Evaluation of variability and RTN in scaled RRAM

RRAM devices utilizing a filamentary conduction mechanism have attracted significant attention due to their unique scalability, excellent switching speed, and endurance. On the other hand, the RTN-like read current instability and cycle-to-cycle variability observed in these devices are still a concern from operational standpoint. In this study, we investigate the impact of switching conditions on HRS/LRS read instability/noise and variability by employing a fully automated measurement setup, which is capable of effectively collecting low resistive state (LRS) and high resistive state (HRS) read current values during the cycling under different AC SET/RESET conditions,. Analysis of the read current variati on over a statistically significant number of switching cycles allows extracting the parameters of the distributions of variability and reading instability amplitudes in both HRS and LRS. We discuss physical mechanisms for the LRS and HRS instability explaining how it is impacted by scaling of the operating current.