4H polytype grain formation in PVT-grown 6H-SiC ingots

Multi-domained PVT (physical vapor transport)-grown 6H-SiC ingots, in which large 4H-SiC grains exist with their crystal directions strongly misoriented with regard to the single crystal matrix geometry, are investigated extensively from the viewpoint of the generation mechanism of the misoriented grains. Microstructural observations reveal that there exist a number of fine SiC inclusions inside the 6H-SiC matrix. We suggest that these inclusions are likely to be the embryos of the misoriented grains.