The effects of grain boundaries on the characteristics of Pb(Zr,Ti)O-3 (PZT) thin films were investigated by locating the micro-sized top electrode within grain and on the grain-boundary in a controlled manner. It turned out that, when there was no grain boundary in the area measured, excellent ferroelectric and electrical performance was obtained. On the other hand, serious degradation was observed in terms of polarization, leakage current, breakdown field, fatigue, and hydrogen-induced degradation characteristics when grain boundaries were included in the area studied. It was found that degradation of PZT thin films was closely correlated with the length of grain boundary in the area measured. (C) 2002 Elsevier Science Ltd. All rights reserved.