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

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. (C) 2012 American Institute of Physics. [doi:10.1063/1.3685222]