Crystal growth of micropipe free 4H–SiC on 4H–SiC{033¯8} seed and high-purity semi-insulating 6H–SiC

Micropipe free c-plane 4H–SiC wafers were achieved by sublimation growth on the 4H–SiC {033¯8} seed. 4H–SiC {033¯8} seeds were obtained by inclining the c  -plane to 〈011¯0〉 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 (vanadium-free) semi-insulating 6H–SiC was carried out by our sublimation system. In order to achieve high resistivity, high-purity SiC source and controlled instruments were used for the reduction of nitrogen, boron and metal impurity backgrounds. Hence high-purity and high-resistivity 6H–SiC 2 and 3 in in diameter were developed for high-frequency power transistors.