Deposition of TiO2 thin films using RF magnetron sputtering method and study of their surface characteristics

Titanium dioxide (TiO2) thin films were successfully grown on Si(100) and micro cover glass substrates using radio frequency (RF) magnetron sputtering. Highly oriented, crack-free, stoichiometric polycrystalline rutile TiO2 thin film was obtained after annealing at 1000 °C for 1 h. The maximum UV-visible transmittance and hardness of the film were over 90% and 1700 HK0.025, respectively. Different contact angles and crystal growth directions were observed with the various deposition parameters such as annealing temperature, RF power magnitude, and added O2 amounts. These differences were dependent on a phase transition from anatase to rutile phases, reflecting the changes of the crystal structure. In this study, moreover, we found that the transmittance and hardness of the TiO2 thin films were strongly influenced by both the film thickness and the surface roughness. The growth rate was also increased with increasing RF power up to 150 W, and the maximum growth rate observed at 150 W was 1500 nm/h. The most optimum deposition condition for TiO2 thin film growth was determined to be 80 W of RF power, 1000 °C of annealing temperature, 1 h of deposition time, and 30 sccm of O2.