Electrical properties and fatigue behaviors of ZrO2 resistive switching thin films

Abstract

The resistive switching mechanisms of ZrO2 memory films are proposed to explain why resistive switching characteristics of Ti/ZrO2/Pt device are more stable than those of Pt/ZrO2/Pt and Al/ZrO2/Pt devices in this study. Different from the Pt/ZrO2/Pt and the Al/ZrO2/Pt devices, the carrier conduction mechanisms in the Ti/ZrO2/Pt device obey space charge limited current theory, which may be caused by the formation of the interface layer between Ti and ZrO2. Moreover, the resistive switching mechanisms are proposed to be related to the filament formation/rupture theory and oxygen ion migration. The location where filament formation/rupture takes place should be confined near the interface between Ti and ZrO2, leading to the stable resistive switching characteristics and a better endurance performance. During successive resistive cycles at room temperature and 150 degrees C, the fatigue behaviors are observed due to the degradation of both two memory states, which might be related to the transformation of the interface layers between Ti and ZrO2 and the coalescence of ZrOx clusters. (C) 2008 The Electrochemical Society.