Investigation of Factors Affecting SET-Disturb Failure Time in a Resistive Switching Memory

Abstract

Factors affecting SET-disturb failure time (tau(f)) in a tungsten oxide resistive switching memory including SET/RESET cycling stress, resistance window in operation and SET-disturb voltage are investigated. A SET-disturb failure time in high resistance state (HRS) may degrade by orders of magnitude in a post-cycling cell. The degradation is attributed to the formation of a current percolation path of cycling stress-generated traps. A one-dimensional percolation model is proposed for the tau(f) degradation. The dependence of tau(f) on resistance window in operation is characterized. We find that tau(f) is greatly affected by the current level of LRS. The strong LRS dependence of tf is attributed to a small Weibull slope of tau(f). In addition, we perform statistical characterizations of tau(f) at different SET-disturb voltages. A relationship between tau(f) and a SET-disturb voltage in a stressed cell is given.