Annealing effects on optical and structural properties of TiO2 thin films deposited by ion beam sputtering

Titanium dioxide (TiO2) thin films have been receiving much attention in the past as their chemical stability and high refractive index. In this paper, TiO2 thin films were prepared on fused silica substrates by ion beam sputtering technique and then are annealed at different temperature. The effects of the annealing temperature on the optical and structural properties of TiO2 thin films were studied. The results show that the refractive index, extinction coefficient of the TiO2 thin film decrease with the increase of annealing temperature. When the annealing temperature is higher than 350°C, the surface of TiO2 thin films shows an uneven mesh crack, which forms a significant film damage. The experimental results indicated that thermal treatment can effectively change the optical properties of the TiO2 thin films.