Simulation of analog resistance change characteristics in Pt/TaO x /Ta2O5/Pt cells

Abstract

Abstract Resistive random access memories are strongly expected as not only an emerging nonvolatile memory but a neuromorphic device. However, the universal physical mechanism of resistance change phenomena has not been completely elucidated. In this study, we performed coupled simulation of analog resistance change phenomena in asymmetric Pt/TaO x /Ta2O5/Pt cells. We adopted a truncated cone-shaped conductive filament model and an appropriate amount of oxygen-vacancy storage in the Pt electrodes to demonstrate the gradual polarity swap of repeatable set and reset by control of the maximum negative voltage. As a result, mode control of the analog resistance change characteristics originates from an analog distribution inversion of the truncated cone-shaped filament without a clear depletion gap. The experimental and simulation results in this study indicate necessary conditions or dominant driving force of repeatable analog resistance change phenomena in the memristive cells.