Silicon carbide (SiC) has a high temperature strength, and excellent wear resistance, oxidation resistance, corrosion resistance and creep resistance. Silicon carbide is present in a β phase having a cubic crystal structure and in an α phase having a hexagonal crystal structure. The β phase is stable at a temperature of 1400 to 1800° C., and the α phase is formed at 2000° C. or more.
Silicon carbide is widely used for industrial structures, and has recently been applied in the semiconductor industry. To use silicon carbide in single crystal growth, granular silicon carbide powder having uniform size distribution is needed. The granular silicon carbide powder may be obtained by annealing fine silicon carbide powder under predetermined conditions.
However, when the fine silicon carbide powder is annealed at a temperature lower than 2000° C., β-phase silicon carbide powder having uniform size distribution may be obtained, but granular silicon carbide powder having a size of 40 μm or more is difficult to obtain.
However, when the fine silicon carbide powder is annealed at 2000° C. or more, α-phase silicon carbide powder having a size of 100 μm or more may be obtained, but it has non-uniform size distribution due to the fine silicon carbide powder mixed therein.