A grease for domain walls motion in HfO2-based ferroelectrics

Alireza Kashir; Mehrdad Ghiasabadi Farahani; Ján Lančok; Hyunsang Hwang; Stanislav Kamba

doi:10.1088/1361-6528/ac4679

A grease for domain walls motion in HfO₂-based ferroelectrics

Nanotechnology. 2022 Jan 18;33(15). doi: 10.1088/1361-6528/ac4679.

Authors

Alireza Kashir^{1

2}, Mehrdad Ghiasabadi Farahani³, Ján Lančok¹, Hyunsang Hwang², Stanislav Kamba¹

Affiliations

¹ Institute of Physics of the Czech Academy of Sciences, Na Slovance 2, 182 21 Prague 8, Czech Republic.
² Center for Single Atom-based Semiconductor Device and Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea.
³ Department of Mechanical and Materials Engineering, Queen's University, Kingston, Ontario, K7L 2N8, Canada.

PMID: 34959226
DOI: 10.1088/1361-6528/ac4679

Abstract

A large coercive fieldE_Cof HfO₂based ferroelectric devices poses critical performance issues in their applications as ferroelectric memories and ferroelectric field effect transistors. A new design to reduceE_Cby fabricating nanolaminate Hf_0.5Zr_0.5O₂/ZrO₂(HZZ) thin films is used, followed by an ensuing annealing process at a comparatively high temperature 700 °C. High-resolution electron microscopy imaging detects tetragonal-like domain walls between orthorhombic polar regions. These walls decrease the potential barrier of polarization reversal in HfO₂based films compared to the conventional domain walls with a single non-polar spacer, causing about a 40% decrease inE_C. Capacitance versus electric field measurements on HZZ thin film uncovered a substantial increase of dielectric permittivity near theE_Ccompared to the conventional Hf_0.5Zr_0.5O₂thin film, justifying the higher mobility of domain walls in the developed HZZ film. The tetragonal-like regions served as grease easing the movement of the domain wall and reducingE_C.

Keywords: Hf0.5Zr0.5O2; Polarization switching; Topological domain wall; coercive filed; endurance.