A two-dimensional electron gas heterojunction structure based on nitride material and nitrogen-terminated diamond and a preparation method thereof

Abstract

The application discloses a two-dimensional electron gas heterojunction structure based on a nitride material and a nitrogen-terminated diamond and a preparation method thereof, and comprises the following steps: step one, obtaining a diamond layer; step two, performing nitrogen termination treatment on the surface of the diamond layer to form a nitrogen-terminated surface; and step three, epitaxially growing single-crystal aluminum nitride or boron aluminum nitride with an Al-face polar wurtzite structure on the nitrogen-terminated surface to form an aluminum nitride epitaxial layer or a boron aluminum nitride epitaxial layer, so as to form a two-dimensional electron gas heterojunction structure based on a nitrogen-terminated diamond. The application can form high-quality aluminum nitride / nitrogen-terminated diamond heterojunctions or boron aluminum nitride / nitrogen-terminated diamond heterojunctions, can generate a two-dimensional electron gas with high electron mobility and high carrier concentration, and can significantly improve the application potential of the heterojunction-based device in high voltage, high frequency and high power.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of semiconductor process, and particularly relates to a two-dimensional electron gas heterojunction structure based on nitride material and nitrogen terminal diamond and a preparation method thereof. BACKGROUND

[0002] Diamond is a new generation of ultra-wide bandgap semiconductor material, which has the advantages of large bandgap, high carrier mobility, high thermal conductivity, etc., and has great advantages and potential in the application of new generation of high-voltage, high-power, high-temperature-resistant and radiation-resistant electronic devices. The p / n type electric conduction with simple preparation process and excellent performance is crucial to the application potential of diamond material. Like most semiconductor materials currently used, diamond must be doped in some form to introduce a high enough density of mobile carriers. However, the strong covalent bond and close-packed crystal structure of diamond are the source of its excellent material properties, but also make it very difficult to activate the body doping at room temperature. As the most successful acceptor impurity in diamond p-type doping, boron still has an activation energy as high as 0.37eV, resulting in a carrier ionization rate at room temperature of only a few tenths of a percent of the boron doping concentration. In addition, as the boron dopant concentration increases, the hole mobility of the doped diamond will decrease significantly, and heavy boron doping will also have a negative impact on the diamond crystal quality, thereby affecting the device performance. As for n-type doped diamond, the most commonly used donor impurity is phosphorus, and its activation energy is as high as 0.6eV, and the carrier ionization rate at room temperature is even lower. When the doping concentration of phosphorus reaches 6.8×1018cm-3, the activated electron concentration at room temperature is only 10 16 cm -3 . 11 cm -3 The difficulty of doping diamond semiconductor seriously limits its development and application in the field of electronic devices.

[0003] In recent years, it has been widely observed experimentally that hydrogen-terminated diamond surfaces can exhibit p-type conductivity at room temperature. By treating diamond in a hydrogen plasma, a hydrogen-terminated diamond surface covered with C-H bonds is formed, and after being exposed to air, a layer of two-dimensional hole gas (2DHG) accumulation layer can be formed about 10nm below the diamond surface due to the transfer doping effect. The concentration of 2DHG is in the order of 10 12 -10 14 cm -2 , and the mobility is in the range of dozens to 200cm 2 / Vs. Field effect transistors (FETs) based on hydrogen-terminated diamond p-type conduction have become the mainstream of diamond electronic device research, and have achieved a maximum output current density of 1.3A / mm, a cutoff frequency of 70GHz, a breakdown voltage of 2608V, and an output power density of 4.2W / mm at 2GHz.

[0004] Given the extreme difficulty in ionizing n-type bulk doping of diamond, while significant progress has been made in p-type surface conductivity, achieving two-dimensional electron gas (2DEG) surface conductivity based on diamond heterojunctions could provide a new approach for diamond n-type conductivity. The two-dimensional electron gas at the diamond-based heterojunction interface can be provided by electrons donated by donor impurities in the barrier layer, or by principles similar to nitride heterojunctions, namely barrier layer polarization and surface state ionization. This overcomes the key challenge of extremely low ionization rates in n-type bulk doping of diamond, making it difficult to achieve high conductivity at room temperature, and significantly increases the current density of diamond devices. First-principles studies have shown that by inducing channel charge through gate voltage, diamond / cubic boron nitride (c-BN) heterojunction interfaces can achieve current densities as high as 5 × 10⁻⁶. 12 cm -2 Two-dimensional electron gas can be used to fabricate high-performance high-electron-mobility transistors (HEMTs).

[0005] However, in practical device fabrication, there are still some key issues to be addressed regarding diamond-based heterojunctions based on the n-type conductivity of two-dimensional electron gas. If an ultrawide bandgap (5.5 eV) diamond material is used as the channel layer to accommodate the two-dimensional electron gas, and another material is used as the barrier layer, then the bandgap of the barrier layer should be greater than that of diamond. Only ultrawide bandgap semiconductor materials such as boron aluminum nitride (AlN) and boron nitride (BN) meet this requirement.

[0006] The two materials forming the heterojunction also need to form a band structure suitable for the transport of two-dimensional electron gas in diamond, that is, to form a potential well on one side of diamond and a barrier on the other side of the barrier layer; when the barrier layer is doped and ionized to provide electrons to form a two-dimensional electron gas, the height of the barrier should be greater than the ionization energy of the donor impurities in the barrier layer, so that the donor impurities can be ionized.

[0007] Aluminum nitride (ANT) belongs to the III-V group of compounds and is a hexagonal wurtzite-structured compound semiconductor with a large band gap (6.2 eV), high breakdown field strength (14 MV / cm), and high thermal conductivity (3.0 W / cm·K), making it particularly suitable for high-temperature, high-power electronic devices. Single-crystal ANT has lattice constants similar to diamond (a = 0.3114 nm, c = 0.14947 nm), and its coefficient of thermal expansion (4.5 ppm / K) is very close to that of single-crystal diamond (4.2 ppm / K). Theoretically, it can form high-quality ANT / diamond heterojunctions with diamond.

[0008] However, due to the difference in crystal structure between aluminum nitride (hexagonal) and diamond (cubic), and the resulting lattice constants, conventional processes (such as magnetron sputtering) for depositing aluminum nitride on diamond often result in polycrystalline aluminum nitride due to severe lattice mismatch. This leads to dangling bonds, introducing numerous interface states and making it difficult to obtain a high-quality heterojunction interface. Even if a two-dimensional electron gas is generated, achieving high carrier concentration and mobility is challenging, thus affecting device performance. The heterojunction interface formed by conventional hydrogen-terminated diamond and aluminum nitride is not suitable for forming a two-dimensional electron gas on the diamond side. Therefore, how to fabricate a high-quality heterojunction structure with two-dimensional electron gas n-type conductivity on a diamond substrate remains a problem to be solved. Summary of the Invention

[0009] To address the aforementioned problems in the prior art, this invention provides a two-dimensional electron gas heterojunction structure based on nitride materials and nitrogen-terminated diamond, and its preparation method. The technical problem to be solved by this invention is achieved through the following technical solution:

[0010] A first aspect of this invention provides a method for preparing a two-dimensional electron gas heterojunction structure based on nitride materials and nitrogen-terminated diamond, comprising the following steps:

[0011] Step 1: Obtain the diamond layer;

[0012] The diamond layer is made of single-crystal diamond material or polycrystalline diamond material;

[0013] Step 2: Perform nitrogen termination treatment on the surface of the diamond layer to form a nitrogen-terminated surface;

[0014] Step 3: Epitaxially grow single-crystal aluminum nitride or boron aluminum nitride with an Al-plane polar fibrous wurtzite structure on the nitrogen-terminated surface to form an aluminum nitride epitaxial layer or a boron aluminum nitride epitaxial layer, thereby forming a two-dimensional electron gas heterojunction structure based on nitrogen-terminated diamond; wherein, during the epitaxial growth of boron aluminum nitride, the boron and aluminum composition of the boron aluminum nitride epitaxial layer is generated by controlling the ratio of boron source to aluminum source during the growth process of boron aluminum nitride.

[0015] When the diamond is a single-crystal diamond material, the crystal orientation is (111) or... When the crystal orientation of the diamond layer is (111), the crystal orientation of the aluminum nitride epitaxial layer is (0001); when the crystal orientation of the diamond layer is (01_1), the crystal orientation of the aluminum nitride epitaxial layer is...

[0016] When the diamond layer is a polycrystalline diamond material, donor impurity doping is performed during the epitaxial growth of single-crystal aluminum nitride or boron aluminum nitride.

[0017] In one embodiment of the present invention, the nitrogen terminal treatment in step two adopts the MBE process, RIE process or ICP process.

[0018] In one embodiment of the present invention, the thickness of the aluminum nitride epitaxial layer or the boron aluminum nitride epitaxial layer is 1 to 30 nm.

[0019] The second aspect of this invention provides a two-dimensional electron gas heterojunction structure based on nitride materials and nitrogen-terminated diamond, which is prepared by the preparation method described in the first aspect of this invention, and includes: a diamond layer, a nitrogen-terminated surface located on the diamond layer, and an aluminum nitride epitaxial layer or a boron-aluminum-nitrogen epitaxial layer with an Al-plane polar fibrous wurtzite structure located on the nitrogen-terminated surface.

[0020] The diamond layer is made of single-crystal diamond material or polycrystalline diamond material;

[0021] When the diamond is a single-crystal diamond material, the crystal orientation is (111) or... When the crystal orientation of the diamond layer is (111), the crystal orientation of the aluminum nitride epitaxial layer is (0001); when the crystal orientation of the diamond layer is... At that time, the crystal orientation of the aluminum nitride epitaxial layer is

[0022] When the diamond layer is a polycrystalline diamond material, the aluminum nitride epitaxial layer or the boron aluminum nitride epitaxial layer is an epitaxial layer with donor doping.

[0023] The beneficial effects of this invention are:

[0024] 1. By using interface control methods to perform nitrogen termination treatment on the surface of diamond layers, the surface states of diamond can be reduced and the surface energy state of diamond can be changed. This is conducive to the atomic bonding between diamond and aluminum nitride or boron aluminum nitrogen materials, and increases the nucleation density of boron aluminum nitrogen epitaxial layers on the diamond surface, so as to form high-quality diamond novel wide bandgap heterojunctions.

[0025] 2. Nitrogen-terminated treatment alters the electron affinity of the diamond surface, thereby modulating its band structure. This creates an electron potential well within the band structure of the heterojunction formed with aluminum nitride or boron-aluminum-nitrogen. First-principles calculations and X-ray photoelectron spectroscopy (XPS) band structure show that the aluminum nitride conduction band is 0.54 eV higher than that of nitrogen-terminated diamond in the aluminum nitride / nitrogen-terminated diamond heterojunction. This allows for the creation of an electron potential well that facilitates 2DEG transport.

[0026] 3. By selecting a single-crystal diamond layer, 2DEG can be formed on the diamond side of the heterojunction interface through the polarization effect between the diamond layer and the Al-faced polar fibrous wurtzite epitaxial layer of aluminum nitride or boron aluminum nitride. By selecting a polycrystalline diamond layer, 2DEG can be formed on the diamond side of the heterojunction interface by utilizing the charge transfer effect between the doped aluminum nitride or boron aluminum nitride epitaxial layer and diamond. Combined with the above-mentioned terminal processing technology, the band structure of the heterojunction interface can be controlled to form an electron potential well that is conducive to 2DEG transport.

[0027] 4. By using polar materials such as aluminum nitride or boron aluminum nitride to achieve heterostructures, and based on the band-order control achieved by end-processing, 2DEGs with high electron mobility and high carrier concentration can be generated in aluminum nitride / diamond or boron aluminum nitride / diamond heterojunctions through the polarization effect of the materials.

[0028] 5. As ultrawide bandgap semiconductor materials with high breakdown field strength and high thermal conductivity, aluminum nitride and diamond can significantly enhance the application potential of heterojunction-based devices in high voltage, high frequency and high power applications compared with traditional heterojunction materials.

[0029] 6. By using a boron-aluminum-nitrogen epitaxial layer, the lattice constant can be controlled by adjusting the composition of the ternary compound, further reducing its lattice mismatch rate with diamond, effectively alleviating the lattice distortion of boron-aluminum-nitrogen during the epitaxial process, reducing the surface states and dangling bonds at the heterojunction interface, and improving the quality of the boron-aluminum-nitrogen / nitrogen-terminated diamond heterojunction.

[0030] 7. A heterostructure is achieved by using the ternary compound boron-aluminum-nitrogen with variable composition. By changing the composition of the ternary compound, the band structure of the material is controlled. Combined with the terminal processing technology, the band level of the heterojunction interface is further controlled to achieve an electron potential well that is conducive to 2DEG transport.

[0031] 8. Boron aluminum nitrogen, as a novel nitride alloy material, theoretically possesses characteristics such as high breakdown field strength and high polarization intensity. Combining it with diamond, an ultra-wide bandgap semiconductor material, to form a novel semiconductor heterojunction material device broadens the application fields and development prospects of semiconductor heterojunction devices.

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0033] Figure 1 This is a schematic flowchart of a method for preparing a two-dimensional electron gas heterojunction structure based on nitride materials and nitrogen-terminated diamond, provided in an embodiment of the present invention.

[0034] Figure 2 This is a schematic diagram of a two-dimensional electron gas heterojunction structure based on nitride materials and nitrogen-terminated diamond provided in an embodiment of the present invention. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0036] Example 1

[0037] like Figure 1 and Figure 2 As shown, a method for preparing a two-dimensional electron gas heterojunction structure based on nitride materials and nitrogen-terminated diamond includes the following steps:

[0038] Step 101: Obtain diamond layer 10; wherein, diamond layer 10 is a single-crystal diamond material or a polycrystalline diamond material;

[0039] Step 102: Perform nitrogen termination treatment on the surface of the diamond layer 10 to form a nitrogen-terminated surface 11;

[0040] Nitrogen termination is achieved using MBE, RIE, or ICP equipment in a nitrogen-containing gas atmosphere. Specifically, single-crystal diamond can be fed into an MBE device with an N-Plasma output power of 150W, a substrate temperature of 450℃, and a nitrogen flow rate of 1 sccm. Under these conditions, the diamond layer 10 is nitrided for 60 minutes to form a nitrogen-terminated surface 11.

[0041] Step 103: Epitaxially grow single-crystal aluminum nitride with an Al-plane polar fibrous wurtzite structure on the nitrogen-terminated surface 11 to form an aluminum nitride epitaxial layer 20, thereby forming a two-dimensional electron gas heterojunction structure based on nitrogen-terminated diamond, that is, an aluminum nitride / nitrogen-terminated diamond heterojunction.

[0042] Specifically, using the MBE process under aluminum-rich conditions of a substrate temperature of 500℃, N-Plasma output power of 200W, nitrogen flow rate of 3sccm, and Al / N beam current ratio of 3:2, aluminum films with a thickness of 1–30 nm were grown on the hydrogen-terminated surface at a growth rate of 0.05 μm / h to form an aluminum nitride / nitrogen-terminated diamond heterojunction. The aluminum nitride epitaxial layer 20 has an Al-faceted polar fibrous wurtzite structure and a thickness of 1–30 nm.

[0043] When the diamond is a single-crystal diamond material, the thickness is 100-1000 μm, and the crystal orientation is (111) or When the crystal orientation of diamond layer 10 is (111), the crystal orientation of aluminum nitride epitaxial layer 20 is (0001); the crystal orientation of diamond layer 10 is... At that time, the crystal orientation of the aluminum nitride epitaxial layer 20 is

[0044] When the diamond layer 10 is made of polycrystalline diamond, donor impurity doping is performed during the epitaxial growth of single-crystal aluminum nitride. Specifically, a phosphorus source or other suitable donor elements are added during the growth of single-crystal aluminum nitride to achieve a donor-doped aluminum nitride epitaxial layer 20.

[0045] Specifically, a two-dimensional electron gas heterojunction structure based on nitrogen-terminated diamond is prepared through the above steps 101-103, including: a diamond layer 10, a nitrogen-terminated surface 11 on the diamond layer 10, and an aluminum nitride epitaxial layer 20 with an Al-plane polar fibrous wurtzite structure on the nitrogen-terminated surface.

[0046] In this embodiment, by selecting a diamond layer with a suitable crystal orientation and performing nitrogen termination treatment on the surface of the diamond layer, it is beneficial for aluminum nitride nucleation on the diamond surface. High-quality aluminum nitride with a specific crystal orientation is epitaxially grown on the nitrogen-terminated diamond surface using a molecular beam epitaxy (MBE) device, which can reduce interface defects such as surface states and dangling bonds at the heterojunction interface and effectively improve the interface quality of the heterojunction.

[0047] Furthermore, nitrogen termination alters the electron affinity of the diamond surface, thereby enabling bandgap modulation at the diamond / aluminum nitride heterojunction interface. For single-crystal diamond layers, the polarization effect between the diamond layer and the Al-faced polar fibrous wurtzite aluminum nitride layer can be utilized to generate 2DEGs on the nitrogen-terminated diamond surface; for polycrystalline diamond layers, the transfer doping effect between the diamond layer and the donor-doped aluminum nitride layer can be utilized to form 2DEGs on the nitrogen-terminated surface.

[0048] Example 2

[0049] Step 201: Obtain the diamond layer; wherein the diamond layer is a single-crystal diamond material or a polycrystalline diamond material;

[0050] Step 202: Perform nitrogen termination treatment on the surface of the diamond layer to form a nitrogen-terminated surface;

[0051] Nitrogen termination is achieved using MBE, RIE, or ICP equipment in a nitrogen-containing gas atmosphere. Specifically, single-crystal diamond can be fed into an MBE device with an N-Plasma output power of 150W, a substrate temperature of 450℃, and a nitrogen flow rate of 1 sccm. Under these conditions, the diamond layer surface is nitrided for 60 minutes to form a nitrogen-terminated surface.

[0052] Step 203: Epitaxially grow single-crystal boron aluminum nitrogen with Al-plane polar fibrous wurtzite structure on the nitrogen-terminated surface to form a boron aluminum nitrogen epitaxial layer, thereby forming a two-dimensional electron gas heterojunction structure based on nitrogen-terminated diamond, that is, a boron aluminum nitrogen / nitrogen-terminated diamond heterojunction.

[0053] Specifically, the MOVPE process can be used at 1280℃ and 90 mBar, with trimethylaluminum, trimethylboron, and nitrogen as the aluminum, boron, and nitrogen sources, respectively. The boron and aluminum composition of the boron-aluminum-nitrogen epitaxial layer is determined by controlling the ratio of the boron to aluminum source during the boron-aluminum-nitrogen growth process. The ratio of trimethylaluminum to trimethylboron is determined based on the desired boron-aluminum-nitrogen alloy composition. The boron-aluminum-nitrogen epitaxial layer has an Al-plane polar fibrous wurtzite structure with a thickness of 1–30 nm.

[0054] When the diamond is a single-crystal diamond material, the thickness is 100-1000 μm, and the crystal orientation is (111) or

[0055] When the diamond layer is made of polycrystalline diamond, donor impurity doping is performed during the epitaxial growth of boron aluminum nitride. Specifically, silicon sources, oxygen sources, or other suitable donor elements are added during the growth of single-crystal boron aluminum nitride to achieve an n-type doped boron aluminum nitride epitaxial layer.

[0056] Specifically, a two-dimensional electron gas heterojunction structure based on nitrogen-terminated diamond is prepared through the above steps 201-203, including: a diamond layer, a nitrogen-terminated surface on the diamond layer, and a boron-aluminum-nitrogen epitaxial layer with an Al-faced polar fibrous wurtzite structure on the nitrogen-terminated surface.

[0057] This embodiment applies nitrogen termination treatment to the diamond surface, which reduces the number of surface states and promotes boron-aluminum-nitrogen nucleation, thereby improving the quality of the heterojunction interface. Nitrogen termination treatment alters the electron affinity of the diamond surface, enabling bandgap modulation and the formation of bandgap structures suitable for two-dimensional electron gas transport.

[0058] This embodiment adjusts the lattice constant of the boron-aluminum-nitrogen epitaxial layer by regulating the boron-aluminum-nitrogen composition ratio, effectively alleviating the lattice mismatch problem between boron-aluminum-nitrogen and diamond. Simultaneously, it modulates the band structure of boron-aluminum-nitrogen, and combined with surface termination treatment of diamond, it further facilitates the achievement of band levels suitable for 2DEG transport. Furthermore, for single-crystal diamond layers, the polarization effect between the diamond layer and the Al-plane polar fibrous wurtzite structure boron-aluminum-nitrogen layer can be utilized to generate 2DEG on the nitrogen-terminated diamond surface; for polycrystalline diamond layers, the transfer doping effect between the diamond layer and the donor-doped boron-aluminum-nitrogen layer can be utilized to form 2DEG on the nitrogen-terminated surface.

[0059] The heterostructure achieved in this invention differs from traditional AlGaAs / GaAs heterostructures in several ways, and therefore the requirements for materials and processing conditions are also different:

[0060] First, the requirements for heterojunction materials differ. Traditional AlGaAs / GaAs heterostructures are purely single-crystal semiconductor heterojunctions, requiring both AlGaAs and GaAs materials to be single-crystal semiconductors. However, for the diamond-based heterojunction achieved in this invention, the diamond can be either single-crystal or polycrystalline.

[0061] Second, the requirements for material surface properties differ. Traditional heterostructures such as AlGaAs / GaAs do not require the GaAs material surface to have a terminal structure. However, for nitrogen-terminated diamond heterostructures that can generate two-dimensional electron gas n-type conductivity, the diamond surface must have a surface terminal in order to adjust the electron affinity of diamond and form a heterostructure interface band that is suitable for 2DEG transport.

[0062] Third, the formation mechanisms of 2DEGs differ. In traditional AlGaAs / GaAs heterostructures, doping the AlGaAs barrier layer causes the Fermi levels of the two materials to become aligned. The doped AlGaAs barrier layer then has a higher Fermi level than the GaAs layer, leading to ionization of donor impurities, the emergence of charge carriers, and their entry into the channel layer, thus forming a 2DEG. However, in nitrogen-terminated diamond heterojunctions, 2DEGs are formed on the diamond surface through the polarization effect or transfer doping of the epitaxial layer material.

[0063] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0064] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0065] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0066] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0067] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0068] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a two-dimensional electron gas heterojunction structure based on nitride materials and nitrogen-terminated diamond, characterized in that, Includes the following steps: Step 1: Obtain the diamond layer; The diamond layer is made of single-crystal diamond material or polycrystalline diamond material; Step 2: Perform nitrogen termination treatment on the surface of the diamond layer to form a nitrogen-terminated surface; Step 3: Epitaxially grow single-crystal aluminum nitride or boron aluminum nitride with an Al-plane polar fibrous wurtzite structure on the nitrogen-terminated surface to form an aluminum nitride epitaxial layer or a boron aluminum nitride epitaxial layer, thereby forming a two-dimensional electron gas heterojunction structure based on nitrogen-terminated diamond; wherein, during the epitaxial growth of boron aluminum nitride, the boron and aluminum composition of the boron aluminum nitride epitaxial layer is generated by controlling the ratio of boron source to aluminum source during the growth process of boron aluminum nitride. When the diamond is a single-crystal diamond material, the crystal orientation is (111) or... When the crystal orientation of the diamond layer is (111), the crystal orientation of the aluminum nitride epitaxial layer is (0001); when the crystal orientation of the diamond layer is... At that time, the crystal orientation of the aluminum nitride epitaxial layer is When the diamond layer is a polycrystalline diamond material, donor impurity doping is performed during the epitaxial growth of aluminum nitride or boron aluminum nitride.

2. The method for preparing a two-dimensional electron gas heterojunction structure based on nitride materials and nitrogen-terminated diamond according to claim 1, characterized in that, The nitrogen terminal treatment in step two adopts the MBE process, RIE process, or ICP process.

3. The method for preparing a two-dimensional electron gas heterostructure based on nitride materials and nitrogen-terminated diamond according to claim 1, characterized in that, The thickness of the aluminum nitride epitaxial layer or boron aluminum nitride epitaxial layer is 1–30 nm.

4. A two-dimensional electron gas heterojunction structure based on nitride materials and nitrogen-terminated diamond, characterized in that, Prepared by the preparation method according to any one of claims 1-3, comprising: a diamond layer, a nitrogen-terminated surface on the diamond layer, and an aluminum nitride epitaxial layer or a boron-aluminum-nitrogen epitaxial layer with an Al-faced polar fibrous wurtzite structure on the nitrogen-terminated surface. The diamond layer is made of single-crystal diamond material or polycrystalline diamond material; When the diamond is a single-crystal diamond material, the crystal orientation is (111) or... When the crystal orientation of the diamond layer is (111), the crystal orientation of the aluminum nitride epitaxial layer is (0001); when the crystal orientation of the diamond layer is... At that time, the crystal orientation of the aluminum nitride epitaxial layer is When the diamond layer is a polycrystalline diamond material, the aluminum nitride epitaxial layer or the boron aluminum nitride epitaxial layer is an epitaxial layer with donor doping.

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