Abstract
The reaction-sintered (RS) SiC is very useful material for mold of glass lens, parts of equipment for fabrication of semiconductor device, and substrate of space telescope. However, it is difficult to obtain high precision surface efficiently because of its high hardness and chemical inertness. We proposed a new finishing technique named plasma-assisted polishing (PAP) which combining the irradiation of atmospheric pressure water vapor plasma and abrasive polishing. The processed surfaces were observed by microscopic interferometer, AFM, and SEM to evaluate the roughness and scratches. The observation results showed that plasma assisted polishing using CeO2 abrasive obviously decreased the scratches on the surface compared with the surface polished by diamond abrasive though these two kinds of abrasive had the same average diameter of 0.5 μm. In the case of low RF power condition (12 W), protrusions with a height of 10-20 nm were formed on the surface. In contrast, increase of the RF power (30 W) resulted in no protrusion and surface roughness was improved from 4.625 nm rms to 2.314 nm rms.
