Electrical properties of Pb(Zr_0.52Ti_0.48)O₃thin films prepared by SOL-GEL processing

Abstract

Thin films of Pb (Zr,,,, Tio,48)03 were prepared on Pt/SiO,/Si substrates by sol-gel processing and rapid thermal annealing (RTA). The variations of hysteresis curves of the films with different upper electrode materials were studied. In order to investigate the effects of electrode -film interface on the electrical characteristics of the PZT film, the leakage current of the film was observed. While the PZT films with silver electrodes deposited at the substrate temperature of 150 "C showed ferroelectric characteristics, the films with silver electrodes deposited at room temperature showed the decreased remanent polarization and the asymmetric hysteresis curves. The films thicker than 0.5 pm with platinum electrodes exhibited fine squareness on the hysteresis curves. However, 0.28 pm thick PZT films with silver electrodes and with platinum electrodes have the coercive fields of 39 kV/cm and 68 kV/cm, the remanent polarization of 21 pC/cmZ and 20 pC/cm2, and the switching voltages of V ' = 6 V and Vp = 8 V, respectively. The leakage current of the PZT films was increased continuously as the time passed due to the influence of the non-perovskite layers formed at film -substrate interface. The leakage current was linearly increased which is inversely proportional to the cube of the film thickness as the thickness decreased.