Research on Chemical Mechanical Polishing Technology of SiC Mirror

摘要

This paper makes an researches on high precision polishing process of SiC mirror by using mechanical and chemical polishing combined methods. The chemical compositions, mechanical characteristics of SiC and the factors which affect the polishing precision and quality are analyzed. Also, the components of polishing liquid, polishing pad and the pressure of the millstone are also optimized. Then the author polishes a 220mm diameter SiC mirror which the roughness is less than 1 nm. The results show that the combination of chemical and mechanical polishing can overcome the traditional shortcomings of mechanical polishing and chemical etching method, improve the removal rate, further improve the polishing surface roughness, get the small surface damage layer and high integrity of smooth surfaces.