The Enhanced Polarization Switching Speed and Endurance in Hf0.5Zr0.5O2 Ferroelectric Thin Film by Modulating Oxygen Dose in Ferroelectric Layers

In this letter, the ferroelectric capacitors featuring Hf0.5Zr0.5O2 films with different oxygen dose have been constructed. It is found that the sample grown at oxygen-deficient condition exhibits a smaller remanent polarization (P-r), a larger dielectric constant (epsilon(r)), a faster switching and better cycle reliability (over 108 @ 4 MV/cm). The connection between its better reliability and polarization switching speed with its dielectric and ferroelectric properties is established with the switching-induced charge-injection model. The larger interfacial depolarization field (E-dep) impedes the domain switching at the early nucleation process and wears out the metal/ferroelectric interface, leading to the endurance degradation. Our work reveals that the oxygen-deficient sample with a smaller Pr and a large er shows a smaller Edep near the interface, tend to switch faster, thus also benefits the reliability. It provides better understanding of process modulating domain switch kinetics and reliability in HfO2 based ferroelectric devices from both theoretical and experiment perspective.