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Impact of Annealing on the Thermoelectric Properties of Ge2Sb2Te5 Films

Published online by Cambridge University Press:  07 December 2012

Jaeho Lee ,
Takashi Kodama ,
Yoonjin Won ,
Mehdi Asheghi  and
Kenneth E. Goodson
Jaeho Lee
Affiliation:
Department of Mechanical Engineering, Stanford University, Stanford, California 94305, U.S.A.
Takashi Kodama
Affiliation:
Department of Mechanical Engineering, Stanford University, Stanford, California 94305, U.S.A.
Yoonjin Won
Affiliation:
Department of Mechanical Engineering, Stanford University, Stanford, California 94305, U.S.A.
Mehdi Asheghi
Affiliation:
Department of Mechanical Engineering, Stanford University, Stanford, California 94305, U.S.A.
Kenneth E. Goodson
Affiliation:
Department of Mechanical Engineering, Stanford University, Stanford, California 94305, U.S.A.
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Abstract

Thermoelectric phenomena strongly influence the behavior of chalcogenide materials in nanoelectronic devices including phase-change memory cells. This paper presents the annealing temperature and phase dependent thermoelectric properties of Ge2Sb2Te5 films including the thermoelectric power factor and the figure of merit. The Ge2Sb2Te5 films annealed at different temperatures contain varying fractions of the amorphous and crystalline phases which strongly influence the thermoelectric properties. The thermoelectric power factor increases fom 3.2 μW/mK2 to 65 μW/mK2as the crystal phase changes from face-centered cubic to hexagonal close-packed. The data are consistent with modeling based on effective medium theory and suggest that careful consideration of phase purity is needed to improve the figures of merit for phase change memories and potentially for thermoelectric energy conversion applications.

Keywords

thermoelectricthin filmphase transformation
Type
Articles
Information
MRS Online Proceedings Library (OPL) , Volume 1490: Symposium B – Thermoelectric Materials Research and Device Development for Power Conversion and Refrigeration , 2013 , pp. 223 - 228
Copyright
Copyright © Materials Research Society 2012 

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References

REFERENCES

Castro, D. T., Goux, L., Hurkx, G. A. M., Attenborough, K., Delhougne, R., Lisoni, J., Jedema, F. J., t Zandt, M. A. A., Wolters, R. A. M., and Gravesteijn, D. J., “Evidence of the thermo-electric Thomson effect and influence on the program conditions and cell optimization in phase-change memory cells,” in IEDM Tech. Dig., pp. 315–318, 2007.Google Scholar
Suh, D.-S., Kim, C., Kim, K. H. P., Kang, Y.-S., Lee, T.-Y., Khang, Y., Park, T. S., Yoon, Y.-G., Im, J., Ihm, J., “Thermoelectric heating of Ge2Sb2Te5 in phase change memory devices,” Appl. Phys. Lett., vol. 96, no.12, Mar 2010.Google Scholar
Grosse, K. L., Bae, M.-H., Lian, F., Pop, E., King, W. P., “Nanoscale Joule Heating, Peltier Cooling and Current Crowding at Graphene-Metal Contacts,” Nature Nano 2011, 6, 287.CrossRefGoogle ScholarPubMed
Kim, D.-K., and Park, Yoondong, “Polarity-Dependent Morphological Changes of Ti/TiN/W Via Under High Current Density,” Electron Device Letters, IEEE, vol. 31, no.2, pp.120–122, Feb. 2010.Google Scholar
Lee, J., Asheghi, M., and Goodson, K. E., “Impact of thermoelectric effects on phase-change memory performance metrics and scaling,” Nanotechnology, 23, 205201, 2012.CrossRefGoogle Scholar
Yan, F., Zhu, T.J., Zhao, X.B., and Dong, S.R., “Microstructures and thermoelectric properties of GeSbTe based layered compounds,” Appl. Phys. A 88, 425, 2007.CrossRefGoogle Scholar
Baily, S. A., Emin, D., and Li, H., “Hall mobility of amorphous Ge2Sb2Te5,” Solid State Commun., 139 161, 2006.CrossRefGoogle Scholar
Kato, T. and Tanaka, K., “Electronic properties of amorphous and crystalline Ge2Sb2Te5 films,” Jpn. J. Appl. Phys., vol. 44, no. 10, pp. 7340–7344, Oct. 2005.CrossRefGoogle Scholar
Lee, J., Li, Z., Reifenberg, J. P., Asheghi, M., and Goodson, K. E., “Thermal Conductivity Anisotropy and Grain Structure of Ge2Sb2Te5 Films,” Journal of Applied Physics, vol. 109, 084902, Apr. 2011.CrossRefGoogle Scholar
Lee, J., Kodama, T., Won, Y., Asheghi, M., and Goodson, K. E., “Phase Purity and the Thermoelectric Properties of Ge2Sb2Te5 Films down to 25 nm Thickness,” Journal of Applied Physics, 112, 014902, Jul. 2012 CrossRefGoogle Scholar
Sonntag, J., “Thermoelectric power in alloys with phase separation (composites),” Phys. Rev. B, 73, 045126, 2006.CrossRefGoogle Scholar
Ziman, J. M., “Electrons and Phonons,” Clarendon, Oxford, p. 397, 1962 Google Scholar
Tellier, C. R. and Tosser, A. J., “THERMOELECTRIC POWER OF METALLIC FILMS IN THE MAYADAS-SHATZKES MODEL,” Thin Solid Films 41, 161–166 (1977).CrossRefGoogle Scholar
Pichard, C. R., Tellier, C. R., and Tosser, A. J., “Thermoelectric power of thin polycrystalline metal films in an effective mean free path model,” J. Phys. F: Metal Phys. 10, 2009–14 (1980).CrossRefGoogle Scholar