Abstract
We have tried to process many materials by acting the oxidization/reduction reactions of electron and hole provided in photocatalyst and fluorescent substance by irradiating an ultraviolet ray, and by applying the mechanical scratching action of photocatalyst and abrasive grit. The polishing phenomena of 4H-SiC wafer are discussed as a fundamental study of ultraviolet-ray aided machining. The following conclusions are obtained by discussing a polishing characterization of 4H-SiC wafer. XPS qualitative analysis and ICPS quantitative analysis estimate the chemical forms induced on 4H-SiC wafer that was irradiated by an ultraviolet ray. The as-received sample provides the spectra of SiO and SiOx. An irradiation of an ultraviolet ray forms SiO2 on the as-received 4H-SiC wafer. Polishing using 0-2 μm-sized diamond grit cannot remove the deep dents that sand blast processed 4H-SiC wafer, completely. Polishing using 28.8 nm-sized diamond grit attains about 0.5 nm Ra of surface roughness, when 4H-SiC wafer was polished using 7nm-sized TiO2-Cathilon-H2O slurry in ultraviolet-ray irradiation. Polishing after sand blasting appears a spectrum of SiC, and forms a spectrum of SiO2 on Si plane.
