HF-originated radicals generated in a
plasma-forming chamber are fed to a treatment chamber via feed holes, while HF gas molecules as the treatment gas are supplied to the treatment chamber from near the radical feed holes to suppress the excitation energy, thereby increasing the selectivity to Si to remove a native
oxide film. Even with the dry-treatment, the surface treatment provides good
surface flatness equivalent to that obtained by the wet-cleaning which requires high-
temperature treatment, and further attains growth of Si
single crystal film on the substrate after the surface treatment. The surface of formed Si
single crystal film has small quantity of impurities of
oxygen, carbon, and the like. After
sputtering Hf and the like onto the surface of the grown Si
single crystal film, oxidation and
nitrification are applied thereto to form a
dielectric insulation film such as HfO thereon, thus forming a
metal electrode film. All through the above steps, the substrate is not exposed to
atmospheric air, thereby suppressing the adsorption of impurities onto the interface, and thus obtaining a C-
V curve with small
hysteresis. As a result, good device characteristics are obtained in MOS-FET.