Re-Annealing-Induced Recovery in 7nm Hf_0.5Zr_0.5O₂ Ferroelectric Film: Phase Transition and Non-Switchable Region Repair

To achieve HfO2-based ferroelectric (FE) devices with robust reliabilities, the impacts of re-annealing on 7nm FE-Hf $_{{0}.{5}}$ 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 ( $\text{E}_{\text {C}}{)}$ , 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.