Analysis of Sputter Process on a New ZrTi+PbO Target System and Its Application to Low-Temperature Deposition of Ferroelectric Pb(Zr,Ti)O3 Films

An rf reactive sputter deposition technique was adopted to deposit ferroelectric lead zirconate titanate (PZT) thin films from a ZrTi (50%/50%) alloy target combined with PbO pellets. Deposition characteristics including the effects of PbO area ratio were discussed. A new deposition mode called the near-metallic mode was observed. The crystallinity and the composition of the films prepared in the near-metallic mode were investigated as functions of PbO area ratio and substrate temperature. Excess Pb supply tended to enhance perovskite phase formation. Near-stoichiometric perovskite PZT films were obtained at a substrate temperature as low as 450° C. On the other hand, for a PZT+PbO target, perovskite PZT films were obtained only at temperatures higher than 540° C. Deposition rate of perovskite films from the ZrTi+PbO target was 2–3 times higher than that from the PZT+PbO target.