Polarization Switching Induced Decrease of Bulk Resistivity in Ferroelectric Pb(Zr_0.45Ti_0.55)O₃ Thin Films and a Method to Improve Their Fatigue Endurance

Significant reduction of the bulk resistivity in a ferroelectric Pb(Zr_0.45Ti_0.55)O₃ thin film is observed before the remnant polarization started to decrease noticeably at the onset of its fatigue switching process. It is associated with the increase of charge carriers within the central bulk region of the film. The decrease of bulk resistivity would result in the increase of Joule heating effect, improving the temperature of the thin film, which is evaluated by the heat conduction analysis. The Joule heating effect in turn accelerates the polarization reduction, i.e. fatigue. Enhancing the heat dissipation of a ferroelectric capacitor is shown to be able to improve the device's fatigue endurance effectively.