Faradaic currents during electroforming of resistively switching Ag–Ge–Se type electrochemical metallization memory cells

Abstract

Resistive switching due to electrochemical filament formation and dissolution is observed in a variety of materials. Mostly, an electroforming process is required to modify the active material and form a first filament. In this study, the forming process and low current resistive switching in Ag/Ag–Ge–Se/Pt memory cells was investigated. In contrast to most other resistively switching memory devices, the first current–voltage cycle was needed to reduce the metal content in the chalcogenide layer. Temperature dependent and sweep-rate dependent measurements of the faradaic current were performed, and the metal content in the Ag–Ge–Se thin film was estimated. After forming, resistive switching with a write current of only 1 nA was observed demonstrating the feasibility of the fabrication of memory cells with ultra low power consumption.