Abstract
We simultaneously determined the thickness, surface roughness, index of refraction, and extinction coefficient of amorphous TiO2 films through the analysis of ellipsometric spectra using parameterized optical functions. Moreover, we made a detailed comparison among various parameterized optical functions and found that the parameterization presented by Jellison and Modine [Appl. Phys. Lett. 69 (1996) 371] was superior to others in fitting the ellipsometric spectra in the wide photon-energy range that encompasses both the transparent and the interband-transition region. The more popular parameterization proposed by Forouhi and Bloomer [Phys. Rev. B 34 (1986) 7018] failed to produce a satisfactory fit to the measured spectra. However, the modification in which the Sellmeier dispersion function was substituted for the original parameterization of Forouhi and Bloomer in the transparent region resulted in significantly improved fits.