Ferroelectric enhancement of Al-doped HfO2 thin films by rapid electron beam annealing in a low thermal budget
Journal
Journal of the European Ceramic Society
Journal Volume
42
Journal Issue
10
Pages
4221-4226
Date Issued
2022
Author(s)
Abstract
In past few years, there was a great amount of research on ferroelectric Al-doped HfO2 (HAO) thin films which suffer from the need of high annealing temperatures to achieve significant ferroelectricity. In this work, we realize pronounced remnant polarization 2Pr~29μC/cm2 of HAO using rapid electron beam annealing (EBA) with a large area. The simulation of electron beam trajectories reveals that the effect of EBA concentrates on the region ~20 nm below the sample surface, which highly benefits the process integration where a low thermal budget is required. The energy-dispersive X-ray and high-angle annular dark-field analyses reveal the interdiffusion between Al and Hf in the HAO layer treated by EBA. The pronounced ferroelectricity of HAO can be accounted for by the lattice strain, which facilities the formation of the orthorhombic phase, due to the substitution of Al for Hf as supported by the fast Fourier transformation diffraction pattern. © 2022
Subjects
Al-doped HfO2; Electron beam annealing; Ferroelectricity; Interdiffusion; Thin film
SDGs
Other Subjects
Aluminum compounds; Budget control; Electron beams; Electrons; Ferroelectric films; Ferroelectricity; Hafnium; Hafnium oxides; Al-doped; Al-doped HfO2; Annealing temperatures; Electron beam annealing; Electron beam trajectory; Interdiffusion; Low thermal budget; Remnant polarizations; Sample surface; Thin-films; Thin films
Type
journal article