Evidence for Non-Arrhenius Kinetics of Crystallization in Phase Change Memory Devices

The programming speed in a phase change memory (PCM) relies on the kinetics of crystallization in the pulsed regime. To predict the programming speed and retention of a PCM, a careful understanding and modeling of crystallization in the phase change material is essential. In this paper, we study crystallization kinetics directly in PCM devices. From thermal annealing and pulsed-set experiments, we extract the temperature dependence of the crystallization in a wide temperature range between 170°C and the melting point (about 620°C). Our results indicate two markedly different activation energies below/above 300°C, thus providing evidence for a non-Arrhenius crystallization kinetics in PCM.