Off-Orientation Influence on C-Face (0001) 4H-SiC Surface Morphology Produced by Etching Using Chlorine Trifluoride Gas

Abstract

The C-face (0001) 4H-SiC surface morphology produced by etching using chlorine trifluoride gas was studied, focusing on the influence of the off-orientation. The etching pit at the 4° off-oriented surface was formed at a temperature higher than 973 K, which was higher than 623 K for the on-axis surface. At 1073 K, the hexagonal-shaped etching pits were observed after the etching at the chlorine trifluoride gas concentration of less than 3%. In the temperature range lower than 900 K, the mirror surface could be maintained after the etching. Thus, the mirror surface and the pitted surface are expected to be formed on the 4° off-oriented surface by means of appropriately adjusting the parameters, such as the temperature and the chlorine trifluoride gas concentration.