Thickness-dependent ferroelectric behavior of predominantly (117)-oriented Bi3.15Nd0.85Ti3O12 thin-film capacitors

Abstract

Ferroelectric hysteresis loops, remanent polarization, coercive field, and leakage current characteristics were investigated by increasing the film thickness (from 103 nm to 401 nm) of predominantly (117)-oriented Bi3.15Nd0.85Ti3O12 films. The thickness dependence of the coercive fields shows log coercive field vs. log thickness with a slope of approximately −0.65, which is characteristics of the Kay–Dunn scaling law. The films exhibited very low leakage current on the order of 10−7A/cm2 at an applied electric field of 100 kV/cm. Without a discernible thickness-dependence behavior, the leakage current characteristics, including both Schottky emission and space-charge-limited conduction, were well described by a modified Schottky contact model.