Preparation and characterization of PZT ferroelectric thin films by plasma enhanced metalorganic chemical vapor deposition

Abstract

Abstract PZT thin films with a uniform distribution of components were prepared by plasma enhanced chemical vapor deposition (PECVD) using Pb(C2H5)4, Z (O-i-C4H9)4, Ti(O-i-C3H7)4, and oxygen. The crystallization of films was occure after annealing in the temperature range between 450 and 550°C under O2 ambient for 1 hr. The significant change of Pb concentration in PECVD PZT thin films was not observed in the relation to annealing temperature and time. The dielectric constant PECVD PZT thin films increased with the Ti content, showed the maximum value in the vicinity of morphotropic phase boundary (MPB) composition of PZT material, and decreased with the Ti content. The leakage current density of PZT (65/35) thin film of 180 nm in thickness was 3·37 × 10−7 A/cm2 at the applied voltage of 3 V. Remanent polarization increased with increasing of Zr content in the film and coercive field was nearly independent of the composition. The typical values of electrical properties were εr = 570, Ec = 90 kV/cm, and Pr = 19 μC/cm2 in the PECVD PZT (54/46) thin film of 220 nm in thickness.