Clearance of 4H-SiC Sub-Trench in Hot Chlorine Treatment

Abstract

The sub-trenches in 4H-SiC Si- and C-faces could be disappeared by the thermal treatment in chlorine ambience at 900-1000oC. The surface morphologies of the thermally treated trench-sidewalls were unchanged. It is considered that the sub-trench is selectively removed because thermally Cl2 etching rate of the (0001) Si- and (000-1) C-face are different to the (11-20) and (1-100).