YTTRIA-STABILIZED ZIRCONIA THIN-FILMS GROWN BY REACTIVE RF MAGNETRON SPUTTERING

Zirconia thin films were deposited on different substrates by reactive r.f, magnetron sputtering. It was found that zirconia layers grew pre ferentially in the (200) direction with a columnar microstructure that is independent of the oxygen flow, argon to oxygen flow ratios and sp uttering pressure. On the other hand the substrate roughness clearly a ffects the orientation of zirconia. Distinct changes were observed in the case of heated substrates. The heating of the substrates does not change the form of the zirconia, but strongly influences its orientati on. When the substrate temperature increases, the crystallographic ori entation gets more and more random, typically for the polycrystalline state. A decrease in the optical transmittance and an increase in the colour intensity of the layers with an increase in the substrate tempe rature was also found. As is shown, the oxygen non-stoichiometry of th e zirconia is responsible for these changes.