Abstract
The Ti(N,O)/Ti thin films has been successfully deposited by unbalanced magnetron sputtering (UBMS) system. The purpose of this thesis was to study the influence of Ti interlayer on the structure and related properties of the Ti(N,O) thin film. Secondary ion mass spectroscopy (SIMS) and scanning electron microscopy (SEM) were used to determine the thickness of the Ti interlayer. An interdiffusion zone was found to form between the Ti(N,O) film and the pure-Ti interlayer, where oxygen and nitrogen atoms diffused from the film and reacted with the Ti interlayer. As a result, instead of TiO2, a oxygen deficient Ti3O5 was formed in the Ti(N,O) film at 0.75 and 1.5 sccm O2, and thereby affecting the related film properties. The X-ray diffraction (XRD) results showed that the major phase of the Ti(N,O) thin film was TiN at 0 and 0.25 sccm O2 and Ti3O5 at 0.75 and 1.5 sccm O2; TiO2 was observed in the upper layer of the film deposited at 1.5 sccm O2. The film hardness significantly decreased, residual stress moderately decreased and the electrical resistivity substantially increased as the dominant phase changed from TiN to Ti3O5. As the film thickness increased, the diffusion distance of the O atoms that absorbed by the Ti interlayer also increased, and therefore, TiO2 could form in the upper layer of the film deposited at the 0.75 and 1.5 sccm O2 for 6 hours. In summary, the effect of Ti interlayer was mainly from the absorption and reaction of O and N in the Ti(N,O) film, which significantly affected the phase transition and the related properties of the film.