Resistive Switching Characteristics of WO 3 /ZrO 2 Structure With Forming-Free, Self-Compliance, and Submicroampere Current Operation

The homogeneous switching of Ti/WO 3 /ZrO 2 /W resistive switching memory devices with stable resistive switching, forming-free, self-compliance, and multilevel operation characteristics are demonstrated. The area dependence of current at the low resistance and high resistance states confirms that the switching mechanisms of the devices are homogeneous conduction. The devices exhibit the stable bipolar resistive switching behavior with a low operating current ( $ A) by inserting the WO 3 layer with high electron affinity between the Ti top electrode and the ZrO 2 layer and modulating the potential profiles at the WO 3 /ZrO 2 interface. In addition, multilevel operation can be achieved by adjusting the magnitudes of set/ reset voltages.