Amorphous TiO x N y films of varying stoichiometry have been deposited on Si and Cu substrates using ionassisted deposition (IAD). The structure of the films and the effects of annealing in the 200-450 Β°C range have been examined.
Secondary ion mass spectrometry (SIMS) has been used to investigate the near surface and the buried film/substrate interface. The Cs Y adduct approach has proved well suited to the depth profiling of these films, and provides a good test of the degree to which some of the common problems associated with SIMS depth profiles can be mitigated. Work function corrections based on the Cs Y yield have been used to refine further the MCs Y intensities and resolve structure, particularly at the film/metal interface. Under most experimental conditions for these films, the knock-on effect is observed to distort profiles by more than the matrix effects on ion yields.
Profiles reveal a complex degradation mechanism, which is somewhat contradictory to that reported in the previous literature. The suggested mechanism of Cu migration through the film driven by oxide formation at the outer surface, is operative only at elevated temperatures approaching complete breakdown of the films. In the operational range up to ~350 Β°C, Cu is observed to migrate through the film to the outer surface, however a nitrogen-rich layer is observed overlying a thin oxide zone and a largely intact TiON film.