Epitaxial growth method of gallium oxide material, gallium oxide epitaxial structure, and ultraviolet detection device

Abstract

This application relates to a method for epitaxial growth of gallium oxide materials, a gallium oxide epitaxial structure, and an ultraviolet detection device. The method comprises: providing a substrate; forming an aluminum nitride layer on the substrate; epitaxially growing at least one composite interface layer on the aluminum nitride layer, the composite interface layer comprising an aluminum oxide layer and an indium oxide layer stacked in sequence; and epitaxially growing a gallium oxide layer on the composite interface layer. This method can reduce dislocation density and thermal stress in the gallium oxide layer, thereby improving the quality and performance of the gallium oxide epitaxial structure. When the resulting gallium oxide epitaxial structure is applied to a photodetector device, the device's performance and reliability can be significantly improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a method for epitaxial growth of gallium oxide materials, a gallium oxide epitaxial structure, and an ultraviolet detection device. Background Art

[0002] Ultraviolet detection technology has a wide range of applications in environmental monitoring, solar-blind imaging, flame detection, missile warning, secure communications, and biomedicine. In particular, UV detection devices operating in the solar-blind band (200nm-280nm) are minimally affected by solar background radiation and offer advantages such as strong anti-interference capabilities, high sensitivity, and low background noise, thus holding significant application prospects.

[0003] Gallium oxide has an ultra-wide band gap (4.8eV~4.9eV), a high breakdown field strength (8MV·cm -1 ) and a high Baliga figure of merit, and demonstrates significant advantages in power electronics and ultraviolet optoelectronic devices. Because its bandgap width closely matches the solar-blind ultraviolet band, gallium oxide is well-suited for use in solar-blind ultraviolet detection devices.

[0004] Currently, gallium oxide is usually obtained by epitaxially growing gallium oxide materials on substrates. However, heteroepitaxial growth of gallium oxide materials has problems such as lattice mismatch and differences in thermal expansion coefficients. The prepared gallium oxide films are prone to high dislocation density and thermal stress, which seriously affects the performance and reliability of devices prepared using gallium oxide films and hinders the industrialization of gallium oxide devices. Summary of the Invention

[0005] In view of this, embodiments of the present application provide a gallium oxide material epitaxial growth method, a gallium oxide epitaxial structure, and an ultraviolet detection device to solve at least one problem existing in the background technology.

[0006] In a first aspect, an embodiment of the present application provides a method for epitaxial growth of a gallium oxide material, the method comprising:

[0007] providing a substrate;

[0008] forming an aluminum nitride layer on the substrate;

[0009] epitaxially growing at least one composite interface layer on the aluminum nitride layer, wherein the composite interface layer comprises an aluminum oxide layer and an indium oxide layer stacked in sequence;

[0010] A gallium oxide layer is epitaxially grown on the composite interface layer.

[0011] In conjunction with the first aspect of the present application, in an optional embodiment, epitaxially growing the composite interface layer includes:

[0012] A first aluminum source and a first oxygen source are introduced to epitaxially grow the aluminum oxide layer; the epitaxial growth of the aluminum oxide layer satisfies at least one of the following conditions:

[0013] (1) The temperature of epitaxial growth is 600℃~800℃;

[0014] (2) The pressure of epitaxial growth is 20mbar~150mbar;

[0015] (3) The flow rate of the first aluminum source is greater than or equal to 5 sccm and less than or equal to 20 sccm;

[0016] (4) The flow rate of the first oxygen source is greater than 0 sccm and less than or equal to 100 sccm;

[0017] (5) The time for epitaxial growth is 1s~5s.

[0018] In conjunction with the first aspect of the present application, in an optional embodiment, epitaxially growing the composite interface layer further comprises:

[0019] An indium source and a second oxygen source are introduced to epitaxially grow the indium oxide layer on the aluminum oxide layer; the epitaxial growth of the indium oxide layer satisfies at least one of the following conditions:

[0020] (1) The temperature of epitaxial growth is 600℃~800℃;

[0021] (2) The pressure of epitaxial growth is 20mbar~150mbar;

[0022] (3) The flow rate of the indium source is greater than or equal to 5 sccm and less than or equal to 20 sccm;

[0023] (4) The flow rate of the second oxygen source is greater than 0 sccm and less than or equal to 100 sccm;

[0024] (5) The time of epitaxial growth is 1s~10s.

[0025] In conjunction with the first aspect of the present application, in an optional embodiment, before epitaxially growing at least one layer of the composite interface layer on the aluminum nitride layer, the method further includes:

[0026] A second aluminum source, a gallium source, and a nitrogen source are introduced to epitaxially grow Al on the aluminum nitride layer. x Ga 1-x N layer, wherein 0.2≤x≤0.5; epitaxially growing the Al x Ga 1-x N layers, meeting at least one of the following conditions:

[0027] (1) The temperature of epitaxial growth is 1000℃~1200℃;

[0028] (2) The pressure of epitaxial growth is 50mbar~100mbar;

[0029] (3) The flow rate of the second aluminum source is greater than or equal to 50 sccm and less than or equal to 300 sccm;

[0030] (4) The flow rate of the gallium source is greater than or equal to 20 sccm and less than or equal to 100 sccm;

[0031] (5) The flow rate of the nitrogen source is greater than or equal to 0.5 slm and less than or equal to 2 slm;

[0032] (6) Al x Ga 1-x The thickness of the N layer is 5nm~30nm.

[0033] In conjunction with the first aspect of the present application, in an optional embodiment, before epitaxially growing the gallium oxide layer on the composite interface layer, the method further includes:

[0034] The composite interface layer is subjected to a heat treatment, wherein the heat treatment satisfies at least one of the following conditions:

[0035] (1) The temperature of the heat treatment is 1000°C to 1400°C;

[0036] (2) The heat treatment time is 10 min to 30 min;

[0037] (3) The heat treatment is performed in an atmosphere including hydrogen.

[0038] In conjunction with the first aspect of the present application, in an optional implementation manner, the method satisfies at least one of the following conditions:

[0039] (1) The thickness of the composite interface layer is 1 nm to 5 nm;

[0040] (2) The thickness of the aluminum oxide layer is 0.5 nm to 3 nm;

[0041] (3) The thickness of the indium oxide layer is 0.5 nm to 2 nm;

[0042] (4) The thickness of the aluminum nitride layer is 5 nm to 50 nm;

[0043] (5) The thickness of the gallium oxide layer is 500 nm to 2500 nm;

[0044] (6) The number of the composite interface layers is greater than or equal to 2, and the composite interface layers are identical.

[0045] In a second aspect, an embodiment of the present application provides a gallium oxide epitaxial structure, comprising:

[0046] substrate;

[0047] an aluminum nitride layer on the substrate;

[0048] at least one composite interface layer located on the aluminum nitride layer, the composite interface layer comprising an aluminum oxide layer and an indium oxide layer stacked in sequence;

[0049] A gallium oxide layer is located on the composite interface layer.

[0050] In conjunction with the second aspect of the present application, in an optional embodiment, the gallium oxide epitaxial structure satisfies at least one of the following conditions:

[0051] (1) The thickness of the composite interface layer is 1 nm to 5 nm;

[0052] (2) The thickness of the aluminum oxide layer is 0.5 nm to 3 nm;

[0053] (3) The thickness of the indium oxide layer is 0.5 nm to 2 nm;

[0054] (4) The thickness of the aluminum nitride layer is 5 nm to 50 nm;

[0055] (5) The thickness of the gallium oxide layer is 500 nm to 2500 nm;

[0056] (6) The number of the composite interface layers is greater than or equal to 2, and the composite interface layers are identical.

[0057] In conjunction with the second aspect of the present application, in an optional embodiment, the gallium oxide epitaxial structure further includes: an Al2O3 layer located between the aluminum nitride layer and the composite interface layer. x Ga 1-x N layers, where 0.2≤x≤0.5.

[0058] In a third aspect, an embodiment of the present application provides an ultraviolet detection device, comprising a gallium oxide epitaxial structure produced by the epitaxial growth method of gallium oxide material according to any one of the first aspects or comprising the gallium oxide epitaxial structure according to any one of the second aspects.

[0059] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0060] The present invention provides a method for epitaxial growth of a gallium oxide material, a gallium oxide epitaxial structure, and an ultraviolet detection device. The epitaxial growth method of the gallium oxide material comprises: providing a substrate; forming an aluminum nitride layer on the substrate; epitaxially growing at least one composite interface layer on the aluminum nitride layer, the composite interface layer comprising a sequentially stacked aluminum oxide layer and an indium oxide layer; and epitaxially growing a gallium oxide layer on the composite interface layer. In the present invention, the aluminum nitride layer is first formed on the substrate. The aluminum nitride layer can improve the lattice mismatch between the substrate and the subsequently epitaxially grown composite interface layer, thereby ensuring high-quality growth of the composite interface layer. Next, at least one composite interface layer is epitaxially grown on the aluminum nitride layer. The composite interface layer comprises a sequentially stacked aluminum oxide layer and an indium oxide layer. The composite interface layer has the functions of blocking defect diffusion, forming low interface states, and reducing phonon scattering, thereby promoting better interfacial heat transfer, reducing the generation of thermal stress and the proliferation of defects caused by thermal stress, thereby reducing the dislocation density and thermal stress in the gallium oxide layer epitaxially grown on the composite interface layer, thereby improving the quality and performance of the gallium oxide epitaxial structure. When the prepared gallium oxide epitaxial structure is applied to a photoelectric detection device, the performance and reliability of the device can be significantly improved.

[0061] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0063] Figure 1 A schematic flow chart of a method for epitaxial growth of gallium oxide material provided in an embodiment of the present application;

[0064] Figures 2 to 6 A schematic cross-sectional view of an epitaxial structure of a gallium oxide material during growth according to an epitaxial growth method provided in an embodiment of the present application;

[0065] Figure 7 This is an atomic force microscope image of the surface of the gallium oxide epitaxial structure prepared in Example 1;

[0066] Figure 8 This is an atomic force microscope image of the surface of the gallium oxide epitaxial structure prepared in Comparative Example 1. DETAILED DESCRIPTION

[0067] The exemplary embodiments disclosed herein will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the specific embodiments described herein. Rather, these embodiments are provided to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0068] In the following description, numerous specific details are provided to provide a more thorough understanding of the present application. However, it will be apparent to those skilled in the art that the present application can be practiced without one or more of these details. In other instances, certain technical features known in the art are not described to avoid confusion with the present application; that is, all features of actual embodiments are not described herein, nor are well-known functions and structures described in detail.

[0069] In the drawings, the sizes of layers, regions, elements and their relative sizes may be exaggerated for clarity. Like reference numerals denote like elements throughout.

[0070] When an element or layer is referred to as being "on," "adjacent to," "connected to," or "coupled to" another element or layer, it may be directly on, adjacent to, connected to, or coupled to the other element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" another element or layer, there are no intervening elements or layers. Although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, or part from another element, component, region, layer, or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer, or part discussed below may be represented as the second element, component, region, layer, or part. However, when the second element, component, region, layer, or part is discussed, it does not necessarily mean that the first element, component, region, layer, or part exists in the present application.

[0071] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," etc., may be used herein for convenience of description to describe the relationship of an element or feature shown in the figures to other elements or features. In addition to the orientations shown in the figures, spatially relative terms are intended to also include different orientations of the device in use and operation. For example, if the device in the drawings is turned over, then, the elements or features described as "under" or "beneath" or "beneath" the other elements will be oriented "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both the above and below orientations. The device may be oriented otherwise (rotated 90 degrees or in other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0072] The purpose of the terms used herein is only to describe specific embodiments and is not intended to limit the present application. When used herein, the singular forms "a", "an", and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise. The terms "comprising" and / or "including", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0073] In order to fully understand the present application, detailed steps and detailed structures will be presented in the following description to illustrate the technical solution of the present application. The preferred embodiments of the present application are described in detail below. However, in addition to these detailed descriptions, the present application may also have other implementation methods.

[0074] Based on this, an embodiment of the present application provides a method for epitaxial growth of a gallium oxide material. Figure 1 Schematic diagram of the process of epitaxial growth of gallium oxide material provided in the embodiment of the present application; Figure 1 As shown, the method includes:

[0075] Step S1, providing a substrate;

[0076] Step S2, forming an aluminum nitride layer on the substrate;

[0077] Step S3, epitaxially growing at least one composite interface layer on the aluminum nitride layer, the composite interface layer comprising an aluminum oxide layer and an indium oxide layer stacked in sequence;

[0078] Step S4: epitaxially growing a gallium oxide layer on the composite interface layer.

[0079] As can be understood, the above method first forms an aluminum nitride layer on the substrate. The aluminum nitride layer can improve the lattice mismatch between the substrate and the subsequently epitaxially grown composite interface layer, thereby ensuring high-quality growth of the composite interface layer. Next, at least one composite interface layer is epitaxially grown on the aluminum nitride layer. The composite interface layer is composed of sequentially stacked aluminum oxide layers and indium oxide layers, which have the functions of blocking defect diffusion, forming low interface states, and reducing phonon scattering. This is conducive to forming better interface heat transfer, reducing the generation of thermal stress and the proliferation of defects caused by thermal stress, thereby reducing the dislocation density and thermal stress in the gallium oxide layer epitaxially grown on the composite interface layer, thereby improving the quality and performance of the resulting gallium oxide epitaxial structure. When the resulting gallium oxide epitaxial structure is applied to a photodetection device, the performance and reliability of the device can be significantly improved.

[0080] Next, combine Figures 2 to 6 , the epitaxial growth method of the gallium oxide material and the gallium oxide epitaxial structure provided in the embodiments of the present application and the corresponding beneficial effects are further described in detail.

[0081] First, please refer to Figure 2 , perform step S1 and provide a substrate 100.

[0082] Here, the substrate 100 may include, for example, a sapphire substrate, a silicon substrate, a silicon carbide substrate, an Al2O3 / AlN composite substrate, a Si / AlN composite substrate, or a SiC / AlN composite substrate, etc. In a specific embodiment, the substrate 100 is a sapphire substrate or a silicon substrate.

[0083] Next, please refer to Figure 3 , step S2 is performed to form an aluminum nitride layer 200 on the substrate 100. This can improve the lattice mismatch and interface stress between the substrate 100 and the subsequently epitaxially grown composite interface layer, thereby ensuring high-quality growth of the composite interface layer and improving the quality of the subsequently grown gallium oxide layer.

[0084] In an actual preparation process, the aluminum nitride layer 200 may be formed by at least one of a physical vapor deposition process (such as magnetron sputtering), a chemical vapor deposition process (such as metal organic chemical vapor deposition), and an atomic layer deposition process.

[0085] In some embodiments, the aluminum nitride layer 200 can be formed on the substrate 100 using a magnetron sputtering process. Compared to heteroepitaxial growth of the aluminum nitride layer 200 on the substrate 100, the magnetron sputtering process has greater process controllability and facilitates the formation of a higher quality aluminum nitride layer 200 on the substrate 100.

[0086] Specifically, the magnetron sputtering temperature can be 200°C to 800°C; the power can be 20W to 200W; the nitrogen flow rate can be greater than 0 sccm and less than or equal to 200 sccm; the oxygen flow rate can be greater than 0 sccm and less than or equal to 1 sccm; the carrier gas (specifically, argon) flow rate can be greater than 0 sccm and less than or equal to 200 sccm; and the magnetron sputtering time can be 10 seconds to 100 seconds. Meeting at least one of the above conditions facilitates the preparation of a high-quality aluminum nitride layer 200.

[0087] In some embodiments, the thickness of the aluminum nitride layer 200 can be 5 nm to 50 nm, for example, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, or any value between any two of the above ranges. This not only effectively improves the lattice mismatch and interface stress between the substrate 100 and the subsequently epitaxially grown composite interface layer, thereby ensuring high-quality growth of the composite interface layer, but also avoids problems such as carrier transport that may be affected by an excessively thick aluminum nitride layer 200.

[0088] In some embodiments, after forming the aluminum nitride layer 200 on the substrate 100, the epitaxial growth method of the gallium oxide material may further include: performing a high-temperature annealing on the aluminum nitride layer 200. This can improve the interface quality between the aluminum nitride layer 200 and the substrate 100 and facilitate the subsequent epitaxial growth of high-quality films on the aluminum nitride layer 200.

[0089] In the actual preparation process, for example, high-temperature annealing can be performed in an inert gas (specifically, nitrogen) atmosphere. Specifically, the high-temperature annealing temperature can be 1600° C. to 1700° C., and the high-temperature annealing time can be 30 min to 60 min.

[0090] In some embodiments, please refer to Figure 4 Before epitaxially growing at least one composite interface layer on the aluminum nitride layer 200, the epitaxial growth method of the gallium oxide material may further include: introducing a second aluminum source, a gallium source, and a nitrogen source, and epitaxially growing Al on the aluminum nitride layer 200. x Ga 1-x N layers 300, where 0.2≤x≤0.5.

[0091] In the embodiment of the present application, Al is epitaxially grown on the aluminum nitride layer 200. x Ga 1-x N layer 300, Al x Ga 1-xThe lattice compatibility between the N layer 300 and the subsequently grown composite interface layer is higher, which is conducive to the high-quality growth of the subsequent composite interface layer, reduces defects such as dislocations and interface stress at the epitaxial layer interface, and thus can improve the quality and performance of the final gallium oxide epitaxial structure.

[0092] Specifically, during the epitaxial growth of Al x Ga 1-x During the process of growing the N layer 300, the temperature of epitaxial growth can be 1000°C to 1200°C. The pressure of epitaxial growth can be 50mbar to 100mbar. The flow rate of the second aluminum source can be greater than or equal to 50sccm and less than or equal to 350sccm, and can further be greater than or equal to 80sccm and less than or equal to 300sccm. The flow rate of the gallium source can be greater than or equal to 20sccm and less than or equal to 35sccm. The flow rate of the nitrogen source can be greater than or equal to 0.5slm and less than or equal to 2slm. Meeting at least one of the above conditions is conducive to the formation of Al with higher quality and appropriate Al composition. x Ga 1-x N-layer 300.

[0093] The second aluminum source may include, for example, trimethylaluminum (TMAl), the gallium source may include, for example, triethylgallium (TEGa) and / or trimethylgallium (TMGa), and the nitrogen source may include, for example, ammonia (NH 3 ).

[0094] In some embodiments, during epitaxial growth of Al x Ga 1-x During the process of forming the N layer 300, element doping can be performed to form n-type Al x Ga 1-x N layers.

[0095] For example, Al can be grown epitaxially. x Ga 1-x During the formation of the N layer 300, a silicon source (for example, silane) is introduced to form an n-type Al x Ga 1-x N layer, in which n-type Al x Ga 1-x In the N layer, the doping concentration of Si can be greater than or equal to 1E17 atoms / cm³.

[0096] In some embodiments, Al x Ga 1-x The thickness of the N layer 300 can be 5 nm to 30 nm, for example, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm or any value between any two of the above ranges. x Ga 1-xThe lattice adaptability between the N layer 300 and the composite interface layer is higher, and the Al x Ga 1-x An excessive thickness of the N layer 300 may affect carrier transport and other issues.

[0097] Next, please refer to Figure 5 , executing step S3, epitaxially growing at least one composite interface layer 400 on the aluminum nitride layer 200, the composite interface layer 400 including an aluminum oxide layer 401 and an indium oxide layer 402 stacked in sequence.

[0098] In the embodiment of the present application, at least one composite interface layer 400 epitaxially grown on the aluminum nitride layer 200 has the following functions: First, it blocks defect diffusion; the composite interface layer 400 can effectively prevent defects from the underlying heteroepitaxial layer from diffusing to the upper layers. In heteroepitaxial structures, lattice mismatch inevitably generates a large number of defects at the interface. The high interface traps caused by these defects act as recombination and generation centers, severely affecting carrier transport at the interface, shortening carrier lifetime and increasing the dark current of the photodetector device. The composite interface layer 400 not only blocks defect diffusion but also acts as a buffer under thermal stress, thereby improving interface quality and reducing dislocation density and thermal stress in subsequent epitaxially grown layers. Second, it forms low interface states; the composite interface layer 400 can form a low-state density interface at the interface, with a sufficiently low density of recombination and generation centers, reducing the interface state density and passivating the surface, thereby allowing electrons and holes to pass through with minimal loss. Third, it reduces phonon scattering. The composite interface layer 400 enhances interfacial atomic interactions, weakens phonon mismatch, and reduces phonon scattering, thereby enhancing device thermal transport, reducing thermal stress, and inhibiting the rapid proliferation of defects caused by thermal stress. Therefore, epitaxially growing at least one composite interface layer 400 can significantly improve the quality and performance of the gallium oxide epitaxial structure.

[0099] It should be noted that Figure 5 FIG. 4 shows that before the composite interface layer 400 is epitaxially grown, Al2O3 is epitaxially grown on the aluminum nitride layer 200. x Ga 1-x In the case of the N layer 300, the composite interface layer 400 is epitaxially grown on the Al x Ga 1-x The surface of the N layer 300. Of course, in some other embodiments of the present application, the composite interface layer 400 can also be epitaxially grown on the surface of the aluminum nitride layer 200.

[0100] In some embodiments, please refer to Figure 5Epitaxially growing the composite interface layer 400 may include: first, introducing a first aluminum source and a first oxygen source to epitaxially grow an aluminum oxide layer 401 ; then, introducing an indium source and a second oxygen source to epitaxially grow an indium oxide layer 402 on the aluminum oxide layer 401 .

[0101] Specifically, during the epitaxial growth of the aluminum oxide layer 401, the epitaxial growth temperature can be 600°C to 800°C, for example, 600°C, 700°C, 800°C, or any value between any two numerical ranges. The epitaxial growth pressure can be 20 mbar to 150 mbar, for example, 20 mbar, 50 mbar, 80 mbar, 110 mbar, 130 mbar, 150 mbar, or any value between any two numerical ranges. The flow rate of the first aluminum source can be greater than or equal to 5 sccm and less than or equal to 20 sccm, for example, 5 sccm, 10 sccm, 15 sccm, 20 sccm, or any value between any two numerical ranges. The flow rate of the first oxygen source can be greater than 0 sccm and less than or equal to 100 sccm, for example, 10 sccm, 20 sccm, 30 sccm, 40 sccm, 50 sccm, 60 sccm, 70 sccm, 80 sccm, 90 sccm, 100 sccm, or any value between any two numerical ranges. The epitaxial growth time can be 1s to 5s, for example, 1s, 2s, 3s, 4s, 5s, or any value between any two of the aforementioned ranges. Meeting at least one of the aforementioned conditions facilitates the formation of a high-quality aluminum oxide layer 401 with an appropriate thickness. For example, the first aluminum source can include trimethylaluminum (TMAl). The first oxygen source can include oxygen.

[0102] Specifically, during the epitaxial growth of the indium oxide layer 402, the epitaxial growth temperature can be 600° C. to 800° C., for example, 600° C., 700° C., 800° C., or any value between any two numerical ranges. The epitaxial growth pressure can be 20 mbar to 150 mbar, for example, 20 mbar, 50 mbar, 80 mbar, 110 mbar, 130 mbar, 150 mbar, or any value between any two numerical ranges. The flow rate of the indium source can be greater than or equal to 5 sccm and less than or equal to 20 sccm, for example, 5 sccm, 10 sccm, 15 sccm, 20 sccm, or any value between any two numerical ranges. The flow rate of the second oxygen source can be greater than 0 sccm and less than or equal to 100 sccm, for example, 10 sccm, 20 sccm, 30 sccm, 40 sccm, 50 sccm, 60 sccm, 70 sccm, 80 sccm, 90 sccm, 100 sccm, or any value between any two numerical ranges. The epitaxial growth time can be 1s to 10s, for example, 1s, 2s, 3s, 4s, 5s, 6s, 7s, 8s, 9s, 10s, or any value between any two of the aforementioned ranges. Meeting at least one of the aforementioned conditions facilitates the formation of a high-quality indium oxide layer 402 with an appropriate thickness. For example, the indium source can include trimethylindium (TMIn). The second oxygen source can include oxygen.

[0103] In the actual preparation process, the temperature and pressure of the epitaxial growth of the aluminum oxide layer 401 and the indium oxide layer 402 can be the same or different. The type and flow rate of the first oxygen source and the second oxygen source can be the same or different. In a specific embodiment, at least one of the temperature and pressure of the epitaxial growth of the aluminum oxide layer 401 and the indium oxide layer 402 is the same. In this way, when the epitaxial growth of the aluminum oxide layer 401 and the indium oxide layer 402 is switched, there is no need to adjust the temperature and / or pressure, which can simplify the process and improve efficiency. Furthermore, the type and flow rate of the first oxygen source and the second oxygen source are the same. In this way, when the epitaxial growth of the aluminum oxide layer 401 and the indium oxide layer 402 is switched, there is no need to switch and adjust the oxygen source, which can further simplify the process and improve efficiency. In a more specific embodiment, the temperature and pressure of the epitaxial growth of the aluminum oxide layer 401 and the indium oxide layer 402 are the same, and the type and flow rate of the first oxygen source and the second oxygen source are the same. In this way, when switching the epitaxial growth of the aluminum oxide layer 401 and the indium oxide layer 402 , it is only necessary to switch the aluminum source and the indium source, which simplifies the process, improves the epitaxial growth efficiency, and makes the quality of the epitaxial layer more uniform and stable.

[0104] It will be understood that the above embodiment only illustrates the steps of epitaxially growing a single composite interface layer 400. In some specific embodiments, the number of composite interface layer 400 layers can be greater than or equal to two. When epitaxially growing multiple composite interface layers 400, the steps of epitaxially growing the aluminum oxide layer 401 and the indium oxide layer 402 in the above embodiment can be performed alternately (which can be referred to as superlattice cyclic structure growth). For example, the aluminum oxide layer 401 can be epitaxially grown first, followed by epitaxially growing the indium oxide layer 402 on the aluminum oxide layer 401, then epitaxially growing the aluminum oxide layer 401 on the indium oxide layer 402, and then epitaxially growing the indium oxide layer 402 on the aluminum oxide layer 401 again, and so on, until the target number of composite interface layers 400 is epitaxially grown. In other words, in the resulting multiple composite interface layers 400, the aluminum oxide layers 401 and the indium oxide layers 402 are arranged alternately. Furthermore, when the number of composite interface layers 400 layers is greater than or equal to two, each composite interface layer 400 can be identical. In this way, not only the preparation process can be simplified, but also the quality and performance of the multi-layer composite interface layer 400 can be made more uniform and stable, thereby facilitating the improvement of the quality and performance of the ultimately prepared gallium oxide epitaxial structure.

[0105] When the thickness of the composite interface layer 400 is too thin, it may affect its role in blocking defect diffusion, forming low interface states, and reducing phonon scattering; when the thickness of the composite interface layer 400 is too thick, it will extend the carrier transmission path, and will affect thermal conductivity, which may generate thermal stress, and thermal stress will further lead to the proliferation of defects. Therefore, in some embodiments, the thickness of the composite interface layer 400 can be 1nm~5nm, for example, it can be 1nm, 2nm, 3nm, 4nm, 5nm or any value between any two of the above numerical ranges. Controlling the thickness of the composite interface layer 400 within the above range is conducive to fully exerting the role of the composite interface layer 400, better reducing the dislocation density and thermal stress in the subsequently prepared gallium oxide layer, and thus improving the quality and performance of the gallium oxide epitaxial structure.

[0106] In some embodiments, the thickness of the aluminum oxide layer 401 can be 0.5 nm to 3 nm, for example, 0.5 nm, 1 nm, 1.5 nm, 2 nm, 2.5 nm, 3 nm, or any value between any two of the above ranges. This helps to control the thickness of the composite interface layer 400 within a suitable range.

[0107] In some embodiments, the thickness of the indium oxide layer 402 may be 0.5 nm to 2 nm, for example, 0.5 nm, 1 nm, 1.5 nm, 2 nm, or any value between any two of the above ranges. This helps to control the thickness of the composite interface layer 400 within a suitable range.

[0108] In some embodiments, after epitaxially growing the composite interface layer 400 and before epitaxially growing the gallium oxide layer on the composite interface layer 400, the method for epitaxially growing the gallium oxide material may further include: thermally treating the composite interface layer 400. Thermal treatment (e.g., annealing) facilitates covalent bonding between atoms at the film interface, thereby enabling better interfacial heat transfer.

[0109] In the actual preparation process, the heat treatment temperature can be 1000°C to 1400°C, for example, 1000°C, 1100°C, 1200°C, 1300°C, 1400°C, or any value between any two of the above numerical ranges. The heat treatment time can be 10 minutes to 30 minutes, for example, 10 minutes, 20 minutes, 30 minutes, or any value between any two of the above numerical ranges. Controlling the heat treatment temperature and / or time within the above range is beneficial to improving the effect of the heat treatment, while effectively promoting covalent bonding between interface atoms and forming better interface heat transfer, while avoiding affecting the composite interface layer 400.

[0110] Furthermore, the heat treatment can be performed in an atmosphere containing hydrogen. This can improve the effect and efficiency of the heat treatment. For example, the heat treatment can be performed in a hydrogen atmosphere, where the hydrogen flow rate can be 80 slm to 120 slm.

[0111] Finally, please refer to Figure 6 , executing step S4 , epitaxially growing a gallium oxide layer 500 on the composite interface layer 400 .

[0112] In the embodiment of the present application, since at least one composite interface layer 400 has been epitaxially grown before the epitaxial growth of the gallium oxide layer 500, the composite interface layer 400 can block defect diffusion, form low interface states, and reduce phonon scattering, thereby facilitating better interface heat transfer and reducing thermal stress and the resulting defect proliferation. Therefore, the dislocation density and thermal stress in the gallium oxide layer 500 can be significantly reduced, thereby improving the quality and performance of the gallium oxide layer 500.

[0113] In an actual fabrication process, a second gallium source and a third oxygen source may be introduced to epitaxially grow the gallium oxide layer 500. Specifically, the gallium oxide layer 500 may be grown at a temperature of 800°C to 1200°C, a pressure of 50 mbar to 100 mbar, a second gallium source flow rate of 50 sccm to 500 sccm, and a third oxygen source flow rate of 50 sccm to 100 sccm.

[0114] In some embodiments, element doping may be performed during the epitaxial growth of the gallium oxide layer 500 to form a p-type or n-type gallium oxide layer 500 .

[0115] For example, a silicon source (for example, silane) may be introduced during the epitaxial growth of the gallium oxide layer 500 to form an n-type gallium oxide layer. In the n-type gallium oxide layer, the doping concentration of Si may be between 1E17 atoms / cm³ and 1E19 atoms / cm³.

[0116] In some embodiments, the thickness of the gallium oxide layer 500 may be 500 nm to 2500 nm, which can meet the requirements for manufacturing various types of gallium oxide devices.

[0117] The present application also provides a gallium oxide epitaxial structure, such as Figure 6 As shown, the gallium oxide epitaxial structure includes: a substrate 100; an aluminum nitride layer 200 located on the substrate 100; at least one composite interface layer 400 located on the aluminum nitride layer 200, the composite interface layer 400 including an aluminum oxide layer 401 and an indium oxide layer 402 stacked in sequence; and a gallium oxide layer 500 located on the composite interface layer 400.

[0118] In the embodiment of the present application, an aluminum nitride layer 200 is disposed between the substrate 100 and the composite interface layer 400. The aluminum nitride layer 200 can improve the lattice mismatch between the substrate 100 and the composite interface layer 400, reducing interface defects and interface stress. In the actual preparation process, this is conducive to the growth of a high-quality composite interface layer 400. At least one composite interface layer 400 is disposed between the aluminum nitride layer 200 and the gallium oxide layer 500. The composite interface layer 400 is composed of a sequentially stacked aluminum oxide layer 401 and an indium oxide layer 402. The composite interface layer 400 has the functions of blocking defect diffusion, forming low interface states, and reducing phonon scattering. This facilitates better interfacial heat transfer, reduces the generation of thermal stress and the proliferation of defects caused by thermal stress, thereby reducing the dislocation density and thermal stress in the gallium oxide layer 500, thereby improving the quality and performance of the gallium oxide epitaxial structure. When the resulting gallium oxide epitaxial structure is applied to a photodetector device, the performance and reliability of the device can be significantly improved.

[0119] In some embodiments, the thickness of the aluminum nitride layer 200 can be 5 nm to 50 nm, for example, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, or any value between any two of the above ranges. This not only effectively improves the lattice mismatch and interface stress between the substrate 100 and the composite interface layer 400, thereby improving the quality of the composite interface layer 400, but also avoids problems such as carrier transport that may be affected by an overly thick aluminum nitride layer 200.

[0120] In the embodiment of the present application, at least one composite interface layer 400 has the following functions: First, it blocks the diffusion of defects; the composite interface layer 400 can effectively prevent defects from the underlying heteroepitaxial layer from diffusing to the upper layer. In heteroepitaxial growth, due to lattice mismatch, a large number of defects are inevitably generated at the interface. The high interface traps caused by these defects act as recombination centers and generation centers, which can seriously affect carrier transport at the interface, shorten carrier lifetime, and increase the dark current of the photodetector device. The composite interface layer 400 not only blocks the diffusion of defects, but also acts as a buffer under thermal stress, thereby improving the interface quality and reducing the dislocation density and thermal stress in the subsequent epitaxial growth film layer. Second, it forms low interface states; the composite interface layer 400 can form a low state density interface at the interface, with a sufficiently low density of recombination centers and generation centers on the interface, reducing the interface state density and passivating the surface, thereby allowing electrons and holes to pass through with minimal loss. Third, it reduces phonon scattering. The composite interface layer 400 enhances interfacial atomic interactions, weakens phonon mismatch, and reduces phonon scattering, thereby enhancing device thermal transport, reducing thermal stress, and inhibiting the rapid proliferation of defects caused by thermal stress. Therefore, epitaxially growing at least one composite interface layer 400 can significantly improve the quality and performance of the gallium oxide epitaxial structure.

[0121] I understand. Figure 6 The figure only shows, by way of example, the case where a single composite interface layer 400 is included in the gallium oxide epitaxial structure. In some specific embodiments, the number of composite interface layers 400 may be greater than or equal to 2. In the multi-layer composite interface layer 400, the aluminum oxide layer 401 and the indium oxide layer 402 are alternately arranged in sequence. Furthermore, when the number of composite interface layers 400 is greater than or equal to 2, each composite interface layer 400 may be identical. In this way, not only can the actual preparation process be simplified, but the quality and performance of the multi-layer composite interface layer 400 can also be made more uniform and stable, thereby facilitating the improvement of the quality and performance of the gallium oxide epitaxial structure.

[0122] In some embodiments, the thickness of the composite interface layer 400 can be 1 nm to 5 nm, for example, 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, or any value between any two of the aforementioned ranges. Controlling the thickness of the composite interface layer 400 within the aforementioned range facilitates fully utilizing the composite interface layer 400, effectively reducing dislocation density and thermal stress in the gallium oxide layer 500, and thereby improving the quality and performance of the gallium oxide epitaxial structure.

[0123] In some embodiments, the thickness of the aluminum oxide layer 401 can be 0.5 nm to 3 nm, for example, 0.5 nm, 1 nm, 1.5 nm, 2 nm, 2.5 nm, 3 nm, or any value between any two of the above ranges. This helps to control the thickness of the composite interface layer 400 within a suitable range.

[0124] In some embodiments, the thickness of the indium oxide layer 402 may be 0.5 nm to 2 nm, for example, 0.5 nm, 1 nm, 1.5 nm, 2 nm, or any value between any two of the above ranges. This helps to control the thickness of the composite interface layer 400 within a suitable range.

[0125] In some embodiments, the thickness of the gallium oxide layer 500 may be 500 nm to 2500 nm, which can meet the requirements for manufacturing various types of gallium oxide devices.

[0126] In the embodiments of the present application, the conductivity type of the gallium oxide layer 500 can be p-type or n-type. In some specific embodiments, the conductivity type of the gallium oxide layer 500 is n-type. For example, the n-type gallium oxide layer can contain the doping element Si, wherein the Si doping concentration can be between 1E17 atoms / cm³ and 1E19 atoms / cm³.

[0127] In some embodiments, please refer to Figure 6 The gallium oxide epitaxial structure may further include: an Al2O3 layer located between the aluminum nitride layer 200 and the composite interface layer 400; x Ga 1-x N layers 300, where 0.2≤x≤0.5.

[0128] In the embodiment of the present application, an Al2O3 layer is provided between the aluminum nitride layer 200 and the composite interface layer 400. x Ga 1-x N layer 300, due to Al x Ga 1-x The lattice fit between the N layer 300 and the composite interface layer 400 is higher, which can reduce defects such as dislocations and interface stress at the epitaxial layer interface, thereby improving the quality of the composite interface layer 400 and the overall quality and performance of the gallium oxide epitaxial structure.

[0129] Al x Ga 1-x The conductivity type of the N layer 300 may be n-type. For example, n-type Al x Ga 1-x The N layer may include a doping element Si, wherein the doping concentration of Si may be greater than or equal to 1E17 atoms / cm³.

[0130] In some embodiments, Al x Ga 1-x The thickness of the N layer 300 can be 5 nm to 30 nm, for example, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm or any value between any two of the above ranges.x Ga 1-x The lattice matching between the N layer 300 and the composite interface layer 400 is higher, and the Al x Ga 1-x An excessive thickness of the N layer 300 may affect carrier transport and other issues.

[0131] An embodiment of the present application further provides an ultraviolet detection device, comprising a gallium oxide epitaxial structure produced by the epitaxial growth method of the gallium oxide material described in any of the aforementioned embodiments, or comprising the gallium oxide epitaxial structure described in any of the aforementioned embodiments.

[0132] The ultraviolet detection device herein may be, for example, a solar-blind ultraviolet detection device. In ultraviolet detection devices, the gallium oxide layer is key to their performance. It is understood that, because the gallium oxide layer in the gallium oxide epitaxial structure described in any of the aforementioned embodiments has a low dislocation density and thermal stress, the high-quality gallium oxide layer not only provides excellent ultraviolet light absorption characteristics, but also has high carrier mobility and good electrical stability. Therefore, the performance and reliability of the ultraviolet detection device can be significantly improved.

[0133] In practical applications, the gallium oxide epitaxial structure described in any of the foregoing embodiments can be directly used to prepare ultraviolet detection devices; or the gallium oxide epitaxial structure described in any of the foregoing embodiments can be processed and then used to prepare ultraviolet detection devices, such as by thinning or removing the substrate in the gallium oxide epitaxial structure.

[0134] For example, an electrode may be deposited on the gallium oxide layer of the gallium oxide epitaxial structure described in any of the above embodiments to produce an ultraviolet detection device, wherein the material of the electrode may include titanium and / or gold, for example.

[0135] The ultraviolet detection device in the embodiment of the present application is prepared by using the gallium oxide epitaxial structure prepared by the epitaxial growth method of the gallium oxide material described in any of the aforementioned embodiments, or the gallium oxide epitaxial structure described in any of the aforementioned embodiments.

[0136] The technical solution of the present application is further described below with reference to embodiments and comparative examples. Example 1

[0137] The epitaxial growth method of the gallium oxide material in this embodiment includes:

[0138] Step S101: using a physical vapor deposition device, at a temperature of 650° C., a power of 100 W, an argon flow rate of 50 sccm, a nitrogen flow rate of 120 sccm, and an oxygen flow rate of 0.5 sccm, AlN material is magnetron sputtered on a sapphire substrate to form an aluminum nitride layer with a thickness of 15 nm;

[0139] Step S102: placing the structure obtained in step S101 in a box-type annealing furnace and performing high-temperature annealing in a nitrogen atmosphere, wherein the high-temperature annealing temperature is 1680° C. and the high-temperature annealing time is 60 minutes;

[0140] Step S103: Under the conditions of temperature of 1150°C, pressure of 100 mbar, flow rate of TMAl (second aluminum source) of 90 sccm, flow rate of TMGa (gallium source) of 25 sccm, and flow rate of NH3 (nitrogen source) of 2 slm, an Al2O3 layer with a thickness of 20 nm is epitaxially grown on the aluminum nitride layer after high temperature annealing. x Ga 1-x N layer (0.2≤x≤0.5); during the epitaxial growth process, silane (silicon source) is introduced to make the growing Al x Ga 1-x The doping concentration of Si in the N layer is 5E17 atoms / cm³;

[0141] Step S104: First, under the conditions of temperature of 1000°C, pressure of 100 mbar, flow rate of TMAl (first aluminum source) of 15 sccm, and flow rate of oxygen (first oxygen source) of 50 sccm, x Ga 1-x A 2nm thick aluminum oxide layer was epitaxially grown on the N layer. A 1nm thick indium oxide layer was then epitaxially grown on the aluminum oxide layer at a temperature of 750°C, a pressure of 100mbar, a TMIn (indium source) flow rate of 15sccm, and an oxygen (secondary oxygen source) flow rate of 50sccm. The aluminum oxide layer and the indium oxide layer together formed a composite interface layer.

[0142] Step S105: annealing (heat treatment) the structure obtained in step S104 in a hydrogen atmosphere, wherein the hydrogen flow rate is 100 slm, the annealing temperature is 1200° C., and the annealing time is 20 min;

[0143] Step S106: epitaxially growing a 1500 nm thick gallium oxide layer on the annealed composite interface layer at a temperature of 1000°C, a pressure of 100 mbar, a TEGa (second gallium source) flow rate of 300 sccm, and an oxygen (third oxygen source) flow rate of 75 sccm. During the epitaxial growth process, silane (silicon source) is introduced to ensure that the Si doping concentration in the grown gallium oxide layer is 1E18 atoms / cm³.

[0144] Comparative Example 1

[0145] The epitaxial growth method of the gallium oxide material in this comparative example includes:

[0146] Step S201: using a physical vapor deposition device to perform magnetron sputtering, under the conditions of a temperature of 650° C., a power of 100 W, an argon flow rate of 50 sccm, a nitrogen flow rate of 120 sccm, and an oxygen flow rate of 0.5 sccm, AlN material is sputtered on the sapphire substrate to form an aluminum nitride layer with a thickness of 15 nm;

[0147] Step S202: placing the structure obtained in step S201 in a box-type annealing furnace and performing high-temperature annealing in a nitrogen atmosphere, wherein the high-temperature annealing temperature is 1680° C. and the high-temperature annealing time is 60 minutes;

[0148] Step S203: epitaxially grow Al2O3 with a thickness of 20 nm on the aluminum nitride layer after high temperature annealing under the conditions of temperature 1150°C, pressure 100 mbar, flow rate of TMAl 90 sccm, flow rate of TMGa 25 sccm, and flow rate of NH3 2 slm. x Ga 1-x N layer (0.2≤x≤0.5); during the epitaxial growth process, silane is introduced to make the growing Al x Ga 1-x The doping concentration of Si in the N layer is 5E17 atoms / cm³;

[0149] Step S204: Under the conditions of temperature 1000°C, pressure 100mbar, TEGa flow rate 300sccm, oxygen flow rate 75sccm, x Ga 1-x A 1500nm thick gallium oxide layer is epitaxially grown on the N layer. During the epitaxial growth process, silane is introduced to ensure that the Si doping concentration in the growing gallium oxide layer is 1E18 atoms / cm³.

[0150] The main difference between Comparative Example 1 and Example 1 is that there is no Al x Ga 1-x Instead of epitaxially growing the composite interface layer on the N layer, it is directly grown on the Al x Ga 1-x A gallium oxide layer is epitaxially grown on the N layer.

[0151] An electrode was formed on the gallium oxide layer of the gallium oxide epitaxial structure obtained in Example 1 and Comparative Example 1 to obtain an MSM (Metal-Semiconductor-Metal) solar-blind ultraviolet photodetector. The transmittance, dark current, and response speed of the gallium oxide layer were tested. The test results are shown in Table 1.

[0152] The transmittance was measured using an ultraviolet-visible spectrophotometer UV-VIS.

[0153] The dark current test method is: under 254nm ultraviolet light irradiation, the current and voltage of the MSM day-blind ultraviolet photodetector are sampled to obtain an IV (current-voltage) curve. The current with light source irradiation is called photocurrent, and the current collected without light source irradiation is dark current. The dark current in the present invention corresponds to the current at a voltage of 5V.

[0154] The response speed can be characterized by the response time, which includes the rise time t r and fall time t f Among them, t r t is the time taken for the dark current to rise to the highest stable value of the photocurrent from no light signal input to light signal input. Specifically, it can be the time taken for the current of the device to rise from 10% of the maximum photocurrent value to 90% of the maximum photocurrent value. f t is the time required for the device current to drop from photocurrent to dark current after the light signal is removed from the onset of illumination. Specifically, it can be the time required for the device current to drop from 90% of the maximum photocurrent to 10% of the maximum photocurrent. r and t f The smaller it is, the faster the device responds to changes in optical signals.

[0155] Table 1

[0156]

[0157] It can be seen from the data in Table 1 that, compared with Comparative Example 1, the transmittance of the gallium oxide layer in the gallium oxide epitaxial structure prepared in Example 1 to ultraviolet light is significantly improved, and the device has a lower dark current and a faster response speed. This shows that in the present application, before epitaxially growing the gallium oxide layer, at least one composite interface layer is epitaxially grown. The composite interface layer is used to block defect diffusion, form low interface states, and reduce phonon scattering, which is conducive to forming better interface heat transfer in the gallium oxide epitaxial structure, reducing the generation of thermal stress and the resulting defect proliferation. Therefore, it is possible to reduce the dislocation density and thermal stress in the gallium oxide layer, thereby significantly improving the quality and performance of the gallium oxide layer, and significantly improving the performance and reliability of the device prepared using the gallium oxide epitaxial structure.

[0158] Figure 7 and Figure 8 Atomic force microscope (AFM) images of the surface of the gallium oxide epitaxial structure prepared in Example 1 and Comparative Example 1, respectively.

[0159] Depend on Figure 7 and Figure 8From the comparison, it can be seen that the surface of the gallium oxide epitaxial structure obtained in Example 1 (which can also be considered as the surface of the gallium oxide layer) is significantly smoother than the surface of the gallium oxide epitaxial structure obtained in Comparative Example 1 (which can also be considered as the surface of the gallium oxide layer). The AFM test results also show that the surface roughness of the gallium oxide epitaxial structure obtained in Example 1 is 0.61nm, and the surface roughness of the gallium oxide epitaxial structure obtained in Comparative Example 1 is 3.46nm. This further shows that in the present application, since the composite interface layer has the functions of blocking defect diffusion, forming low interface states, and reducing phonon scattering, it can effectively block the diffusion of defects such as dislocations to the upper epitaxial layer, improve the thermal management of the device, and make the dislocation density and thermal stress in the gallium oxide layer lower. Therefore, the gallium oxide layer has a relatively flat surface and higher quality. In Comparative Example 1, since no composite interface layer is formed, defects such as dislocations easily diffuse to the upper epitaxial layer, interface heat transfer cannot be improved, and thermal stress is easily generated. Thermal stress further leads to rapid proliferation of defects, resulting in high dislocation density and thermal stress in the gallium oxide layer, which in turn causes the surface of the gallium oxide layer to have a significantly uneven morphology, resulting in poor quality of the gallium oxide layer, which in turn affects the performance and reliability of the corresponding device.

[0160] It should be noted that the gallium oxide epitaxial structure embodiments, the epitaxial growth method embodiments of gallium oxide materials, and the ultraviolet detection device embodiments provided in this application are based on the same concept; the various technical features in the technical solutions described in each embodiment can be arbitrarily combined without conflict. However, it should be further noted that the gallium oxide epitaxial structure provided in the embodiments of this application, with its various technical features in combination, can already solve the technical problem to be solved by this application; therefore, the gallium oxide epitaxial structure provided in the embodiments of this application is not limited by the epitaxial growth method of the gallium oxide material provided in the embodiments of this application. Any epitaxial structure grown by any epitaxial growth method capable of forming the gallium oxide epitaxial structure provided in the embodiments of this application is within the scope of protection of this application.

[0161] It should be understood that the above embodiments are exemplary and are not intended to include all possible implementation methods. Various modifications and changes may be made to the above embodiments without departing from the scope of the present disclosure. Similarly, the various technical features of the above embodiments may be arbitrarily combined to form other embodiments of the present application that may not be explicitly described. Therefore, the above embodiments merely express several implementation methods of the present application and do not limit the scope of protection of the patent application.

Claims

1. A method for epitaxial growth of gallium oxide material, characterized in that: The method comprises: providing a substrate; forming an aluminum nitride layer on the substrate; Epitaxially growing at least one composite interface layer on the aluminum nitride layer, the composite interface layer comprising an aluminum oxide layer and an indium oxide layer stacked in sequence; the composite interface layer has a thickness of 1 nm to 5 nm; the aluminum oxide layer has a thickness of 0.5 nm to 3 nm; and the indium oxide layer has a thickness of 0.5 nm to 2 nm; Epitaxially growing the composite interface layer includes: first, introducing a first aluminum source and a first oxygen source, and epitaxially growing the aluminum oxide layer under the conditions of a temperature of 600° C. to 800° C., a pressure of 20 mbar to 150 mbar, a flow rate of the first aluminum source greater than or equal to 5 sccm and less than or equal to 20 sccm, and a flow rate of the first oxygen source greater than 0 sccm and less than or equal to 100 sccm; then, introducing an indium source and a second oxygen source, and epitaxially growing the indium oxide layer on the aluminum oxide under the conditions of a temperature of 600° C. to 800° C., a pressure of 20 mbar to 150 mbar, a flow rate of the indium source greater than or equal to 5 sccm and less than or equal to 20 sccm, and a flow rate of the second oxygen source greater than 0 sccm and less than or equal to 100 sccm; A gallium oxide layer is epitaxially grown on the composite interface layer.

2. The epitaxial growth method of gallium oxide material according to claim 1, characterized in that: The time for epitaxially growing the aluminum oxide layer is 1s to 5s.

3. The epitaxial growth method of gallium oxide material according to claim 2, characterized in that: The time for epitaxially growing the indium oxide layer is 1s to 10s.

4. The epitaxial growth method of gallium oxide material according to claim 1, characterized in that: Before epitaxially growing at least one composite interface layer on the aluminum nitride layer, the method further comprises: A second aluminum source, a gallium source, and a nitrogen source are introduced to epitaxially grow Al on the aluminum nitride layer. x Ga 1-x N layer, wherein 0.2≤x≤0.5; epitaxially growing the Al x Ga 1-x N layers, meeting at least one of the following conditions: (1) The temperature of epitaxial growth is 1000℃~1200℃; (2) The pressure of epitaxial growth is 50mbar~100mbar; (3) The flow rate of the second aluminum source is greater than or equal to 50 sccm and less than or equal to 300 sccm; (4) The flow rate of the gallium source is greater than or equal to 20 sccm and less than or equal to 100 sccm; (5) The flow rate of the nitrogen source is greater than or equal to 0.5 slm and less than or equal to 2 slm; (6) Al x Ga 1-x The thickness of the N layer is 5nm~30nm.

5. The epitaxial growth method of gallium oxide material according to claim 1, characterized in that: Before epitaxially growing the gallium oxide layer on the composite interface layer, the method further includes: The composite interface layer is subjected to a heat treatment, wherein the heat treatment satisfies at least one of the following conditions: (1) The temperature of the heat treatment is 1000°C to 1400°C; (2) The heat treatment time is 10 min to 30 min; (3) The heat treatment is performed in an atmosphere including hydrogen.

6. The epitaxial growth method of gallium oxide material according to any one of claims 1 to 5, characterized in that: The method satisfies at least one of the following conditions: (1) The thickness of the aluminum nitride layer is 5 nm to 50 nm; (2) The thickness of the gallium oxide layer is 500 nm to 2500 nm; (3) The number of the composite interface layers is greater than or equal to 2, and the composite interface layers are identical.

7. A gallium oxide epitaxial structure, characterized in that: include: substrate; an aluminum nitride layer on the substrate; At least one composite interface layer located on the aluminum nitride layer, the composite interface layer comprising an aluminum oxide layer and an indium oxide layer stacked in sequence; the composite interface layer has a thickness of 1 nm to 5 nm; the aluminum oxide layer has a thickness of 0.5 nm to 3 nm; and the indium oxide layer has a thickness of 0.5 nm to 2 nm; A gallium oxide layer is located on the composite interface layer.

8. The gallium oxide epitaxial structure according to claim 7, characterized in that: The gallium oxide epitaxial structure satisfies at least one of the following conditions: (1) The thickness of the aluminum nitride layer is 5 nm to 50 nm; (2) The thickness of the gallium oxide layer is 500 nm to 2500 nm; (3) The number of the composite interface layers is greater than or equal to 2, and the composite interface layers are identical.

9. The gallium oxide epitaxial structure according to claim 7 or 8, characterized in that: The gallium oxide epitaxial structure further includes: an Al2O3 layer located between the aluminum nitride layer and the composite interface layer. x Ga 1-x N layers, where 0.2≤x≤0.

5.

10. An ultraviolet detection device, characterized in that: A gallium oxide epitaxial structure obtained by the epitaxial growth method of the gallium oxide material according to any one of claims 1 to 6, or a gallium oxide epitaxial structure according to any one of claims 7 to 9.

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