Influence of Impurities in SiC Powder on High Quality SiC Crystal Growth

SiC powders having different purities were prepared by carbothermal reduction under different conditions from traditional process and SiC single crystals were grown by the PVT method from the powders. After crystal growth, boule was cut to wafers and they were polished for chemical and defect analyses. Total impurities including Al, B and Ti which were derived from powders decreased remarkably during crystal growth. The formation of defects including micropipe and dislocations such as TED, TSD and BPD was strongly influenced by impurity content. The effect of impurity seemed to be negligible at below 1ppm level for MPD. On the other hand, dislocations continuously decreased even more when higher purity SiC powder below 1ppm level was used.