CN101445392A - Graphite matrix flawless TaC coating and manufacturing method thereof - Google Patents

Abstract

The invention discloses a graphite matrix flawless TaC coating and a manufacturing method thereof. A tie coat is deposited on a graphite matrix. A TaC main coating is deposited on the outer layer of the tie coat. The tie coat is composed of a SiC-TaC codeposition coating or compounded by two transition layers of the SiC-TaC codeposition coating and a SiC-TaC laminated coating. When the tie coat is compounded by two transition layers of the SiC-TaC codeposition coating and the SiC-TaC laminated coating, the SiC-TaC codeposition coating serves as a first transition layer, and the SiC-TaC laminated coating serves as a second transition layer; and then the deposition of the tie coat is ended; or the SiC-TaC codeposition coating and the SiC-TaC laminated coating are alternatively deposited many times. Good TaC coating which has small heat stress, no macroscopic cracking, corrosion-resistance, and good thermal stability is deposited out of the surface of the graphite material. The method is suitable for preparing graphite substrate, graphite crucible, graphite windpipe, graphite guide shell coating in the crystal and semiconductor production, protecting and cleaning coating such as antisepsis, anti-pollution, anti-infiltration, anti-oxidation of graphite parts in other various hot environments.

Description

A kind of crackless TaC coating on graphite substrate and its manufacturing method

technical field

The invention relates to a TaC coating without cracks on graphite substrates. The invention also relates to a method for manufacturing the TaC coating without cracks on graphite substrates. It belongs to the field of production and preparation of crystals and semiconductor materials, and is mainly used for carbon materials such as graphite for crystals and semiconductor production. Or the preparation of high-performance coatings for components.

technical background

Graphite materials for crystal and semiconductor production refer to high-temperature and high-purity graphite materials or components such as bases, crucibles, heating elements, guide tubes, operators, tooling graphite, etc. for crystals and semiconductor production. Its purity and chemical stability and other properties It is directly related to the purity, performance and quality of semiconductor materials, so it is the key material for crystal and semiconductor production. Due to the volatile gases or crystals in graphite, semiconductor production process and graphite reaction gas, it has a significant impact on the performance and quality of crystals and semiconductors. The international common practice is to use high-temperature corrosion-resistant and anti-erosion coatings with good sealing performance Technology, to modify the surface of graphite, reduce or eliminate the influence of graphite on crystal, semiconductor composition, structure and performance, so as to achieve precise control of crystal, semiconductor composition and performance, and improve the quality of materials.

At present, chemical vapor deposition high-performance SiC and BN coating technologies are commonly used at home and abroad. On the one hand, it prevents the volatile gases in graphite from affecting crystals and semiconductors, and improves the quality of graphite; on the other hand, it prevents corrosion. The reaction of gas and graphite and the gas phase diffusion of carbon. However, practice has proved that for some new types of semiconductors with higher requirements or high-temperature corrosive gases, graphite parts after SiC and BN coating may still cause greater pollution and greater impact on the produced semiconductors. For example, when GaN and GaAlN epitaxial wafers are prepared by MOCVD growth technology, the carbon in SiC and boron in BN will still be in gaseous form (such as CH ₄ , SiH ₄ , BH ₃ ) due to the corrosion of high-temperature NH ₃ , H ₂ and other gases. have an impact on the quality of GaN semiconductors. Therefore, it is necessary to use substances with higher high temperature stability and stronger corrosion resistance as coating materials in order to obtain high-quality GaN and other semiconductors.

TaC has a high melting point (3880°C), and can withstand the erosion of almost all substances including aqua regia, acid, alkali, and salt in a reducing atmosphere (except for HF+HNO ₃ complex acid), and its high-temperature chemical stability and corrosion resistance are far superior. It is higher than SiC and BN, and TaC has good chemical compatibility with graphite, so TaC is an excellent graphite coating material. At present, the United States and Japan have begun to develop TaC coatings for GaN, GaAlN, AlN, GaAs, InP and other new crystals and graphite coatings for semiconductor production.

For example, Japan Toyo Tanso Co., Ltd. has started the research on TaC coating, and in 2006, it applied for a single TaC preparation technology patent (tantalum carbide coated carbon material and its manufacturing method, published in 200680000138.5, not authorized) in my country in 2006.

But as far as the current TaC preparation technology is concerned, it is mainly the preparation of a single TaC coating. Its disadvantages are: when the coating is thin, the air resistance is not high, and the desired purpose cannot be achieved; and when the thickness of the coating exceeds At a certain value (such as 20 μm), the coating is prone to cracks, thus losing the protection of graphite. The main reason is that the thermal expansion coefficient of TaC coating is large, which is more than twice that of high-purity graphite for semiconductors. If TaC coating is directly applied to high-purity graphite, it is easy to crack and be scrapped. The thermal expansion mismatch between TaC coating and semiconducting graphite must be solved in order to successfully realize the surface modification of semiconducting graphite with high performance TaC coating.

Contents of the invention

The first technical problem to be solved by the present invention is to provide a crack-free TaC coating deposited on the surface of a graphite substrate with small thermal stress, no macro cracks, corrosion resistance and good thermal stability.

The second technical problem to be solved by the present invention is to provide a method for manufacturing a carbide coating without cracks on a graphite substrate, which has good thermal shock resistance and can improve the anti-corrosion and anti-diffusion capabilities of the overall coating. .

In order to solve the above-mentioned technical problems, the graphite substrate crack-free TaC coating provided by the present invention includes a graphite substrate, a transition coating is deposited on the graphite substrate, and a TaC main coating is deposited on the outer layer of the transition coating ; The transition coating is composed of SiC—TaC co-deposition coating, or is composed of two transition layers of SiC—TaC co-deposition coating and SiC/TaC multilayer coating; the transition coating is SiC— When the TaC co-deposition coating and the SiC/TaC multi-layer coating are composed of two transition layers, the SiC-TaC co-deposition coating is used as the first transition layer, and the SiC/TaC multi-layer coating is used as the second transition layer. transition layer, and then end the deposition of the transition coating or alternately deposit SiC-TaC co-deposition coating and SiC/TaC multi-layer coating multiple times; The thickness of the SiC coating in the layer coating is 0.05-5 μm, the thickness of the TaC coating is 0.05-5 μm, and the thickness of the pure TaC coating is 5-1000 μm.

The manufacture method of graphite substrate without crack TaC coating provided by the invention, its method is:

(A) The preparation process of SiC—TaC co-deposited transition coating is as follows: the graphite substrate is placed in a chemical vapor deposition furnace, vacuumed to below 50Pa, heated to 900-1500°C, and carbon source gas, TaCl ₅ , trichloromethylsilane, hydrogen and Ar gas as a diluent gas, in which TaCl ₅ and trichloromethylsilane are brought in by Ar gas, the furnace pressure is maintained at 100-5000Pa, and the gas ratio is adjusted so that the molar ratio of TaC and SiC in the coating is between 0.15-7 range, SiC-TaC co-deposition transition coating thickness is 15-30μm;

(B), the preparation process of SiC/TaC multilayer transition coating is as follows: the graphite substrate is placed in a chemical vapor deposition furnace, vacuumed to below 50Pa, heated to 900-1500°C, and the furnace pressure is controlled to 100-5000Pa. Introduce trichloromethylsilane, hydrogen and diluent gas Ar to carry out SiC coating deposition _. Dilute the gas Ar gas to deposit TaC coating, the thickness of TaC coating is 0.05~5μm; stop the deposition of TaC coating, and proceed to the deposition of SiC coating again; stop the deposition of SiC coating again, and redo the deposition of TaC coating ; Repeatedly, multi-layer SiC/TaC coating deposition;

(C) The preparation process of the TaC main coating is as follows: the furnace pressure is controlled at 100-5000Pa, and carbon source gas, TaCl ₅ , hydrogen and Ar gas are introduced at the same time to deposit a pure TaC coating with a thickness of 5 ~1000μm.

The carbon source gas is CH ₄ , C ₂ H ₆ , C ₃ H ₈ , C ₃ H ₆ , C ₂ H ₄ or C ₂ H ₂ gaseous hydrocarbons or vaporizable hydrocarbons such as liquefied gas, natural gas, _Cyclohexane or _C6H6 .

The graphite substrate crack-free TaC coating and its manufacturing method adopting the above-mentioned technical scheme, in order to avoid the shortcomings of easy cracking and poor thermal shock resistance of the carbide coating on the surface of carbon materials such as graphite, multi-layer coating, gradient coating, co-deposition Thermal shock resistance of coating materials, and a method for manufacturing crack-free TaC composite coatings on graphite substrates was proposed. In the present invention, the SiC coating and the TaC coating are organically compounded, and the transition layer composed of SiC and TaC is deposited before depositing the TaC main coating, which can not only solve the problem of thermal expansion mismatch between the TaC coating and the semiconductor graphite, but also improve the The ability of the overall coating to resist corrosion and diffusion. The process technology of the present invention is simple, and control is convenient, mainly utilizes the principle of the designability of the chemical vapor deposition coating and the preparation principle of the transition coating to solve the key problem of thermal expansion mismatch between TaC and graphite and other substrates, so that the coating has Good thermal shock resistance. This method is suitable for the preparation of graphite bases, graphite gas pipes, graphite guide cylinders, graphite crucibles, TaC coatings for semiconductor production, and other graphite and other carbon parts used in various high-temperature environments for anti-corrosion, anti-pollution, anti-penetration, anti-oxidation, etc. Protective and cleaning coatings.

In summary, the present invention is a method for manufacturing a carbide coating without cracks, good thermal shock resistance, and can improve the corrosion resistance and diffusion resistance of the overall coating.

Description of drawings

Fig. 1 is a block diagram of the manufacturing process of a graphite substrate without a crack TaC coating;

Figure 2 is a SEM photo of TaC-SiC co-deposition coating;

Figure 3 is a SEM photo of TaC-SiC co-deposition coating and TaC/SiC multilayer transition coating;

Fig. 4 is the SEM photo of the TaC coating surface with TaC-SiC co-deposition and TaC/SiC multilayer composite transition coating;

Figure 5 is a SEM photo of the TaC coating section with TaC-SiC co-deposition and TaC/SiC multilayer composite transition coating;

Figure 6 is a SEM photo of a TaC coating with multiple TaC-SiC co-depositions and multiple TaC/SiC multilayer composite transition coatings.

Detailed ways

The present invention will be further described now in conjunction with accompanying drawing.

Example 1:

See Figure 1 for the process flow. Take high-purity graphite with a density higher than 1.80g/cm ³ as the base material, cut it into a sample of Φ50mm×7mm, and use 200 ^# , 400 ^# , 1000 ^# alumina water-resistant sandpaper to grind and polish successively. Wash with ultrasonic waves for 30-60 minutes, take it out and dry it in an oven at 130°C for 2 hours, weigh it, and put _it into a chemical vapor deposition furnace; evacuate it to below 50Pa, heat it to ₁₃₀₀ °C; _5. Trichloromethylsilane (CH ₃ SiCl ₃ ), hydrogen and diluent gas Ar gas, wherein TaCl ₅ and trichloromethylsilane (CH ₃ SiCl ₃ ) are brought in by Ar gas, the furnace pressure is kept at 2000Pa, and SiC— TaC co-deposition coating was deposited, after 10 hours, the thickness of SiC—TaC co-deposition coating was 23 μm (structure as shown in Figure 2); stop feeding trichloromethylsilane, and feed C ₃ H ₆ , TaCl ₅ , hydrogen and diluent gas Ar gas, keep the furnace pressure below 2000Pa, and deposit TaC coating. After 30 hours, the thickness of TaC coating is 100μm; stop feeding C ₃ H ₆ , TaCl ₅ , hydrogen, and only feed Ar gas; power off and cool; Baked out below 200°C. The obtained TaC coating is uniform golden yellow, with a dense, bright surface and no cracks.

Example 2:

See Figure 1 for the process flow. Take high-purity graphite with a density higher than 1.80g/cm ³ as the base material, cut it into a sample of Φ150mm×7mm, and use 200 ^# , 400 ^# , 1000 ^# alumina water-resistant sandpaper to grind and polish successively. Wash with ultrasonic waves for 30-60 minutes, take it out and dry it in an oven at 130°C for 2 hours, weigh it, and put it into a chemical vapor deposition furnace; vacuumize it below 50Pa, and heat it to _{970 °} C; TaCl ₅ , trichloromethylsilane (CH ₃ SiCl ₃ ), hydrogen and diluent gas Ar gas, wherein TaCl ₅ and trichloromethylsilane (CH ₃ SiCl ₃ ) are brought in by Ar gas, and the furnace pressure is maintained at 2000-3000Pa, Deposit SiC—TaC co-deposited coating for 10 hours, and the thickness of SiC—TaC co-deposited coating is 50 μm; ② Stop feeding trichloromethylsilane, and feed C ₃ H ₆ , TaCl ₅ , hydrogen and diluent gas Ar, and the furnace The pressure was kept below 3000Pa, and the TaC coating was deposited. After 2 _hours of deposition, the thickness of the TaC coating was _{about 1} μm. The furnace pressure is kept below 2000Pa, and the SiC coating is deposited. The thickness of the SiC coating is about 1 μm; alternately repeat ② and ③ several times; stop feeding trichloromethylsilane, and feed C ₃ H ₆ , TaCl ₅ , hydrogen and diluted Gas Ar gas, the furnace pressure is kept at 1000-2000Pa, and the TaC main coating is deposited, the thickness of the TaC main coating is 15μm; stop feeding C ₃ H ₆ , TaCl ₅ , hydrogen, and only feed Ar gas; power off and cool down; cooling Take it out of the oven below 200°C. The obtained TaC coating is uniform golden yellow, and the surface is dense, bright and free of cracks (as shown in Fig. 3 and Fig. 4).

Example 3:

See Figure 1, take high-purity graphite with a density higher than 1.80g/ ^cm3 as the base material, cut it into a sample of Φ150mm×7mm, use 200 ^# , 400 ^# , 1000 ^# alumina water-resistant sandpaper to grind and polish successively, and use ultrasonic Wash for 30-60 minutes, take it out and dry it in an oven at 130°C for 2 hours, weigh it, put it into a chemical vapor deposition furnace; vacuumize it to below 50Pa, and heat it to 900°C. (1) Simultaneously feed C ₃ H ₆ , TaCl ₅ , trichloromethylsilane (CH ₃ SiCl ₃ ), hydrogen and diluent gas Ar, wherein TaCl ₅ and trichloromethylsilane (CH ₃ SiCl ₃ ) are replaced by Ar The gas is brought in, the furnace pressure is kept at 2000-3000Pa, and the SiC-TaC co-deposition coating is deposited for 20 hours, and the thickness of the SiC-TaC co-deposition coating is 30 μm. (2) It consists of the following steps: ① stop feeding trichloromethylsilane, feed C ₃ H ₆ , TaCl ₅ , hydrogen gas and Ar gas as a diluent gas, keep the furnace pressure below 2000Pa, and deposit TaC coating, after 1 hr of deposition , the thickness of TaC coating is 0.05μm; ②Stop feeding C ₃ H ₆ , TaCl ₅ gas, and feeding trichloromethylsilane, hydrogen gas and diluent gas Ar, keep the furnace pressure below 2000Pa, and deposit SiC coating, after 1hr , the SiC coating thickness is 0.05 μm; alternately repeat ① and ② multiple times. (3) Repeat (1) and (2) alternately once (the structure is shown in Figure 5). Stop feeding trichloromethylsilane, feed C ₃ H ₆ , TaCl ₅ , hydrogen and diluent gas Ar, keep the furnace pressure at 1000-2000Pa, and deposit TaC main coating for 10 hours, the thickness of TaC main coating is 100μm ; If the deposition time is 100hr, the thickness of the TaC main coating is 1000μm. Stop feeding C ₃ H ₆ , TaCl ₅ , and hydrogen, and only feed Ar gas; turn off the power and cool down; cool to below 200°C and take out of the furnace. The obtained TaC coating is uniform golden yellow, with a dense, bright surface and no cracks.

Example 4:

See Figure 1, take high-purity graphite with a density higher than 1.80g/ ^cm3 as the base material, cut it into a sample of Φ150mm×7mm, use 200 ^# , 400 ^# , 1000 ^# alumina water-resistant sandpaper to grind and polish successively, and use ultrasonic Wash for 30 to 60 minutes, take it out and dry it in an oven at 130°C for 2 hours, weigh it, and put it into a chemical vapor deposition furnace; evacuate it to below 50Pa, and heat it to 1000°C. (1) Simultaneously feed C ₃ H ₆ , TaCl ₅ , trichloromethylsilane (CH ₃ SiCl ₃ ), hydrogen and diluent gas Ar, wherein TaCl ₅ and trichloromethylsilane (CH ₃ SiCl ₃ ) are replaced by Ar The gas is brought in, the furnace pressure is kept at 2000-3000Pa, and the SiC-TaC co-deposition coating is deposited for 10 hours, and the thickness of the SiC-TaC co-deposition coating is 5 μm. (2) It consists of the following steps: ① stop feeding trichloromethylsilane, feed C ₃ H ₆ , TaCl ₅ , hydrogen gas and Ar gas as a diluent gas, keep the furnace pressure below 200Pa, and deposit TaC coating, after 1 hr of deposition , the thickness of the TaC coating is 0.65μm; ② stop feeding C ₃ H ₆ , TaCl ₅ gas, feed trichloromethylsilane, hydrogen and diluent gas Ar, keep the furnace pressure below 200Pa, and deposit SiC coating, after 1hr , the SiC coating thickness is 0.25 μm; alternately repeat ① and ② multiple times. (3) Alternately repeat (1), (2) multiple times. Stop feeding trichloromethylsilane, feed C ₃ H ₆ , TaCl ₅ , hydrogen and diluent gas Ar, keep the furnace pressure at 100-200 Pa, and deposit the main TaC coating for 10 hours, and the TaC main coating is 8 μm. Stop feeding C ₃ H ₆ , TaCl ₅ , and hydrogen, and only feed Ar gas; turn off the power and cool down; cool to below 200°C and take out of the furnace. The obtained TaC coating is uniform golden yellow, with a dense, bright, and crack-free surface (the structure is shown in Figure 6).

Example 5:

See Figure 1 for the process flow. Take high-purity graphite with a density higher than 1.80g/cm ³ as the base material, cut it into a sample of Φ50mm×7mm, and use 200 ^# , 400 ^# , 1000 ^# alumina water-resistant sandpaper to grind and polish successively. Wash with ultrasonic waves for 30-60 minutes, take it out and dry it in an oven at 130°C for 2 hours, weigh it, and put it into a chemical vapor deposition furnace; evacuate it to below 50Pa, and heat it to 1500°C; simultaneously pass C ₃ H ₆ , TaCl _5. Trichloromethylsilane (CH ₃ SiCl ₃ ), hydrogen and diluent gas Ar gas, wherein TaCl ₅ and trichloromethylsilane (CH ₆ SiCl ₆ ) are brought in by Ar gas, the furnace pressure is kept at 5000Pa, and SiC— After 20 hours of deposition of the TaC co-deposition coating, the thickness of the SiC-TaC co-deposition coating was 50 μm; the feeding of trichloromethylsilane was stopped, and C ₆ H ₆ , TaCl ₅ , hydrogen and the dilution gas Ar were fed, and the furnace pressure was kept 5000Pa, for TaC coating deposition, after 30hrs, the thickness of TaC coating is 1000μm; stop feeding C ₃ H ₆ , TaCl ₅ , hydrogen, and only feed Ar gas; power off and cool down; cool down to below 200°C and leave the furnace. The obtained TaC coating is uniform golden yellow, with a dense, bright surface and no cracks.

Embodiment 6:

See Figure 1, take high-purity graphite with a density higher than 1.80g/ ^cm3 as the base material, cut it into a sample of Φ150mm×7mm, use 200 ^# , 400 ^# , 1000 ^# alumina water-resistant sandpaper to grind and polish successively, and use ultrasonic Wash for 30 to 60 minutes, take it out and dry it in an oven at 130°C for 2 hours, weigh it, and put it into a chemical vapor deposition furnace; evacuate it to below 50Pa, and heat it to 1000°C. (1) Simultaneously feed C ₃ H ₆ , TaCl ₅ , trichloromethylsilane (CH ₃ SiCl ₃ ), hydrogen and diluent gas Ar, wherein TaCl ₅ and trichloromethylsilane (CH ₃ SiCl ₃ ) are replaced by Ar The gas is brought in, the furnace pressure is kept at 2000-3000Pa, and the SiC-TaC co-deposition coating is deposited for 10 hours, and the thickness of the SiC-TaC co-deposition coating is 5 μm. (2) Consisting of the following steps, ① Stop feeding trichloromethylsilane, feed C ₃ H ₆ , TaCl ₅ , hydrogen and Ar gas as a diluent gas, keep the furnace pressure below 100Pa, and deposit TaC coating, after 1 hr of deposition , TaC coating thickness is 0.05μm; ②Stop feeding C ₃ H ₆ , TaCl ₅ gas, feeding trichloromethylsilane, hydrogen gas and diluent gas Ar, keep the furnace pressure below 100Pa, and deposit SiC coating, after 1hr , the SiC coating thickness is 0.05 μm; alternately repeat ① and ② multiple times. (3) Alternately repeat (1), (2) multiple times. Stop feeding trichloromethylsilane, feed C ₃ H ₆ , TaCl ₅ , hydrogen and diluent Ar gas, keep the furnace pressure at 100-200 Pa, and deposit TaC coating with a thickness of 80 μm. Stop feeding C ₃ H ₆ , TaCl ₅ , and hydrogen, and only feed Ar gas; turn off the power and cool down; cool to below 200°C and take out of the furnace. The obtained TaC coating is uniform golden yellow, with a dense, bright surface and no cracks.

Embodiment 7:

See Figure 1 for the process flow. Take high-purity graphite with a density higher than 1.80g/cm ³ as the base material, cut it into a sample of Φ330mm×8mm, and use 200 ^# , 400 ^# , 1000 ^# alumina water-resistant sandpaper to grind and polish successively. Wash with ultrasonic waves for 30-60 minutes, take it out and dry it in an oven at 130°C for 2 hours, weigh it, and put it into a chemical vapor deposition furnace; evacuate it to below 50Pa, and heat it to _{900 °} C; TaCl ₅ , trichloromethylsilane (CH ₃ SiCl ₃ ), hydrogen and diluent gas Ar gas, where TaCl ₅ and trichloromethylsilane (CH ₃ SiCl ₃ ) are brought in by Ar gas, the furnace pressure is kept at 5000Pa, and the SiC —TaC co-deposited coating was deposited for 10 hours, and the thickness of SiC—TaC co-deposited coating was 5 μm; ② Stop feeding trichloromethylsilane, and feed C ₃ H ₆ , TaCl ₅ , hydrogen and diluent gas Ar, and keep the furnace pressure 5000Pa, for TaC coating deposition, the thickness of TaC coating is 5μm, after deposition for 2hr; ③Stop feeding C ₃ H ₆ , TaCl ₅ gas, feeding trichloromethylsilane, hydrogen and diluent gas Ar, and keep the furnace pressure at 5000Pa , carry out SiC coating deposition, after 2 hours, SiC coating thickness is 5μm; alternately repeat ②, ③ multiple times; stop feeding trichloromethylsilane, and feed C ₃ H ₆ , TaCl ₅ , hydrogen and diluent gas Ar , the furnace pressure was maintained at 5000Pa, and the TaC coating was deposited for 20 hours, and the thickness of the TaC coating was 5 μm; stop feeding C ₃ H ₆ , TaCl ₅ , hydrogen, and only feed Ar gas; power off and cool down; cool to below 200°C out of the oven. The obtained TaC coating is uniform golden yellow, with a dense, bright surface and no cracks.

Claims (3)

1, a kind of graphite matrix flawless TaC coating comprises graphite matrix, it is characterized in that: deposit tie coat on described graphite matrix, in the outer deposition of described tie coat one deck TaC master coating; Described tie coat is made of SiC-TaC codeposition coating, or by SiC-TaC codeposition coating and two kinds of compound formations of transition layer of SiC/TaC laminated coating; When described tie coat is the compound formation of SiC-TaC codeposition coating and two kinds of transition layers of SiC/TaC laminated coating, described SiC-TaC codeposition coating is as first transition layer, described SiC/TaC laminated coating is as second transition layer, finish the deposition of tie coat then or carry out SiC-TaC codeposition coating and SiC/TaC laminated coating alternating deposit repeatedly; SiC-TaC codeposition tie coat thickness is 15～30 μ m, and the SiC coat-thickness is 0.05～5 μ m in the SiC/TaC laminated coating, and the TaC coat-thickness is 0.05～5 μ m, and pure TaC coat-thickness is 5～1000 μ m.

2, make the method for the described graphite matrix flawless TaC coating of claim 1, it is characterized in that:

(A), the preparation technology of SiC-TaC codeposition tie coat is as follows: in chemical vapor deposition stove, be evacuated down to below the 50Pa, be warmed to 900～1500 ℃, feed carbon source gas, TaCl simultaneously ₅, trichloromethyl silane, hydrogen and diluent gas Ar gas, wherein TaCl ₅, trichloromethyl silane is written into by Ar gas, furnace pressure keeps below the 5000Pa, adjusts gas ratio and makes TaC in the coating and SiC molar ratio in 0.15～7 scope, SiC-TaC codeposition tie coat thickness is 15～30 μ m;

(B), the preparation technology of SiC/TaC multilayer tie coat is as follows: in chemical vapor deposition stove, be warmed to 900～1500 ℃, the control furnace pressure feeds trichloromethyl silane, hydrogen and diluent gas Ar gas earlier below 5000Pa, carry out SiC coating deposition, the SiC coat-thickness is 0.05～5 μ m; Then, stop the deposition of SiC coating, feed carbon source gas, TaCl ₅, hydrogen and diluent gas Ar gas, carry out TaC coating deposition, the TaC coat-thickness is 0.05～5 μ m; Stop the deposition of TaC coating, carry out the deposition of SiC coating once more; Stop the deposition of SiC coating once more, carry out the deposition of TaC coating again; Repeatedly repeat, carry out multilayer SiC/TaC coating deposition;

(C), the preparation technology of TaC master's coating is as follows: furnace pressure keeps feeding carbon source gas, TaCl simultaneously below the 5000Pa ₅, hydrogen and diluent gas Ar gas, carry out pure TaC coating deposition, the TaC coat-thickness is 5～1000 μ m.

3, the manufacture method of graphite matrix flawless TaC coating according to claim 2 is characterized in that: described carbon source gas is CH ₄, C ₂H ₆, C ₃H ₈, C ₃H ₆, C ₂H ₄Or C ₂H ₂Gaseous hydrocarbon maybe can vaporize hydrocarbon polymer such as liquefied gas, Sweet natural gas, hexanaphthene or C ₆H ₆

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