Nanostructure of Rutile TiO<sub>2</sub> Thin Films Prepared on Unheated Substrate by Dual Cathode DC Unbalanced Magnetron Sputtering

Abstract

In this work, structural and optical properties of the TiO 2 films deposited on unheated substrates by dual cathode dc unbalanced magnetron sputtering at long substrate-target distance (d s-t) were studied. Titanium dioxide (TiO 2) thin films were deposited on unheated Si (110) wafers, glass slides and carbon coated copper grids at different substrate to target (d s-t) distances. The structural properties of TiO 2 thin films were characterized by X-ray diffraction (XRD) and transmission electron microcopy (TEM) with selected-area electron diffraction (SAED), surface morphology using atomic force microscopy (AFM) and optical transmission spectra using a spectrophotometer. XRD results show that TiO 2 films deposited at various d s-t distances have only rutile crystal structure. The crystallinity and thickness of the films increased while the roughness decreased with decreasing d s-t distance. The refractive indices of the deposited films were found to be in the range of 2.51-2.82 and increased with decreasing d s-t distance.