Micropipe-free c-plane 4H–SiC wafers were achieved by sublimation growth on the 4H–SiC {0338} seed. 4H–SiC {0338} seeds were obtained by inclining the c-plane to <0110> at 54.7°. A transmission X-ray topograph of the micropipe-free c-plane wafer revealed that there were no macroscopic defects with lattice displacements. Crystal growth of undoped (V-free) semi-insulating 6H–SiC was carried out by the sublimation system. In order to achieve high resistivity, high-purity SiC source and controlled instruments were used for the reduction of N, B and metal impurity backgrounds. Thus, high-purity and high-resistivity 6H–SiC, 2 and 3in in diameter, were developed for high-frequency power transistors.

Crystal Growth of Micropipe-Free 4H–SiC on 4H–SiC {0338} Seed and High-Purity Semi-Insulating 6H–SiC. H.Shiomi, H.Kinoshita, T.Furusho, T.Hayashi, M.Tajima, E.Higashi: Journal of Crystal Growth, 2006, 292[2], 188-91