Transient Simulation of Delay and Switching Effects in Phase-Change Memories

The transient simulation of threshold switching in phase-change memory (PCM) devices is essential for the prediction and optimization of cell behavior depending on the circuit parameters and for the understanding of the ultimate limit of operation speed. This paper presents a simulation study of threshold switching in PCM devices aimed at investigating the role of delay and switching times in cell behavior. The analytical Poole-Frenkel model for conduction and the energy gain model for threshold switching are used to evaluate the transient effects. The current and field transients at the basis of the switching phenomenon are shown and discussed with the aid of the numerical model. The impact of cell parasitics, in particular the parallel capacitance, is finally addressed.