P-type diamond-based gallium oxide heterojunction schottky diode and preparation method thereof

Abstract

The application relates to a gallium oxide heterojunction Schottky diode based on P-type diamond and a preparation method, the diode comprising a substrate layer, a drift layer, a plurality of P-type diamond regions, a cathode and an anode, wherein the cathode, the substrate layer and the drift layer are sequentially stacked; the plurality of P-type diamond regions are distributed in the surface layer of the drift layer at intervals; the anode is located on the surface of the drift layer, and one end of the anode partially overlaps one P-type diamond region, and the other end of the anode partially overlaps another P-type diamond region; the P-type diamond region comprises a first-order region and a second-order region, the first-order region is located on the second-order region, and at least one side surface of the first-order region and the second-order region is inclined to the surface of the drift layer. The Schottky diode alleviates the electric field concentration problem of the junction barrier Schottky diode, avoids the difficulty in preparing P-type Ga2O3, and realizes a high-quality Schottky diode.

Description

Technical Field

[0001] This invention belongs to the field of microelectronics technology, specifically relating to a gallium oxide heterojunction Schottky diode based on P-type diamond and its fabrication method. Background Technology

[0002] As power electronics technology develops towards high voltage and low power consumption, gallium oxide (Ga2O3) has once again come into focus. With its wider bandgap (about 4.9 eV) and higher critical breakdown field strength (about 8 MV / cm) compared to SiC and GaN, this compound semiconductor has unique advantages in higher power applications. In particular, Ga2O3 Schottky diodes have the advantages of low forward conduction voltage (about 0.7V) and short reverse recovery time (as small as a few nanoseconds), exhibiting excellent frequency characteristics.

[0003] However, under high reverse bias, the leakage current of Schottky barrier diodes (SBDs) is very large due to the presence of image forces and electron tunneling, making it difficult to improve the device's breakdown voltage. Since the breakdown of Ga2O3 SBDs mainly occurs at the edge of the Schottky junction where the electric field distribution is concentrated, effective termination techniques are needed to adjust the electric field distribution at the Schottky junction, thereby improving the device's breakdown voltage. Initially, in 1983, IBM Wilamowski used a pn junction barrier to adjust the electric field distribution of the SBD, protecting the Schottky barrier from the influence of the applied reverse voltage and preventing the Schottky barrier from decreasing with increasing reverse bias, thus improving the SBD's breakdown voltage. Subsequently, introducing a p-region under the Schottky metal to form a pn junction has become a common termination technique for improving the breakdown voltage of SBDs.

[0004] Currently, Schottky diodes using pn junction technology mainly include junction barrier Schottky diodes and hybrid PIN Schottky diodes. However, conventionally used rectangular grooves still have electric field concentration at right angles, leaving room for further improvement in device performance.

[0005] Furthermore, due to factors such as the self-compensation effect of n-type background carriers, the lack of shallow-level acceptors, and the easy passivation of acceptor ions, p-type Ga2O3 is difficult to prepare. Therefore, the current approach mainly involves finding effective p-region substitute materials to prepare Schottky diodes with junction termination structures. Reported p-region substitute materials mainly include NiO and CuI, but the p-type concentration of the prepared p-type NiO and CuI is difficult to control precisely, and the p-type doping concentration is difficult to characterize accurately. In addition, CuI has three crystal phases: α, β, and γ. Only when the growth temperature is below 350℃ does CuI become the p-type conductive γ phase. Therefore, the preparation of p-type CuI requires additional temperature control, which increases the difficulty of thin film preparation, and it is difficult to guarantee the purity of the γ crystal phase in the grown CuI.

[0006] In summary, Schottky diodes currently suffer from problems such as electric field concentration, difficulty in fabricating P-region materials, and low quality. Summary of the Invention

[0007] To address the aforementioned problems in the prior art, this invention provides a gallium oxide heterojunction Schottky diode based on p-type diamond and its fabrication method. The technical problem to be solved by this invention is achieved through the following technical solution:

[0008] This invention provides a gallium oxide heterojunction Schottky diode based on p-type diamond, comprising: a substrate layer, a drift layer, a plurality of p-type diamond regions, a cathode, and an anode, wherein...

[0009] The cathode, the substrate layer, and the drift layer are stacked sequentially.

[0010] The plurality of P-type diamond regions are spaced apart in the surface of the drift layer;

[0011] The anode is located on the surface of the drift layer, and one end of the anode overlaps with one of the P-type diamond regions, while the other end overlaps with another of the P-type diamond regions.

[0012] The P-type diamond region includes a first-order region and a second-order region, the first-order region being located on the second-order region, and at least one side of the first-order region and the second-order region being inclined relative to the surface of the drift layer.

[0013] In one embodiment of the present invention, the substrate layer is made of first n-type Ga2O3, and the doping ions include Si ions or Sn ions, with a doping concentration of 1×10⁻⁶. 18 ~1×10 20 cm -3 The thickness is 300–650 μm.

[0014] In one embodiment of the present invention, the material of the drift layer comprises second n-type Ga2O3, and the doping ions comprise Si ions or Sn ions, with a doping concentration of 1×10⁻⁶. 16 ~1×10 18 cm -3 The thickness is 5–15 μm.

[0015] In one embodiment of the present invention, the doping ions in the P-type diamond region include boron ions, and the doping concentration is 1×10⁻⁶. 17 ~1×10 20 cm -3 The thickness is 0.2–4 μm.

[0016] In one embodiment of the present invention, the shape of the first-order region includes an inverted trapezoid.

[0017] In one embodiment of the present invention, the upper bottom lateral length of the first-stage region is 0.5μm to 5μm, the height is 0.2 to 2μm, and the tilt angle of the side of the first-stage region relative to the surface of the drift layer is 30° to 80°.

[0018] In one embodiment of the invention, the shape of the second-order region includes an inverted trapezoid.

[0019] In one embodiment of the present invention, the height of the second-order region is 0.2 to 2 μm, and the tilt angle of the side of the second-order region relative to the surface of the drift layer is 10° to 60°.

[0020] Another embodiment of the present invention provides a method for fabricating a gallium oxide heterojunction Schottky diode based on p-type diamond, comprising the steps of:

[0021] S1. An epitaxial drift layer is grown on one side of the substrate layer.

[0022] S2. A P-type diamond region is prepared in the surface layer of the drift layer, such that the P-type diamond region includes a first-order region and a second-order region, wherein the second-order region is located on the first-order region and communicates with the first-order region, and at least one side of the first-order region and the second-order region forms an acute angle with the surface of the drift layer.

[0023] S3. A cathode is fabricated on the other side surface of the substrate layer;

[0024] S4. An anode is prepared on the surface of the drift layer such that one end of the anode overlaps with one of the P-type diamond regions and the other end overlaps with another of the P-type diamond regions.

[0025] In one embodiment of the present invention, step S2 includes:

[0026] S21. Etch the drift layer to form a first-order groove;

[0027] S22. The drift layer is etched through the first-order groove to form a second-order groove, wherein at least one side of the first-order groove and the second-order groove forms an acute angle with the surface of the drift layer.

[0028] S23. The P-type diamond region is prepared in the first-order groove and the second-order groove.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] In the heterojunction Schottky diode of this invention, P-type diamond is used as the P-type region. The doping concentration of the P-type diamond can be specifically characterized and precisely controlled. Moreover, the fabrication process is relatively mature, and the quality of the prepared diamond is excellent. At the same time, the P-type diamond region includes two regions, and at least one side of each region forms an acute angle with the drift layer, which increases the contact area between the P-type diamond region and the drift layer. The modulation effect of the pn junction on the electric field is more obvious, the electric field distribution is more uniform, and the electric field concentration is effectively mitigated. Thus, this Schottky diode alleviates the electric field concentration problem of junction barrier Schottky diodes, while avoiding the difficulties in preparing P-type Ga2O3, and realizes a high-quality Schottky diode. Attached Figure Description

[0031] Figure 1 A schematic diagram of a gallium oxide heterojunction Schottky diode based on P-type diamond is provided in an embodiment of the present invention.

[0032] Figure 2 A schematic flowchart of a method for fabricating a gallium oxide heterojunction Schottky diode based on P-type diamond provided in this embodiment of the invention;

[0033] Figures 3a-3g This is a schematic diagram illustrating the process of fabricating a gallium oxide heterojunction Schottky diode based on P-type diamond, as provided in an embodiment of the present invention. Detailed Implementation

[0034] 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.

[0035] Example 1

[0036] Please see Figure 1 , Figure 1 This is a schematic diagram of a gallium oxide heterojunction Schottky diode based on P-type diamond, provided as an embodiment of the present invention.

[0037] The Schottky diode includes: a substrate layer 1, a drift layer 2, several P-type diamond regions 3, a cathode 4, and an anode 5.

[0038] The cathode 4, substrate 1, and drift layer 2 are stacked sequentially. Several P-type diamond regions 3 are spaced apart on the surface of the drift layer 2. The anode 5 is located on the surface of the drift layer 2, with one end of the anode 5 overlapping a portion of a P-type diamond region 3 and the other end overlapping a portion of another P-type diamond region 3.

[0039] Specifically, the multiple P-type diamond regions 3 can be distributed at equal intervals or non-equal intervals. The anode 5 covers several P-type diamond regions 3, and its ends partially overlap with the P-type diamond regions 3. It can be understood that the anode 5 can cover one or more P-type diamond regions 3; the ends of the anode 5 can cover a portion of the outermost P-type diamond region 3 or a portion of the innermost P-type diamond region 3. This embodiment does not impose further restrictions, as long as the ends of the anode 5 partially overlap with the P-type diamond regions 3.

[0040] In this embodiment, P-type diamond is used as the P-type region. The doping concentration of P-type diamond can be specifically characterized and precisely controlled. Furthermore, the fabrication process is relatively mature, resulting in diamond of excellent quality. Simultaneously, diamond has a very high thermal conductivity (10 W / cm·K), far exceeding that of gallium oxide (0.27 W / cm·K), exhibiting excellent thermal conductivity. This can, to some extent, compensate for the poor thermal conductivity of gallium oxide and promote device heat dissipation.

[0041] Specifically, the substrate 1 is made of first n-type Ga2O3, and the doping ions include Si ions or Sn ions, with a doping concentration of 1×10⁻⁶. 18 ~1×10 20 cm -3 The thickness is 300–650 μm. The material of drift layer 2 includes second n-type Ga2O3, and the doping ions include Si ions or Sn ions, with a doping concentration of 1 × 10⁻⁶. 16 ~1×10 18 cm -3 The thickness is 5–15 μm. The doping ions in the P-type diamond region 3 include boron ions, with a doping concentration of 1 × 10⁻⁶. 17 ~1×10 20 cm -3 The thickness is 0.2–4 μm.

[0042] Specifically, the cathode 4 is made of one or more of Ti, Al, Ni, and Au. For example, the cathode 4 is a Ti / Au combination or a Ti / Al / Ni / Au combination. When the cathode 4 is a Ti / Au combination, the thickness of the first Ti metal layer is 10–50 nm, and the thickness of the second Au metal layer is 100–400 nm. When the cathode 4 is a Ti / Al / Ni / Au combination, the growth thickness of the first Ti metal layer is 10–200 nm, the growth thickness of the second Al metal layer is 10–200 nm, the growth thickness of the third Ni metal layer is 10–200 nm, and the growth thickness of the fourth Au metal layer is 50–400 nm.

[0043] Specifically, the material of anode 5 includes one or more of Pt, Ni, and Au. For example, anode 5 is a Ni / Au combination or a Pt / Au combination. When anode 5 is a Ni / Au combination, the thickness of the first Ni layer is 10–50 nm, and the thickness of the second Au layer is 100–400 nm. When anode 5 is a Pt / Au combination, the thickness of the first Pt layer is 10–50 nm, and the thickness of the second Au layer is 100–400 nm. The diameter of anode 5 is 20 μm–150 μm.

[0044] In one specific embodiment, the P-type diamond region 3 includes a first-order region 31 and a second-order region 32, that is, it is formed by splicing the first-order region 31 and the second-order region 32. The first-order region 31 is located on the second-order region 32 and the two are interconnected. At least one side of the first-order region 31 and the second-order region 32 is inclined relative to the surface of the drift layer 2.

[0045] Understandably, the first-order region 31 includes two sides, and the second-order region 32 includes two sides. Among these four sides, at least one side is inclined relative to the upper surface of the drift layer 2. For example, one side of the first-order region 31 is inclined relative to the upper surface of the drift layer 2, forming an acute angle with the upper surface of the drift layer 2, while the other three sides are perpendicular to the upper surface of the drift layer 2; another example is that two sides of the first-order region 31 are inclined relative to the upper surface of the drift layer 2, forming an acute angle with the upper surface of the drift layer 2, while two sides of the second-order region 32 are perpendicular to the upper surface of the drift layer 2; yet another example is that both sides of the first-order region 31 and both sides of the second-order region 32 are inclined relative to the upper surface of the drift layer 2, forming an acute angle with the upper surface of the drift layer 2. In this case, the P-type diamond region 3 forms a second-order inclined groove structure.

[0046] In this embodiment, the P-type diamond region includes two regions, and at least one side of the two regions is inclined relative to the upper surface of the drift layer 2, which increases the contact area between the P-type diamond region and the drift layer. The modulation effect of the pn junction on the electric field is more obvious, the electric field distribution is more uniform, and the electric field concentration is effectively mitigated.

[0047] In one specific embodiment, the shape of the first-order region 31 can be an inverted trapezoid, which can be an isosceles inverted trapezoid or a non-isosceles inverted trapezoid.

[0048] Specifically, when the shape of the first-order region 31 is an isosceles inverted trapezoid, the horizontal length of the upper base of the inverted trapezoid is 0.5μm to 5μm, and the height is 0.2 to 2μm. An acute angle α is formed between the waist of the inverted trapezoid and the upper surface of the drift layer 2, and the angle of the acute angle α is 30° to 80°.

[0049] In one specific embodiment, the shape of the second-order region 32 can be an inverted trapezoid, which can be an isosceles inverted trapezoid or a non-isosceles inverted trapezoid.

[0050] Specifically, when the shape of the second-order region 32 is an isosceles inverted trapezoid, the height of the inverted trapezoid is 0.2 to 2 μm, and an acute angle β is formed between the waist of the inverted trapezoid and the upper surface of the drift layer 2, with the angle of the acute angle β being 10° to 60°.

[0051] Furthermore, when the shapes of the first-order region 31 and the second-order region 32 are both isosceles inverted trapezoids, the P-type diamond region 3 is a splicing of the upper and lower isosceles inverted trapezoids, forming a centrally symmetrical second-order inclined groove structure; at this time, the upper base of the upper inverted trapezoid has a horizontal length of 0.5μm to 5μm, a height of 0.2 to 2μm, and an angle α of 30° to 80°; the lower inverted trapezoid has a height of 0.2 to 2μm and an angle β of 10° to 60°.

[0052] In this embodiment, the P-type diamond region adopts a centrally symmetrical second-order inclined groove structure, which increases the interaction between the P-type diamond and the n-type diamond. - - The contact area of ​​the Ga2O3 drift layer makes the modulation effect of the pn junction on the electric field more obvious, the electric field distribution more uniform, and effectively alleviates the electric field concentration.

[0053] Therefore, in the heterojunction Schottky diode of this embodiment, P-type diamond is used as the P-type region. The doping concentration of the P-type diamond can be specifically characterized and precisely controlled. Moreover, the fabrication process is relatively mature, and the quality of the prepared diamond is excellent. At the same time, the P-type diamond region includes two regions, and at least one side of the two regions forms an acute angle with the drift layer, which increases the contact area between the P-type diamond region and the drift layer. The modulation effect of the pn junction on the electric field is more obvious, the electric field distribution is more uniform, and the electric field concentration is effectively mitigated. Thus, this Schottky diode mitigates the electric field concentration problem of the junction barrier Schottky diode, while avoiding the difficulties in preparing P-type Ga2O3, and realizes a high-quality Schottky diode.

[0054] Example 2

[0055] Based on Example 1, please refer to Figure 2 and Figures 3a-3g , Figure 2 This invention provides a schematic flowchart of a method for fabricating a gallium oxide heterojunction Schottky diode based on P-type diamond, according to an embodiment of the present invention. Figures 3a-3g This is a schematic diagram illustrating the process of fabricating a gallium oxide heterojunction Schottky diode based on P-type diamond, as provided in an embodiment of the present invention.

[0056] The preparation method includes the following steps:

[0057] S1. A drift layer 2 is epitaxially grown on one side surface of substrate layer 1. Please refer to [link to relevant documentation]. Figure 3a .

[0058] First, for a doping concentration of 1×10 18 ~1×10 20 cm -3 The first n-type Ga2O3 substrate layer 1 was cleaned according to standard procedures.

[0059] Then, in heavily doped n + -Low-doped n is epitaxially grown on one side of Ga2O3 substrate layer 1 - -Ga2O3 thin film. Specifically, the cleaned substrate 1 is placed in a metal-organic chemical vapor deposition (MOCVD) apparatus with a trimethylgallium™Ga flow rate of 3.0 × 10⁻⁶. -6 ~9.0×10 -6 mol / min, O2 flow rate 1×10 -2 ~4×10 -2 Under conditions of mol / min, temperature of 70–100℃, and pressure of 500 Pa, an epitaxial growth thickness of 5–15 μm is achieved, with Si or Sn ions as doping ions and a doping concentration range of 1 × 10⁻⁶. 16 ~1×10 18 cm -3 A low-doped n-type Ga2O3 thin film was obtained, and a drift layer 2 was obtained.

[0060] S2. A P-type diamond region 3 is prepared in the surface layer of the drift layer 2, such that the P-type diamond region 3 includes a first-order region 31 and a second-order region 32, wherein the second-order region 32 is located on the first-order region 31 and communicates with the first-order region 31, and at least one side of the first-order region 31 and the second-order region 32 forms an acute angle with the surface of the drift layer 2.

[0061] S21, Etch drift layer 2 to form first-order groove 61, see [link / reference] Figure 3b .

[0062] First, photoresist is spin-coated onto the drift layer 2 to photolithographically pattern the first-order groove region. Then, the first-order groove 61 is etched using an inductively coupled plasma (ICP) device. The tilt angle of the side of the first-order groove is α′. The etching conditions are: upper electrode power 260-300W, lower electrode power 40-80W, chamber pressure 10mTorr, gas flow rate Cl2 20-60sccm, and tray temperature 20℃.

[0063] S22. The drift layer 2 is etched through the first-order groove 61 to form the second-order groove 62, wherein at least one side of the first-order groove 61 and the second-order groove 62 forms an acute angle with the surface of the drift layer 2. Please refer to [link to relevant documentation]. Figure 3c .

[0064] First, photoresist is spin-coated onto the buffer layer to photolithographically pattern the second-order groove region. Then, the second-order groove 62 is etched using an ICP device. At this time, the tilt angle of the first-order groove is α, and the tilt angle of the second-order groove is β. The etching conditions are: upper electrode power 260-300W, lower electrode power 40-80W, chamber pressure 10mTorr, Cl2 gas flow rate 20-60sccm, and tray temperature 20℃.

[0065] Specifically, the etching of the second-order groove 62 etches the sidewall of the first-order groove, causing α>α′. Through process control, the final angle α is 30°~80° and the angle β is 10°~60°.

[0066] S23. Prepare P-type diamond region 3 in first-order groove 61 and second-order groove 62.

[0067] First, using the MPCVD method, in n - A p-type diamond layer was prepared on the Ga2O3 drift layer 2. Please refer to [link / reference]. Figure 3d The growth thickness is 0.2–4 μm, the dopant ion is boron ion, and the doping concentration ranges from 1 × 10⁻⁶. 17 ~1×10 20 cm -3， The main gases reacted were CH4, H2, and diborane (B2H6).

[0068] Then, photoresist is spin-coated onto the P-type diamond 3. After photolithography, the photoresist on the diamonds in the first-order groove 61 and the second-order groove 62 is retained. Excess diamond above the drift layer 2 is removed using an ICP device, retaining the diamonds in the grooves to form the P-type diamond region 3. Please refer to [link to relevant documentation]. Figure 3e The removal conditions were as follows: upper electrode power 260-300W / lower electrode power 40-80W, chamber pressure 10mTorr, O2 gas flow rate 20-60sccm, and tray temperature 20℃.

[0069] S3. Fabricate a cathode 4 on the other side surface of substrate layer 1. See [link to documentation]. Figure 3f .

[0070] Specifically, the epitaxially cleaned sample 1 is placed in an electron beam evaporation stage, and a Ti / Au or Ti / Al / Ni / Au metal combination is evaporated on the back side of the Ga2O3 substrate 1 to form a cathode 4, i.e., the bottom electrode. The cathode 4 metal is either a Ti / Au combination or a Ti / Al / Ni / Au combination: if the cathode 4 metal is a Ti / Au combination, the growth thickness of the first Ti metal layer is 10-50 nm, and the growth thickness of the second Au metal layer is 100-400 nm; if the cathode 4 metal is a Ti / Al / Ni / Au combination, the growth thickness of the first Ti metal layer is 10-200 nm, the growth thickness of the second Al metal layer is 10-200 nm, the growth thickness of the third Ni metal layer is 10-200 nm, and the growth thickness of the fourth Au metal layer is 50-400 nm.

[0071] After the electrode metal evaporates, it undergoes rapid thermal annealing in an N2 environment at 500–1000°C for 40–80 seconds to form an ohmic contact.

[0072] S4. An anode 5 is fabricated on the surface of the drift layer 2, such that one end of the anode 5 overlaps with a portion of a P-type diamond region 3, and the other end overlaps with another portion of a P-type diamond region 3. (See also...) Figure 3g .

[0073] Specifically, after photolithography, a Ni / Au or Pt / Au metal combination is evaporated onto the surface of a P-type diamond to serve as anode 5. The anode metal is either a Ni / Au or Pt / Au combination: when anode 5 is a Ni / Au combination, the thickness of the first Ni layer is 10–50 nm, and the thickness of the second Au layer is 100–400 nm; when anode 5 is a Pt / Au combination, the thickness of the first Pt layer is 10–50 nm, and the thickness of the second Au layer is 100–400 nm. The diameter of anode 5 is 20 μm–150 μm.

[0074] In the heterojunction Schottky diode prepared by the method of this embodiment, P-type diamond is used as the P-type region. The doping concentration of the P-type diamond can be specifically characterized and precisely controlled. Moreover, the preparation process is relatively mature, and the prepared diamond has excellent quality. At the same time, the P-type diamond region includes two regions, and at least one side of the two regions forms an acute angle with the drift layer, which increases the contact area between the P-type diamond region and the drift layer. The modulation effect of the pn junction on the electric field is more obvious, the electric field distribution is more uniform, and the electric field concentration is effectively mitigated. Thus, this Schottky diode alleviates the electric field concentration problem of junction barrier Schottky diodes, while avoiding the difficulties in preparing P-type Ga2O3, and realizes a high-quality Schottky diode.

[0075] 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 gallium oxide heterojunction Schottky diode based on p-type diamond, characterized in that, include: The substrate (1), drift layer (2), several P-type diamond regions (3), cathode (4), and anode (5) are as follows: The cathode (4), the substrate layer (1), and the drift layer (2) are stacked sequentially; The plurality of P-type diamond regions (3) are distributed at intervals in the surface of the drift layer (2); The anode (5) is located on the surface of the drift layer (2), and one end of the anode (5) overlaps with a portion of the P-type diamond region (3), and the other end overlaps with a portion of the other P-type diamond region (3); The substrate layer (1) is made of a first n-type Ga2O3, and the drift layer (2) is made of a second n-type Ga2O3; a pn junction is formed between the drift layer (2) and the plurality of p-type diamond regions (3); The P-type diamond region (3) includes a first-order region (31) and a second-order region (32). The first-order region (31) is located on the second-order region (32) and the second-order region (32) is connected. The shapes of the first-order region (31) and the second-order region (32) both include an inverted trapezoid and form a second-order inclined groove structure. The lower bottom of the first-order region (31) coincides with the upper bottom of the second-order region (32). The tilt angle of the first-order region (31) relative to the surface of the drift layer (2) is greater than the tilt angle of the second-order region (32) relative to the surface of the drift layer (2).

2. The gallium oxide heterojunction Schottky diode based on p-type diamond according to claim 1, characterized in that, The substrate layer (1) is doped with either Si or Sn ions, and the doping concentration is 1 × 10⁻⁶. 18 ~1×10 20 cm -3 The thickness is 300–650 μm.

3. The gallium oxide heterojunction Schottky diode based on p-type diamond according to claim 1, characterized in that, The drift layer (2) is doped with either Si or Sn ions, and the doping concentration is 1 × 10⁻⁶. 16 ~1×10 18 cm -3 The thickness is 5–15 μm.

4. The gallium oxide heterojunction Schottky diode based on p-type diamond according to claim 1, characterized in that, The doped ions in the P-type diamond region (3) include boron ions, with a doping concentration of 1×10⁻⁶. 17 ~1×10 20 cm -3 The thickness is 0.2–4 μm.

5. The gallium oxide heterojunction Schottky diode based on p-type diamond according to claim 1, characterized in that, The upper bottom lateral length of the first-order region (31) is 0.5μm to 5μm, and the height is 0.2 to 2μm. The tilt angle of the side of the first-order region (31) relative to the surface of the drift layer (2) is 30° to 80°.

6. The gallium oxide heterojunction Schottky diode based on p-type diamond according to claim 1, characterized in that, The height of the second-order region (32) is 0.2 to 2 μm, and the tilt angle of the side of the second-order region (32) relative to the surface of the drift layer (2) is 10° to 60°.

7. A method for fabricating a gallium oxide heterojunction Schottky diode based on p-type diamond, characterized in that, Including the following steps: S1. A drift layer (2) is epitaxially grown on one side surface of a substrate layer (1); the material of the substrate layer (1) includes a first n-type Ga2O3, and the material of the drift layer (2) includes a second n-type Ga2O3. S2. A P-type diamond region (3) is prepared in the surface layer of the drift layer (2), such that the P-type diamond region (3) includes a first-order region (31) and a second-order region (32), wherein the second-order region (32) is located on the first-order region (31) and communicates with the first-order region (31), the shape of the first-order region (31) and the second-order region (32) both include an inverted trapezoid and form a second-order inclined groove structure, the lower bottom of the first-order region (31) coincides with the upper bottom of the second-order region (32), and the tilt angle of the first-order region (31) relative to the surface of the drift layer (2) is greater than the tilt angle of the second-order region (32) relative to the surface of the drift layer (2); S3. A cathode (4) is fabricated on the other side surface of the substrate layer (1); S4. An anode (5) is prepared on the surface of the drift layer (2) such that one end of the anode (5) overlaps with a portion of one of the P-type diamond regions (3) and the other end overlaps with a portion of another of the P-type diamond regions (3).

8. The method for fabricating a gallium oxide heterojunction Schottky diode based on p-type diamond according to claim 7, characterized in that, Step S2 includes: S21. Etch the drift layer (2) to form a first-order groove (61); S22. The drift layer (2) is etched through the first-order groove (61) to form a second-order groove (62), wherein at least one side of the side of the first-order groove (61) and the side of the second-order groove (62) forms an acute angle with the surface of the drift layer (2). S23. The P-type diamond region (3) is prepared in the first-order groove (61) and the second-order groove (62).

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