Chemical vapor deposition method and device for preparing polycrystalline silicon carbide

Abstract

The invention provides a chemical vapor deposition method and device for preparing polycrystalline silicon carbide, and belongs to the technical field of chemical vapor deposition. The method comprises the steps: raising the temperature of a chemical vapor deposition chamber to 400-500 DEG C within 2-4 h, and carrying out heat preservation for 4-6 h; raising the temperature to 1100-1500 DEG C within 4-10 h, and carrying out heat preservation for 1-2 h; then carrying out chemical vapor deposition, cooling to 700-800 DEG C within 30-55 h, and carrying out heat preservation for 4-6 h, and coolingto room temperature within 40-60 h, so as to ensure that the obtained silicon carbide product is complete, free of cracking, higher in purity, flatter and smoother in surface and smaller in particlesize. The deposition chamber is divided into the chemical vapor deposition chamber and a dust collection chamber by a partition plate with holes; a gas inlet of the chemical vapor deposition chamber and a gas outlet of the dust collection chamber are positioned above the holes, so airflow flows in the chamber in a Z-shaped mode, the walking path and the retention time of the airflow in the chambers are prolonged, the decomposition degree of methyl trichlorosilane is increased, the yield is increased, meanwhile, methyl trichlorosilane entering a rear-end gas outlet pipeline is reduced, pipelineblockage is avoided, and production is guaranteed to be smoothly carried out.

Description

technical field [0001] The invention belongs to the technical field of chemical vapor deposition, and in particular relates to a chemical vapor deposition method and device for preparing polycrystalline silicon carbide. Background technique [0002] In the semiconductor electronics industry in recent years, SiC (silicon carbide) has attracted great interest, and it is a good candidate material for semiconductor devices used in some extreme conditions, such as high temperature and radiation environments, high power applications, High thermal power dissipation, etc. SiC ceramic materials have many excellent physical and chemical properties, such as high specific strength, high specific modulus, low density, high hardness, high thermal conductivity, low thermal expansion coefficient, corrosion resistance, oxidation resistance, etc., so they are widely used in high temperature structural materials. favor. [0003] There are many methods for preparing SiC ceramics, such as pres...

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Problems solved by technology

However, the SiC mainly prepared at present is a silicon carbide film, and it is seldom possible to prepare a silicon carbide bulk material with a certain thickness.

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