Effects of oxygen vacancies in HfO2-based ferroelectric memories: progress and challenges

HfO 2 -based ferroelectric materials have become core candidates for the next generation of non-volatile memory (NVM) owing to their numerous advantages. Oxygen vacancies (V O ), as the most common intrinsic defects in HfO 2 -based films, their concentration and distribution critically influence the ferroelectric phase formation, polarization switching behavior, and reliability of the devices. However, current researches mainly focus on isolated or localized phenomena but a systematic summary is still lacking. This paper summarizes the formation mechanisms of V O in HfO 2 -based ferroelectrics, outlines common theoretical research and characterization methods, discusses the microscopic mechanisms of reliability issues related to V O . Additionally, recent researches are reviewed to propose potential directions for V O regulation. This review contributes to an in-depth understanding of the role of V O , providing theoretical support for the design of V O defect engineering to optimize device performance and reliability.