas flow ratio of 1:20, and a temperature of 1100°C, a diamond film 30 with a thickness of 100 μm to 200 μm is grown on the surface of the h-BN film 20 facing away from the substrate 10 using a metal-organic chemical vapor deposition (MOCVD) process. The epitaxial layer on the surface of the diamond film 30 is then polished, cleaned, and dried with nitrogen. The thickness of the diamond film 30 is sufficient to support the subsequent formation of a GaN-based HEMT device as a heat sink substrate.

[0041] The technical solution of this invention utilizes metal-organic chemical vapor deposition (MOCVD) to grow h-BN thin film 20 and diamond thin film 30 in situ on a substrate, enabling the direct growth of two different semiconductor materials using the same growth equipment. This effectively eliminates secondary interface contamination of the substrate during the growth of diamond thin film 30, avoids oxidation from the atmospheric environment, and helps improve the purity and quality of diamond thin film 30 while reducing interface thermal resistance.

[0042] Continue to refer to Figure 1 In step S130, a GaN-based HEMT epitaxial structure 40 is formed on the diamond film 30.

[0043] In this embodiment, the GaN-based HEMT epitaxial structure 40 includes a GaN nucleation layer 401, a GaN buffer layer 402, a GaN channel layer 403, and an AlGaN barrier layer 404 stacked sequentially.

[0044] Here, refer to Figure 2C A method for forming a GaN-based HEMT epitaxial structure 40 on the diamond thin film 30 according to an embodiment of the present invention includes:

[0045] First, the substrate 10 is annealed at an annealing temperature of 900°C to 1050°C in an atmosphere of hydrogen and ammonia.

[0046] Secondly, at 530-580℃, a GaN nucleation layer 401 with a thickness of 20nm is formed on the surface of the diamond film 30 opposite to the h-BN film 20 by using metal organic chemical vapor deposition process with trimethylgallium and ammonia as gallium source and nitrogen source respectively, and nitrogen and hydrogen as carrier gas.

[0047] Then, the temperature is increased to 1050℃, and a GaN buffer layer 402 with a thickness of 3.5μm is formed on the surface of the GaN nucleation layer 401 opposite to the diamond film 30 by using metal organic chemical vapor deposition process with trimethylgallium and ammonia as gallium source and nitrogen source respectively, and nitrogen and hydrogen as carrier gas.

[0048] Next, the temperature is increased to 1100℃, and a GaN channel layer 403 with a thickness of 100nm is formed on the surface of the GaN buffer layer 402 opposite to the GaN nucleation layer 401 by using metal organic chemical vapor deposition process with trimethylgallium and ammonia as gallium source and nitrogen source respectively, and nitrogen and hydrogen as carrier gas.

[0049] Finally, the temperature is kept at 1100℃, and an AlGaN barrier layer 404 with a thickness of 25nm is formed on the surface of the GaN channel layer 403 opposite to the GaN buffer layer 402 by using metal organic chemical vapor deposition process with trimethylaluminum, trimethylgallium and ammonia as aluminum source, gallium source and nitrogen source respectively, and nitrogen and hydrogen as carrier gas.

[0050] In the GaN-based HEMT device, the AlGaN barrier layer 404 and the GaN channel layer 403 form a heterojunction to generate a two-dimensional electron gas layer (2DEG) 405, and the higher the concentration of the two-dimensional electron gas is, the higher the Idss (saturated drain-source current) is.

[0051] The manufacturing method directly forms the GaN-based HEMT epitaxial structure 40 on the surface of the diamond film 30, avoids introducing a dielectric layer, eliminates the influence of the thermal resistance of other dielectric layer materials, and makes the diamond film 30 closer to the two-dimensional electron gas layer (2DEG) 405, thereby improving the lateral heat dissipation performance of the device and being beneficial to improving the reliability of the device.

[0052] Here, reference is made to Figure 2D After the GaN-based HEMT epitaxial structure 40 is formed on the diamond film 30, the manufacturing method further includes: etching and removing part of the GaN channel layer 403 and part of the AlGaN barrier layer 404 of the GaN-based HEMT epitaxial structure 40 by using inductively coupled plasma etching process (ICP) to expose the GaN buffer layer 402.

[0053] By using ICP etching to etch the GaN-based HEMT epitaxial structure 40, device chip isolation is achieved, ensuring that the GaN-based HEMT chips on the wafer do not interfere with each other through the substrate.

[0054] Continue to refer to Figure 1 In step S140, an electrode 50 is fabricated on the GaN-based HEMT epitaxial structure 40.

[0055] Here, refer to Figure 2E According to an embodiment of the present invention, a method for fabricating an electrode 50 on the GaN-based HEMT epitaxial structure 40 includes: fabricating the electrode 50 on the AlGaN barrier layer 404 that has not been etched away.

[0056] Specifically, a first composite metal layer is deposited in the first and second predetermined regions of the AlGaN barrier layer 404 using a magnetron sputtering device, and then rapidly annealed in a nitrogen atmosphere at an annealing temperature of 800°C and an annealing time of 30s to form ohmic contacts, thereby forming a source electrode 501 and a drain electrode 502, respectively; wherein, the first composite metal layer comprises a composite metal layer of Ti metal layer / Al metal layer / Ni metal layer / Au metal layer;

[0057] Then, a second composite metal layer is deposited in the third predetermined region of the AlGaN barrier layer 404 using a magnetron sputtering device, and annealed in a nitrogen atmosphere at an annealing temperature of 400°C and an annealing time of 10 min to form a Schottky contact to form a gate electrode 503; the second composite metal layer includes a Ni metal layer / Au metal layer composite metal layer.

[0058] Here, the gate electrode 503 is located between the source electrode 501 and the drain electrode 502.

[0059] Reference Figure 2F After the electrode 50 is fabricated on the GaN-based HEMT epitaxial structure 40, the fabrication method further includes: using silane and ammonia as silicon and nitrogen sources respectively, and using plasma-enhanced chemical vapor deposition to form a silicon nitride passivation layer with a thickness of 500 nm covering the AlGaN barrier layer 404 and the exposed GaN buffer layer; wherein the silicon nitride passivation layer 60 covers the AlGaN barrier layer 404 opposite to the region outside the electrode 50 region.

[0060] In the embodiment, after forming the silicon nitride passivation layer 60, the manufacturing method further comprises: etching and removing the silicon nitride passivation layer 60 of the contact hole of the gate electrode 503 by ICP, and then re-depositing the second composite metal layer in the area of the gate electrode 503 by a magnetron sputtering device to thicken the gate electrode 503 and fill the contact hole.

[0061] With reference to the foregoing description, the manufacturing method of the GaN-based HEMT device according to the embodiment of the present application is described in detail. Figure 1 In step S150, the substrate 10 is mechanically peeled to obtain the GaN-based HEMT device.

[0062] Specifically, referring to the foregoing description, Figure 2G The substrate 10 is peeled by the tape peeling technology using a water-soluble tape to obtain the GaN-based HEMT device. The interfacial force between the tape and the device is greater than the van der Waals interlayer force between the h-BN film and the substrate, so that the device can be completely mechanically separated from the substrate under the action of an external force, and the water-soluble tape can be removed by water immersion treatment of the device.

[0063] The manufacturing method utilizes the peelable property of the h-BN film, and replaces the laser peeling technology with the tape peeling technology to peel off the traditional sapphire substrate, thereby avoiding damage to the GaN-based HEMT device in the process of peeling off the traditional substrate and improving the yield of the device.

[0064] In summary, in the manufacturing method of the GaN-based HEMT device according to the embodiment of the present application, the h-BN film / diamond film / GaN-based HEMT epitaxial structure device structure is directly grown in situ on the traditional substrate, and then the peelable property of the h-BN film is utilized to peel off the traditional substrate, so that the device can directly utilize the diamond film with high thermal conductivity as a heat sink substrate for heat dissipation, the excellent thermal conductivity of the diamond film is effectively utilized, which not only helps to reduce the overall thermal resistance of the device, but also further improves the overall heat dissipation capacity of the device, solves the heat dissipation problem of the high-power GaN-based HEMT device, reduces the temperature of the device, and further improves the reliability of the device; moreover, by utilizing the tape peeling technology, damage to the GaN-based HEMT device in the process of peeling off the traditional substrate is avoided, which helps to improve the yield of the device. Furthermore, the manufacturing method can directly grow each device structure in situ on the substrate, effectively eliminates the secondary interface contamination caused in the process of growing each device structure, avoids oxidation in the atmospheric environment, and reduces the interface thermal resistance. In addition, the manufacturing method is simple and convenient, which helps to reduce the manufacturing cost of the device.

[0065] Figure 3 is a structural diagram of a GaN-based HEMT device according to an embodiment of the present application. Figure 3The illustrated GaN-based HEMT device is a GaN-based HEMT device fabricated using the fabrication method described above. Referring to Figure 3 , the GaN-based HEMT device includes an h-BN thin film 20, a diamond thin film 30, a GaN-based HEMT epitaxial structure 40 (including a GaN nucleation layer 401, a GaN buffer layer 402, a GaN channel layer 403, an AlGaN barrier layer 404, a two-dimensional electron gas layer 405), an electrode 50 (including a source electrode 501, a gate electrode 503, and a drain electrode 502), and a silicon nitride passivation layer 60.

[0066] The specific embodiments of the application have been described. Other embodiments are within the scope of the following claims.

[0067] The terms "exemplary," "example," and the like are used as adjectives to indicate that certain examples, although the preferred, are examples, or instances, and not "preferred" over other embodiments. The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, can be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described embodiments.

[0068] The above describes optional implementations of the embodiments of the application in detail in combination with the drawings, but the embodiments of the application are not limited to the specific details in the above implementations. Within the technical concept scope of the embodiments of the application, the technical solutions of the embodiments of the application can be variously modified, and these simple modifications all belong to the protection scope of the embodiments of the application.

[0069] The above description of the content of the present specification is provided so that any ordinary person skilled in the art can implement or use the content of the present specification. Various modifications to the content of the present specification are obvious to those skilled in the art, and the general principles defined herein can also be applied to other variants without departing from the protection scope of the content of the present specification. Therefore, the content of the present specification is not limited to the examples and designs described herein, but is consistent with the broadest scope that meets the principles and novel features disclosed herein.

Claims

1. A method of fabricating a GaN-based HEMT device, comprising: The manufacturing method comprises: forming an h-BN film on a substrate by using a metal organic compound chemical vapor deposition device; after the h-BN film is manufactured, directly forming a diamond film on the h-BN film in the same metal organic compound chemical vapor deposition device; forming a GaN-based HEMT epitaxial structure on the diamond film, wherein the diamond film is in direct contact with the GaN-based HEMT epitaxial structure; preparing electrodes on the GaN-based HEMT epitaxial structure; mechanically peeling the substrate to obtain the GaN-based HEMT device; wherein the method for forming the h-BN film on the substrate comprises: subjecting the substrate to a surface nitriding treatment at 850 °C to 950 °C to form an amorphous Al x N y layer on the substrate surface; The h-BN film is formed by growing on the AlN layer under the conditions of triethylboron and ammonia as carrier gas, temperature of 850 DEG C to 950 DEG C, V / III ratio of 600 to 1500, and normal pressure by using a metal organic compound chemical vapor deposition equipment. x N y Layer wherein the method for forming the diamond film on the h-BN film comprises: under the conditions of using methane and hydrogen as carrier gas, the gas flow ratio of methane and hydrogen being 1:20, and the temperature being 1100 ℃, growing a diamond film 30 with a thickness of 100 μm-200 μm on the surface of the h-BN film away from the substrate by using the same metal organic compound chemical vapor deposition device; polishing the surface epitaxial layer of the diamond film and blowing dry with nitrogen after cleaning.

2. The method of manufacturing according to claim 1, wherein, The GaN-based HEMT epitaxial structure comprises a GaN nucleation layer, a GaN buffer layer, a GaN channel layer and an AlGaN barrier layer which are stacked in sequence.

3. The production method according to claim 1 or 2, characterized by, The method for forming the GaN-based HEMT epitaxial structure on the diamond film comprises: annealing the substrate in the atmosphere of hydrogen and ammonia at an annealing temperature of 900 ℃-1050 ℃; growing a GaN nucleation layer, a GaN buffer layer and a GaN channel layer which are stacked in sequence on the surface of the diamond film away from the h-BN film by using a metal organic compound chemical vapor deposition process, with trimethylgallium and ammonia as gallium source and nitrogen source respectively, and nitrogen and hydrogen as carrier gas; growing an AlGaN barrier layer on the surface of the GaN channel layer away from the GaN buffer layer by using a metal organic compound chemical vapor deposition process, with trimethylaluminum, trimethylgallium and ammonia as aluminum source, gallium source and nitrogen source respectively, and nitrogen and hydrogen as carrier gas.

4. The method of manufacturing according to claim 3, wherein, The growth temperature of the GaN nucleation layer is 530 ℃-580 ℃, the thickness of the GaN nucleation layer is 20 nm-50 nm; and / or the growth temperature of the GaN buffer layer is 1050 ℃, the thickness of the GaN buffer layer is 3.5 μm; and / or the growth temperature of the GaN channel layer is 1100 ℃, the thickness of the GaN buffer layer is 100 nm; and / or the growth temperature of the AlGaN barrier layer is 1100 ℃, the thickness of the AlGaN barrier layer is 25 nm.

5. The production method according to claim 1 or 2, wherein After forming the GaN-based HEMT epitaxial structure on the diamond thin film, and before preparing electrodes on the GaN-based HEMT epitaxial structure, the forming method further comprises: etching and removing part of the GaN channel layer and part of the AlGaN barrier layer of the GaN-based HEMT epitaxial structure by using an inductively coupled plasma etching process, to expose the GaN buffer layer. The method for preparing electrodes on the GaN-based HEMT epitaxial structure comprises: preparing electrodes on the AlGaN barrier layer which is not etched and removed.

6. The method of manufacturing according to claim 5, wherein, The method for preparing electrodes on the AlGaN barrier layer which is not etched and removed specifically comprises: Depositing a first composite metal layer in a first predetermined area and a second predetermined area of the AlGaN barrier layer by using a magnetron sputtering device, and forming an ohmic contact through an annealing process to form a source electrode and a drain electrode, respectively; the first composite metal layer comprises a composite metal layer of Ti metal layer / Al metal layer / Ni metal layer / Au metal layer; Depositing a second composite metal layer in a third predetermined area of the AlGaN barrier layer by using a magnetron sputtering device, and forming a Schottky contact through an annealing process to form a gate electrode; the second composite metal layer comprises a composite metal layer of Ni metal layer / Au metal layer.

7. The method of manufacturing according to claim 5, wherein, After preparing electrodes on the GaN-based HEMT epitaxial structure, and before mechanically peeling off the substrate to obtain the GaN-based HEMT device, the forming method further comprises: Forming a silicon nitride passivation layer covering the AlGaN barrier layer and the exposed GaN buffer layer by using a plasma-enhanced chemical vapor deposition method.

8. A GaN-based HEMT device obtained by the forming method of any one of claims 1-7.

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