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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:
lacaita@elet.polimi.it, Politecnico di Milano, Dipartimento di elettronica e informazione, Piazza L. Da Vinci, 33, Milano, 20052, Italy
Ugo Russo
Affiliation:
ugo.russo@polimi.it, Politecnico di Milano and IU.NET, Dipartimento di elettronica e informazione, Piazza L. Da Vinci, 33, Milano, 20133, Italy
Daniele Ielmini
Affiliation:
ielmini@elet.polimi.it, 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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References

REFERENCES

1. Ovshinsky, S. R. “Reversible electrical switching phenomena in disordered structures,” Phys. Rev. Lett., vol. 21, pp. 1450–1453, 1968.Google Scholar
2. Ahn, S. J. et al. , “Highly manufacturable high density phase change memory of 64Mb and beyond,” in IEDM Tech. Dig., pp. 907–910, 2004.Google Scholar
3. Pellizzer, F. et al. , “A 90nm phase change memory technology for stand-alone non-volatile memory applications,” in Symp. VLSI Tech. Dig., pp. 122–123, 2006.Google Scholar
4. Chen, Y. C. et al. , “Ultra-thin phase-change bridge memory device using GeSb,” in IEDM Tech. Dig., 777–780, 2006.Google Scholar
5. Horii, H. et al. , “A novel cell technology using N-doped GeSbTe films for phase change RAM,” in Symp. on VLSI Tech. Dig., 177–178, 2003.Google Scholar
6. Kang, S. et al. , “A 0.1-mm 1.8-V 256-Mb Phase-Change Random Access Memory (PRAM)With 66-MHz Synchronous Burst-Read Operation,” in IEEE Journ. Of Solid-State Circuits, vol. 42, pp 210–218 Google Scholar
7. Matsuzaki, N. et al. , “Oxygen-doped Ge2Sb2Te5 phase-change memory cells featuring 1.5-V/100-mA standard 0.13mm CMOS operations,“ in IEDM Tech. Dig., 738–741, 2005.Google Scholar
8. Lai, S. “Current status of the phase change memory and its future,” in IEDM Tech. Dig., pp. 255–258, 2003.Google Scholar
9. Pirovano, A. et al. , “Reliability study of phase-change nonvolatile memories,” IEEE Trans. Device Mater. Rel., vol. 4, no. 3, pp. 422–427, Sep. 2004 Google Scholar
10. Pirovano, A. et al. , “Low-field amorphous state resistance and threshold voltage drift in chal-cogenide materials,” IEEE Trans. Electron Devices, vol. 51, no. 5, pp. 714–719, May 2004.Google Scholar
11. Kim, K. and Ahn, S.-J., “Reliability investigations for manufacturable high density PRAM,” in Proc. IRPS, 2005, pp. 157–162.Google Scholar
12. Lacaita, A. L. et al. , “Electrothermal and phase-change dynamics in chalcogenide-based memories,” in IEDM Tech. Dig., 2004, pp. 911–914.Google Scholar
13. Russo, U. et al. , “Modeling of Programming and Read Performance in Phase-Change Memo-ries—Part I: Cell Optimization and Scaling,” IEEE Trans. Electron Devices, 55, 506, 2008.Google Scholar
14. Ahn, S. J. et al. , “Highly reliable 50 nm contact cell technology for 256 Mb PRAM,” in VLSI Symp. Tech. Dig., 2005, pp. 98–99.Google Scholar
15. Jeong, G. T. et al. , “Process technologies for the integration of high density phase change RAM,” in Proc. Integr. Circuit Des. Technol. Int. Conf., 2005, pp. 19–22.Google Scholar
16. Ielmini, D. et al. , “Recovery and drift dynamics of resistance and threshold voltages in phase-change memories,” IEEE Trans. Electron Devices 54, 308, 2007.Google Scholar
17. Russo, U. et al. , “Intrinsic data retention in nanoscaled phase-change memories – Part I: Monte Carlo Model for Crystallization and Percolation,” IEEE Trans. Electron Devices 53, 3032, 2006 Google Scholar
18. Redaelli, A. et al. , “Intrinsic data retention in nanoscaled phase-change memories – Part I: Statistical analysis and prediction of failure time,” IEEE Trans. Electron Devices 53, 3040, 2006.Google Scholar
19. Peng, C. et al. , “Experimental and theoretical investigations of laser-induced crystallization and amorphization in phase change optical recording media,” J. Appl. Phys., vol. 82, no. 9, pp. 4183–4191, Nov. 1997.Google Scholar
20. Ielmini, D. and Zhang, Y. “Evidence for trap-limited transport in the sub-threshold conduction regime of chalcogenide glasses,” Appl. Phys. Lett. 90, 192102, 2007 Google Scholar
21. Christian, J. W. The Theory of Transformations in Metals and Alloys, Oxford, U.K.: Perga-mon, 1975.Google Scholar
22. Singh, H. B. and Holz, A. “Stability limit of supercooled liquids,” Solid State Commun., vol. 45, no. 11, pp. 985–987, Mar. 1983.Google Scholar
23. Senkader, S. and Wright, C. D. “Models for phase-change of Ge2Sb2Te5 in optical and electrical memory devices,” J. Appl. Phys., vol. 95, no. 2, pp. 504–511, Jan. 2004.Google Scholar
24. Russo, U. et al. , “Analytical Modeling of Chalcogenide Crystallization for PCM Data-Retention Extrapolation,” IEEE Trans. On Electron Devices 54, 2769, 2007 Google Scholar
25. Kalb, J. A. et al. , “Kinetics of crystal nucleation in undercooled droplets of Sb- and Te- based alloys used for phase change recording,” J. Appl. Phys., vol. 98, no. 5, p. 054 910, Sep. 2005.Google Scholar
26. Hirasawa, M. et al. , “Size-dependent crystallization of Si nanoparticles”, Appl. Phys. Lett., vol. 88, p. 093119, 2006.Google Scholar
27. Milliron, D. J. et al. , “Solution-phase deposition and nanopatterning of GeSbSe phase-change materials”, Nature Mater., vol. 6, pp. 352–356, 2007.Google Scholar
28. Raoux, S. et al. , “Scaling properties of phase change nanostructures and thin films,” in EPCOS Confer. Proc., pp. 905–908, 2006.Google Scholar
29. Lee, S.-H., et al. ,, “Highly scalable non-volatile and ultra-low-power phase-change nanowire memory”, Nature Nanotech., vol. 2, pp. 626–630, 2007 Google Scholar
30. Lacaita, A. L. and Ielmini, D. “Reliability issues and scaling projections for phase change non volatile memories,” IEDM Tech. Dig. 2007, pp.157–160, 2007 Google Scholar
31. Yamada, N. et al. , “Rapid phase transitions of GeTe - Sb2Te3 psuedobinary amorphous thin films for an optical disk memory,” J. Appl. Phys., vol. 69, no. 5, pp. 2849–2856, Mar. 1991.Google Scholar
32. Olson, J. K. et al. , Optical properties of amorphous GeTe, Sb2Te3, and Ge2Sb2Te5: The role of oxygen, J. Appl. Phys., vol. 99, p. 103508, 2006.Google Scholar