Enhanced Ferroelectricity in Hf‐Based Ferroelectric Device with ZrO2 Regulating Layer

• Published in: Advanced electronic materials 2023-08, Vol.9 (8), p.n/a
• Main Authors: Liu, Yongkai, Wang, Tianyu, Li, Zhenhai, Yu, Jiajie, Meng, Jialin, Xu, Kangli, Liu, Pei, Zhu, Hao, Sun, Qingqing, Zhang, David Wei, Chen, Lin
• Format: Article
• Language: English
• Subjects: Annealing; Electric fields; ferroelectric enhancement; Ferroelectric materials; Ferroelectricity; HfAlO; Phase transitions; Polarization; regulating layers; Retention; Spectrum analysis; Temperature; Zirconium dioxide; ZrO2
• ISSN: 2199-160X; 2199-160X
• DOI: 10.1002/aelm.202300208

HfAlO film‐based ferroelectric memory is a strong contender for the next‐generation nonvolatile memories. However, the remanent polarization intensity of HfAlO films is small compared to other Hf‐based ferroelectric films at low annealing temperatures. In order to further improve the remnant polarization of the device, the ferroelectric memory with metal‐ferroelectric‐metal structure using ZrO2 as the regulating layer (RL) is designed and fabricated. Experimental results show that the device with the ZrO2 regulating layer exhibits triple enhancement, which may be due to the fact that ZrO2 RL has an effect on the enhancement of the ferroelectric phase. In addition, the device with ZrO2 regulating layer exhibits a superior ON/OFF conductance ratio, endurance, and retention characteristics, demonstrating potential for application to memory. This work provides an effective way to improve the ferroelectricity in HfAlO films at low annealing temperatures. The effect of ZrO2 regulating layer (RL) on the ferroelectric properties of HfAlO film is investigated by using a combination of experiments and simulations. The results clearly demonstrate that ZrO2 RL can effectively facilitate the t‐phase to o‐phase transition and suppress the t‐phase to m‐phase transition, and thus contribute to increased remnant polarization intensity, uniformity, retention, endurance, and ON/OFF ratio.