Physical Origin of Recovable Ferroelectric Fatigue and Recovery for Doped-HfO<sub>2</sub>: Toward Endurance Immunity
Jiajia Chen, Haoji Qian, Hongrui Zhang, Rongzong Shen, Gaobo Lin, Jiani Gu, Chengji Jin, Miaomiao Zhang, Huan Liu, Yan Liu, Xiao Yu, Genquan Han
Abstract
We have experimentally and theoretically confirmed that the ferroelectric fatigue and recovery in doped-HfO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> under external electric field (E <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ext</inf> ) is dominated by the redistribution of oxygen vacancies (V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</inf> ), rather than the charge detrapping effects. The fatigue under low E <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ext</inf> is mainly due to the non-uniform distribution of V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</inf> caused by migration in the in-plane direction during the polarization switching, while the recover under high E <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ext</inf> can be attributed to the V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</inf> uniformly redistribution. The proposed mechanism has been confirmed by 2D V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</inf> distribution characterization based on EELS, and the calculation based on first principle and the phase-field modeling. Moreover, the increased cycles of fatigue-recovery leads to enhanced V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</inf> stability and further improved endurance, which is expected to realize infinite endurance of HfO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> -based ferroelectric.