Preparation method of diamond film and diamond film

Abstract

The embodiment of the invention provides a preparation method of a diamond film. The preparation method comprises the following steps that a graphite sheet layer is placed on a sample table of a reaction cavity; reaction gas is introduced into the reaction cavity, the reaction gas is converted into plasma through microwaves, and the graphite sheet layer is heated and etched, so that the graphite sheet layer is converted into a diamond film; and cooling the diamond film to stabilize the diamond film. According to the preparation method of the diamond film provided by the embodiment of the invention, the graphite is etched under the high-temperature condition through the microwave plasma, so that efficient phase change from the graphite to the diamond is realized. The embodiment of the invention further provides the diamond film.

Description

Technical Field

[0001] This application belongs to the technical field of material manufacturing, and particularly relates to a method for preparing a diamond film and a diamond film. Background Art

[0002] Due to its excellent physical and chemical properties, such as extremely high hardness, high thermal conductivity, excellent electrical insulation, and chemical stability, diamond has a wide range of applications in industries, electronics, optics, and jewelry. However, natural diamond resources are limited and costly, so the technology of artificial diamond synthesis has become a research hotspot.

[0003] Currently, the main methods for artificial diamond synthesis include the high-pressure high-temperature method (HPHT) and the chemical vapor deposition method (CVD). The high-pressure high-temperature method needs to be carried out under extremely high pressure and temperature, with complex equipment and high cost; although the chemical vapor deposition method can be carried out under lower pressure, the growth rate is slow, and the requirements for the substrate material are high. Summary of the Invention

[0004] Aiming at the problems existing in the above-mentioned related technologies, the present invention provides a method for preparing a diamond film and a diamond film, which realizes the efficient phase transformation from graphite to diamond by etching graphite with microwave plasma under high-temperature conditions.

[0005] In a first aspect, an embodiment of the present application provides a method for preparing a diamond film, including the following steps:

[0006] Place a graphite sheet on the sample stage of the reaction chamber;

[0007] Introduce a reaction gas into the reaction chamber, convert the reaction gas into plasma by microwave, and heat-etch the graphite sheet so that the graphite sheet is transformed into a diamond film; and

[0008] Cool the diamond film to stabilize the diamond film.

[0009] Further, the reaction gas is hydrogen.

[0010] Further, the frequency of the microwave is 2.45 GHz.

[0011] Further, the frequency of the microwave is 915 MHz.

[0012] Further, the heating temperature of the graphite sheet is between 2000°C and 2500°C.

[0013] Further, the pressure of the reaction chamber is between 1 and 10 Torr.

[0014] Further, the flow rate of the hydrogen is between 100 and 500 sccm.

[0015] Further, cooling the diamond film to stabilize the diamond film includes:

[0016] Rapidly cooling the diamond film with cooling circulating water to stabilize the diamond film.

[0017] Further, the purity of the diamond film is between 95% and 99%.

[0018] In a second aspect, an embodiment of the present application provides a diamond film, which is made by the method described in any one of the above.

[0019] In the method for preparing a diamond film provided by the embodiment of the present application, first place a graphite sheet on the sample stage of the reaction chamber, introduce a reaction gas into the reaction chamber, convert the reaction gas into plasma by microwave, and heat and etch the graphite sheet, so that the graphite sheet is converted into a diamond film. Finally, cool the diamond film to stabilize the diamond film. In the method for preparing a diamond film provided by the embodiment of the present application, the graphite sheet is heated and excited by microwave plasma, and the carbon atoms in the graphite sheet are activated and rearranged to gradually form diamond crystals. Therefore, the method for preparing a diamond film and the diamond film provided by the present invention etch graphite under high temperature conditions by microwave plasma to realize the efficient phase change from graphite to diamond. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for the description of the embodiments or related technologies. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts.

[0021] Figure 1 It is a schematic flow chart of the method for preparing a diamond film provided by the embodiment of the present application;

[0022] Figure 2 It is a schematic structural diagram of the preparation equipment adopted by the method for preparing a diamond film provided by the embodiment of the present application.

[0023] The realization of the purpose of the present application, functional features and advantages will be further described with reference to the embodiments and the drawings. Detailed Embodiments

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0025] It should be understood that when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0026] It should also be understood that the terms used in this specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in this specification of the present application and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to include the plural forms. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present application according to specific circumstances.

[0027] Referring to Figure 1 and Figure 2 , an embodiment of the present application provides a method for preparing a diamond film, including the following steps:

[0028] S101: Place a graphite sheet on the sample stage of the reaction chamber;

[0029] S102: Introduce a reaction gas into the reaction chamber, convert the reaction gas into plasma by microwaves, and heat-etch the graphite sheet so that the graphite sheet is converted into a diamond film; and

[0030] S103: Cool the diamond film to stabilize the diamond film.

[0031] Specifically, in the method for preparing a diamond film provided by the embodiments of the present application, first, a graphite sheet layer is placed on a sample stage in a reaction chamber, and a reaction gas is introduced into the reaction chamber. The reaction gas is converted into plasma by microwaves, and the graphite sheet layer is heated and etched, so that the graphite sheet layer is converted into a diamond film. Finally, the diamond film is cooled to stabilize the diamond film. The method for preparing a diamond film provided by the embodiments of the present application uses microwave plasma to heat and excite the graphite sheet layer, and the carbon atoms in the graphite sheet layer are activated and rearranged to gradually form diamond crystals. Therefore, the method for preparing a diamond film and the diamond film provided by the present invention etch graphite under high-temperature conditions by microwave plasma to achieve an efficient phase change from graphite to diamond. In addition, by adjusting the microwave power and heating time, the growth rate and crystal quality of diamond can be effectively controlled.

[0032] Refer to Figure 2 , the preparation equipment used in the method for preparing a diamond film provided by the embodiments of the present application includes a microwave generator, a waveguide, a reaction chamber, a sample stage, a cooling system, and a control system. Among them, the microwave generator generates microwave energy and transmits it to the reaction chamber through the waveguide. A sample stage is provided in the reaction chamber for placing the graphite sheet layer, the cooling system is used to rapidly cool the sample, and the control system is used to adjust the microwave frequency, temperature, and reaction time.

[0033] As Figure 2 shown, it is necessary to place the graphite sheet layer on the sample stage and adjust the sample height to be at the same height as the waveguide to ensure precise alignment of the position between the sample and the waveguide, so as to ensure that the microwave energy can be effectively transmitted to the sample.

[0034] Further, the reaction gas is hydrogen.

[0035] Specifically, a reaction gas is introduced into the reaction chamber, and the reaction gas is hydrogen (H 2 ). Hydrogen not only acts as a reaction gas in the reaction but also plays a role in cleaning and activating the graphite surface.

[0036] In addition, by introducing a small amount of methane (CH 4 ) or other carbon source gases, the carbon source supply of the diamond film can be adjusted, thereby affecting the purity and structure of the film.

[0037] Further, the frequency of the microwave is 2.45 GHz.

[0038] Specifically, microwaves are generated by a microwave generator, and the frequency of the microwaves can be selected as 2.45 GHz. The microwave energy excites the reaction gas into a plasma state, and the high-energy particles in the plasma interact with the graphite surface to initiate a chemical reaction.

[0039] Further, the frequency of the microwave is 915 MHz.

[0040] Specifically, microwaves are generated by a microwave generator, and the frequency of the microwaves can be selected as 915 MHz to adapt to different cavity sizes and power requirements. The microwave energy excites the reaction gas into a plasma state, and the high-energy particles in the plasma interact with the graphite surface, triggering a chemical reaction.

[0041] Further, the heating temperature of the graphite sheet layer is between 2000 °C and 2500 °C.

[0042] Specifically, under the action of the microwave plasma, the graphite sheet layer is heated to between 2000 °C and 2500 °C. At this high temperature, the graphite structure is gradually etched, and the carbon atoms are rearranged to form a diamond structure.

[0043] Further, the pressure in the reaction chamber is between 1 and 10 Torr.

[0044] As described above, under the action of the microwave plasma, the graphite sheet layer is heated to between 2000 °C and 2500 °C. At this high temperature, the graphite structure is gradually etched, and the carbon atoms are rearranged to form a diamond structure. The pressure in the reaction chamber is maintained between 1 and 10 Torr to optimize the reaction conditions.

[0045] Further, the flow rate of the hydrogen gas is between 100 and 500 sccm.

[0046] As described above, a reaction gas is introduced into the reaction chamber, and the reaction gas is hydrogen (H 2 ). The flow rate of the hydrogen gas is controlled between 100 and 500 sccm (standard cubic centimeters per minute) to ensure a sufficient supply of hydrogen gas. Hydrogen gas not only acts as a reaction gas in the reaction but also plays a role in cleaning and activating the graphite surface.

[0047] Further, cooling the diamond film to stabilize the diamond film includes:

[0048] Rapidly cooling the diamond film through cooling circulating water to stabilize the diamond film.

[0049] Specifically, after the reaction is completed, the diamond film is rapidly cooled through a cooling circulating water system. Rapid cooling helps to stabilize the structure of the diamond film and prevent cracking or peeling of the film layer caused by sudden temperature changes. During the cooling process, the water temperature should be controlled within an appropriate range to ensure the quality of the diamond film.

[0050] In addition, the cooled diamond film can be further post-processed, such as surface polishing, cutting, or doping treatment, to meet the requirements of different applications. For example, doping with boron or nitrogen can change the electrical properties of the diamond film, making it suitable for electronic devices or sensors.

[0051] During the entire preparation process, the temperature, pressure, gas flow rate, and microwave power in the reaction chamber need to be monitored and adjusted in real time to ensure the quality and consistency of the diamond film. Through analytical means such as X-ray diffraction (XRD) and Raman spectroscopy, the crystal structure, purity, and defects of the diamond film can be characterized.

[0052] Furthermore, the purity of the diamond film is between 95% and 99%.

[0053] Specifically, as the reaction progresses, the graphite sheets gradually transform into a diamond film. The purity of the diamond film can reach between 95% and 99%, and the specific purity depends on the control of reaction conditions, such as temperature, pressure, gas flow rate, and microwave power, etc.

[0054] The diamond film prepared by the method provided in the embodiments of the present application has high hardness, high thermal conductivity, excellent chemical stability, and optical transparency, and can be widely used in fields such as cutting tools, optical windows, thermal management materials, semiconductor devices, etc. For example, in electronic devices, the diamond film can be used as an efficient heat dissipation material; in the optical field, high-purity diamond films can be used to manufacture the windows of high-power lasers.

[0055] In addition, the embodiments of the present application also provide a diamond film, which is made by the method described in any one of the above. The specific preparation method of this diamond film refers to the above embodiments. Since the specific preparation method of the diamond film adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, and will not be elaborated here one by one.

[0056] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for preparing a diamond film, characterized in that: The following steps are involved: Placing a graphite sheet on a sample stage of a reaction chamber; Introducing a reaction gas into the reaction chamber, converting the reaction gas into plasma by microwaves, and heating and etching the graphite sheet to convert the graphite sheet into a diamond film; and The diamond film is cooled to stabilize the diamond film.

2. The method according to claim 1, characterized in that The reaction gas is hydrogen.

3. The method according to claim 2, characterized in that The frequency of the microwave is 2.45 GHz.

4. The method according to claim 3, characterized in that The frequency of the microwave is 915 MHz.

5. The method according to claim 3 or 4, characterized in that The heating temperature of the graphite sheet is between 2000°C and 2500°C.

6. The method according to claim 2, characterized in that The pressure of the reaction chamber is between 1-10 Torr.

7. The method according to claim 6, characterized in that The flow rate of the hydrogen gas is between 100-500 sccm.

8. The method according to claim 1, characterized in that The step of cooling the diamond film to stabilize the diamond film comprises: The diamond film is quickly cooled by cooling circulating water to stabilize the diamond film.

9. The method according to claim 8, characterized in that The purity of the diamond film is between 95% and 99%.

10. A diamond film, characterized in that: The diamond film is produced by the method according to any one of claims 1 to 9.

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