Native oxide consumption during the atomic layer deposition of TiO_2 films on GaAs (100) surfaces

摘要

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 ℃ 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.