Effect of RF deposition power on the properties of Al-doped TiO2 thin films

The Al-doped TiO2 (TiO2:Al) films were deposited by simultaneous RF (Radio Frequency) magnetron sputtering of TiO2 and DC (Direct Current) magnetron sputtering of Al. The advantage of this method is that the Al content could be independently controlled. TiO was more favorable to form and the deposited films became nonstoichiometric by increasing RF power density. The morphologies of TiO2 and TiO2:Al films were significantly affected by RF power density. The nonlinear refractive index of TiO2:Al film on the glass substrate was measured by Moiré deflectometry, and was of the order of 10− 8 cm2 W− 1. Compared with TiO2 film, TiO2:Al film had smaller grain size, lower porosity, higher linear refractive index, lower stress-optical coefficient and higher VIS-IR transmission.