Sub-7-nm textured ZrO2 with giant ferroelectricity
Journal
Acta Materialia
Journal Volume
205
Date Issued
2021
Author(s)
Abstract
An ~6.5 nm pure ZrO2 thin film with a giant ferroelectric remanent polarization (Pr) of ~50 μCcm?2 and an effective piezoelectric coefficient (d33) of 7?9 pm/V is reported. The film was prepared on a (111)-oriented Pt electrode using plasma-enhanced atomic layer deposition at 300 °C, followed by annealing at 400 °C, and exhibited a preferred orientation of the orthorhombic (111) planes in the in-plane direction. The Pr value of ~50 μCcm?2 is the largest reported to date for both perovskite and fluorite nanoscale ferroelectric thin films (< 120 nm) on a Pt electrode. Furthermore, the processing temperature of 300?400 °C is the lowest reported to date to produce a Pr of ~50 μCcm?2 in nanoscale ferroelectrics on a Pt electrode. The giant Pr, ascribed to the preferred crystal orientation, was confirmed by the positive-up negative-down (PUND) polarization measurement with a long delay time to allow the relaxation of polarization. The effective d33 was obtained using piezoresponse force microscopy with an interferometric displacement sensor to minimize the frequency-dependent artifacts and the effects of cantilever dynamics. The low-temperature preparation of the textured ZrO2 ultrathin film with a giant Pr is extremely advantageous for device scaling and process integration in advanced nanoelectronics. ? 2020
Subjects
Atomic layer deposition; Crystal orientation; Electrodes; Ferroelectric films; Ferroelectric thin films; Ferroelectricity; Fluorspar; Nanotechnology; Perovskite; Piezoelectricity; Platinum; Polarization; Praseodymium; Processing; Scanning probe microscopy; Temperature; Textures; Ultrathin films; Zirconia; Frequency dependent; Low temperature preparation; Piezoelectric coefficient; Piezoresponse force microscopy; Plasma-enhanced atomic layer deposition; Polarization measurements; Preferred orientations; Processing temperature; Film preparation
Type
journal article