The Enhancement of the Resistance Window of TaN/GeTe/Cu Device by Controlling GeTe Film Structure

TaN/GeTe/Cu devices showed a switching behavior and a considerable increase in the on/off ratio due to GeTe microstructural changes. The Cu diffusion to the GeTe should be the origin of the switching behavior of the prepared devices, which indicates that the conductive bridging characteristics could be obtained even when using a pure GeTe solid electrolyte. The structural characterization suggested that voids are the main diffusion path of metallic bridges and that the electrical resistance of the on state is dependent on the quantity of voids in the GeTe film. We also found a method for controlling the quantity of voids in a solid electrolyte.