Re-Annealing-Induced Recovery in 7nm Hf<sub>0.5</sub>Zr<sub>0.5</sub>O<sub>2</sub> Ferroelectric Film: Phase Transition and Non-Switchable Region Repair
Xiaopeng Li, Lu Tai, Guoqing Zhao, Xuepeng Zhan, Xiaolei Wang, Masaharu Kobayashi, Jixuan Wu, Jiezhi Chen
Abstract
To achieve HfO2-based ferroelectric (FE) devices with robust reliabilities, the impacts of re-annealing on 7nm FE-Hf <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{{0}.{5}}$ </tex-math></inline-formula> Zr0.5O2 (HZO) capacitors are comprehensively studied in this work. Impressively, the re-initialization phenomenon can be clearly observed by re-annealing cycled HZO capacitors. It is found that FE properties (remanent polarization (Pr), coercive electric field ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{E}_{\text {C}}{)}$ </tex-math></inline-formula> , polarization switching speed, wakeup/fatigue effect, and symmetry) can be obviously improved after re-annealing. With in-depth discussions, it is considered that temperature-dependent phase transition and non-switchable region repairing could be the dominant mechanisms. Our results indicate that re-annealing could effectively improve FE-HZO performance and shed light on reliability optimizations.