PRODUCTION OF SILICON CARBIDE

摘要

PROBLEM TO BE SOLVED: To efficiently reutilize a ground sludge by adding carbon to the ground sludge generated at the time of cutting a silicon wafer with a wire saw using an grinding slurry containing a silicon carbide grinding grain as a medium and heating under a non-oxidizing condition to obtain a silicon carbide crystal body. SOLUTION: The silicon carbide crystal body is obtained by adding the quantity of carbon necessary for converting metal silicon in the ground sludge to silicon carbide into the ground sludge generated at the time of cutting the wafer from a high purity silicon lump with the wire saw using the grinding slurry containing the silicon carbide grinding grain and a mineral oil. or an aq. solution as the medium and heating to >=1200 deg.C under the non-oxidizing condition. As the carbon to be added, a powdery, particularly <=75 μm particle diameter carbonaceous raw material such as a powdery petroleum based coke is preferably used. If an α-SiC useful as the grinding material is wanted, the heating temp. can be 2000-2500 deg.C and if a mixture base of α-SiC with β-SiC is wanted, the heating temp. can be 1400-2000 deg.C.