Reset–Set Instability in Unipolar Resistive-Switching Memory

Unipolar resistive-switching memory attracts a strong interest as high-density nonvolatile memory for future technology nodes. The high-to-low-resistance change is achieved by the set operation, whereas the reverse transition is obtained by the reset process. Due to the similarities in the set and reset pulses, instabilities may arise, e.g., set may occur after reset within a reset pulse. This reset-set instability (RSI) can result in long program-verify loops to achieve a desired cell state. This letter discusses RSI, showing that the crossover of set and reset times as a function of voltage allows for stable set/reset processes at relatively high and low voltages, respectively.