Syntaxy and defect distribution during the bulk growth of 4H-SiC Single crystal

In the present study, the inclusion of 6H foreign polytype was seen during the initial growth of 4H polytype silicon carbide single crystal by PVT technique. The foreign polytype inclusion was gradually diminished with growth time; the mechanism is described in the present paper. In order to study the defects, the SiC specimen was wet etched using KOH solution at higher temperature and it was found that the foreign polytype inclusions i.e. 6H polytype introduced high density of defects at the polytype boundary. The defect distribution in different regions viz. 6H polytype foreign inclusion, 4H polytype region and polytype boundary were found to be different. It is interesting to note that the threading screw dislocation was not seen in 6H-polytype inclusion region.