Highly enhanced ferroelectricity in HfO <sub>2</sub> -based ferroelectric thin film by light ion bombardment
Seunghun Kang, Woo‐Sung Jang, Anna N. Morozovska, Owoong Kwon, Yeongrok Jin, Young‐Hoon Kim, Hagyoul Bae, Chenxi Wang, Sang‐Hyeok Yang, Alex Belianinov, Steven Randolph, Eugene А. Eliseev, Liam Collins, Yeehyun Park, Sanghyun Jo, Min‐Hyoung Jung, Kyoung‐June Go, Hae Won Cho, Si‐Young Choi, Jae Hyuck Jang, Sunkook Kim, Hu Young Jeong, Jaekwang Lee, Olga S. Ovchinnikova, Jinseong Heo, Sergei V. Kalinin, Young‐Min Kim, Yunseok Kim
Abstract
Continuous advancement in nonvolatile and morphotropic beyond-Moore electronic devices requires integration of ferroelectric and semiconductor materials. The emergence of hafnium oxide (HfO 2 )–based ferroelectrics that are compatible with atomic-layer deposition has opened interesting and promising avenues of research. However, the origins of ferroelectricity and pathways to controlling it in HfO 2 are still mysterious. We demonstrate that local helium (He) implantation can activate ferroelectricity in these materials. The possible competing mechanisms, including He ion–induced molar volume changes, vacancy redistribution, vacancy generation, and activation of vacancy mobility, are analyzed. These findings both reveal the origins of ferroelectricity in this system and open pathways for nanoengineered binary ferroelectrics.