Optimized chalcogenide medium for inherently activated resistive switching device

Abstract

The suitability of thin films of the chalcogenide germanium telluride (GeTex) with various chemical compositions for use as an active medium in a conductive bridge resistive switching memory device with Cu and TiN as the active and counter electrodes, respectively, was examined. Experimental results showed that all of the tested resistive switching devices showed identical current-voltage hysteresis curves for the first and second cycles, the electroforming (EF)-free characteristic, which is favourable for achieving high operational reliability. From a comparative study of different active electrodes, we concluded that the intrinsic electronic traps and diffused Cu ions in the GeTex layer were responsible for the EF-free characteristic. Furthermore, as the Te content increased, the retention characteristics of the programmed resistance state became unstable since the short-range-ordered Te-Te clusters in the GeTex layer caused the Cu conductive filament to dissolve in Cu-Te locally. Experimental results indicated that the chalcogenide materials were good candidates for a highly reliable active layer in a conducting-bridge resistive switching memory device. This report presents various microscopic analysis results to show the superior performance of chalcogenide-based resistive switching memory devices.