We have grown SiO2 film on the polycrystalline Si layer using excited ozone gas, which is produced by ultra-violet light irradiation to ozone gas, and characterized the electric properties of the SiO2 film at the MIS capacitor configuration. Even at room temperature, the SiO2 of ~8.5 nm thick can be grown in 60 min. on 1.5×1.5 cm2 poly-Si chips. The leakage current density across the SiO2 film was well fitted to the F-N tunnel current over 6 MV/cm and the breakdown occurred at above 12 MV/cm showing that the film properties satisfy the device quality. The oxidation rate of Si by the excited ozone gas did not show difference on between Si(100) and Si(111) wafers. These results indicate that excited ozone gas can form homogenous SiO2 film on the poly-silicon layer with grains with various silicon crystal orientations at the surfaces.