Interface state density reduction by ultraviolet–ozone treatment on Al₂O₃/GeO₂ films

Abstract GeO2 prepared via thermal oxidation at ambient pressure is known to be of poor-quality owing to numerous defects and high interface states. Several methods for fabricating high-quality GeO2 films been reported, such as applying pressure, but all of them present challenges. Therefore, a simpler fabrication method is required. In this study, we attempted to reduce defects and interface states in GeO2/Ge prepared via atmospheric-pressure thermal oxidation using ultraviolet–ozone (UVO) treatment. Measurement results indicated that UVO treatment can reduce defects and interface states to the same level as that of high-quality GeO2/Ge reported thus far.