Kinetic Monte Carlo Simulation of Interface-Controlled Hafnia-Based Resistive Memory

Kinetic Monte Carlo simulations of resistive memory devices have been performed by paying attention to the vacancy-interstitial generation near the Hafnia-metal electrode interface. In our model, an oxygen vacancy is generated in Hafnia near the interface, with the corresponding oxygen atom residing in the metal electrode. These oxygen atoms form a thin insulating oxide layer at the Hafnia-active electrode interface. This interfacial layer is essential to thicken the filament, even after the filament bridges the two metal electrodes at low current levels. This thickening of the conducting filament is captured by the model and it naturally explains the trend of resistance decrease with an increase in compliance current found in some experiments. Simulations results as a function of the bonding energy between vacancies show a large increase in retention time with an increase in bonding energy. We also find that as the compliance current increases, the morphology of the filament transitions from conical to dumbbell-shaped. Finally, using a single set of values for various energies, our simulations capture the SET, RESET, and retention processes.