Effects of bottom electrode on resistive switching characteristics of ZnO films

In this paper, thin films of ZnO were deposited on different bottom electrodes (BEs) by DC magnetron sputtering to fabricate resistive random access memory (ReRAM) with a W/ZnO/BEs structure. The effects of different BEs on the resistive switching characteristics of the fabricated device have been investigated. The results reveal that the devices fabricated on different BEs exhibit reversible and steady unipolar resistive switching behaviors. The conduction behavior in the low resistance state has an Ohmic behavior. However, the conduction mechanism in the high resistance state fits well with the classical space charge limited conduction. Schottky barrier heights between ZnO and different BEs have great effect on the operation voltages during the resistive switching processes. The resistances in low resistance state and the reset currents of the ZnO films fabricated on different BEs were discussed based on the filamentary model.