Characterization of oxide films on SiC by spectroscopic ellipsometry

We have, for the first time. evaluated the optical constants of thermally o xidized films on SIC by spectroscopic ellipsometry, and discussed the chara cteristics of SiC/SiO2 interfaces. It was found that the effective refracti ve indices are smaller than those of the oxide films on Si. They increase w ith oxidation time, or oxide thickness, reaching to the values of Si oxides . The refractive indices also depend on the oxidation methods, and the pyro genic oxidation brings about larger refractive indices than dry oxidation. The origin of the small refractive indices of oxide films on SiC was discus sed in terms of interface structures and composition in comparison with tho se of oxide films on Si.