Electrochemical Metallization and Trapping/Detrapping Resistive Switching Mechanism in Al/VOx/Cu RRAM

Abstract

We investigated resistive switching mechanism in Al/VOx/Cu RRAM structure. The temperature dependence of resistance on low resistive state (LRS) and conductive atomic force microscopy (CAFM) measurement confirmed the formation and rupture of Cu conductive filaments (Cu-CF) in VOx dielectric. Cu-CF was formed after a trapping process (HRS→LRS) and ruptured at Schottky junction Al/VOx interface (LRS→HRS) judged by rectification and C-V characteristics of high resistive state (HRS). A model combining trapping/detrapping and Cu-CF formation/rupture is proposed to describe resistive switching mechanism. Based on the combined resistive switching mechanism, an application of multi-level states in Al/AlOx/VOx/Cu device is achieved successfully.