High endurance of 1011cycles is demonstrated in ~9–10-nm stoichiometric Hafnium Zirconate (HZO) metal–ferroelectric–metal (MFM) capacitors deposited using Cl precursors with La and Y dopants. La doping is shown to offer higher remnant polarization than Y. Investigation of doped layers with asymmetric polarization versus electric field (P–E) measurements and unipolar fatigue cycles suggests that in the pristine state, the HZO is comprised of ferroelectric domains with internal built-in electric field-induced pinned coercive field (Ec). Doping is shown to increase the pinning effect and two distinct groups of ferroelectric domains emerge, which is antialigned at zero applied electric field (E). The antiferroelectric-like (pinchedP–Eloop) behavior is therefore attributed to internal built-inE-induced pinning of the domains during growth and/or annealing steps. The initial wake-up is attributed to gradual depinning of the domains with bipolar electric pulses. Suppression of monoclinic phase was observed in doped layers that survive 1011cycles. The wake-up is shown to be dependent on total duration and magnitude of bipolar electric pulses. Precycling scheme is demonstrated for stable operation at a lower field.
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Walke et al. (2022) studied this question.