Investigation on resistive switching characteristics of ZnO thin film

Abstract

Recently resistive switching (RS) based on ZnO thin film has attracted considerable attention since ZnO with doping can improve the switching ratio and device performance. In this work, Cu/ZnO/AZO (Al-doped ZnO) and Cu/ZnO:Cu (Cudoped ZnO) /AZO structures were fabricated for RS, using AZO as bottom electrodes due to its lattice matching with ZnO, and metal Cu was deposited as the top electrodes. The current-voltage (I-V) characteristics of these RS devices using different doped ZnO thin films as a dielectric layer were analyzed and compared. The results demonstrated that ZnO:Cu RS had a higher switching ratio and a larger range of setup and reset voltage than ZnO RS. In addition, we also found that the high resistance state（HRS）and the low resistance state (LRS) were accordance with space charge limited current (SCLC) and Ohm’s law respectively. In addition, the effect on RS performance by the top electrode was investigated by depositing top electrode with different sizes and annealing treatment, and the results indicate that the RS phenomenon occurred in these Cu/ZnO:Cu/AZO structure devices is caused by bulk effect and interfacial effect synthetically.