Internal Bias Field in Ferroelectric Polymer Thin Film for Nonvolatile Memory Applications

Abstract

Coercive voltages (V(C), the voltage which makes remanent polarization zero in ferroelectrics) of metal-ferroelectric polymer-metal capacitors were measured with different pulse periods. From the measured V(C), coercive fields (E(C), normalized V(C) for thickness) and internal bias fields (E(BIAS)) were calculated. Although E(C) was found to be nearly constant with thickness, E(BIAS) increased as thickness decreased. Based on these findings, it appears that E(BIAS) can be induced from interface phenomenon and greatly affects retention performance in thin ferroelectric films used for nonvolatile memory devices.