Localization of Joule Heating in Phase-Change Memory With Incorporated Nanostructures and Nanolayer for Reducing Reset Current

In this paper, we intensively investigated the proposed nanocontact phase-change memory (nano-C PCM) with incorporated nanostructures and high-resistivity nanolayer (nano-L) for reducing reset current. The high resistivity was able to be tuned by doping N into the conventional Ge₂Sb₂Te₅ phase-change material. The analysis based on finite-element method exhibited that the current density in the nano-C PCM could be locally enhanced to about two times that of both conventional and nano-L PCM devices. This resulted in the localization of Joule heating in the nano-C PCM, making it have the highest temperature at the same programming current among the three types of PCM devices. Reset current of nano-C PCM could be greatly reduced to 8.2% of that of the conventional one, owing to its high-efficiency heating for amorphization.