Low power W:AlOx/WOx bilayer resistive switching structure based on conductive filament formation and rupture mechanism

We report the design and fabrication of W:AlOx/WOx bilayer based resistive switching cells in a standard 0.18 μm CMOS process with only one extra mask. The devices show excellent performance with low power consumption. Low operation voltages (SET voltage 1.5 V, RESET voltage 1.3 V) are achieved, and specifically, the RESET and SET currents are lower than 1 μA. For the 0.3 μm×0.3 μm active area of the cell, the current density is below 1.1×103A/cm2, which is much smaller than previous reported results. To reveal the resistive switching mechanism, various physical analysis techniques were employed to examine the microstructures, compositions, and chemical states. Current-voltage and capacitance-voltage electrical characterizations were carried out on these devices. Based on the physical and electrical characteristics, a conductive filament formation and rupture mechanism is proposed to explain the W:AlOx/WOx bilayer structure resistive switching phenomena.