Fatigue effect on the I-V characteristics of sol-gel derived PZT thin films

The effect of fatigue on sol-gel-derived PZT (lead zirconate titanate) thin films were analyzed using the I-V measurement method. Under bipolar stress, polarization reduction was correlated with a decrease in the switching current and an increase in the leakage current. Neither a significant decrease in the polarization nor an increase in the leakage current was observed under unipolar stress. The fatigue effects are explained by an increase in the space-charge regions near the electrodes or oxygen-deficient dendrite growth. A static I-V measurement method for ferroelectric thin films was developed to distinguish the leakage current from the switching current. The initial polarization state and the exponential decay behavior of the switching current were considered in this method