Current-limiting amplifier for high speed measurement of resistive switching data

Resistive switching devices, important for emerging memory and neuromorphic applications, face significant challenges related to control of delicate filamentary states in the oxide material. As a device switches, its rapid conductivity change is involved in a positive feedback process that would lead to runaway destruction of the cell without current, voltage, or energy limitation. Typically, cells are directly patterned on MOS transistors to limit the current, but this approach is very restrictive as the necessary integration limits the materials available as well as the fabrication cycle time. In this article we propose an external circuit to cycle resistive memory cells, capturing the full transfer curves while driving the cells in such a way to suppress runaway transitions. Using this circuit, we demonstrate the acquisition of $10^5$ I-V loops per second without the use of on-wafer current limiting transistors. This setup brings voltage sweeping measurements to a relevant timescale for applications, and enables many new experimental possibilities for device evaluation in a statistical context.