Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-23T07:34:46.315Z Has data issue: false hasContentIssue false

The Influence of Nitrogen Doping on the Chemical and Local Bonding Environment of Amorphous and Crystalline Ge2Sb2Te5

Published online by Cambridge University Press:  31 January 2011

Joseph Washington
Affiliation:
[email protected], North Carolina State University, Physics, Raleigh, North Carolina, United States
Eric A. Joseph
Affiliation:
[email protected], T. J. Watson Research Center, IBM/Macronix PCRAM Joint Project, Yorktown Heights, New York, United States
Michael A. Paesler
Affiliation:
[email protected], North Carolina State University, Physics, Raleigh, North Carolina, United States
Gerald Lucovsky
Affiliation:
[email protected], North Carolina State University, Physics, Raleigh, North Carolina, United States
Jean L. Jordan-Sweet
Affiliation:
[email protected], IBM T.J. Watson Research Center, Yorktown Heights, New York, United States
Simone Raoux
Affiliation:
[email protected], IBM Almaden Research Center, San Jose, California, United States
Chieh-Fang Chen
Affiliation:
[email protected], T. J. Watson Research Center, IBM/Macronix PCRAM Joint Project, Yorktown Heights, New York, United States
Adam Pyzyna
Affiliation:
[email protected], T. J. Watson Research Center, IBM/Macronix PCRAM Joint Project, Yorktown Heights, New York, United States
Ravi K. Dasaka
Affiliation:
[email protected], IBM T.J. Watson Research Center, Yorktown Heights, New York, United States
Chung H. Lam
Affiliation:
[email protected], T. J. Watson Research Center, IBM/Macronix PCRAM Joint Project, Yorktown Heights, New York, United States
Alejandro Schrott
Affiliation:
[email protected], T. J. Watson Research Center, IBM/Macronix PCRAM Joint Project, Yorktown Heights, New York, United States
Joseph C. Woicik
Affiliation:
[email protected], National Institute of Standards and Technology, Synchrotron Methods Group, Upton, New York, United States
Bruce Ravel
Affiliation:
[email protected], 2National Institute of Standards and Technology, Gaithersburg, Maryland, United States
Get access

Abstract

Recent interest in phase change materials (PCMs) for non-volatile memory applications has been fueled by the promise of scalability beyond the limit of conventional DRAM and NAND flash memory [1]. However, for such solid state device applications, Ge2Sb2Te5 (GST), GeSb, and other chalcogenide PCMs require doping. Doping favorably modifies crystallization speed, crystallization temperature, and thermal stability but the chemical role of the dopant is not yet fully understood. In this work, X-ray Absorption Fine Spectroscopy (XAFS) is used to examine the chemical and structural role of nitrogen doping (N-) in as-deposited and crystalline GST thin films. The study focuses on the chemical and local bonding environment around each of the elements in the sample, in pre and post-anneal states, and at various doping concentrations. We conclude that the nitrogen dopant forms stable Ge-N bonds as deposited, which is distinct from GST bonds, and remain at the grain boundary of the crystallites such that the annealed film is comprised of crystallites with a dopant rich grain boundary.

Type
Research Article
Copyright
Copyright © Materials Research Society 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Chen, Y.C., Rettner, C.T., Raoux, S. et al., IEDM Tech. Dig., p. S30P3, 2006.Google Scholar
2 Ahn, S. J., Song, Y. J., Jeong, C. W. et al., 2004 IEEE Int. Electron Devices Meeting, San Francisco, CA, Dec. 2004.Google Scholar
3 Seo, H, Jeong, T., Park, J., Yeon, C., Kim, S. and Kim, S-Y., Jpn. J. Appl. Phys. 39, 745 (2000).Google Scholar
4 Raoux, S., Salinga, M., Jordan-Sweet, J. L., Kellock, A. J., J. Appl. Phys. 101, 044909 (2007).Google Scholar
5 Ravel, B. and Newville, M., J. Synchrotron Rad. 12, 537 (2005).Google Scholar
6 Rehr, J.J., Leon, J. Mustre de, Zabinsky, S.I., and Albers, T.C., J. Am. Chem. Soc. 113, 5135 (1991).Google Scholar
7 Newville, M., J. Synchrotron Rad. 8, 322 (2001).Google Scholar
8 Kim, Y., Jang, M. H., et al, App. Phys. Lett. 92, 061910 (2008).Google Scholar
9 Bull, C., McMillan, P. F., Itié, J., and Polian, A., Phys. stat. sol. (a) 201, 5 (2004).Google Scholar
10 Chambouleyron, I. and Zanatta, A.R. J. Appl. Phys., 84, 1, 1998 Google Scholar
11 Ruddlesden, S. N. and Popper, P., Acta Cryst. 11, 465 (1958).Google Scholar
12 Baker, D. A., Paesler, M. A., Lucovsky, G., Agarwal, S. C., and Tayor, P. C., Phys. Rev. Lett. 96, 255501 (2006).Google Scholar
13 Maeda, T., Yasuda, T., Nishizawa, M. et al., Appl. Phys. Lett. 85, 3181 (2004).Google Scholar
14 Seo, H., Jeong, T., Park, J. et al., Jpn. J. Appl. Phys. 39, 745 (2000).Google Scholar