We have grown SiO2 films on polycrystalline Si using excited ozone produced by ultraviolet light irradiation of ozone, and characterized their electrical properties in the metal-insulator-semiconductor capacitor configuration. SiO2 films of similar to 8.5 nm thickness on poly- Si layers were grown in 60 min even at room temperature. The leakage current density across the SiO2 film fitted well the Fowler-Nordheim tunnel current behavior and breakdown occurred at above 12 MV/cm, showing that the film was of device quality. The rate of Si oxidation by excited ozone was similar for both Si (100) and Si (111) wafers, as was the interface trap density ( D-it ). These results indicate that excited ozone can form a homogenous SiO2 film on poly-silicon. We conclude that excited ozone is one of the most efficient reactive species for SiO2 film formation on poly- Si at room temperature. (c) 2007 The Electrochemical Society.