Modeling of Phase-Change Memory: Nucleation, Growth, and Amorphization Dynamics During Set and Reset: Part I—Effective Media Approximation

We have constructed a framework that enables finite-element modeling of nucleation, growth, and amorphization processes in phase-change memory devices using a single rate equation that tracks evolution of local crystal density at each mesh point. The rate equation, current continuity equation, and Fourier heat transfer equation are solved simultaneously to perform electro-thermal simulations that capture the device dynamics during set and reset operations. The functionality of this framework is demonstrated through simulation of various set and reset operations and consecutive set/reset cycles of a mushroom cell using temperature and crystallinity dependent parameters for Ge
₂
Sb
₂
Te
₅
.