CF4/O-2 mole ratio dependence of the RIE rate of SiC, Si and C reveals the RIE rate of SiC is controlled by the sputtering rate of the constituent C atoms. The chemical reaction, which removes Si atoms from the reaction surface, contributes to Battening the surface. XPS analysis shows light etching (about 0.5nm depth) after the RTE removes residual impurities on the etched surface. An accumulation-mode MOS channel is fabricated by RIE. An effective mobility as high as 100cm(2)/Vs is obtained, which indicates that a high quality MOS channel is fabricated using RIE in CF4/O-2 gas mixtures.