Defect Engineering of HfO<sub>2</sub>-Based Thin Films for Simultaneously Achieving High Polarization and Excellent Fatigue Resistance: Mediating Double-Edged Role of Oxygen Vacancies.

Ma, Mingsheng; Li, Yunpeng; Yu, Tao; Wang, Borui; Wang, Junhui; Bao, Keyu; Liao, Jiajia; Xu, Hejun et al. · Nano Lett · 2026

basic_science · Level V

Where this comes from

Abstract

HfO<sub>2</sub>-based ferroelectric thin films can be used in advanced memory applications. The oxygen vacancies (V<sub>O</sub>) present in HfO<sub>2</sub> are essential for stabilizing the ferroelectric phase; however, they are detrimental to fatigue resistance because of domain pinning and leakage path formation induced by V<sub>O</sub> aggregation. A defect engineering strategy was developed to reconcile the contradictory role of V<sub>O</sub> in HfO<sub>2</sub>-based ferroelectric thin films. At a 2-V operating voltage, the 8 mol % Ti-doped Hf<sub>0.5</sub>Zr<sub>0.5</sub>O<sub>2</sub> (HZO) ferroelectric thin film exhibited excellent ferroelectric properties and tolerated 1 × 10<sup>10</sup> endurance cycles. First-principles calculations and X-ray photoelectron spectroscopy characterization revealed that the Ti dopants did not affect the V<sub>O</sub> concentration in HZO, but they served as a fastener for binding V<sub>O</sub>, thus impeding the aggregation and diffusion of V<sub>O</sub> under cyclic electric fields. This study provides a viable pathway to resolve the double-edged role of V<sub>O</sub> and thus enhance fatigue resistance while maintaining high polarization.