Optical and Structural Properties of TiO2 Thin Films Deposited by RF Magnetron Sputtering

Titanium dioxide thin films were grown by RF magnetron sputtering. After that, deposited TiO2 films were annealed at 300 degrees C for 2 h. Having used different oxygen flow rates as a reactive gas, optical properties of TiO2 thin films changed. Refractive index n, extinction coefficient k and the thickness of the films were calculated from the transmittance spectra and the refractive indices were optimized. The extinction coefficient decreased due to the film oxidation. Different structures characterized by X-ray diffraction pattern and the crystallization of TiO2 films improved. Moreover, the stability of crystalline phase was studied, and the optical gap energy was calculated by Tauc relation.