Study of ultraviolet-ray aided machining (22th Report)

Polishing characterization of 4H-SiC wafer under ultraviolet-ray excitation (Part 3)

Abstract

X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) were used to qualitatively analyze the 4H-SiC surface. These analyses were used to estimate the compounds that are formed/removed by decomposition of cathilon in water during the polishing of 4H-SiC using TiO₂-cathilon slurry which included diamond powder. The ICPS measurement indicates that 4H-SiC dissolves in the aqueous solution of cathilon, very slightly. The XAS and the XPS indicate that the immersion of an as received 4H-SiC in TiO₂-cathilon aqueous solution results the interface oxide in SiC. The chemical-mechanical polishing of the 4H-SiC using TiO₂-cathilon slurry forms oxide, interface oxide, oxynitride and nitride. Polishing using TiO₂-cathilon slurry included 28.8 nm-sized diamond attains the surface roughness of about 0.5 nm of Ra or several nm of Rz under ultraviolet-ray irradiation, tentatively.