Ferroelectric and Dielectric Properties of Hf0.5Zr0.5O2 Thin Film Near Morphotropic Phase Boundary

Abstract

Recently, based on the phase-field modeling, it is predicted that Hf1-xZrxO2 (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 (Formula presented.) 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 (Pr and Ec) of the sample that contains the minimum t-phase fraction (Formula presented.). This sample shows the lowest (Formula presented.) compared with the other samples, which is due to the formation of FE o-phase. The sample that contains the maximum (Formula presented.) demonstrates the highest dielectric response. By adjusting (Formula presented.), a large (Formula presented.) of ?55 is achieved. The study reveals a direct relation between (Formula presented.) and (Formula presented.) of HZO thin films, which can be understood by considering the density of MPB region. ? 2021 Wiley-VCH GmbH