Structural, optical and Raman scattering studies on DC magnetron sputtered titanium dioxide thin films

Thin films of TiO2 were deposited by DC magnetron sputtering. The thicknesses of the films were measured using alpha step profilometer technique. Auger electron spectroscopy (AES) is used to determine the composition of the films. The influence of post-deposition annealing at 673 and 773 K on the structural, optical and Raman scattering was studied. The thicknesses of the films were found to be more or less the same irrespective of the annealing temperature and time. XRD results reveal the amorphous nature of the as-deposited film while the annealed samples were found to be crystalline with a tetragonal symmetry. Using the optical transmittance method, the optical constants such as band gap, refractive index and absorption coefficient were calculated and the influence of thermal annealing on these properties was reported. Raman study was employed to study the existence of different frequency modes and improvement of crystallinity of the TiO2 films and the effect of annealing temperature on the Raman shift is studied and reported.