FATIGUE BEHAVIOR IN LEAD-ZIRCONATE-TITANATE THIN-FILM CAPACITORS PREPARED BY PULSED-LASER ABLATION ON NI-ALLOY ELECTRODES

Ferroelectric lead-zirconate-titanate (Pb(Zr0.52Ti0.48)O-3: PZT) thin-film capacitors were fabricated by pulsed laser ablation using Ni-alloy electrodes on oxidized (100) silicon. Polarization fatigue after a large number of switchings was investigated with a variety of frequencies. The frequencies for acceleration of fatigue and for measurement of the switched charge density Q(sw) were varied simultaneously or independently. The fatigue test revealed that the increase in the frequency both for acceleration and measurement of switching pulse increases the life of polarization reversal while it decreases Q(sw). At 50 kHz, Q(sw) keeps the initial value even after switching above 10(10) cycles. The measurement frequency dependence of Q(sw) suggests that a homogeneous fatigue takes place irrespective of fast and slow domains and additional layers of a low dielectric constant are probably formed in the ferroelectric-metal interface.