Growth of [111]-Oriented Lead Zirconate Titanate Thin Film with Smooth Surface to Improve Electrical Properties

Abstract

[111]-Oriented lead zirconate titanate (PZT) films with smooth surfaces were successfully grown on (111)-oriented polycrystalline Pt substrates after in-situ Ar-plasma cleaning by low-temperature reactive sputtering and rapid thermal annealing. The Pb composition was stoichiometrically controlled not only for total composition but also in the depth direction by low-temperature reactive sputtering. A (111)-oriented perovskite-phase PZT film with a very smooth surface was then obtained by rapid thermal annealing. The leakage current of quasi-epitaxial PZT films was markedly reduced to 10-7 A/cm2 and the equivalent SiO2 layer thickness of around 0.4 nm was obtained for the fatigue-free PZT films thinner than 100 nm.