Re-Annealing-Induced Recovery in 7nm Hf0.5Zr0.5O2 Ferroelectric Film: Phase Transition and Non-Switchable Region Repair

Abstract

To achieve HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -based ferroelectric (FE) devices with robust reliabilities, the impacts of re-annealing on 7nm FE-Hf <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub> Zr <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> (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 (E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</sub> ), 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.