Variability and cycling endurance in nanoscale resistive switching memory

Resistive switching memory (RRAM) devices are currently under consideration for applications as high-density memory, embedded memory and storage class memory. For such applications, low operation current, high uniformity of programmed/erased distributions and high cycling endurance are required. This work addresses switching variability and endurance in RRAM under pulsed operation. Variability of set/reset states is attributed to the Poissonian distribution of defect numbers in the conductive filament (CF). Variability and endurance are mainly controlled by the maximum voltage V-stop used for the reset operation. The negative set and the consequent collapse of the resistance window are evidenced to play the dominant role in limiting endurance lifetime of RRAM. Physical mechanisms and models for voltage-controlled variability and endurance are discussed.