Preparation method of diamond material and semiconductor device

Abstract

The invention relates to the field of diamond materials, in particular to a preparation method of a diamond material and a semiconductor device.The preparation method specifically comprises the steps that a polyion liquid layer containing nanometer nickel powder is formed on the surface of a diamond film; then carrying out pyrolysis at the temperature of 400 to 500 DEG C, and then growing graphene at the temperature of 800 to 1000 DEG C; according to the method, the dependence on expensive coating equipment is broken through, the preparation cost is greatly reduced while the performance of the diamond material is guaranteed, and more economical preparation options are provided for industrialization of field emission devices, thermal management devices and high-frequency electronic devices.

Description

A method for preparing diamond material and semiconductor devices Technical Field

[0001] This invention relates to the field of diamond materials, specifically to a method for preparing diamond materials and a semiconductor device. Background Technology

[0002] With breakthroughs in diamond growth and synthesis technology, the cost of artificial diamonds has been significantly reduced, sparking a surge in diamond research. As CVD technology continues to improve, scientists are able to more precisely control the deposition process on the diamond surface, growing high-quality diamond crystals. Researchers have begun to explore the formation of heterostructures by combining diamond with other materials, optimizing the performance of heterostructures by precisely controlling the interface structure and chemical composition. There are three common types of materials used to construct diamond heterostructures: metal oxides, nitride semiconductor materials, and sp2 carbon materials.

[0003] Among them, the combination of diamond with sp2 carbon materials such as graphene is one of the important research directions for diamond heterostructures. The high hardness, high thermal conductivity and chemical stability of diamond, combined with the good electrical conductivity, mechanical flexibility and good catalytic properties of graphene, can be used to prepare high-performance all-carbon composite materials, which is expected to further broaden the application of diamond in the semiconductor field.

[0004] Currently, there are three main methods for preparing graphene / diamond heterostructures: transfer method, direct catalytic growth method, and metal-catalyzed growth method. The metal-catalyzed growth method uses a metal film deposited on the diamond surface as a catalyst, with diamond as the sole carbon source, and employs a high-temperature annealing process to directly grow graphene on the surface of a single diamond crystal. However, the deposition of the metal film requires expensive magnetron sputtering or electron beam evaporation coating machines, which greatly limits its industrial application. Summary of the Invention

[0005] Purpose of the invention: To address the above-mentioned technical problems, this invention proposes a method for preparing diamond materials and a semiconductor device.

[0006] The technical solution adopted is as follows: A method for preparing diamond material, specifically as follows: forming a polyionic liquid layer containing nano-nickel powder on the surface of a diamond film; then pyrolyzing it at 400-500℃, then growing graphene at 800-1000℃; finally removing the nickel.

[0007] Furthermore, the diamond film is pre-polished mechanically to reduce its surface roughness to below 1 nm, then boiled in a mixed acid solution of concentrated sulfuric acid and concentrated nitric acid, cooled, and then ultrasonically cleaned with acetone, alcohol, and deionized water in sequence, and finally dried.

[0008] Furthermore, the polyionic liquid layer is composed of nano-nickel powder, vinylimidazolium ionic liquid, photoinitiator, polyethylene glycol, and organic diluent.

[0009] Furthermore, the mass ratio of the nano-nickel powder to the vinylimidazole ionic liquid is 1-3:1-3.

[0010] Furthermore, the structural formula of the vinylimidazole ionic liquid is as follows: In this context, R1 is an alkenyl group and R2 is an alkyl group.

[0011] Furthermore, R1 is vinyl or allyl, and R2 is an alkyl group with ≤6 carbon atoms.

[0012] Furthermore, R1 is vinyl and R2 is butyl.

[0013] Furthermore, the vinylimidazolium ionic liquid is obtained by reacting a vinylimidazolium chloride ionic liquid with nickel chloride.

[0014] Furthermore, the vinylimidazolium ionic liquid is obtained by reacting 1-vinyl-3-butylimidazolium chloride ionic liquid with nickel chloride.

[0015] Furthermore, the molar ratio of 1-vinyl-3-butylimidazolium chloride ionic liquid to nickel chloride is 2:1.

[0016] Furthermore, the preparation method of the polyionic liquid layer is as follows: nano-nickel powder, vinylimidazolium ionic liquid, photoinitiator, polyethylene glycol and organic diluent are mixed and ultrasonically dispersed to obtain a dispersion, which is then attached to the surface of the diamond film and cured under ultraviolet light irradiation.

[0017] Furthermore, the curing temperature is ≥100℃.

[0018] Furthermore, nickel removal is carried out in a dilute hydrochloric acid solution.

[0019] Furthermore, before removing nickel, the diamond film needs to be treated with hydrogen plasma.

[0020] The present invention also provides a semiconductor device comprising diamond material prepared by the above-described method for preparing diamond material.

[0021] The invention has the following beneficial effects: It adopts a synergistic system of vinylimidazolium ionic liquid and nano-nickel powder. Through ultrasonic dispersion and the steric hindrance effect of polyethylene glycol, the nano-nickel powder is highly dispersed in the suspension. A nano-scale uniform catalytic nickel layer can be formed on the surface of diamond film. Pyrolysis at 400-500℃ fully decomposes the organic components. Under hydrogen heating, the nickel atoms generated by decomposition migrate and recombine to form nickel nanocrystals with uniform particle size and distribution. These nanocrystals are deposited on the surface of the nano-nickel powder to form an active shell, filling the vacancies between the nano-nickel powder particles, forming a denser and more uniform nickel layer and preventing Ostwald ripening. Based on the high solubility of carbon atoms in the nickel layer during the heat treatment process at 800-1000℃, graphene is grown in a controlled manner through high-temperature dissolution, diffusion, and low-temperature precipitation. Without exogenous carbon, pure nickel-catalyzed diamond graphitization follows a unidirectional etching mechanism, which easily leads to local carbon supersaturation and the formation of disordered carbon stacks. However, the active carbon atoms generated by the decomposition of the polyionic liquid layer form a gaseous carbon supply layer on the surface of nickel nanoparticles. The real-time supply of active carbon increases the nucleation density of graphene, which not only protects the integrity of the diamond lattice but also constructs a high-quality graphene network. The prepared diamond material has superior performance.

[0022] This invention breaks through the dependence on expensive coating equipment, and while ensuring the performance of diamond materials, it significantly reduces the preparation cost, providing a more economical preparation option for the industrialization of field emission devices, thermal management devices and high-frequency electronic devices. Detailed Implementation

[0023] Unless otherwise specified in the examples, the conditions were performed under standard conditions or as recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products. Techniques not mentioned in this invention refer to existing technologies. Unless otherwise specified, the following examples and comparative examples are parallel experiments, using the same processing steps and parameters.

[0024] Example 1: A method for preparing a diamond material: A type Ib single-crystal diamond film with dimensions of 3mm × 3mm × 1mm was mechanically polished to reduce its surface roughness to below 1nm. The polished single-crystal diamond was then boiled in a mixed acid solution of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 1:3 for 3 hours. After cooling, it was ultrasonically cleaned sequentially with acetone, alcohol, and deionized water for 15 minutes each. 1-vinyl-3-butylimidazolium chloride and nickel chloride in a molar ratio of 2:1 were added to anhydrous ethanol and heated to reflux for 48 hours. After the reaction, the anhydrous ethanol was removed by vacuum distillation to obtain [VBIm]2[NiCl4], and its composition was determined by elemental analysis. In a light-protected environment, 1g of nano-nickel powder, 1g of [VBIm]2[NiCl4], 0.005g of photoinitiator TPO, and 2g of polyethylene glycol-2000 were added to 200ml of anhydrous ethanol and sonicated for 30min under stirring to obtain a suspension. 2ml of the suspension was sprayed onto the surface of a diamond film and then irradiated with ultraviolet light at 100℃ for 10min. The diamond film was then placed in a quartz tube. The tube furnace was first evacuated to 5Pa, and then 500sccm of argon gas was introduced for purging to remove residual air from the quartz tube. Subsequently, 100sccm of argon gas was introduced, and the temperature was initially increased to 450℃ at a rate of 10℃ / min. After holding at this temperature for 2h for pyrolysis, 50sccm of hydrogen gas was introduced, and the temperature was increased to 900℃ at a rate of 20℃ / min and held for 10min before naturally cooling to room temperature. The diamond film after high-temperature treatment is treated with 50W hydrogen plasma for 3 minutes, then immersed in 1mol / L dilute hydrochloric acid solution for 5 hours to remove metallic nickel, and finally thoroughly cleaned with deionized water.

[0025] In this embodiment, a Hall effect testing device (model ET9105-HS) ​​was used to test the conductivity of diamond material at room temperature. The test magnetic field was 0.55T, the test current was 1mA, and the measurement was performed three times. The measured carrier concentration was 2.2 × 10⁻⁶. 14 cm -2 Hall mobility is 648 cm⁻¹ 2 / Vs.

[0026] Example 2: A method for preparing a diamond material: A type Ib single-crystal diamond film with dimensions of 3mm × 3mm × 1mm was mechanically polished to reduce its surface roughness to below 1nm. The polished single-crystal diamond was then boiled in a mixed acid solution of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 1:3 for 3 hours. After cooling, it was ultrasonically cleaned sequentially with acetone, alcohol, and deionized water for 15 minutes each. 1-vinyl-3-butylimidazolium chloride and nickel chloride in a molar ratio of 2:1 were added to anhydrous ethanol and heated to reflux for 48 hours. After the reaction was completed, the anhydrous ethanol was removed by vacuum distillation to obtain [VBIm]2[NiCl4]. In a light-protected environment, 1g of nano-nickel powder, 1g of [VBIm]2[NiCl4], 0.005g of photoinitiator TPO, and 2g of polyethylene glycol-2000 were added to 200ml of anhydrous ethanol and sonicated for 30min under stirring to obtain a suspension. 2ml of the suspension was sprayed onto the surface of a diamond film and then irradiated with ultraviolet light at 100℃ for 10min. The diamond film was then placed in a quartz tube. The tube furnace was first evacuated to 5Pa, and then 500sccm of argon gas was introduced for purging to remove residual air from the quartz tube. Subsequently, 100sccm of argon gas was introduced, and the temperature was initially increased to 500℃ at a rate of 10℃ / min. After holding at this temperature for 2h for pyrolysis, 50sccm of hydrogen gas was introduced, and the temperature was increased to 1000℃ at a rate of 20℃ / min and held for 10min before naturally cooling to room temperature. The diamond film after high-temperature treatment is treated with 50W hydrogen plasma for 3 minutes, then immersed in 1mol / L dilute hydrochloric acid solution for 5 hours to remove metallic nickel, and finally thoroughly cleaned with deionized water.

[0027] In this embodiment, a Hall effect testing device (model ET9105-HS) ​​was used to test the conductivity of diamond material at room temperature. The test magnetic field was 0.55T, the test current was 1mA, and the measurement was performed three times. The measured carrier concentration was 2.0 × 10⁻⁶. 14 cm -2 Hall mobility is 720 cm⁻¹ 2 / Vs. Higher temperatures promote nickel particle crystallization and diamond lattice repair, reducing scattering.

[0028] Example 3: A method for preparing a diamond material: A type Ib single-crystal diamond film with dimensions of 3mm × 3mm × 1mm was mechanically polished to reduce its surface roughness to below 1nm. The polished single-crystal diamond was then boiled in a mixed acid solution of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 1:3 for 3 hours. After cooling, it was ultrasonically cleaned sequentially with acetone, alcohol, and deionized water for 15 minutes each. 1-vinyl-3-butylimidazolium chloride and nickel chloride in a molar ratio of 2:1 were added to anhydrous ethanol and heated to reflux for 48 hours. After the reaction was completed, the anhydrous ethanol was removed by vacuum distillation to obtain [VBIm]2[NiCl4]. In a light-protected environment, 1g of nano-nickel powder, 1g of [VBIm]2[NiCl4], 0.005g of photoinitiator TPO, and 2g of polyethylene glycol-2000 were added to 200ml of anhydrous ethanol and sonicated for 30min under stirring to obtain a suspension. 2ml of the suspension was sprayed onto the surface of a diamond film and then irradiated with ultraviolet light at 100℃ for 10min. The diamond film was then placed in a quartz tube. The tube furnace was first evacuated to 5Pa, and then 500sccm of argon gas was introduced for purging to remove residual air from the quartz tube. Subsequently, 100sccm of argon gas was introduced, and the temperature was initially increased to 400℃ at a rate of 10℃ / min. After holding at this temperature for 2h for pyrolysis, 50sccm of hydrogen gas was introduced, and the temperature was increased to 800℃ at a rate of 20℃ / min and held for 10min before naturally cooling to room temperature. The diamond film after high-temperature treatment is treated with 50W hydrogen plasma for 3 minutes, then immersed in 1mol / L dilute hydrochloric acid solution for 5 hours to remove metallic nickel, and finally thoroughly cleaned with deionized water.

[0029] This embodiment uses an ET9105-HS Hall effect testing device to test the conductivity of diamond material at room temperature. The test magnetic field is 0.55T, the test current is 1mA, and the measurement is performed three times. The measured carrier concentration is 2.5 × 10⁻⁶. 14 cm -2 Hall mobility is 580 cm⁻¹ 2 / Vs. Lower temperatures result in uneven dispersion of nickel particles and more diamond defects.

[0030] Example 4: A method for preparing a diamond material: A type Ib single-crystal diamond film with dimensions of 3mm × 3mm × 1mm was mechanically polished to reduce its surface roughness to below 1nm. The polished single-crystal diamond was then boiled in a mixed acid solution of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 1:3 for 3 hours. After cooling, it was ultrasonically cleaned sequentially with acetone, alcohol, and deionized water for 15 minutes each. 1-vinyl-3-butylimidazolium chloride and nickel chloride in a molar ratio of 2:1 were added to anhydrous ethanol and heated to reflux for 48 hours. After the reaction, the anhydrous ethanol was removed by vacuum distillation to obtain [VBIm]2[NiCl4]. In a light-protected environment, 1.5g of nano-nickel powder, 0.5g of [VBIm]2[NiCl4], 0.005g of photoinitiator TPO, and 2g of polyethylene glycol-2000 were added to 200ml of anhydrous ethanol and sonicated for 30min under stirring to obtain a suspension. 2ml of the suspension was sprayed onto the surface of a diamond film and then irradiated with ultraviolet light at 100℃ for 10min. The diamond film was then placed in a quartz tube. The tube furnace was first evacuated to 5Pa, and then 500sccm of argon gas was introduced for purging to remove residual air from the quartz tube. Subsequently, 100sccm of argon gas was introduced, and the temperature was initially increased to 450℃ at a rate of 10℃ / min. After holding at this temperature for 2h for pyrolysis, 50sccm of hydrogen gas was introduced, and the temperature was increased to 900℃ at a rate of 20℃ / min and held for 10min before naturally cooling to room temperature. The diamond film after high-temperature treatment is treated with 50W hydrogen plasma for 3 minutes, then immersed in 1mol / L dilute hydrochloric acid solution for 5 hours to remove metallic nickel, and finally thoroughly cleaned with deionized water.

[0031] In this embodiment, a Hall effect testing device (model ET9105-HS) ​​was used to test the conductivity of diamond material at room temperature. The test magnetic field was 0.55T, the test current was 1mA, and the measurement was performed three times. The measured carrier concentration was 3.0 × 10⁻⁶. 14 cm -2 Hall mobility is 602 cm⁻¹ 2 / Vs. More nucleation sites enhance doping, but particle aggregation slightly affects mobility.

[0032] Example 5: A method for preparing a diamond material: A type Ib single-crystal diamond film with dimensions of 3mm × 3mm × 1mm was mechanically polished to reduce its surface roughness to below 1nm. The polished single-crystal diamond was then boiled in a mixed acid solution of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 1:3 for 3 hours. After cooling, it was ultrasonically cleaned sequentially with acetone, alcohol, and deionized water for 15 minutes each. 1-vinyl-3-butylimidazolium chloride and nickel chloride in a molar ratio of 2:1 were added to anhydrous ethanol and heated to reflux for 48 hours. After the reaction was completed, the anhydrous ethanol was removed by vacuum distillation to obtain [VBIm]2[NiCl4]. In a light-protected environment, 0.5g of nano-nickel powder, 1.5g of [VBIm]2[NiCl4], 0.005g of photoinitiator TPO, and 2g of polyethylene glycol-2000 were added to 200ml of anhydrous ethanol and sonicated for 30min under stirring to obtain a suspension. 2ml of the suspension was sprayed onto the surface of a diamond film and then irradiated with ultraviolet light at 100℃ for 10min. The diamond film was then placed in a quartz tube. The tube furnace was first evacuated to 5Pa, and then 500sccm of argon gas was introduced for purging to remove residual air from the quartz tube. Subsequently, 100sccm of argon gas was introduced, and the temperature was initially increased to 450℃ at a rate of 10℃ / min. After holding at this temperature for 2h for pyrolysis, 50sccm of hydrogen gas was introduced, and the temperature was increased to 900℃ at a rate of 20℃ / min and held for 10min before naturally cooling to room temperature. The diamond film after high-temperature treatment is treated with 50W hydrogen plasma for 3 minutes, then immersed in 1mol / L dilute hydrochloric acid solution for 5 hours to remove metallic nickel, and finally thoroughly cleaned with deionized water.

[0033] In this embodiment, a Hall effect testing device (model ET9105-HS) ​​was used to test the conductivity of diamond material at room temperature. The test magnetic field was 0.55T, the test current was 1mA, and the measurement was performed three times. The measured carrier concentration was 2.3 × 10⁻⁶. 14 cm -2 Hall mobility is 685 cm⁻¹ 2 / Vs.

[0034] Comparative Example 1: Basically the same as Example 1, except that 1-vinyl-3-butylimidazolium chloride was used instead of [VBIm]2[NiCl4].

[0035] A method for preparing diamond material: A type Ib single crystal diamond film with a size of 3mm×3mm×1mm is mechanically polished to reduce its surface roughness value to below 1nm. Then, the polished single crystal diamond is boiled in a mixed acid solution of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 1:3 for 3h for 3h. After cooling, it is ultrasonically cleaned in sequence with acetone, alcohol and deionized water for 15min each time. In a light-protected environment, 1g of nano-nickel powder, 1g of 1-vinyl-3-butylimidazolium chloride, 0.005g of photoinitiator TPO, and 2g of polyethylene glycol-2000 were added to 200ml of anhydrous ethanol and sonicated for 30min under stirring to obtain a suspension. 2ml of the suspension was sprayed onto the surface of a diamond film and then irradiated with ultraviolet light at 100℃ for 10min. The diamond film was then placed in a quartz tube. The tube furnace was first evacuated to 5Pa, and then 500sccm of argon gas was introduced for purging to remove residual air from the quartz tube. Subsequently, 100sccm of argon gas was introduced, and the temperature was initially increased to 450℃ at a rate of 10℃ / min. After holding at this temperature for 2h for pyrolysis, 50sccm of hydrogen gas was introduced, and the temperature was increased to 900℃ at a rate of 20℃ / min and held for 10min before naturally cooling to room temperature. The diamond film after high-temperature treatment is treated with 50W hydrogen plasma for 3 minutes, then immersed in 1mol / L dilute hydrochloric acid solution for 5 hours to remove metallic nickel, and finally thoroughly cleaned with deionized water.

[0036] In this embodiment, a Hall effect testing device (model ET9105-HS) ​​was used to test the conductivity of diamond material at room temperature. The test magnetic field was 0.55T, the test current was 1mA, and the measurement was performed three times. The measured carrier concentration was 2.2 × 10⁻⁶. 13 cm -2 Hall mobility is 79 cm 2 / Vs.

[0037] Comparative Example 2: Basically the same as Example 1, except that [VBIm]2[NiCl4] and photoinitiator TPO were not added.

[0038] A method for preparing diamond material: A type Ib single crystal diamond film with a size of 3mm×3mm×1mm is mechanically polished to reduce its surface roughness value to below 1nm. Then, the polished single crystal diamond is boiled in a mixed acid solution of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 1:3 for 3h for 3h. After cooling, it is ultrasonically cleaned in sequence with acetone, alcohol and deionized water for 15min each time. In a light-protected environment, 1g of nano-nickel powder and 2g of polyethylene glycol-2000 were added to 200ml of anhydrous ethanol and sonicated for 30min under stirring to obtain a suspension. 2ml of this suspension was sprayed onto the surface of a diamond film, and then irradiated with ultraviolet light at 100℃ for 10min. The diamond film was then placed in a quartz tube. The tube furnace was first evacuated to 5Pa, and then 500sccm of argon gas was introduced for purging to remove residual air from the quartz tube. Subsequently, 100sccm of argon gas was introduced, and the temperature was initially increased to 450℃ at a rate of 10℃ / min. After holding at this temperature for 2h, 50sccm of hydrogen gas was introduced, and the temperature was increased to 900℃ at a rate of 20℃ / min and held for 10min, followed by natural cooling to room temperature. The high-temperature treated diamond film was then treated under 50W hydrogen plasma for 3min, then immersed in a 1mol / L dilute hydrochloric acid solution for 5h to remove metallic nickel. Finally, it was thoroughly cleaned with deionized water.

[0039] In this embodiment, a Hall effect testing device (model ET9105-HS) ​​was used to test the conductivity of diamond material at room temperature. The test magnetic field was 0.55T, the test current was 1mA, and the measurement was performed three times. The measured carrier concentration was 1.9 × 10⁻⁶. 13 cm -2 Hall mobility is 56 cm⁻¹ 2 / Vs.

[0040] Comparative Example 3: Basically the same as Example 1, except that a nickel film was deposited using magnetron sputtering.

[0041] A method for preparing diamond material: A type Ib single crystal diamond film with a size of 3mm×3mm×1mm is mechanically polished to reduce its surface roughness value to below 1nm. Then, the polished single crystal diamond is boiled in a mixed acid solution of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 1:3 for 3h for 3h. After cooling, it is ultrasonically cleaned in sequence with acetone, alcohol and deionized water for 15min each time. A diamond film was placed in a magnetron sputtering apparatus and a nickel film with a thickness of approximately 30 nm was deposited under an argon atmosphere at a pressure of 1 Pa, a sputtering power of 150 W, and a sputtering time of 1 min. The diamond film was then placed in a quartz tube, and the tube furnace was first evacuated to 5 Pa. Then, 500 sccm of argon gas was introduced for purging to remove residual air from the quartz tube. Subsequently, 100 sccm of argon gas was introduced, and the temperature was initially increased to 450 °C at a rate of 10 °C / min. After holding at this temperature for 2 h, 50 sccm of hydrogen gas was introduced, and the temperature was increased to 900 °C at a rate of 20 °C / min and held for 10 min, followed by natural cooling to room temperature. The high-temperature treated diamond film was then treated under 50 W hydrogen plasma for 3 min, then immersed in a 1 mol / L dilute hydrochloric acid solution for 5 h to remove metallic nickel. Finally, it was thoroughly rinsed with deionized water.

[0042] In this embodiment, a Hall effect testing device (model ET9105-HS) ​​was used to test the conductivity of diamond material at room temperature. The test magnetic field was 0.55T, the test current was 1mA, and the measurement was performed three times. The measured carrier concentration was 1.4 × 10⁻⁶. 14 cm -2 Hall mobility is 122 cm⁻¹ 2 / Vs.

[0043] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a diamond material, characterized in that, Specifically, the process involves forming a polyionic liquid layer containing nano-nickel powder on the surface of a diamond film; then pyrolyzing it at 400-500℃, followed by growing graphene at 800-1000℃; and finally removing the nickel.

2. The method for preparing diamond material as described in claim 1, characterized in that, The polyionic liquid layer is composed of nano-nickel powder, vinylimidazolium ionic liquid, photoinitiator, polyethylene glycol and organic diluent.

3. The method for preparing diamond material as described in claim 2, characterized in that, The mass ratio of the nano-nickel powder to the vinylimidazolium ionic liquid is 1-3:1-3.

4. The method for preparing diamond material as described in claim 3, characterized in that, The structural formula of the vinylimidazolium-based ionic liquid is as follows: In this context, R1 is an alkenyl group and R2 is an alkyl group.

5. The method for preparing diamond material as described in claim 4, characterized in that, R1 is vinyl or allyl, and R2 is an alkyl group with ≤6 carbon atoms.

6. The method for preparing diamond material as described in claim 4, characterized in that, The vinylimidazolium ionic liquid is obtained by reacting a vinylimidazolium chloride ionic liquid with nickel chloride.

7. The method for preparing diamond material as described in claim 2, characterized in that, The preparation method of the polyionic liquid layer is as follows: nano nickel powder, vinyl imidazole ionic liquid, photoinitiator, polyethylene glycol and organic diluent are mixed and ultrasonically dispersed to obtain a dispersion, which is then attached to the surface of the diamond film and cured under ultraviolet light.

8. The method for preparing diamond material as described in claim 7, characterized in that, Curing temperature ≥100℃.

9. The method for preparing diamond material as described in claim 1, characterized in that, Nickel removal is carried out in a dilute hydrochloric acid solution.

10. A semiconductor device, characterized in that, Diamond materials prepared by the method described in any one of claims 1-9.

Images