Bipolar resistive switching in room temperature grown disordered vanadium oxide thin-film devices

Abstract We demonstrate bipolar switching with high OFF/ON resistance ratios (>10 4 ) in Pt/vanadium oxide/Cu structures deposited entirely at room temperature. The SET (RESET) process occurs when negative (positive) bias is applied to the top Cu electrode. The vanadium oxide (VO x ) films are amorphous and close to the vanadium pentoxide stoichiometry. We also investigated Cu/VO x /W structures, reversing the position of the Cu electrode, and found the same polarity dependence with respect to the top and bottom electrodes, which suggests that the bipolar nature is linked to the VO x layer itself. Bipolar switching can be observed at 100 °C, indicating that it not due to a temperature-induced metal–insulator transition of a vanadium dioxide second phase. We discuss how ionic drift can lead to the bipolar electrical behavior of our junctions, similar to those observed in devices based on several other defective oxides. Such low-temperature processed oxide switches could be of relevance to back-end or package integration processing schemes.