Optical properties of sol-gel spin-coated TiO_2 films and comparison of the properties with ion-beam-sputtered films

Abstract

Transparent and optical-grade TiO(2) coatings were prepared by sol-gel spinning and ion-beam sputtering techniques. We investigate process parameters for the fabrication of sol-gel spin-coated TiO(2) films exhibiting high optical quality comparable with that of ion-beam-sputtered TiO( 2) films. X-ray diffraction studies showed the sol-gel-deposited films to be amorphous for heat treatments below 350 degrees C, whereas the ion-beam-sputtered films were slightly crystalline and exhibited the anatase structure. The refractive index and the extinction coefficient were evaluated from transmittance characteristics in the ultraviolet, visible, and nearinfrared regions. Transmission spectra and ellipsometric measurements showed that spin-coated films were essentially optically equivalent to those prepared by ion-beam sputter deposition.