Resistive Switching and Rectification Characteristics with CoO/ZrO2 Double Layers

Abstract

We have observed the unipolar resistive switching with double layers of sputtered CoO/ZrO2. The thicknesses of CoO/ZrO2 were 20 and 30 nm deposited by sputtering, respectively. Because of the different oxygen concentration, it formed larger size filament in CoO layer than that in ZrO2 layer after forming process. During OFF process, a large amount of current flows through the conducting filament, the narrower filament in the ZrO2 layerwould be ruptured because of the locally Joule heating, then we observed the unipolar behavior in this structure. About 400 cycling times of unipolar switching characteristic were obtained. However, due to the p-type conductivity for CoO and the n-type conductivity for ZrO2, it revealed the rectified behavior when we change to the proper thickness of the films and the ratio of sputtering gases(Ar,O-2). It has the potential application of 1DIR structure in the future.