Understanding Endurance in TiN/a-Si/TiOx/TiN RRAM Devices

Amorphous Vacancy Modulated Conductive Oxide resistive switching devices (TiN/a-Si/TiOx/TiN) are attractive for storage class memory applications due to their self-rectifying and self-compliant characteristics with low current switching. However, the endurance is intrinsically limited to 103 cycles. Using specific experiments and insights from kinetic defect distribution models, we identify two modes of failure - first, window closure to the middle due to defect loss and profile symmetrization as the consequences of current and field driven-defect profile modulation, respectively, and second, excess defect generation at higher bias culminating in dielectric breakdown. Based on these findings, we suggest improvement to the device stack.