ON-OFF switching mechanism of resistive-random-access-memories based on the formation and disruption of oxygen vacancy conducting channels

摘要

We study the ON-OFF switching mechanism of oxide-based resistive-random-access-memories using theoretical calculations. Electron deficient vacancies (V_O) up to 1+ charge states would stabilize a cohesive filament, while further electron removal will stabilize the disrupted V_O configurations with 2+ charges. The V_O cohesion-isolation transition upon carrier injection and removal is shown to be a strong driving force in the ON-OFF switching process. We also propose that bipolar or unipolar behavior is determined by how the carriers are injected into V_O. The control of the carrier injection by the electrode material selection is essential for desired bipolar switching.