Super-smooth surface nanometer fabrication of chemical vapor deposition SiC

Silicon Carbide (SiC) is well known as an important optical material in aerospace optical system and high power laser optics. But the optical fabrication of SiC limits its usage widely. In this paper, domestic Chemical Gas Deposition (CVD) SiC material was polished by conventional optical fabrication method, in which ceramic disk and diamond powder were used to grind and lap, and then diamond oil with grain size from 4 μm to 1 μm was used to polish. After polishing nanometer scratches were found under AFM. 20 nm diameter Al2O3 alkali solution was used to continue to polish SiC surface and a surface roughness of 0.6 nm was achieved.