Reset Current Reduction and Set-Reset Instabilities in Unipolar NiO RRAM

Unipolar resistive switching memory (RRAM) based on transition metal-oxides may allow for post-Flash high-density non-volatile storage solutions with crossbar architecture. However, the reset current I_reset must be reduced to allow the downscaling of diode-selected crossbar arrays. This study addresses I_reset reduction under pulsed operation. First, the conditions for proper control of the size of the conductive filament (CF) during set are clarified. Then, pulsed reset is addressed, showing for the first time that I_reset reduction is limited by the competition between set and reset transitions in high-R semiconductor-like CFs.