Influence of Ti film thickness and oxidation temperature on TiO2 thin film formation via thermal oxidation of sputtered Ti film

Abstract Single-phase rutile TiO 2 films with good crystallinity were obtained by thermal oxidation of sputtered Ti films on Si and quartz substrates. The influence of the Ti film thickness on oxidation was systematically investigated. A temperature of 823 K was sufficient to fully oxidize Ti films of 2 films were investigated using X-ray diffraction (XRD), Raman spectroscopy, energy-dispersive X-ray analysis (EDAX), and UV-vis-NIR spectroscopy. XRD and Raman analyses showed that the TiO 2 films are rutile phase. The bandgap of the TiO 2 films decreased with increasing thickness. A growth mechanism for TiO 2 thin films due to thermal oxidation of sputtered Ti films is proposed. Oxidation commences from the surface and proceeds inside the bulk and Ti→TiO 2 phase transformation occurs via different intermediate phases. We found that the oxidation temperature rather than the duration is the dominant factor in the growth of TiO 2 thin films.