Fatigue effect in ferroelectric PbZr1−xTixO3 thin films

Abstract

Pb Zr 1 − x Ti x O 3 (PZT) is one preferred ferroelectric material being used in nonvolatile ferroelectric random access memory devices. The use of oxide electrodes like IrO2 or SrRuO3 (SRO) is necessary to suppress the serious loss of polarization due to bipolar voltage cycling. Although, there are a number of models under discussion, the origin of the fatigue phenomenon is still not completely understood. In this paper, the fatigue effect of ferroelectric Pb(Zr0.40,Ti0.60)O3 thin films has been studied in detail. To achieve a deeper understanding of the effect, several PZT samples with different electrode materials were investigated. After determining the dependence of the single fatigue parameters, a simulation approach was made to analyze the fatigue effect qualitatively. A sample with SRO electrodes was measured up to 1013cycles and no fatigue of the switchable polarization was observed.