Effect of excess Pb and O content on the ferroelectric properties of sputter deposited Pb(Zr0.52Ti0.48)O-3/Pt system

Abstract

The effect of excess Pb and O content on the ferroelectric properties of Pb(Zr0.52Ti0.48)O-3/Pt system has been investigated. PZT films were sputter-deposited from a target containing 50% excess Pb and O on a substrate heated at 520 degrees C. This permitted the PZT films to be crystallized directly to a perovskite phase. The excess content of Pb and O in the sputter-deposited PZT films were controlled by successive furnace-annealing at 500 degrees C by varying the annealing time. Polarization-switching field (P-E), current-applying electric field (I-E), and fatigue property measurements were done after rapid thermal annealing (RTA) of the films at 600 and 700 degrees C. The 700 degrees C-treated PZT film containing 26% of excess Pb before RTA showed better ferroelectric properties than the 600 degrees C-treated film. On the contrary, a degradation of ferroelectric properties was observed with the 700 degrees C-treated films containing 17 or 5% of excess Pb before RTA. These two opposed effects of high temperature-RTA treatment on the ferroelectric properties of the PZT films could be explained using a space charge model. (C) 1998 Elsevier Science S.A. All rights reserved.