Observing ferroelastic switching in Hf_0.5Zr_0.5O₂ thin film

Hafnium zirconium oxides (HZO), which exhibit ferroelectric properties, are promising materials for nanoscale device fabrication due to their high complementary metal-oxide-semiconductor (CMOS) compatibility. In addition to piezoelectricity, ferroelectricity, and flexoelectricity, this study reports the observation of ferroelasticity using piezoelectric force microscopy (PFM) and scanning transmission electron microscopy (STEM). The dynamics of 90° ferroelastic domains in HZO thin films are investigated under the influence of an electric field. Switching of the retentive domains is observed through repeated wake-up measurements. This study presents a possibility of enhancing polarization in HZO thin films during wake-up processes.