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arXiv · 2309.12800

Engineering ferroelectricity in monoclinic hafnia

Hong Jian Zhao·Yuhao Fu·Longju Yu·Yanchao Wang·Yurong Yang·Laurent Bellaiche·Yanming Ma
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Abstract

Ferroelectricity in the complementary metal-oxide semiconductor (CMOS)-compatible hafnia (HfO$_2$) is crucial for the fabrication of high-integration nonvolatile memory devices. However, the capture of ferroelectricity in HfO$_2$ requires the stabilization of thermodynamically-metastable orthorhombic or rhombohedral phases, which entails the introduction of defects (e.g., dopants and vacancies) and pays the price of crystal imperfections, causing unpleasant wake-up and fatigue effects. Here, we report a theoretical strategy on the realization of robust ferroelectricity in HfO$_2$-based ferroelectrics by designing a series of epitaxial (HfO$_2$)$_1$/(CeO$_2$)$_1$ superlattices. The advantages of the designated ferroelectric superlattices are defects free, and most importantly, on the base of the thermodynamically stable monoclinic phase of HfO$_2$. Consequently, this allows the creation of superior ferroelectric properties with an electric polarization $>$25 $\mu$C/cm$^2$ and an ultralow polarization-switching energy barrier at $\sim$2.5 meV/atom. Our work may open an entirely new route towards the fabrication of high-performance HfO$_2$ based ferroelectric devices.

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Hong Jian Zhao, Yuhao Fu, Longju Yu, Yanchao Wang, Yurong Yang, Laurent Bellaiche, Yanming Ma. 2023-09-22. Engineering ferroelectricity in monoclinic hafnia. https://doi.org/10.1103/physrevlett.132.256801

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