Effetti termoelettrici e migrazione ionica in memorie a cambiamento di fase

Thermoelectric (TE) effects play an important role in phase change memory (PCM), where phase transition and atomic migration are accelerated by temperature. A deep understanding of TE effects may allow a physics-based design of the cell structure and materials to optimize programming speed/energy and reliability. This work addresses the polarity-dependence of PCM characteristics, including crystallization, melting, electrical switching/holding, and ion migration. These characteristics show slower kinetics at negative voltage, which we attribute to TE effects on Joule heating. We demonstrate a universal correlation of positive/negative kinetics, which we reproduce by modeling Thomson and Peltier heating.