D.C. leakage currents in ferroelectric memories

Abstract

Experimental data on d.c. leakage currents in lead zirconate titanate thin films (210 nm) are presented. The data show a flat, ohmic response up to a thresh-hold of approximately 2.0 V, above which they satisfy a modified Childl's Law, with a perfectly quadratic dependence: I = aV². This suggests that at 5 V operation the film behaves as a fully depleted device. The difficulty in distinguishing between Frenkel-Poole, Schottky emission, and true space-charge limited currents is briefly discussed.