Classical-nucleation-theory analysis of priming in chalcogenide phase-change memory
Publication Date
2017-10-15Journal Title
Acta Materialia
ISSN
1359-6454
Publisher
Elsevier
Volume
139
Pages
226-235
Language
English
Type
Article
This Version
AM
Metadata
Show full item recordCitation
Orava, J., & Greer, A. (2017). Classical-nucleation-theory analysis of priming in chalcogenide phase-change memory. Acta Materialia, 139 226-235. https://doi.org/10.1016/j.actamat.2017.08.013
Abstract
The chalcogenide Ge2Sb2Te5 (GST) is of interest for use in phase-change memory. Crystallization is the rate-limiting step for memory operation, and can be accelerated by the prior application of a “priming” heating pulse. There is characteristic fading of the priming effect if there is a time interval between the priming pulse and the main heating pulse to achieve crystallization. We apply classical nucleation theory to interpret these effects, based on a fitting of nucleation kinetics (steady-state and transient) over the full temperature range of the supercooled liquid. The input data come from both physical experiments and atomistic simulations. Prior studies of conventional glass-formers such as lithium disilicate preclude any possibility of fading; the present study shows, however, that fading can be expected with the particular thermodynamic parameters relevant for GST and, possibly, other phase-change chalcogenides. We also use the nucleation analysis to highlight the distinction between GST and the other archetypical chalcogenide system (Ag,In)-doped Sb2Te. Classical nucleation theory appears to be applicable to phase-change chalcogenides, and to predict performance consistent with that of actual memory cells. Nucleation modeling may therefore be useful in optimizing materials selection and performance in device applications.
Keywords
amorphous materials, classical nucleation theory, phase-change chalcogenides, phase transformation kinetics, rapid solidification
Sponsorship
We acknowledge financial support by the World Premier International Research Center Initiative (WPI), MEXT, Japan, and from the European Research Council under the European Union's Horizon 2020 research and innovation program (grant ERC-2015-AdG-695487: ExtendGlass).
Funder references
European Research Council (695487)
Embargo Lift Date
2100-01-01
Identifiers
External DOI: https://doi.org/10.1016/j.actamat.2017.08.013
This record's URL: https://www.repository.cam.ac.uk/handle/1810/266142
Rights
Attribution 4.0 International, Attribution 4.0 International, Attribution 4.0 International
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