A stable rhombohedral phase in ferroelectric Hf(Zr)1+xO2 capacitor with ultralow coercive field

• 成果类型: Article
• 署名作者: Wang, Yuan; Tao, Lei; Guzman, Roger; Luo, Qing; Zhou, Wu; Yang, Yang; Wei, Yingfen; Liu, Yu; Jiang, Pengfei; Chen, Yuting; Lv, Shuxian; Ding, Yaxin; Wei, Wei; Gong, Tiancheng; Wang, Yan; Liu, Qi; Du, Shixuan; Liu, Ming
• 署名单位: Chinese Academy of Sciences; Institute of Microelectronics, CAS; Chinese Academy of Sciences; Institute of Microelectronics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Fudan University; Chinese Academy of Sciences; Institute of Physics, CAS; Songshan Lake Materials Laboratory
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-10836
• DOI: 10.1126/science.adf6137
• 发表日期: 2023-08-04
• 页码: 558-563
• 关键词: initio molecular-dynamics; TRANSITION; films; points; oxide

摘要

Hafnium oxide-based ferroelectric materials are promising candidates for next-generation nanoscale devices because of their ability to integrate into silicon electronics. However, the intrinsic high coercive field of the fluorite-structure oxide ferroelectric devices leads to incompatible operating voltage and limited endurance performance. We discovered a complementary metal-oxide semiconductor (CMOS)-compatible rhombohedral ferroelectric Hf(Zr)(1+x)O-2 material rich in hafnium-zirconium [Hf(Zr)]. X-ray diffraction combined with scanning transmission electron microscopy reveals that the excess Hf(Zr) atoms intercalate within the hollow sites. We found that the intercalated atoms expand the lattice and increase the in-plane and out-of-plane stresses, which stabilize both the rhombohedral phase (r-phase) and its ferroelectric properties. Our ferroelectric devices, which are based on the r-phase Hf(Zr)(1+x)O-2, exhibit an ultralow coercive field (similar to 0.65 megavolts per centimeter). Moreover, we achieved a high endurance of more than 10(12) cycles at saturation polarization. This material discovery may help to realize low-cost and long-life memory chips.