Method of producing silicon-carbide single crystals by sublimation recrystallization process using a seed crystal

Abstract

Abstract There is provided a method of producing a high-quality n-type, 6H silicon carbide single crystal with good reproducibility. A silicon carbide single crystal substrate having a growth orientation of <0001>, as a seed crystal, is mounted to an inner surface of a cover of a graphite crucible. A source material includes a high-purity silicon carbide powder having an impurity proportion of not more than 1 ppm and an aluminum powder of 50 ppm relative to the silicon carbide powder. The source material is loaded into the graphite crucible. The graphite crucible is closed with a seed crystal-mounted cover placed in a double quartz tube. Ar gas and N 2 gas are caused to flow in the double quartz tube. Temperature of the silicon carbide powder and aluminum powder is controlled to 2300° C., and temperature of the silicon carbide single crystal substrate to 2200° C.; and interior of the double quartz tube is controlled to 30 torr. Silicon carbide single crystal growth is effected on the seed crystal under these conditions. A high-quality n-type, 6H silicon carbide single crystal is thus obtained which has a uniform crystal structure with little defect, if any, throughout its structure, from the substrate surface to the outermost grown surface, and has a specific resistance of 0.5 Ωcm.

Inventors

• 👤 Katsuki Furukawa
• 👤 Yoshimitsu Tajima
• 👤 Akira Suzuki

Bibliographic Details