Exploring Different Circuit-level Approaches to the Forming of Resistive Random Access Memories

Advances in emerging resistive random-access memory (ReRAM) technology show promise to be used in future memory-centric computing systems. In ReRAM arrays that consist of two-terminal bipolar resistive switching (RS) devices, SET/RESET programming voltage pulses are used to switch them from low resistance state (LRS) to high resistance state (HRS). The recent commercialization of discrete and crossbar-array organized RS devices have certainly pushed forward experimentation with such emerging memory technology. One barrier still preventing their widespread practical use is the behavioral variability and the lack of a straightforward manner to implement the forming process and achieve uniform SET/RESET programing. In this paper, different circuit topologies and approaches are explored to perform the forming of the conductive channel in commercial discrete RS devices by Knowm Inc. A target-resistance is pursued through pulsed voltage stress, followed by cycle-to-cycle stabilization using a custom transimpedance amplifier circuit. Moreover, a voltage controlled low–current source is proposed as an approach to alleviate the complexity and risk of the forming process in device characterization.