Verfahren zum Herstellen von hochreinem Siliciumcarbidpulver und Verfahren zum Herstellen eines Siliciumcarbid-Einkristalls

摘要

A process for producing high purity silicon carbide uses a high purity tetraethoxysilane or the like as the silicon source and a novolak-type phenol resin or the like as the carbon source. The process comprises a step of forming silicon carbide in which silicon carbide powder is prepared by calcining a mixture of these sources in a non-oxidizing atmosphere, and a step of post-treating silicon carbide in which the silicon carbide powder thus obtained is treated by heating at a temperature of 2000 DEG to 2100 DEG C. for 5 to 20 minutes at least once while the silicon carbide powder is kept at a temperature of 1700 DEG or higher to lower than 2000 DEG C., to obtain silicon carbide powder having an average particle diameter of 10 to 500 mu m and a content of impurity elements of 0.5 ppm or less. The high purity silicon carbide powder is advantageously used as a material for producing an excellent silicon carbide single crystal having a decreased number of crystal defects.