Effect of crucible design on the shape and the quality in 6H-SiC crystals grown by physical vapor transport

In this study, we newly designed the inner shape of crucible to improve the growth morphology and the quality of crystal grown by physical vapor transport. The effect of crucible design on the shape and the quality of grown crystal was investigated. Modified crucible contained a truncated-cone shaped pedestal at the bottom. Recrystallization severely occurred on the surface of source in case of a crucible without truncated cone. But for the crucible with it, sublimation of source was relatively uniformly achieved and sublimation yield was also increased. Crystal grown in a crucible with a truncated cone showed better morphology, smaller value of FWHM and less dislocation density than crystal without it. And a further enlargement was achieved in the crystal. The geometry of truncated cone was optimized in order to grow a crystal with best growth morphology and the highest quality. The experimental results were also discussed with the result of temperature distribution calculation.