Piezoelectric and dielectric reliability of lead zirconate titanate thin films

This work was directed toward developing a database for the long-term reliability of the transverse piezoelectric coefficient d₃₁ under both unipolar and bipolar drive. Under unipolar drive, the films showed excellent reliability, with 99% of the devices surviving to 10⁹ cycles. However, both aging and low amplitude bipolar drive resulted in rapid degradation of d₃₁ due to backswitching of the ferroelectric domains. Both thermal and ultraviolet (UV) imprint prevented backswitching and resulted in improved aging and bipolar degradation behavior. Additionally, the UV imprinted samples showed nonlinear aging due to the presence of an internal space charge field that developed from photo-induced charge carriers.