Improved switching uniformity of a carbon-based conductive-bridge type ReRAM by controlling the size of conducting filament

We investigated the resistive switching properties of a amorphous carbon-based ReRAM device. In order to minimize the fluctuations of switching parameters, we introduced an external load resistor (RLoad) in series, which indirectly acts as a current limiter. Reduced reset current (Ireset) and improved switching uniformity were obtained when the proper external RLoad was connected. The voltage drop at the ReRAM device during switching was directly monitored using an oscilloscope. We have confirmed that fluctuation of the effective voltage applied across the conducting filament was dramatically reduced by adding RLoad. In contrast, we observed degradation of retention characteristic of sample with RLoad. To meet both switching uniformity and retention characteristics, we need to optimize the resistance of low resistance state.