Unified mechanisms for structural relaxation and crystallization in phase-change memory devices

Data retention in phase-change memory (PCM) devices is the result of two physical phenomena: structural relaxation (SR) and crystallization of the amorphous chalcogenide material. Although the two processes are rather different, we show in this paper that a common physical interpretation for SR and crystallization kinetics is possible. Activation energies and Arrhenius pre-factors for SR and crystallization are found to coherently obey a Meyer-Neldel rule and are explained by many-body thermal excitation of weakly-bonded and normally-bonded clusters, respectively. (C) 2009 Elsevier B.V. All rights reserved.