Oxygen diffusion in TiO2 films studied by electron and ion Rutherford backscattering

The diffusivity of oxygen in thin, sputter-deposited TiO2 films, as can be used in RRAMs, is measured using electron and ion backscattering techniques. The as-grown sample consisted of two layers (Ti16O2 and Ti18O2) and was annealed between 500 °C and 900 °C. The depth profiles of 18O, as measured with both techniques, were similar. The extent of diffusion was much larger than expected from the literature data for O diffusion in single-crystal rutile, suggesting that defects in the sputter-deposited film play an essential role in the diffusion process.