Chemical vapor deposition method for integrally preparing C buffer layer and SiC protective coating on single crystal Si substrate

Abstract

The invention belongs to the technical field of preparation of protective coatings, and particularly relates to a chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate. A thermal excitation type chemical vapor deposition system is adopted, an HMDSO / n-Hexane system is selected as a raw material, the proportion of the HMDSO / n-Hexane system is controlled, a graphite rod is placed in a reaction cavity to serve as an auxiliary carbon source, and when the working pressure is 100-1000 Pa and the working temperature is 1000-1250 DEG C, a C buffer layer and a SiC protective coating which are compact in structure are deposited on the surface of a single crystal Si substrate. According to the method, the adopted raw materials are low in price and non-toxic and harmless, reaction by-products are non-toxic and harmless, the C buffer layer and the SiC protective coating can be integrally prepared through the method, and the prepared coating is compact in structure, good in combination with a single crystal Si matrix and capable of playing an excellent anti-corrosion protection role on the single crystal Si matrix.

Description

Technical Field

[0001] The invention belongs to the technical field of protective coating preparation, and in particular relates to a chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate. Background Art

[0002] In the semiconductor dry etching process, the silicon-based focus ring, as one of the core components in the etching chamber, has the function of adjusting the plasma distribution to ensure uniform etching of the wafer edge. However, the continuous and high-density plasma bombardment and the chemical corrosion of fluorine-containing gases during the etching process will cause physical and chemical damage to the surface of the silicon-based focus ring, thereby affecting the service life of the consumables. In order to increase the service life of the silicon-based focus ring, a SiC coating can be prepared on it. Studies have shown that preparing a SiC coating on the surface of a single-crystal Si substrate can increase the service life of the silicon-based focus ring by about 3 times.

[0003] However, due to the differences in lattice constant and thermal expansion coefficient between single crystal Si and SiC of 20% and 8% respectively, the SiC coating directly prepared on the surface of single crystal Si is prone to cracking and peeling. Therefore, the introduction of a C buffer layer between the single crystal Si substrate and the SiC coating has important practical significance for improving the interface bonding between Si and SiC. Summary of the invention

[0004] The purpose of the present invention is to provide a chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate, focusing on solving the problem that single crystal Si is easily lost in an etching environment and that it is difficult to combine single crystal Si with SiC.

[0005] In order to achieve the above object, the present invention adopts the following technical scheme: A chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate, using chemical vapor deposition technology, hexamethyldisiloxane (HMDSO) / n-hexane (n-Hexane) as raw materials, graphite rods as auxiliary carbon sources, and the gas system introduced into the reaction chamber is selected from HMDSO / n-Hexane-H 2 -Ar system, comprising the following steps: (1) Mix HMDSO and n-Hexane in a volume ratio of 1-5:1-5, stir evenly and use as a liquid raw material for preparing a C buffer layer and a SiC protective coating; (2) Before depositing the C buffer layer and the SiC protective coating on the single crystal Si substrate, hydrogen is introduced into the reaction chamber to etch the single crystal Si; (3) When depositing the C buffer layer and SiC protective coating on the single crystal Si substrate, the graphite rod is placed around the single crystal Si substrate, the deposition temperature is 1000℃~1250℃, the working pressure is 100Pa~1000Pa, and the furnace is cooled after the deposition is completed.

[0006] In the chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate, in step (1), HMDSO and n-Hexane are mixed in a volume ratio of 2:1, and the liquid raw material mixed with HMDSO and n-Hexane is fully stirred before use.

[0007] In the chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate, in step (2), the hydrogen flow rate is 10-1000 sccm and the etching time is 1-10 min.

[0008] In the chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate, in step (2), the hydrogen flow rate is 600 sccm and the etching time is 1 min.

[0009] The chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate, in step (3), the flow rate of the liquid raw material mixed with HMDSO and n-Hexane is 0.1-10 g / min, the flow rate of argon is 50-10000 sccm, the flow rate of hydrogen is 10-1000 sccm, the deposition temperature is 1000°C-1150°C, the working pressure is 500 Pa-1000 Pa, and the deposition time is 1-5 h.

[0010] In the chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate, in step (3), the flow rate of the liquid raw material mixed with HMDSO and n-Hexane is 1 g / min.

[0011] In the chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate, in step (3), the argon flow rate is 3000 sccm and the hydrogen flow rate is 600 sccm.

[0012] In the chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate, in step (3), the deposition temperature is 1150° C., the working pressure is 600 Pa, and the deposition time is 2 h.

[0013] The chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate has a thickness of 10 μm to 5 mm for the integrally deposited C buffer layer and SiC corrosion resistant protective layer on the single crystal Si substrate.

[0014] The chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate has a C buffer layer with a thickness of 1 μm to 50 μm and a SiC corrosion resistant protective layer with a thickness of 10 μm to 200 μm.

[0015] The design concept of the present invention is: At present, the preparation of silicon carbide coatings in industrial production mostly uses methyltrichlorosilane (MTS) as raw material. Its tail gas is corrosive and requires additional tail gas treatment equipment. In addition, the preparation of SiC coatings directly on the surface of single-crystalline Si will cause cracking and peeling. In response to the problem of tail gas pollution, the present invention starts with the raw materials, adopts chemical vapor deposition technology (CVD), and uses hexamethyldisiloxane (HMDSO) / n-hexane (n-Hexane) as the raw material system to avoid the introduction of chloride ions and the like. In response to the problem of Si-SiC interface bonding, we introduce a C buffer layer between the single-crystalline Si substrate and the SiC coating, use graphite rods as auxiliary carbon sources, and integrate the C buffer layer and SiC protective coating on the single-crystalline Si substrate to improve the interface bonding between single-crystalline Si and SiC. The introduction of the C buffer layer of the present invention provides a different interface bonding mode between the single-crystalline Si substrate and the SiC coating, which has better adaptability.

[0016] The present invention adopts a chemical vapor deposition method and uses low-cost environmentally friendly raw materials to successfully deposit a densely structured and well-combined C buffer layer and SiC protective coating on the surface of a single crystal Si, thereby solving the demand for longer service life of silicon-based components in an etching environment.

[0017] In addition, before the C buffer layer and SiC protective coating are deposited on the single crystal Si substrate, hydrogen is introduced into the reaction chamber to etch the single crystal Si, which has the functions of removing the oxide layer and pollutants on the surface of the single crystal Si substrate, cleaning the substrate surface, and increasing the surface active sites to promote the adsorption and surface reaction of the precursor. In addition, the process parameters of hydrogen etching of single crystal Si (such as: hydrogen flow rate of 10~1000sccm, etching time of 1~10min) are limited, and these details play an important role in improving the coating quality, bonding strength and other properties.

[0018] Furthermore, the present invention significantly improves the density of the coating and the interface bonding strength through the coordinated control of hydrogen etching pretreatment, a specific deposition temperature of 1000°C to 1250°C, and a working pressure of 100Pa to 1000Pa, which is superior to the performance of a single-layer SiC coating in the prior art.

[0019] The advantages and beneficial effects of the present invention are: 1. The raw materials used in the present invention are HMDSO and n-Hexane, which are inexpensive and non-toxic, and the reaction by-products are non-toxic and non-corrosive, thus avoiding the problem of corrosive tail gas from chlorine-containing raw materials and conforming to the trend of green manufacturing.

[0020] 2. The present invention proposes for the first time a process of depositing a C buffer layer and a SiC protective coating on a single crystal Si substrate by integrated CVD, combined with a graphite rod as an auxiliary carbon source, to achieve optimization of interface bonding, solving the problem of low efficiency caused by step-by-step deposition in traditional processes. The C buffer layer introduced in the present invention can effectively improve the interface bonding problem between Si and SiC, and can realize the integrated deposition of the C buffer layer and the SiC coating, greatly improving production efficiency. The prepared C buffer layer and SiC protective coating have a dense structure and are well bonded to the single crystal Si substrate, and can provide excellent corrosion protection for the single crystal Si substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The chemical vapor deposition process uses HMDSO / n-Hexane-H 2 Surface morphology of the SiC protective coating prepared by -Ar raw material system on single crystal Si surface at a deposition temperature of 1150℃.

[0022] Figure 2 The chemical vapor deposition process uses HMDSO / n-Hexane-H 2 -C buffer layer and SiC protective coating prepared by Ar feedstock system on single crystal Si surface at 1150℃ deposition temperature.

[0023] Figure 3 The chemical vapor deposition process uses HMDSO / n-Hexane-H 2 -Glancing incidence X-ray diffraction (GIXRD) pattern of SiC protective coating prepared by -Ar raw material system on single crystal Si surface at 1150°C deposition temperature. In the figure, the abscissa 2Theta represents the diffraction angle (°), and the ordinate Intensity represents the relative intensity (au).

[0024] Figure 4 The chemical vapor deposition process uses HMDSO / n-Hexane-H 2 -C buffer layer and SiC protective coating prepared by Ar raw material system on single crystal Si surface at 1150℃ deposition temperature.

[0025] Figure 5 The chemical vapor deposition process uses HMDSO / n-Hexane-H 2Surface morphology of the SiC protective coating prepared by -Ar raw material system on single crystal Si surface at a deposition temperature of 1100℃.

[0026] Figure 6 The chemical vapor deposition process uses HMDSO / n-Hexane-H 2 -C buffer layer and SiC protective coating prepared by Ar feedstock system on single crystal Si surface at 1100℃ deposition temperature.

[0027] Figure 7 The chemical vapor deposition process uses HMDSO / n-Hexane-H 2 GIXRD pattern of SiC protective coating prepared by -Ar raw material system on single crystal Si surface at 1100°C deposition temperature. In the figure, the abscissa 2Theta represents the diffraction angle (°), and the ordinate Intensity represents the relative intensity (au).

[0028] Figure 8 The chemical vapor deposition process uses HMDSO / n-Hexane-H 2 Cross-sectional EDS images of the C buffer layer and SiC protective coating prepared by the -Ar raw material system on the single crystal Si surface at a deposition temperature of 1100°C.

[0029] Fig. 9 The chemical vapor deposition process uses HMDSO / n-Hexane-H 2 Surface morphology of the SiC protective coating prepared by -Ar raw material system on single crystal Si surface at a deposition temperature of 1200℃.

[0030] Fig.10 The chemical vapor deposition process uses HMDSO / n-Hexane-H 2 -C buffer layer and SiC protective coating prepared by Ar feedstock system on single crystal Si surface at 1200℃ deposition temperature.

[0031] Fig.11 The chemical vapor deposition process uses HMDSO / n-Hexane-H 2 GIXRD pattern of SiC protective coating prepared by -Ar raw material system on single crystal Si surface at 1200°C deposition temperature. In the figure, the abscissa 2Theta represents the diffraction angle (°), and the ordinate Intensity represents the relative intensity (au).

[0032] Fig.12 The chemical vapor deposition process uses HMDSO / n-Hexane-H 2Cross-sectional EDS images of the C buffer layer and SiC protective coating prepared by the -Ar raw material system on the single crystal Si surface at a deposition temperature of 1200°C. DETAILED DESCRIPTION

[0033] In the specific implementation process, the present invention proposes a chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate, using a thermally excited chemical vapor deposition system, selecting HMDSO / n-Hexane-H 2 -Ar system and control the ratio of raw materials HMDSO and n-Hexane. The gas system introduced into the reaction chamber is HMDSO / n-Hexane-H 2 -Ar system, using a thermally excited chemical vapor deposition system, selecting HMDSO / n-Hexane system as the raw material and controlling its ratio, placing a graphite rod in the reaction chamber as an auxiliary carbon source, when the working pressure is 100Pa~1000Pa and the working temperature is 1000℃~1250℃, a densely structured C buffer layer and SiC protective coating are integrally deposited on the surface of the single crystal Si substrate.

[0034] The specific embodiments of the present invention are further described below. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0035] The experimental methods in the following examples are conventional methods unless otherwise specified. The experimental materials used in the following examples are commercially available unless otherwise specified.

[0036] Example 1 (deposition temperature 1150°C): In this embodiment, a chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate is as follows: (1) HMDSO and n-Hexane are mixed in a certain volume ratio of 2:1, and the mixture is fully stirred and used as a raw material for preparing a C buffer layer and a SiC protective coating; (2) Before depositing the C buffer layer and SiC protective coating on the single crystal Si substrate, hydrogen gas was introduced into the reaction chamber to etch the single crystal Si. The hydrogen flow rate was 600 sccm and the etching time was 1 min. (3) When depositing a C buffer layer and a SiC protective coating on a single crystal Si substrate, the flow rate of the liquid raw material mixed with HMDSO and n-Hexane is 1g / min, a graphite rod is placed around the single crystal Si substrate, the argon flow rate is 3000sccm, the hydrogen flow rate is 600sccm, the deposition temperature is 1150℃, the working pressure is 600Pa, and the deposition time is 2h. After the deposition is completed, the furnace is cooled to room temperature. The thickness of the C buffer layer deposited on the single crystal Si substrate is 10μm, and the thickness of the SiC protective coating is 40μm; (4) The C buffer layer and SiC protective coating deposited on the surface of the single-crystalline Si substrate have a dense structure, strong corrosion resistance, and good bonding with the single-crystalline Si substrate, which can provide excellent etching protection for the single-crystalline Si substrate.

[0037] Example 2 (deposition temperature 1100°C): In this embodiment, a chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate is as follows: (1) HMDSO and n-Hexane are mixed in a certain volume ratio of 2:1, and the mixture is fully stirred and used as a raw material for preparing a C buffer layer and a SiC protective coating; (2) Before depositing the C buffer layer and SiC protective coating on the single crystal Si substrate, hydrogen gas was introduced into the reaction chamber to etch the single crystal Si. The hydrogen flow rate was 600 sccm and the etching time was 1 min. (3) When depositing a C buffer layer and a SiC protective coating on a single crystal Si substrate, the flow rate of the liquid raw material mixed with HMDSO and n-Hexane is 1g / min, a graphite rod is placed around the single crystal Si substrate, the argon flow rate is 3000sccm, the hydrogen flow rate is 600sccm, the deposition temperature is 1100℃, the working pressure is 600Pa, and the deposition time is 2h. After the deposition is completed, the furnace is cooled to room temperature. The thickness of the C buffer layer deposited on the single crystal Si substrate is 4μm, and the thickness of the SiC protective coating is 11μm; (4) The C buffer layer and SiC protective coating deposited on the surface of the single-crystalline Si substrate have a dense structure, strong corrosion resistance, and good bonding with the single-crystalline Si substrate, which can provide excellent etching protection for the single-crystalline Si substrate.

[0038] Example 3 (deposition temperature 1200°C): In this embodiment, a chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate is as follows: (1) HMDSO and n-Hexane are mixed in a certain volume ratio of 2:1, and the mixture is fully stirred and used as a raw material for preparing a C buffer layer and a SiC protective coating; (2) Before depositing the C buffer layer and SiC protective coating on the single crystal Si substrate, hydrogen gas was introduced into the reaction chamber to etch the single crystal Si. The hydrogen flow rate was 600 sccm and the etching time was 1 min. (3) When depositing the C buffer layer and SiC protective coating on the single crystal Si substrate, the flow rate of the liquid raw material mixed with HMDSO and n-Hexane is 1g / min, the graphite rod is placed around the single crystal Si substrate, the argon flow rate is 3000sccm, the hydrogen flow rate is 600sccm, the deposition temperature is 1200℃, the working pressure is 600Pa, and the deposition time is 2h. After the deposition is completed, the furnace is cooled to room temperature, and the thickness of the SiC protective coating deposited on the single crystal Si substrate is 120μm; (4) The SiC protective coating deposited on the surface of the single-crystalline Si substrate has a dense structure and strong corrosion resistance, but there are many holes at the interface with the single-crystalline Si substrate, which can provide a certain etching protection for the single-crystalline Si substrate.

[0039] like Figure 1 As shown, in Example 1, HMDSO / n-Hexane-H is selected by chemical vapor deposition process. 2 Surface morphology of SiC protective coating prepared by -Ar raw material system on single crystal Si surface at 1150℃ deposition temperature, Figure 1 It can be seen that the surface roughness of the prepared SiC protective coating is very small and the arrangement is tight, with almost no defects such as holes and cracks.

[0040] like Figure 2 As shown, in Example 1, HMDSO / n-Hexane-H is selected by chemical vapor deposition process. 2 Cross-sectional view of the C buffer layer and SiC protective coating prepared by the -Ar raw material system on the single crystal Si surface at a deposition temperature of 1150°C, by Figure 2 It can be seen that the prepared C buffer layer and SiC protective coating have a dense structure, good interface bonding, and almost no defects such as holes and cracks.

[0041] like Figure 3 As shown, in Example 1, HMDSO / n-Hexane-H is selected by chemical vapor deposition process. 2 GIXRD patterns of C buffer layer and SiC protective coating prepared by -Ar raw material system on single crystal Si surface at 1150℃ deposition temperature, Figure 3 It can be seen that the diffraction peaks appearing in the figure are all diffraction peaks of 3C-SiC, and the (111) plane is the preferred orientation.

[0042] like Figure 4 As shown, in Example 1, HMDSO / n-Hexane-H is selected by chemical vapor deposition process. 2Cross-sectional EDS images of C buffer layer and SiC protective coating prepared by -Ar raw material system on single crystal Si surface at 1150℃ deposition temperature, Figure 4 It can be seen that the thickness of the prepared C buffer layer is 10 μm and the thickness of the SiC coating is 40 μm.

[0043] like Figure 5 As shown, in Example 2, HMDSO / n-Hexane-H is selected by chemical vapor deposition process. 2 Surface morphology of SiC protective coating prepared by -Ar raw material system on single crystal Si surface at 1100℃ deposition temperature, Figure 5 It can be seen that the surface roughness of the prepared SiC protective coating is very small and the arrangement is tight, with almost no defects such as holes and cracks.

[0044] like Figure 6 As shown, in Example 2, HMDSO / n-Hexane-H is selected by chemical vapor deposition process. 2 Cross-sectional view of the C buffer layer and SiC protective coating prepared by the -Ar raw material system on the single crystal Si surface at a deposition temperature of 1100°C, Figure 6 It can be seen that the prepared C buffer layer and SiC protective coating have a dense structure, good interface bonding, and almost no defects such as holes and cracks.

[0045] like Figure 7 As shown, in Example 2, HMDSO / n-Hexane-H is selected by chemical vapor deposition process. 2 GIXRD patterns of C buffer layer and SiC protective coating prepared by -Ar raw material system on single crystal Si surface at 1100℃ deposition temperature, Figure 7 It can be seen that there is no obvious diffraction peak in the figure, which indicates that the SiC protective coating is amorphous.

[0046] like Figure 8 As shown, in Example 2, HMDSO / n-Hexane-H is selected by chemical vapor deposition process. 2 Cross-sectional EDS images of C buffer layer and SiC protective coating prepared by -Ar raw material system on single crystal Si surface at 1100℃ deposition temperature, Figure 8 It can be seen that the thickness of the prepared C buffer layer is 4 μm and the thickness of the SiC coating is 11 μm.

[0047] like Fig. 9 As shown, in Example 3, HMDSO / n-Hexane-H is selected by chemical vapor deposition process. 2 Surface morphology of SiC protective coating prepared by -Ar raw material system on single crystal Si surface at 1200℃ deposition temperature, Fig. 9It can be seen that the surface roughness of the prepared SiC protective coating is very small and the arrangement is tight, with almost no defects such as holes and cracks.

[0048] like Fig.10 As shown, in Example 3, HMDSO / n-Hexane-H is selected by chemical vapor deposition process. 2 Cross-sectional view of the SiC protective coating prepared by the -Ar raw material system on the single crystal Si surface at a deposition temperature of 1200°C, Fig.10 It can be seen that the prepared SiC protective coating has a dense structure, but there are many holes at the interface between it and the single crystal Si substrate.

[0049] like Fig.11 As shown, in Example 3, HMDSO / n-Hexane-H is selected by chemical vapor deposition process. 2 GIXRD pattern of SiC protective coating prepared by -Ar raw material system on single crystal Si surface at 1200℃ deposition temperature, Fig.11 It can be seen that the diffraction peaks appearing in the figure are all diffraction peaks of 3C-SiC, and the (111) plane is the preferred orientation.

[0050] like Fig.12 As shown, in Example 3, HMDSO / n-Hexane-H is selected by chemical vapor deposition process. 2 Cross-sectional EDS images of C buffer layer and SiC protective coating prepared by -Ar raw material system on single crystal Si surface at 1200℃ deposition temperature, Fig.12 It can be seen that the thickness of the prepared SiC coating is 120 μm.

[0051] The results of the embodiments show that the present invention adopts a chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate. The C buffer layer and SiC protective coating prepared on the single crystal Si have strong corrosion resistance, a dense structure, and are well bonded to the single crystal Si substrate, and can provide excellent anti-etching effect on the single crystal Si substrate.

Claims

1. A chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate, characterized in that: Chemical vapor deposition technology is used, hexamethyldisiloxane HMDSO / n-hexane n-Hexane is used as raw materials, graphite rods are used as auxiliary carbon sources, and the gas system introduced into the reaction chamber is selected from the HMDSO / n-Hexane-H2-Ar system, including the following steps: (1) Mix HMDSO and n-Hexane in a volume ratio of 1-5:1-5, stir evenly and use as a liquid raw material for preparing a C buffer layer and a SiC protective coating; (2) Before depositing the C buffer layer and the SiC protective coating on the single crystal Si substrate, hydrogen is introduced into the reaction chamber to etch the single crystal Si; (3) When depositing the C buffer layer and SiC protective coating on the single crystal Si substrate, the graphite rod is placed around the single crystal Si substrate, the deposition temperature is 1000℃~1250℃, the working pressure is 100Pa~1000Pa, and the furnace is cooled after the deposition is completed.

2. A chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate according to claim 1, characterized in that: In step (1), HMDSO and n-Hexane are mixed in a volume ratio of 2:1, and the liquid raw material mixed with HMDSO and n-Hexane is fully stirred before use.

3. A chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate according to claim 1, characterized in that: In step (2), the hydrogen flow rate is 10~1000sccm and the etching time is 1~10min.

4. A chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate according to claim 3, characterized in that: In step (2), the hydrogen flow rate is 600 sccm and the etching time is 1 min.

5. A chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate according to claim 1, characterized in that: In step (3), the flow rate of the liquid raw material mixed with HMDSO and n-Hexane is 0.1~10g / min, the flow rate of argon gas is 50~10000sccm, the flow rate of hydrogen gas is 10~1000sccm, the deposition temperature is 1000℃~1150℃, the working pressure is 500Pa~1000Pa, and the deposition time is 1~5h.

6. A chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate according to claim 5, characterized in that: In step (3), the flow rate of the liquid raw material mixed with HMDSO and n-Hexane is 1 g / min.

7. A chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate according to claim 5, characterized in that: In step (3), the argon flow rate is 3000 sccm and the hydrogen flow rate is 600 sccm.

8. A chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate according to claim 5, characterized in that: In step (3), the deposition temperature is 1150°C, the working pressure is 600 Pa, and the deposition time is 2 h.

9. A chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate according to claim 1, characterized in that: The thickness of the C buffer layer and the SiC corrosion resistant protective layer deposited integrally on the single crystal Si substrate is 10μm~5mm.

10. A chemical vapor deposition method for integrally preparing a C buffer layer and a SiC protective coating on a single crystal Si substrate according to claim 9, characterized in that: The thickness of the C buffer layer is 1μm~50μm, and the thickness of the SiC corrosion resistant protective layer is 10μm~200μm.

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