Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Aug 14:e09384.
doi: 10.1002/advs.202509384. Online ahead of print.

Zirconium-Rich Strategy in Ultrathin Hf0.5Zr0.5O2 toward Back-End-of-Line-Compatible Ferroelectric Random Access Memory

Yinchi Liu  1   2 , Jiajia Tao  3 , Xiaoyu Dou  4 , Kangli Xu  1   2 , Yuchun Li  2 , Handong Zhu  1   2 , Hongliang Lu  2 , Yanxi Li  2 , Chi Liu  5 , Jiezhi Chen  4 , Lin Chen  1   2 , Shijin Ding  2 , Jixuan Wu  4 , Wenjun Liu  1   2   6
Affiliations

Zirconium-Rich Strategy in Ultrathin Hf0.5Zr0.5O2 toward Back-End-of-Line-Compatible Ferroelectric Random Access Memory

Yinchi Liu et al. Adv Sci (Weinh). .

Abstract

HfO2-based ferroelectric devices have garnered lots of attention in embedded memory due to its exceptional complementary metal oxide semiconductor (CMOS) compatibility as well as sub-10 nm scalability. Nevertheless, challenges such as double remanent polarization (2Pr) degradation and thermal budget issues while scaling the Hf0.5Zr0.5O2 (HZO) thickness have limited its integration in high-intensity memory and high-speed computing. Here, an effective strategy involving the zirconium-rich layer (Zr-RL) is developed to address this dilemma. Remarkably low operating voltage of 1.0 V, alongside exceptional ferroelectricity with 2Pr of 43.4 µC cm-2 and a coercive voltage of 0.75 V are achieved in the ferroelectric capacitor with sub-6 nm HZO/Zr-RL/HZO stack. First-principles calculations reveal that the incorporation of Zr-RL induces a 0.76% tensile strain, which effectively reduces the growth barrier and surface energy of the ferroelectric phase, thereby facilitating the crystallization of the HZO/Zr-RL/HZO stack under a low thermal budget. Moreover, robust reliability, including a high breakdown voltage of 3.69 V, superior endurance characteristics exceeding 1011 cycles, and excellent retention time of 10 years are demonstrated in the ferroelectric capacitor with HZO/Zr-RL/HZO stack. Our investigations provide new insights into building a low-voltage operation, high ferroelectricity and reliability, long data retention, and back-end-of-line-compatible ferroelectric random access memory in scaled CMOS technology nodes.

Keywords: back‐end‐of‐line; ferroelectricity; reliability; tensile strain; zirconium‐rich layer.

PubMed Disclaimer

References

    1. Y. Li, Y. Xiong, X. Zhang, L. Yin, Y. Yu, H. Wang, L. Liao, J. He, Nat. Electron. 2024, 8, 36.
    1. G. Wu, X. Zhang, G. Feng, J. Wang, K. Zhou, J. Zeng, D. Dong, F. Zhu, C. Yang, X. Zhao, D. Gong, M. Zhang, B. Tian, C. Duan, Q. Liu, J. Wang, J. Chu, M. Liu, Nat. Mater. 2023, 22, 1499.
    1. Y. C. Liu, Y. C. Li, Z. Y. Gu, X. L. Zhou, T. Huang, Z. H. Li, T. T. Pi, Y. F. Li, S. J. Ding, L. Chen, H. L. Lu, W. J. Liu, IEEE Electron Device Lett. 2023, 44, 1116.
    1. G. Feng, Q. Zhu, X. Liu, L. Chen, X. Zhao, J. Liu, S. Xiong, K. Shan, Z. Yang, Q. Bao, F. Yue, H. Peng, R. Huang, X. Tang, J. Jiang, W. Tang, X. Guo, J. Wang, A. Jiang, B. Dkhil, B. Tian, J. Chu, C. Duan, Nat. Commun. 2024, 15, 513.
    1. K. Toprasertpong, K. Tahara, Y. Hikosaka, K. Nakamura, H. Saito, M. Takenaka, S. Takagi, ACS Appl. Mater. Interfaces 2022, 14, 51137.