Enhancing ferroelectric stability: Wide-range of adaptive control in epitaxial HfO2/ZrO2 superlattices

Jingxuan Li; Shiqing Deng; Liyang Ma; Yangyang Si; Chao Zhou; Kefan Wang; Sizhe Huang; Jiyuan Yang; Yunlong Tang; Yu-Chieh Ku; Chang-Yang Kuo; Yijie Li; Sujit Das; Shi Liu; Zuhuang Chen

arXiv · 2507.00393

Enhancing ferroelectric stability: Wide-range of adaptive control in epitaxial HfO2/ZrO2 superlattices

Jingxuan Li·Shiqing Deng·Liyang Ma·Yangyang Si·Chao Zhou·Kefan Wang·Sizhe Huang·Jiyuan Yang·Yunlong Tang·Yu-Chieh Ku·Chang-Yang Kuo·Yijie Li·Sujit Das·Shi Liu·Zuhuang Chen

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Abstract

The metastability of the polar phase in HfO2, despite its excellent compatibility with the complementary metal-oxide-semiconductor process, remains a key obstacle for its industrial applications. Traditional stabilization approaches, such as doping, often induce crystal defects and impose constraints on the thickness of ferroelectric HfO2 thin films. These limitations render the ferroelectric properties vulnerable to degradation, particularly due to phase transitions under operational conditions. Here, we demonstrate robust ferroelectricity in high-quality epitaxial (HfO2)n/(ZrO2)n superlattices, which exhibit significantly enhanced ferroelectric stability across an extended thickness range. Optimized-period superlattices maintain stable ferroelectricity from up to 100 nm, excellent fatigue resistance exceeding 109 switching cycles, and a low coercive field of ~0.85 MV/cm. First-principles calculations reveal that the kinetic energy barrier of phase transition and interfacial formation energy are crucial factors in suppressing the formation of non-polar phases. This work establishes a versatile platform for exploring high-performance fluorite-structured superlattices and advances the integration of HfO2-based ferroelectrics into a broader range of applications.

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Jingxuan Li, Shiqing Deng, Liyang Ma, Yangyang Si, Chao Zhou, Kefan Wang, Sizhe Huang, Jiyuan Yang, Yunlong Tang, Yu-Chieh Ku, Chang-Yang Kuo, Yijie Li, Sujit Das, Shi Liu, Zuhuang Chen. 2025-07-01. Enhancing ferroelectric stability: Wide-range of adaptive control in epitaxial HfO2/ZrO2 superlattices. https://arxiv.org/abs/2507.00393

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