A method for preparing silicon carbide coating on graphite surface

Abstract

The invention discloses a method for preparing a silicon carbide coating on a graphite surface. The method includes, firstly, placing a graphite crucible containing solid silicone materials in a high temperature graphitizing furnace and placing a graphite base body on a graphite support in the graphite crucible to generate a silicon carbide coating by means of direct reaction of silicon steam and carbon on the surface of the graphite base body; and secondly, placing the graphite base body which generates the silicon carbide coating on the surface in a chemical vapor deposition (CVD) furnace to be pyrolyzed on the surface of the silicon carbide coating which is located on the surface of the graphite base body to generate a CVD silicon carbide coating. According to the method for preparing the silicon carbide coating on the graphite surface, by means of the direct reaction of the silicon steam formed by heating the solid silicone materials and the carbon on the surface of the graphite base body, an in-situ formed chemical vapor reaction (CVR) silicon carbide coating is firmly combined on the graphite base body so that combination intensity is improved; and then a CVD process is used for pyrolyzing the CVR silicon carbide coating at high temperatures on the CVD silicon carbide coating so that pore space of the CVR silicon carbide coating is effectively filled, and combination strength is improved.

Description

technical field [0001] The invention belongs to the technical field of high-performance graphite coatings, in particular to a method for preparing silicon carbide coatings on graphite surfaces. Background technique [0002] Epitaxial technology and equipment are the key to semiconductor epitaxial wafer manufacturing technology. Metal organic chemical vapor deposition (MOCVD) is the main method for growing thin-layer single crystals of III-V, II-VI compounds and alloys (such as GaN, etc.). In MOCVD equipment, the reaction bases used are SiC-coated graphite materials. At present, SiC coated graphite has the following problems: (1) Bonding strength, due to the difference in expansion coefficient between graphite substrate and silicon carbide, the SiC coating prepared by traditional CVD process often cracks, resulting in coating failure; (2) Due to the difference in bonding strength, the service life of silicon carbide coated graphite is short, generally 100 heats / piece. Cont...

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Problems solved by technology

At present, SiC coated graphite has the following problems: (1) Bonding strength, due to the difference in expansion coefficient between graphite substrate and silicon carbide, the SiC coating prepared by traditional CVD process often cracks, resulting in coating failure; (2) Service life, due to the difference in bonding strength, the service life of silicon carbide coated graphite is short, generally 100 heats / piece

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