Tuning the Crystalline Structure and Properties of TiOx Thin Films Deposited by DC Reactive Magnetron Sputtering by Adjusting the Ar/O2 Ratio

In this study, TiOx thin films were deposited by DC reactive magnetron sputtering (DC-RMS), using different Ar/O-2 ratios in the absence of substrate bias and substrate heating. We observe a gradual change in the crystal structure and stoichiometry of the films with increasing Ar/O-2 ratio, enabling to obtain TiOx films either with a pure anatase phase, a mixture between anatase and rutile, or a pure rutile phase. Our experimental results demonstrate that, by fine tuning the Ar/O-2 ratio during DC-RMS deposition process, a TiOx thin film with tunable crystal structure and properties (surface morphology, atomic density, index of refraction, and film hardness) can be obtained in a simple way.