Ferroelectric and Dielectric Properties of Hf<sub>0.5</sub>Zr<sub>0.5</sub>O<sub>2</sub> Thin Film Near Morphotropic Phase Boundary
Alireza Kashir, Hyunsang Hwang
Abstract
Recently, based on the phase‐field modeling, it is predicted that Hf 1‐ x Zr x O 2 (HZO) exhibits the morphotropic phase boundary (MPB) in its compositional phase diagram. Herein, the effect of structural changes between tetragonal (t) and orthorhombic (o) phases on the ferroelectric (FE) and dielectric properties of HZO films is investigated to probe the existence of MPB region. The structural analysis shows that by adjusting the ozone dosage during the atomic layer deposition process and annealing conditions, different ratios of t‐ to o‐phases are achieved, which consequently affect the FE and dielectric properties of the samples. Polarization versus electric field measurements show a remarkable increase in FE characteristics ( P r and E c ) of the sample that contains the minimum t‐phase fraction . This sample shows the lowest compared with the other samples, which is due to the formation of FE o‐phase. The sample that contains the maximum demonstrates the highest dielectric response. By adjusting , a large of ≈55 is achieved. The study reveals a direct relation between and of HZO thin films, which can be understood by considering the density of MPB region.