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Recent Advances on the Modeling of Phase Change Materials and Devices

Published online by Cambridge University Press:  01 February 2011

Andrea Leonardo Lacaita ,
Ugo Russo  and
Daniele Ielmini
Andrea Leonardo Lacaita
Affiliation:
[email protected], Politecnico di Milano, Dipartimento di elettronica e informazione, Piazza L. Da Vinci, 33, Milano, 20052, Italy
Ugo Russo
Affiliation:
[email protected], Politecnico di Milano and IU.NET, Dipartimento di elettronica e informazione, Piazza L. Da Vinci, 33, Milano, 20133, Italy
Daniele Ielmini
Affiliation:
[email protected], Politecnico di Milano and IU.NET, Dipartimento di elettronica e informazione, Piazza L. Da Vinci, 33, Milano, 20133, Italy
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Abstract

As non-volatile memory technology is approaching the 45nm generation node and in view of severe scaling limitations of conventional Flash, phase-change memory (PCM) is gaining momentum as a reference emerging memory. The high applicative interest in this new technologies asks not only for progress in the integration issues of the new storage concept, but, most importantly, for a significant improvement of the physical understanding of programming, reliability mechanisms and scalability of the new technology. This can only be possible by a detail study of microscopic processes in the chalcogenide material covering a wide range of physics, from electron transport in disordered media to self-heating effects, from solid-state nucleation and growth processes at the nanoscale.

The presentation will review the most recent advances in the understanding and modeling of the programming and reliability mechanisms in chalcogenide-based PCM devices. Electro-thermal simulations of the programming behavior allows to understand the impact of cell geometry and active/electrode materials on the programming current, and to benchmark different scaling rules for future technology nodes. Cell reliability will be discussed with emphasis on the spontaneous crystallization kinetics in the amorphous chalcogenide material, on the acceleration laws to predict retention time at low temperature, and on the possible scaling limitations due to fast phase transition in amorphous chalcogenide nanoclusters/nanowires. An analytical model for nucleation and growth in the amorphous phase will be shown, allowing to draw guidelines for material engineering and reliability improvement. Other scaling-related reliability issues, such as statistical spread of crystallization times and structural relaxation of the amorphous phase, will be discussed.

Keywords

memoryphase transformationamorphous
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1072: Symposium G – Phase-Change Materials for Reconfigurable Electronics and Memory Applications , 2008 , 1072-G06-05
Copyright
Copyright © Materials Research Society 2008

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