Reset Instability in $\hbox{Cu}/\hbox{ZrO}_{2}$:Cu/Pt RRAM Device

The metal oxide solid electrolyte-based RRAM device is a promising candidate for post-Flash nonvolatile memories. The critical operation of such a device is the reset process, and the reliability study of the reset process and its physical understanding are important to RRAM development. This letter reports the observation of the unstable reset behavior in the $\hbox{ZrO}_{2}$ -based solid electrolyte RRAM. During the reset process, the LRS resistance $(R_{L})$ of the device will first reduce and then increase to reach the HRS. It is also seen that $V_{0}$ (i.e., the voltage at which a decrease of $R_{L}$ takes place) decreases with an increase of $R_{L}$ . This instability might be attributed to the subsequent growth of the filament after the energy barrier is reached to overcome electrochemical reactions during the reset process. Based on these experimental results, a physical model is developed to help explain the dependence of $V_{0}$ on $R_{L}$ , which provides an important guideline to the optimization of RRAM operations.