Growth of anodic oxides on reactively sputtered TiNx films

Publisher Website
Google Scholar
Abstract
The anodic oxidation behaviour of reactively sputtered titanium nitride thin films deposited onto silicon substrates has been investigated in order to obtain oxynitride layers at room temperature. It has been found that small differences in the stoichiometry of the titanium nitride films may give rise to large changes in the reactivity with oxygen. Thus, a strong influence of N/Ti atomic ratio value on the oxidation kinetics is observed. Analysis of the films by Rutherford backscattering and secondary ion mass spectroscopy reveals that the oxide structure is formed by an outer oxidized thin layer composed of a mixture of TiO2 + TiNx followed by a thicker layer with oxygen atoms dissolved in the previously deposited layer of titanium nitride. After prolonged oxidation, no nitrogen is detected in the surface layer, which is only composed of TiO2. Interestingly, the thickness of the outer layer is almost independent of the formation voltage and the anodization current.