Dislocation processes during physical vapour transport (PVT) growth of SiC single crystals were investigated by defect selective etching. It was found that foreign polytype inclusions introduced a high density of dislocations at the polytype boundary. In the polytype-transformed areas of the crystal, very few medium size hexagonal etch pits due to threading screw dislocations were observed, indicating that the polytype transformation ceased the propagation of threading screw dislocations. The oval-shaped etch pit arrays observed on the etched vicinal (00▪1)Si surface, indicative of the dislocation multiplication in the basal plane, showed characteristic distribution around micropipes. It was suggested that dislocation interaction and conversion were relevant processes for understanding the observed behavior.

Dislocation Processes during SiC Bulk Crystal Growth. N.Ohtani, M.Katsuno, H.Tsuge, T.Fujimoto, M.Nakabayashi, H.Yashiro, M.Sawamura, T.Aigo, T.Hoshino: Microelectronic Engineering, 2006, 83[1], 142-5