Passivation and temperature effects on the oxidation process of titanium thin films

Auger electron spectroscopy and ion sputtering depth profiling have been used to study Ti thin film oxidation and Ti–O2 co-adsorption processes. The equilibrium oxide stoichiometry depends not only on the substrate temperature and interface effects, but also on the way the oxygen is incorporated. Heating the sample, either when the room temperature saturation has been achieved (post-oxidation), or from the beginning of the process, produces additional oxidation as compared to the room temperature experiment but in neither case the films are completely oxidized, being the saturation state characterized by a mixture of TiO and TiO2. The only way of obtaining a fully oxidized film with sharp oxide–metal interface is through the simultaneous adsorption of oxygen and titanium.