Native oxide consumption during the atomic layer deposition of TiO 2 films on GaAs (100) surfaces

Abstract

The consumption of the surface native oxides is studied during the atomic layer deposition of TiO 2 films on GaAs (100) surfaces. Films are deposited at 200 °C from tetrakis dimethyl amido titanium and H 2O. Transmission electron microscopy data show that the starting surface consists of ~2.6 nm of native oxide and X-ray photoelectron spectroscopy indicates a gradual reduction in the thickness of the oxide layer as the thickness of the TiO 2 film increases. Approximately 0.1–0.2 nm of arsenic and gallium suboxide is detected at the interface after 250 process cycles. For depositions on etched GaAs surfaces no interfacial oxidation is observed.