Effects of deposition temperature and seed layer on the optical properties of lead zirconate titanate films

Abstract

Lead zirconate titanate (PZT) films were deposited on indium tin oxide coated Corning 7059 glass by rf magnetron sputtering at the temperatures ranging from room temperature to 500 °C. The crack-free PZT films with pure perovskite phase could be successfully fabricated through postannealing at 650 °C for 10 min. The films deposited at 400 °C and subsequently postannealed at 650 °C showed the best optical properties with a linear electro-optic coefficient of 80 pm/V and a propagation loss of 2 dB/cm. It was found from our study on the change of crystalline orientation with film thickness that the 50 nm thick PZT thin film annealed at 650 °C exhibited (100) preferred orientation. Using this thin film as a seed layer, we could fabricate PZT films with (100) preferred orientation that showed higher remnant polarization (2Pr=46 μC/cm2) and dielectric constant (ε=1400) compared with randomly oriented films. This highly oriented PZT film also showed an excellent linear electro-optic coefficient of 109 pm/V that is comparable with the value of the PZT film epitaxially grown on the single crystal substrate.