To use SiC substrate as a semiconductor device and epitaxial growth, the surface of SiC substrate should be made smooth at an atomic level in the state of monocrystalline. But, the past slurry caused defects such as the pit and the scratch on the surface. This tendency was very strong in (000-1) C-face. We achieved ideal surface for SiC devices using newly developed slurry. In this surface, the roughness (Ra) of (0001) Si face and (000-1) C face evaluated by the AFM were 0.1nm or less, and confirmed that the surface were monocrystalline by CAICISS measurement. From these results, it is thought that the crystal face obtained by the slurry newly developed. In addition, the Schottky barrier diode was formed directly on the polished surface, that was obtained the breakdown voltage of 1.2kV or more. We thought that this results is possible to make the Schottky barrier diode without epitaxial growth.