Fast and Stable Sub-10uA Pulse Operation in W/SiO2/Ta/Cu 90nm 1T1R CBRAM Devices

Abstract

We demonstrate that CBRAM devices based on SiO2 dielectric can target sub-10μA application, ensuring large programming window, fast and low-voltage switching and limited cycle-to-cycle variability at 5 μA. We report, for the first time, reliable 1-μs forming operation at 5 μA on RRAM devices. The thorough comparison of SiO2- and Al2O3-based devices, in terms of electrical and physical characterization, suggests that the Cu mobility in the switching layers plays a key role, impacting forming/switching speed as well as functionality at low current, and that it can be tuned by properly selecting the switching layer material. We also correlate the mismatch in the electrical performances in the sub-10 μA regime to different filament configurations in the two resistive states.