Self-compliance multilevel storage characteristic in HfO2-based device

In this paper, the self-compliance bipolar resistive switching characteristic of an HfO2-based memory device with Ag/HfO2/Au structure for multilevel storage is investigated. By applying a positive voltage, the dual-step set processes corresponding to three stable resistance states are observed in the device. The multilevel switching characteristics can still be observed after 48 hours. In addition, the resistance values of all the three states show negligible degradation over 104 s,which may be useful for the applications in nonvolatile multilevel storage.