In this paper, the SiC trench with low roughness was formed using ICP etching. A simple post-trench treatment of sacrificial oxidation and Ar annealing was developed to improve the trench surface quality. The sacrificial oxidation can smooth the trench sidewall and eliminate most of the step bunching. Ar annealing further reduce the roughness of the trench sidewall and simultaneously improve the trench shape. Through adopting the post-trench treatment the RMS roughness of the trench sidewall was reduced from 5.25nm to 0.5nm below.

SiC,ICP etching,Annealing,Trench