Evaluation of imprint property of (111)-highly oriented lead zirconate titanate (PZT)-base ferroelectric material

We have investigated the mechanism of static imprint failure in (111)-highly oriented lead zirconate fitanate (PZT)-base ferroelectric material by examining the change in the leakage current density. We prepared Pt/Pb(Zr,Ti,Nb)O-3 (PZTN)/Pt capacitors. Our capacitors passed the static imprint test at 150 degrees C for 1280 h with a write/read voltage of 3 V or higher. After the static imprint test we measured the leakage current densities of capacitors. All capacitors showed an increase in leakage current density on one side and a decrease on the other side. The side on which leakage current increased depended on the voltage polarity of the write pulse. The changes in leakage current density of capacitors with various write/read voltages indicate that static imprint failure has at least two mechanisms, the contributions of which change according to the write/read voltage. When the write/read voltage is lower, capacitors show diode-like behavior after static imprinting.