The effect of interfacial state on electrical properties of PZT-electrode system for applying to nonvolatile memory devices

Abstract

The ferroelectric property of Pb(ZrxTi1-x)O-3 (PZT) films have been reported to be greatly dependent on the interfacial state between PZT and electrode. However, the interfacial state of this system is not studied well and much is not known. In this study, we investigated the effect of phase, compositional and interfacial states of PZT-Pt bi-layered thin film system on its electrical properties using X-ray diffractometer, X-ray photoelectron spectroscopy, Auger electron spectroscopy and Rutherford backscattering spectrometry. The improvement of fatigue property after the post-anneal could be explained based on the space charge layer model. During the post-anneal, the decomposition of alpha-PbO2 phase was observed. This compensates the loss of Pb and O in PZT near the interface which can cause space charge accumulation and fatigue. And also the reduction of Pt oxide was observed which induces the ideal interface state. (C) 1998 Published by Elsevier Science S.A.