Highly Reliable Hf 1‐X Zr X O 2 with Ultra‐Low Operation Voltage (< 1 V) Enabled by Stoichiometric Control of Tungsten Oxide Interfacial Layer

作者：Mostafa Habibi, Alireza Kashir, Tony Schenk, Hojung Jang, Seungyeol Oh, Jaeseon Kim, Geonhui Han, Donghwa Lee, Foroozan Koushan, Hyunsang Hwang · 发表于：Advanced Materials Technologies · 年份：2025 · DOI：10.1002/admt.202500507 · 被引用次数：4 · 研究领域：Ferroelectric and Negative Capacitance Devices、Semiconductor materials and devices、MXene and MAX Phase Materials

Abstract The reliability of hafnia‐based ferroelectrics at operating voltages below 1 V, the required voltage range for compatibility with advanced nodes, remains unexplored. Additionally, the impact of the position and conductivity of the interfacial layer (IL) on capacitor characteristics is not well understood. In this study, an Hf 1‐X Zr X O 2 capacitor capable of ultra‐low operation voltage (<1 V) is developed with excellent endurance (>10 11 cycles) and retention (>10 years at 85 °C). This performance is achieved by modulating the oxygen stoichiometry of the interfacial oxide. By investigating the oxygen content of the tungsten oxide IL and its effects on conductance and oxygen supply, it is demonstrated that an oxygen‐deficient WO 3‐X layer is the optimal IL for enhancing fatigue and switching kinetics. Moreover, placing WO 3‐X at the top interface significantly enhances crystallization, resulting in wake‐up‐free operation, which enables efficient thickness scaling. Finally, by integrating a precisely engineered WO 3‐X layer with optimized atomic layer deposition in a 5.6 nm capacitor, reliable operation is demonstrated at voltages as low as 0.7–0.8 V. These findings are supported by density functional theory calculations and comprehensive physical and electrical analyses. This study represents a critical advancement in addressing the persistent challenge of reliable low‐voltage operation in ferroelectric memories.