Field Cycling Behavior of Ferroelectric HfO2-Based Capacitors

Abstract

Abstract Extensive research has been performed in the past to understand the mechanisms responsible for the instabilities during electric field cycling of ferroelectric HfO2. In this chapter, the wake-up, imprint, and fatigue effect of fluorite structure-type ferroelectrics will be comprehensively reviewed based on the existing literature. The most likely root cause of the wake-up effect is identified as a local imprint mechanism. The constricted hysteresis in the pristine state is caused by the random orientation of domains. The imprint itself is likely generated by charge trapping. Electrons trapped into oxygen vacancies are pinning the domain seeds, which inhibit the ferroelectric switching. Lastly, the fatigue effect is examined. A generation and/or redistribution of oxygen vacancies during ferroelectric switching is occurring. These oxygen vacancies lead to domain wall pinning and finally to the forming of a conductive filament causing dielectric breakdown.