In some embodiments, an oxide layer is grown on a semiconductor substrate by oxidizing the semiconductor substrate by exposure to hydrogen peroxide at a process temperature of about 500° C. or less. The exposure to the hydrogen peroxide may continue until the oxide layer grows by a thickness of about 1 Å or more. Where the substrate is a germanium substrate, while oxidation using H2O has been found to form germanium oxide with densities of about 4.25 g/cm3, oxidation according to some embodiments can form an oxide layer with a density of about 6 g/cm3 or more (for example, about 6.27 g/cm3). In some embodiments, another layer of material is deposited directly on the oxide layer. For example, a dielectric layer may be deposited directly on the oxide layer.