The morphology of etch pits in commercial 4H-SiC epi-wafer were investigated by molten-KOH etching. The etching process was optimized in 525~570℃ at 2~10 min and the novel type of etch pits was revealed. This type of etch pits have been considered as TED (threading edge dislocation) II, its origin and nature, however, are not reported yet. In this work, the morphology and evolution of etch pits during epitaxial growth were analyzed and the different behavior between TED and TEDII was discussed.
