Identification of SiC polytypes by etched Si-face morphology

The relationship between polytypes and etched Si face morphology of SiC was investigated in this paper. The defect-selective wet-etch technique was used to give an anisotropic etching of SiC. The regular but different shape etching pits were observed on the Si face. Raman spectra were applied to verify the polytypes information of the regions with different etching pits. The experimental results show that the green SiC crystal with perfect hexagonal etching pits is 6H-SiC along the (0 0 0 1) direction and the pistachio region with three long-edges and three short-edges hexagon etching pits belong to 15R-SiC along the (0 0 0 1) direction.