Characterization of silver-saturated Ge–Te chalcogenide thin films for nonvolatile random access memory

Abstract

Programmable metallization cell structure with a device diameter of 2μm composed of Ag–Ge–Te chalcogenide films was prepared by a cosputtering technique at room temperature. The device with a 150nm thick Ag30(Ge0.3Te0.7)70 electrolyte switches at 0.2V from an “off” state resistance Roff close to 106Ω to an “on” resistance state Ron more than four orders of magnitude lower for this programming current. The switching characteristics were closely related with a diffusion of silver anode into silver-saturated GeTe electrolyte films.