Electrical properties of lead-zirconate-lead-titanate ferroelectric thin films and their composition analysis by Auger electron spectroscopy

Abstract

Lead-zirconate-lead-titanate (PZT) thin films with perovskite and pyrochlore structures were successfully fabricated on several kinds of substrates by rf diode sputtering. Semiquantitative compositional analysis of the deposited thin films were made with Auger electron spectroscopy (AES). The films were deposited from targets consisting of mixed powder oxides. One target had a composition corresponding to 10 mol% PbO-modified PZT 52/48 (Zr to Ti ratio in the PZT, target A), while the other had the composition corresponding to 10 mol% PbO-modified PZT 42/58 (target B). The films in the perovskite structure had ferroelectricity, while the films in pyrochlore had none. The perovskite films deposited from target A had a dielectric constant of 751, a remanent polarization of 20.4 μC/cm2, and a coercive field of 23.3 kV/cm. The films deposited from target B had a dielectric constant of 654, a remanent polarization of 6.37 μC/cm2, and a coercive field of 12.2 kV/cm. The composition of the former film was PZT 60/40 and the latter, PZT 47/53. The difference in the ferroelectric properties is believed to be in the difference in the compositional ratio of Zr/Ti in the film.