Total Ionizing Dose Effects on Piezoelectric Thin-Film Cantilevers With Oxide Electrodes

This paper reports on the ionizing radiation effects in lead-zirconate-titanate (PZT) with varied top electrode material and bias condition during radiation. A technique to characterize the piezoelectric performance of films unclamped from the substrate is described, and used to demonstrate the effects of radiation on the material's electromechanical behavior. Both platinum and iridium oxide top electrodes were examined, and iridium oxide appears to significantly mitigate radiation-induced damage that is observed in platinum top electrode samples. This mitigation of radiation damage is attributed to the reduced number of oxygen vacancies within the PZT films when an iridium oxide top electrode is used. Devices with applied bias during radiation were compared with devices under applied bias only. Applied bias appears to slightly enhance the electromechanical response in the negative bias polarity for irradiated platinum electrode samples suggesting that the bias can cause defects to orient and therefore improve electromechanical response. Ultimately, iridium oxide top electrodes appear to mitigate radiation damage.