Modeling of field- and time-dependent resistance change phenomena under electrical stresses in Fe–O films

Abstract

An electrical stress-induced resistance change in an Fe–O film was studied in detail. Under constant voltage stress (CVS) and constant current injection, the resistance of the Fe–O film abruptly increased. The observed time-to-resistance increase (tr) was found to depend on the applied voltage as well as on the injected current density. The total input energy until tr also depended on the applied voltage. From these observations, the mechanisms of resistance change are considered to obey a field-enhanced reaction, and this resistance increase is attributed to a high-resistive Fe–O layer formation at the interface between the anode electrode and the low-resistive Fe–O layer. We proposed a simplified two-step model for the time evolution of the current under CVS [ICVS(t)]. The predicted ICVS(t) showed a good agreement with experimental results. The model also explained the field dependence of tr.