XPS Analysis of 4H-SiC Surfaces Oxidized by Helium-Based Atmospheric-Pressure Water Vapor Plasma for Plasma-Assisted Polishing

摘要

Plasma-assisted polishing (PAP) was successfully applied to single-crystal SiC to obtain an atomically flat surface without introducing any scratches. To clarify the flattening mechanism and increase the material removal rate (MRR) of PAP, investigation of the oxidation process in PAP is essential. In this study, we observed 4H-SiC (0001) surfaces processed by water vapor plasma oxidation using angle resolved X-ray photoelectron spectroscopy (ARXPS). Water vapor plasma oxidation was conducted for 1 min and 5 min. SiO_2 and silicon oxycarbide were observed as the oxidation products. A decrease in the plasma irradiation time decreased the thickness of the oxide layer, particularly that of the silicon oxycarbide layer.