Formation of PZT from multilayer-structured PbTiO3 and PbZrO3 thin films prepared by plasma-enhanced chemical vapor deposition

Abstract

From the amorphous multilayer thin films composed of PbTiO3 and PbZrO3 formed by a plasma-enhanced metal-organic chemical vapor deposition method, we have prepared single-phase PZT thin films by interdiffusion through an appropriate thermal annealing process. The transformation to a single-phase PZT from the multilayer was initiated at around 450degreesC and was almost completed at 550degreesC under an annealing time of 1 h. Typically, when a fourfold layer of PbZrO3/PbTiO3/PbZrO3/PbTiO3 was constructed and sequentially annealed at 650degreesC under ambient O-2 for 1 h, the resulting films showed characteristics of a perovskite-type PZT and a uniform distribution of each element along the depth of the film. The electrical properties of the prepared PZT thin film (Zr/Ti = 54/46, 180 nm) on a Pt-coated substrate were as follows: dielectric constant epsilon(r) = 415, coercive field E-c = 200 and - 140 kV/cm, and remanant polarization P-r = 12 muC/cm(2) at an applied voltage of 6 V.