Dependence of resistive switching on ion-migration process in organic electrochemical metallization memory (Conference Presentation)

Organic-based electrochemical metallization memory (ECM) has been paid much attention for non-volatile memory devices owing to high integration and mechanical flexibility. In such ECM systems, the formation of conductive filaments (CFs) is typically composed of two activation steps: i) the electrochemical redox reactions at an interface between an electrode and an electrolyte and ii) the migration of the cations of metal across the electrolyte. Accordingly, the overall electrical performance of the ECM device is primarily governed by the kinetics of the two steps. However, in the ECM devices using organic electrolytes, a rather compete picture of the resistive switching during the ion-migration process has not been described so far since filamentary paths are barely observable. In this work, we investigated how the resistive switching depends on the ion-migration properties including the drift velocity and the migration path in the organic ECM device. Two types of polymer electrolytes, having different molecular weights, were used for the control of the ion drift velocity. The topography of ion-migration paths was modified by the deposition rate of metal for the top electrode. The formation and the retention of the CFs depend critically on the ion mobility of the polymer electrolyte and the topography of the ion-migration paths as well. These results will provide a useful guideline for constructing high- performance ECM storage systems based on organic materials. This work was supported by the Brain Korea 21 Plus Project in 2018.