Effects of RESET Current Overshoot and Resistance State on Reliability of RRAM

Current overshoot has severe effects on the reliability of resistive random access memory (RRAM). It is well known that the current overshoot during the SET process is caused by parasitic capacitance. In this letter, we observed a different type of current overshoot during the RESET process. The RESET current overshoot was confirmed to have severe effects on the endurance of RRAM. We also demonstrated the relation between the current overshoot and the intrinsic capacitive elements of each state of RRAM. Finally, an optimized pulse shape was proposed to minimize the current overshoot and was experimentally verified to significantly improve the variability and endurance in a typical RRAM device with a W/Zr/HfO2/TiN structure.