Spectroellipsometric characterization of ZnO films produced by chemical spray pyrolysis

Abstract

In this study, zinc oxide thin films (ZnO) were produced on glass substrate by using spray pyrolysis. Ellipsometric measurements of ZnO thin films were taken using spectroscopic ellipsometry (SE) technique. An important optical parameters of films such as refractive index (n), extinction coefficient (k) and thicknesses (d) of ZnO thin films were determined variable-angle (50°-60°-70°) by spectroscopic ellipsometry (SE) technique. Variable angle spectroscopic ellipsometry was used for thickness and optical constant calculations. Multiple angle measurements were taken in the most sensitive angle of incidence region. The optical parameters (n, k and d) were then obtained the different two ellipsometric angles (ψ and ) by a fitting procedure were experimental data, which were generated from the Cauchy-Urbach dispersion model, were compared with the experimental ones. Also, the surfaces properties and roughness values of ZnO thin films, is an important factor in the ellipsometric measurements, were examined by atomic force microscopy. In conclusion, the ellipsometric incidence angle and surface properties effects were discussed on the optical parameters of ZnO thin films such as thickness and optical constants (refractive index and extinction coefficient).