Optimizing the Ferroelectric Properties of Hf<sub>1–<i>x</i></sub>Zr<i><sub>x</sub></i>O<sub>2</sub> Films via Crystal Orientation
Chih-Yu Teng, Chia-Chieh Cheng, Kai‐Shin Li, Chenming Hu, Jhih‐Min Lin, Bi‐Hsuan Lin, Mau‐Tsu Tang, Yuan‐Chieh Tseng
Abstract
This study exploits the coupling of crystallographic and ferroelectric (FE) properties in an effort to enhance the FE performance of Hf 1– x Zr x O 2 (HZO). The proposed scheme involved optimizing the orientation of orthorhombic (O)-phase crystals along the preferred polarization axis by applying an electric pulse during annealing. The proposed electric pulse annealing (EPA) process reduced the need for wake-up treatment; however, it imposed limited changes on the amount of the O-phase and leakage performance, compared with rapid thermal annealing (RTA). Excessively high EPA doses induced an O → M (monoclinic) phase transformation, which sacrificed FE polarization but preserved the wake-up-free-like properties. Our results demonstrate that optimizing the orientation of polycrystalline O-phase may be as important as maximizing the quantity of O-phase for HZO applications.