Formation of excess silicon on 6H-SiC(OOOl) during hydrogen etching

Abstract

The surface of 6H-SiC(OOOl) samples was subjected to etching under H2/Ar gas mixture in a cold-wall tubular furnace. Its topography and properties were characterized by atomic force microscopy and X-ray photoelectron spectroscopy before and after hydrogen etching. The conditions have been found, under which surface polishing-related damages could be removed. Si droplets were observed under certain etching conditions. The effect of the samples' cooling rate on the obtained surface morphology and chemistry was investigated to unveil the mechanism of Si recrystallization onto the crystal surface upon etching.