A Compact Model of Phase-Change Memory Based on Rate Equations of Crystallization and Amorphization

In this paper, a compact model of phase-change memory based on the rate equations of crystallization and amorphization will be presented and confirmed by measurement. The model reproduces the nonlinear current-voltage behavior of both the "set" and "reset" states. Temperatures in the phase-change layer are calculated by a thermal equivalent circuit. The temperature-dependent crystallization and amorphization of the phase-change layer are taken into account in order to express resistance changes between the "set" and "reset" states. The crystallization rate is calculated based on the nucleation-growth model. The heat of fusion (the latent heat) is taken into account in the calculation of the amorphization rate.