Reversible fatigue-rejuvenation procedure and its mechanism in Hf 0.5 Zr 0.5 O 2 epitaxial films.

HfO 2 -based ferroelectrics, such as Hf 0.5 Zr 0.5 O 2 , 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 2 -based ferroelectrics is different from conventional ferroelectric materials, and research on the fatigue mechanism in HfO 2 -based epitaxial films have been rarely reported. In this work, we fabricate 10 nm Hf 0.5 Zr 0.5 O 2 epitaxial films and investigate the fatigue mechanism. The experimental data show that the remanent ferroelectric polarization value decreased by 50% after 10 8 cycles. It is worth noting that the fatigued Hf 0.5 Zr 0.5 O 2 epitaxial films can be recovered through applying electric stimulus. Combined with the temperature-dependent endurance analysis, we propose that fatigue of our Hf 0.5 Zr 0.5 O 2 films comes from both phase transition between ferroelectric Pca2 1 and antiferroelectric Pbca as well as defects generation and dipole pinned. This result offers a fundamental understanding of HfO 2 -based film system, and could provide an important guideline for subsequent studies and future applications.