Characterization of inclusions in SiC bulk crystals grown by modified lely method

We have investigated two types of inclusions. They were a dendrite and a transparent inclusion, which have been seldom reported. The dendrite consisted of carbon, titanium and vanadium except for silicon. It should be carbide of titanium and vanadium. The titanium and vanadium might be incorporated from the source. By using a high purity source, it is possible to prevent generation of the dendrite. The transparent inclusion was observed in the SiC bulk crystal even in the growth with the chemical treated SiC source powder. A remarkable feature of the transparent inclusion was to have a small empty core. It was considered that the core might be a trace of Si droplet caused by C/Si ratio fluctuation of sublimated gas. Therefore, the C/Si ratio during the growth should be stabilized to prevent generation of the transparent inclusions.