Gallium oxide composite copper diamond ceramic material substrate and preparation method and application thereof

Abstract

The invention provides a gallium oxide composite copper diamond ceramic material substrate and a preparation method and application thereof. The method comprises the steps that (1) a GaN superlattice buffer layer is formed on a sapphire substrate through low-temperature sputtering; (2) epitaxially growing a gallium oxide single crystal on the superlattice buffer layer to obtain a gallium oxide wafer; (3) bonding the gallium oxide wafer to a copper diamond ceramic material substrate; (4) decomposing the superlattice buffer layer by adopting a laser lift-off technology to obtain a gallium oxide wafer composite substrate; and (5) performing chemical mechanical polishing on the gallium oxide wafer surface of the gallium oxide wafer composite substrate to obtain the gallium oxide composite copper diamond ceramic material substrate. The gallium oxide composite copper diamond ceramic material substrate provided by the invention can be used as a substrate of a gallium oxide-based power device, the matching range is wide, the quality of a gallium oxide wafer is high, not only is the performance of the device improved, but also the heat dissipation problem of the device is effectively solved, and the method is simple in process and low in cost.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a gallium oxide composite copper diamond ceramic material substrate, a preparation method thereof, and applications thereof. Background Art

[0002] Gallium oxide, an ultra-wide bandgap semiconductor material that has rapidly developed in recent years, boasts a wider bandgap and higher breakdown field strength than previous generations of semiconductor materials, including silicon, germanium, gallium arsenide, and gallium nitride. This offers significant advantages in the fabrication of high-temperature, high-voltage, and radiation-resistant power electronic devices. However, gallium oxide's extremely low thermal conductivity has become a significant bottleneck restricting the use of its electronic devices in high-power applications. This low thermal conductivity of gallium oxide has resulted in heat being primarily concentrated near the gallium oxide material and electrodes in currently fabricated gallium oxide electronic devices. Under high voltage conditions, this heat accumulation severely impacts device stability and reliability.

[0003] Currently, some solutions have been proposed to address the heat dissipation problem of gallium oxide power devices. For example, for devices prepared by homoepitaxial growth, substrate thinning or external heat dissipation systems can be used to reduce thermal resistance, but the yield and reliability will be significantly reduced. In contrast, heterogeneous integration methods are more widely used. Transferring gallium oxide materials to some substrates with high thermal conductivity can effectively improve heat dissipation efficiency, but its process is relatively complex. Summary of the Invention

[0004] The present invention aims to solve one of the technical problems in the prior art to at least a certain extent. To this end, one object of the present invention is to provide a gallium oxide composite copper diamond ceramic material substrate and its preparation method and application.

[0005] In a first aspect of the present invention, a method for preparing a gallium oxide composite copper diamond ceramic material substrate is provided, the method comprising: (1) Forming a GaN superlattice buffer layer on a sapphire substrate by low-temperature sputtering; (2) epitaxially growing a gallium oxide single crystal on the superlattice buffer layer to obtain a gallium oxide wafer; (3) bonding the gallium oxide wafer to a copper diamond ceramic material substrate; (4) Decomposing the superlattice buffer layer by laser lift-off technology to obtain a gallium oxide wafer composite substrate; (5) Chemically mechanically polishing the surface of the gallium oxide wafer of the gallium oxide wafer composite substrate to obtain a gallium oxide composite copper diamond ceramic material substrate.

[0006] According to the method for preparing a gallium oxide composite copper diamond ceramic substrate of the present invention, a GaN superlattice buffer layer is first formed on a sapphire substrate by low-temperature sputtering. This low-temperature sputtering method is suitable for large-area deposition and is relatively low-cost. Furthermore, the GaN superlattice buffer layer relieves stress during the subsequent epitaxial growth of a gallium oxide single crystal thin film, improving the quality of the gallium oxide single crystal. Furthermore, the GaN superlattice buffer layer facilitates subsequent laser lift-off, reducing process requirements. A gallium oxide single crystal is then epitaxially grown on the superlattice buffer layer. The resulting gallium oxide wafer is then bonded to a copper diamond ceramic substrate. The copper diamond ceramic substrate combines the high thermal conductivity of diamond with the excellent thermal conductivity of copper, resulting in excellent heat dissipation performance. By adjusting the ratio of diamond to copper, the thermal expansion coefficient of the ceramic material can be adjusted to match that of the gallium oxide wafer, reducing stress issues. Finally, the superlattice buffer layer is decomposed using laser lift-off technology. After removing the buffer layer, a gallium oxide wafer composite substrate is obtained. The surface of the gallium oxide wafer is then chemically mechanically polished to obtain a gallium oxide composite copper diamond ceramic substrate.

[0007] In some embodiments of the present invention, in step (1), the thickness of the superlattice buffer layer is 1 nm-10 μm.

[0008] In some embodiments of the present invention, the temperature of the low-temperature sputtering is 200°C-400°C, the gas pressure of the low-temperature sputtering is 0.5Pa-1.5Pa, the power of the low-temperature sputtering is 100W-200W, and the distance between the target and the substrate is 5cm-10cm.

[0009] In some embodiments of the present invention, the GaN superlattice buffer layer includes an AlGaN / GaN superlattice buffer layer, an InGaN / GaN superlattice buffer layer, or an AlN / GaN superlattice buffer layer.

[0010] In some embodiments of the present invention, in step (2), the thickness of the gallium oxide wafer is 10 nm-10 mm.

[0011] In some embodiments of the present invention, the surface roughness of the gallium oxide wafer is less than 20 nm.

[0012] In some embodiments of the present invention, in step (2), the doping type of the gallium oxide single crystal includes unintentional doping, p-type doping, n-type low doping, n-type high doping, or alternating n-type low doping and high doping.

[0013] In some embodiments of the present invention, the epitaxial growth method of gallium oxide single crystal includes hydride vapor phase epitaxy, metal organic compound vapor deposition or mist chemical vapor deposition.

[0014] In some embodiments of the present invention, in step (3), the mass ratio of copper to diamond in the copper-diamond ceramic material substrate is (1-99): (99-1).

[0015] In some embodiments of the present invention, the copper diamond ceramic material substrate has a thickness of 10 μm-1 cm.

[0016] In some embodiments of the present invention, the gallium oxide wafer bonding is selected from metal bonding or dielectric layer bonding.

[0017] In some embodiments of the present invention, in step (4), the laser wavelength of the laser lift-off is 193 nm-248 nm.

[0018] In its second aspect, the present invention provides a gallium oxide composite copper-diamond ceramic substrate, prepared using the aforementioned method. This gallium oxide composite copper-diamond ceramic substrate can be used as a substrate for gallium oxide-based power devices. It offers a wide compatibility range and high gallium oxide wafer quality, improving device performance while effectively addressing heat dissipation issues.

[0019] In a third aspect of the present invention, the present invention proposes the use of the above-mentioned gallium oxide composite copper diamond ceramic material substrate in electronic devices.

[0020] In a fourth aspect of the present invention, a vertical structure Schottky barrier diode is proposed, comprising an ohmic contact layer and the above-mentioned gallium oxide composite copper diamond ceramic material substrate stacked in sequence, a Schottky contact layer is stacked in the middle of the gallium oxide composite copper diamond ceramic material substrate, SiO2 layers are connected to both ends of the Schottky contact layer, one side of the SiO2 layer contacts the gallium oxide composite copper diamond ceramic material substrate, the SiO2 layer and the Schottky contact layer are in the same plane, the gallium oxide composite copper diamond ceramic material substrate is composed of a copper diamond ceramic material substrate, a bonding layer and a gallium oxide wafer stacked in sequence, and the ohmic contact layer contacts the copper diamond ceramic material substrate.

[0021] The present invention has at least the following beneficial effects: (1) The present invention uses a copper-diamond ceramic material as a transfer substrate, which acts as a heat dissipation substrate that can be connected to an external circuit. This improves the heat dissipation capacity of the device, reduces the impact of temperature on electron drift, and allows the heat generated by the gallium oxide device to be promptly dissipated, thereby reducing the temperature of the device itself and improving the pressure resistance, reliability, and operating stability of the gallium oxide device. The gallium oxide high thermal conductivity composite substrate provided by the present invention can be used as a substrate for gallium oxide-based power devices, significantly improving the heat dissipation performance of the device.

[0022] (2) The traditional process of forming a damaged layer through ion implantation and subsequent heat treatment and stripping is relatively complicated. However, the introduction of a GaN superlattice buffer layer between the sapphire substrate and the gallium oxide single crystal not only releases stress during the subsequent epitaxial growth of the gallium oxide single crystal film, thereby improving the quality of the gallium oxide single crystal, but also allows the superlattice buffer layer to be decomposed by laser stripping technology and the gallium oxide wafer to be completely stripped. The process is simpler, the sapphire substrate can be reused, and the cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 This is a structural demonstration diagram of the preparation process of the gallium oxide composite copper diamond ceramic material substrate of the present invention; Figure 2 1 is a schematic structural diagram of a gallium oxide composite copper diamond ceramic material substrate according to an embodiment of the present invention; Figure 3 1 is a schematic structural diagram of a vertical Schottky barrier diode according to an embodiment of the present invention; Figure 4 It is a schematic diagram of the structural changes during the preparation process of a vertical structure Schottky barrier diode according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

[0026] In a first aspect of the present invention, a method for preparing a gallium oxide composite copper diamond ceramic material substrate is provided, the method comprising: (1) Forming a GaN superlattice buffer layer on a sapphire substrate by low-temperature sputtering; (2) epitaxially growing a gallium oxide single crystal on the superlattice buffer layer to obtain a gallium oxide wafer; (3) bonding the gallium oxide wafer to a copper diamond ceramic material substrate; (4) Decomposing the superlattice buffer layer by laser lift-off technology to obtain a gallium oxide wafer composite substrate; (5) Chemically mechanically polishing the surface of the gallium oxide wafer of the gallium oxide wafer composite substrate to obtain a gallium oxide composite copper diamond ceramic material substrate.

[0027] According to the method for preparing a gallium oxide composite copper diamond ceramic substrate of the present invention, a GaN superlattice buffer layer is first formed on a sapphire substrate by low-temperature sputtering. This low-temperature sputtering method is suitable for large-area deposition and is relatively low-cost. Furthermore, the GaN superlattice buffer layer relieves stress during the subsequent epitaxial growth of a gallium oxide single crystal thin film, improving the quality of the gallium oxide single crystal. Furthermore, the GaN superlattice buffer layer facilitates subsequent laser lift-off, reducing process requirements. A gallium oxide single crystal is then epitaxially grown on the superlattice buffer layer. The resulting gallium oxide wafer is then bonded to a copper diamond ceramic substrate. The copper diamond ceramic substrate combines the high thermal conductivity of diamond with the excellent thermal conductivity of copper, resulting in excellent heat dissipation performance. By adjusting the ratio of diamond to copper, the thermal expansion coefficient of the ceramic material can be adjusted to match that of the gallium oxide wafer, reducing stress issues. Finally, the superlattice buffer layer is decomposed using laser lift-off technology. After removing the buffer layer, a gallium oxide wafer composite substrate is obtained. The surface of the gallium oxide wafer is then chemically mechanically polished to obtain a gallium oxide composite copper diamond ceramic substrate.

[0028] Specifically, please refer to Figure 1 A nitride superlattice buffer layer 2 is formed on a sapphire substrate 1, and a gallium oxide single crystal is grown on the nitride superlattice buffer layer 2 to obtain a gallium oxide wafer 5. Furthermore, the gallium oxide wafer 5 includes a stacked low-doped gallium oxide epitaxial layer 3 and a highly-doped gallium oxide epitaxial layer 4, with the low-doped gallium oxide epitaxial layer 3 contacting the nitride superlattice buffer layer 2.

[0029] According to an embodiment of the present invention, in step (1), the thickness of the superlattice buffer layer is 1 nm-10 μm.

[0030] According to an embodiment of the present invention, the GaN superlattice buffer layer includes an AlGaN / GaN superlattice buffer layer, an InGaN / GaN superlattice buffer layer, or an AlN / GaN superlattice buffer layer. Specifically, the GaN superlattice buffer layer comprises a multilayer film structure formed by alternating thin layers of gallium nitride and another semiconductor material (AlGaN, InGaN, or AlN). Furthermore, each layer of the film structure has a thickness of 1 nm to 100 nm.

[0031] According to an embodiment of the present invention, the temperature of the low-temperature sputtering is 200°C-400°C, the gas pressure of the low-temperature sputtering is 0.5Pa-1.5Pa, the power of the low-temperature sputtering is 100W-200W, and the distance between the target and the substrate is 5cm-10cm.

[0032] According to an embodiment of the present invention, the low-temperature sputtering process steps include: (1) Substrate preparation: Select a high-quality sapphire substrate, perform cleaning and surface treatment, and remove surface impurities and oxide layers. (2) Sputtering system preparation: Place the sapphire substrate in the sputtering system and evacuate to the required vacuum level. (3) Low-temperature sputtering: Under low-temperature conditions, use radio frequency or direct current sputtering technology to sputter the GaN target onto the sapphire substrate. Specifically, according to the designed superlattice structure, the GaN layer and another semiconductor material layer are alternately sputtered to form a multi-period superlattice structure. Specifically, the superlattice period is 1-100 periods, and the thickness of the GaN layer and the other material layer are both between 1nm and 100nm.

[0033] According to an embodiment of the present invention, the sapphire substrate is selected from a c-plane sapphire substrate.

[0034] According to an embodiment of the present invention, in step (2), the thickness of the gallium oxide wafer is 10 nm-10 mm.

[0035] According to an embodiment of the present invention, the surface roughness of the gallium oxide wafer is less than 20 nm. It should be noted that the surface roughness referred to in the present invention refers to the unevenness of the processed surface, including small peaks and valleys with small spacing. It is typically assessed using the average arithmetic deviation (Ra) of the surface profile, which is the arithmetic mean of the distances from each point on the profile to a reference line.

[0036] According to an embodiment of the present invention, in step (2), the doping type of the gallium oxide single crystal includes unintentional doping, p-type doping, n-type low doping, n-type high doping, or alternating n-type low doping and high doping.

[0037] According to an embodiment of the present invention, the epitaxial growth method of gallium oxide single crystal includes hydride vapor phase epitaxy, metal organic compound vapor deposition or mist chemical vapor deposition.

[0038] According to an embodiment of the present invention, in step (3), the mass ratio of copper to diamond in the copper-diamond ceramic material substrate is (1-99):(99-1). By controlling the ratio of the different components, the advantages of the Cu component or the diamond component can be fully utilized according to the application scenario of the device being prepared.

[0039] According to an embodiment of the present invention, the preparation process of the copper diamond ceramic material substrate includes powder metallurgy, melt infiltration, high temperature and high pressure sintering, vacuum hot pressing sintering, etc.

[0040] Specifically, taking high temperature and high pressure sintering as an example, diamond and copper powders are mixed and sintered into a mold under high temperature and high pressure conditions.

[0041] According to an embodiment of the present invention, the thickness of the copper diamond ceramic material substrate is 10 μm-1 cm.

[0042] According to an embodiment of the present invention, the gallium oxide wafer bonding is selected from metal bonding or dielectric layer bonding.

[0043] Furthermore, the metal bonding material system includes Au-Au, Au-Sn, Au-In, Au-W, Au-Mo and combinations thereof, and also includes Ti-Au, Ti-Sn, Ti-In, Ti-W, Ti-Mo, Ti-Al, Ti-Ag and combinations thereof. The dielectric layer bonding material system includes SiO2, SiN x , TiO x , SOG, Al2O3, SU-8, UV glue, PMMA, resin and other materials.

[0044] According to an embodiment of the present invention, in step (4), the laser wavelength of the laser lift-off is 193 nm-248 nm.

[0045] According to an embodiment of the present invention, laser lift-off is performed by incident laser light from the front side of the sapphire substrate, and utilizing the laser energy in the ultraviolet band to thermally decompose the GaN superlattice buffer layer material (the GaN layer therein) between the gallium oxide and the sapphire substrate, thereby achieving lift-off.

[0046] According to an embodiment of the present invention, in step (5), the chemical mechanical polishing (CMP) step is to fix the peeled gallium oxide composite high thermal conductivity substrate under the polishing head, add flowing grinding liquid between the substrate surface and the polishing pad, and evenly apply the grinding liquid under the transmission of the polishing pad and the action of centrifugal force; achieve surface flattening through the alternating process of chemical stripping and mechanical stripping; and clean the polished substrate to remove debris generated by polishing.

[0047] In its second aspect, the present invention provides a gallium oxide composite copper-diamond ceramic substrate, prepared using the aforementioned method. This gallium oxide composite copper-diamond ceramic substrate can be used as a substrate for gallium oxide-based power devices. It offers a wide compatibility range and high gallium oxide wafer quality, improving device performance while effectively addressing heat dissipation issues.

[0048] In some embodiments of the present invention, reference Figure 2 The gallium oxide composite copper-diamond ceramic substrate includes a copper-diamond ceramic substrate 7, a bonding layer 6, and a gallium oxide wafer 5 stacked in sequence. Furthermore, the gallium oxide wafer 6 includes a stacked low-doped gallium oxide epitaxial layer 3 and a highly-doped gallium oxide epitaxial layer 4, with the highly-doped gallium oxide epitaxial layer 4 contacting the bonding layer 6.

[0049] In a third aspect of the present invention, the present invention proposes the use of the above-mentioned gallium oxide composite copper diamond ceramic material substrate in electronic devices.

[0050] In a fourth aspect of the present invention, a vertical Schottky barrier diode is provided. Figure 3 It includes an ohmic contact layer 10 and the above-mentioned gallium oxide composite copper diamond ceramic material substrate 20 stacked in sequence, a Schottky contact layer 30 stacked in the middle of the gallium oxide composite copper diamond ceramic material substrate 20, and SiO2 layers 40 connected to both ends of the Schottky contact layer 30. One side of the SiO2 layer 40 contacts the gallium oxide composite copper diamond ceramic material substrate 20, and the SiO2 layer 40 and the Schottky contact layer 30 are in the same plane. The gallium oxide composite copper diamond ceramic material substrate 20 is composed of a copper diamond ceramic material substrate 7, a bonding layer 6 and a gallium oxide wafer 5 stacked in sequence, and the ohmic contact layer 10 contacts the copper diamond ceramic material substrate 7.

[0051] In some embodiments of the present invention, the Schottky contact layer 30 is composed of a stack of a Ni layer and an Au layer, and the Ni layer contacts the gallium oxide composite copper diamond ceramic material substrate 20 .

[0052] In some embodiments of the present invention, the ohmic contact layer 10 is composed of a stack of a Ti layer and an Au layer. The Ti layer contacts the gallium oxide composite copper diamond ceramic material substrate 20 and forms an ohmic contact with the gallium oxide composite copper diamond ceramic material substrate.

[0053] In some embodiments of the present invention, reference may be made to Figure 4 The preparation method of the vertical structure Schottky barrier diode includes: (1) cleaning the high thermal conductivity gallium oxide composite substrate 20; (2) performing photolithography on the gallium oxide wafer 5 of the high thermal conductivity gallium oxide composite substrate 20 and sequentially depositing a Ni metal layer and an Au metal layer, and rapidly thermally annealing to form a Schottky contact between the metal and the low-doped gallium oxide epitaxial layer of the gallium oxide wafer 5; (3) sequentially depositing a Ti metal layer and an Au metal layer on the back side of the copper diamond ceramic material substrate 7, and rapidly thermally annealing to form an ohmic contact layer 10 to form a good ohmic contact.

[0054] In some embodiments of the present invention, the Schottky contact and ohmic contact layers are fabricated using one or more processes such as metal thermal evaporation, magnetron sputtering, and electron beam evaporation. Furthermore, rapid thermal annealing is used to establish ohmic contact between the ohmic contact layer 10 and the copper-diamond ceramic substrate 7 at a temperature of 400°C-500°C. Rapid thermal annealing is used to establish Schottky contact between the Schottky contact layer 30 and the gallium oxide wafer 5 at a temperature of 400°C-500°C.

[0055] The present invention is described below with reference to specific examples. It should be noted that these examples are merely illustrative and do not limit the present invention in any way.

[0056] Example 1 This embodiment provides a gallium oxide composite copper diamond ceramic material substrate, the specific preparation process of which is as follows: (1) A GaN superlattice buffer layer is formed on a c-plane sapphire substrate by low-temperature sputtering. Specifically, the temperature of the low-temperature sputtering is 300°C, the gas pressure of the low-temperature sputtering is 1 Pa, the power of the low-temperature sputtering is 100 W, and the distance between the target and the substrate is 7 cm. The GaN superlattice buffer layer is an alternating stack of GaN layers and AlN layers, and the GaN layer is in contact with the substrate. The thickness of the single-layer GaN layer is 50 nm, the thickness of the single-layer AlN layer is 50 nm, and the total thickness of the GaN superlattice buffer layer is 1 μm.

[0057] (2) epitaxially growing a gallium oxide single crystal on the GaN superlattice buffer layer obtained in step (1) by using a metal organic compound vapor deposition method to obtain a gallium oxide wafer, wherein the thickness of the gallium oxide wafer is 10 μm and the surface roughness of the gallium oxide wafer is 10 nm; (3) The gallium oxide wafer is metal-bonded to a copper-diamond ceramic substrate, wherein the mass ratio of copper to diamond in the substrate is 1:1, and the substrate is prepared by high-temperature sintering, and the thickness of the substrate is 500 μm; (4) Using a 193nm argon fluoride (ArF) excimer laser wavelength to irradiate the laser from the front of the sapphire substrate, the GaN layer in the superlattice buffer layer is decomposed and peeled off to obtain a gallium oxide wafer composite substrate; (5) The surface of the gallium oxide wafer of the gallium oxide wafer composite substrate is subjected to CMP chemical mechanical polishing to make the surface roughness Ra of the gallium oxide wafer reach below 0.3 nm, thereby obtaining a gallium oxide composite copper diamond ceramic material substrate.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for preparing a gallium oxide composite copper diamond ceramic material substrate, characterized in that: include: (1) Forming a GaN superlattice buffer layer on a sapphire substrate by low-temperature sputtering; (2) epitaxially growing a gallium oxide single crystal on the superlattice buffer layer to obtain a gallium oxide wafer; (3) bonding the gallium oxide wafer to a copper diamond ceramic material substrate; (4) Decomposing the superlattice buffer layer by laser lift-off technology to obtain a gallium oxide wafer composite substrate; (5) Chemically mechanically polishing the surface of the gallium oxide wafer of the gallium oxide wafer composite substrate to obtain a gallium oxide composite copper diamond ceramic material substrate.

2. The method according to claim 1, characterized in that In step (1), the thickness of the superlattice buffer layer is 1 nm-10 μm; And / or, the GaN superlattice buffer layer includes an AlGaN / GaN superlattice buffer layer, an InGaN / GaN superlattice buffer layer or an AlN / GaN superlattice buffer layer.

3. The method according to claim 1 or 2, characterized in that In step (1), the temperature of the low-temperature sputtering is 200°C-400°C, the gas pressure of the low-temperature sputtering is 0.5Pa-1.5Pa, the power of the low-temperature sputtering is 100W-200W, and the distance between the target and the substrate is 5cm-10cm.

4. The method according to claim 1 or 2, characterized in that In step (2), the thickness of the gallium oxide wafer is 10 nm-10 mm; And / or, the surface roughness of the gallium oxide wafer is less than 20 nm.

5. The method according to claim 1 or 2, characterized in that: In step (2), the doping type of the gallium oxide single crystal includes unintentional doping, p-type doping, n-type low doping, n-type high doping, or alternating n-type low doping and high doping; And / or, the epitaxial growth method of the gallium oxide single crystal includes hydride vapor phase epitaxy, metal organic compound vapor deposition or mist chemical vapor deposition.

6. The method according to claim 1 or 2, characterized in that: In step (3), the mass ratio of copper to diamond in the copper-diamond ceramic material substrate is (1-99): (99-1); And / or, the thickness of the copper diamond ceramic material substrate is 10 μm-1 cm; And / or, the gallium oxide wafer bonding is selected from metal bonding or dielectric layer bonding.

7. The method according to claim 1 or 2, characterized in that: In step (4), the laser wavelength of the laser stripping is 193nm-248nm.

8. A gallium oxide composite copper diamond ceramic material substrate, characterized in that: The method according to any one of claims 1 to 7 is used to prepare the present invention.

9. Use of the gallium oxide composite copper diamond ceramic material substrate according to claim 8 in electronic devices.

10. A vertical Schottky barrier diode, characterized in that: It comprises an ohmic contact layer stacked in sequence and the gallium oxide composite copper diamond ceramic material substrate according to claim 8, a Schottky contact layer stacked in the middle of the gallium oxide composite copper diamond ceramic material substrate, SiO2 layers are connected to both ends of the Schottky contact layer, one side of the SiO2 layer contacts the gallium oxide composite copper diamond ceramic material substrate, the SiO2 layer and the Schottky contact layer are in the same plane, the gallium oxide composite copper diamond ceramic material substrate is composed of a copper diamond ceramic material substrate, a bonding layer and a gallium oxide wafer stacked in sequence, and the ohmic contact layer contacts the copper diamond ceramic material substrate.

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