Modeling of diffusion mechanism of conductive channel oxidation in a Pt/NiO/Pt memory switching structure

• Diffusion oxidation model in ReRAM structure developed by numerical modeling.
• Spatial dynamics of oxidation process defines the channel interrupting in its central part.
• The increase in critical current above the limit by 10% reduces RESET time by an order of magnitude.

The transition process from the low resistance state into the high resistance state in a Pt/NiO/Pt memory switching structure has been studied by numerical modeling. Detailed analysis shows, that thermally induced diffusion oxidation by nickel vacancies is the key factor for distortion of the channel metallic conductivity. Spatial dynamics of the process of oxidation defines channel narrowing mainly in its central part, and also sets the critical current through the structure sufficient for final rupture of the channel and the transition to high resistance state. The increase in critical current above the limit even by 10% reduces the switching time by an order of magnitude, which is in agreement with experiments. The developed radial diffusion model of conductive channel (or filaments) oxidation may be suitable for the analysis of switching effect a number of other ReRAM oxide structures.