Fatigue and data retention characteristics of single-grained Pb(Zr,Ti)O/sub 3/ thin films

摘要

Fatigue and data retention characteristics of single-grained lead zirconate titanate (PZT) thin films obtained by the PZT seeding method were investigated. There is no loss in switched polarization up to 2/spl times/10/sup 11/ cycles using a 1 MHz square wave form at /spl plusmn/10 V in fatigue testing and no data loss after 30000 sec of memory retention at room temperature. From the activation energy measured at high temperatures, the time required 20% loss in remanent polarization is estimated to be 6.6/spl times/10/sup 7/ years at room temperature. In this study, we show that when there were no grain boundaries in the area measured, degradation such as fatigue and retention was not observed even with Pt electrodes. Thus, the main source of degradation is the grain boundary in the PZT thin films.