New Set/Reset Scheme for Excellent Uniformity in Bipolar Resistive Memory

We proposed a new set/reset operation scheme to improve the switching uniformity of filament-type resistive memory. By controlling the magnitude of the sweep voltage in the pulse-sweep mode at each set and reset operation, similar resistance of a conducting filament in a low-resistance state and a homogeneously dissolved conducting filament in high resistance state were obtained continuously. As compared with a normal operation scheme involving a fixed voltage, our new operation scheme exhibits dramatically improved switching uniformity. By combining the new operation scheme with a gradual reset operation, we successfully achieved a stable multibit operation.