Etching of poly 3C-SiC by magnetron RIE and its application to surface micromachining

Magnetron reactive ion etching (RIE) properties of polycrystalline (poly) 3C-SiC thin films grown on thermally oxidized Si wafers by atmospheric pressure chemical vapor deposition (APCVD) were characterized in this paper. Poly 3C-SiC has been etched by CHF₃, which can form a polymer as a function of side wall protective layers, O₂ and Ar gases. The magnetron RIE, in particular, can etch SiC at a lower ion energy than the commercial RlE system. Etch rates were obtained ranged from 20 Aring/min to 400 Aring/min according to various conditions, such as gas flow rates, chamber pressure, and RF power The etched poly 3C-SiC film was undamaged and stable at 70 W. Moreover, the best vertical structures were improved by the addition of 40 % O₂ and 16 % Ar with the CHF₃ reactive gas. Therefore, poly 3C-SiC etched by the magnetron RIE has the potential to be applied to microstructures for micro/nano electro mechanical systems (M/NEMS) applications.