High quality gate dielectric film on poly-silicon grown at room temperature using UV light excited ozone

We have grown Si O2 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. Si O2 films of ∼8.5 nm thickness on poly-Si layers were grown in 60 min even at room temperature. The leakage current density across the Si O2 film fitted well the Fowler-Nordheim tunnel current behavior and breakdown occurred at above 12 MVcm, 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 (Dit). These results indicate that excited ozone can form a homogenous Si O2 film on poly-silicon. We conclude that excited ozone is one of the most efficient reactive species for Si O2 film formation on poly-Si at room temperature.