Reversible fatigue-rejuvenation procedure and its mechanism in HfZrOepitaxial films.

HfO-based ferroelectrics, such as HfZrO, arouse great attention in recent years because of their CMOS compatibility and robust nano-scale ferroelectricity. However, fatigue is one of the toughest problems for ferroelectric applications. The fatigue mechanism of HfO-based ferroelectrics is different from conventional ferroelectric materials, and research on the fatigue mechanism in HfO-based epitaxial films have been rarely reported.

Reversible transition between the polar and antipolar phases and its implications for wake-up and fatigue in HfO-based ferroelectric thin film.

Atomic-resolution Cs-corrected scanning transmission electron microscopy revealed local shifting of two oxygen positions (O and O) within the unit cells of a ferroelectric (HfZr)O thin film. A reversible transition between the polar Pbc2 and antipolar Pbca phases, where the crystal structures of the 180° domain wall of the Pbc2 phase and the unit cell structure of the Pbca phase were identical, was induced by applying appropriate cycling voltages. The critical field strength that determined whether the film would be woken up or fatigued was ~0.

Optimization of the In Situ Biasing FIB Sample Preparation for Hafnia-Based Ferroelectric Capacitor.

Hafnia-based ferroelectric (FE) thin films have received extensive attention in both academia and industry, benefitting from their outstanding scalability and excellent CMOS compatibility. Hafnia-based FE capacitors in particular have the potential to be used in dynamic random-access memory (DRAM) applications. Obtaining fine structure characterization at ultra-high spatial resolution is helpful for device performance optimization.