Mechanisms for retention loss in ferroelectric Pt/Pb(Zr0.4Ti0.6)O3/Pt capacitors

The switching current profiles of ferroelectric Pt/Pb(Zr0.4Ti0.6)O-3/Pt capacitors were investigated after high-temperature baking to elucidate the mechanisms for retention loss. In the same-state retention, a decrease in the peak value of switching current and increase in the switching time were observed. These changes in the switching characteristics were attributed to the growth of an internal field. By comparing with the switching characteristics of a virgin capacitor and using the Merz equations, we estimated quantitatively the magnitude of the internal field. In the opposite-state retention, backswitching of polarization, triggered by the internal field, was found to be the main cause of the retention loss. (C) 2003 American Institute of Physics.