Physics-Based Modeling Strategies of Phase-Change Random Access Memory

Abstract

Phase-change random access memory (PCRAM) has been regarded as one of the most promising candidates for future “universal” memory due to its mature fabrication techniques and profitable commercialized prospect. To further improve its physical performance and exploit more application areas, it is imperative to develop a physically realistic model that can closely mimic the electrical, thermal, and phase-change mechanisms of PCRAM. Although plenty of phase-change memory models have been proposed during the last two decades, they were constructed from various physical principles and, thus, targeted for different practical applications. As a result, a comprehensive review to elucidate the state-of-the-art modeling strategies of PCRAMs based on their phase-change mechanisms and application targets remains mysterious. To address this issue, we here reviewed the reported modeling approaches of PCRAMs mainly in terms of the finite-element method, the physics-based analytical model, and compact modeling techniques. For each technique, its adopted strategies to simulate the electrothermal and phase-change processes of phase-change materials at the device level were elaborated, respectively, and their respective merits and drawbacks were also given. The application fields, for which these models suit, were eventually discussed.