Hostname: page-component-78c5997874-mlc7c Total loading time: 0 Render date: 2024-11-17T14:53:28.807Z Has data issue: false hasContentIssue false
  • English
  • Français

Thickness-dependent Crystallization Behavior of Phase Change Materials

Published online by Cambridge University Press:  01 February 2011

Simone Raoux ,
Jean L. Jordan-Sweet  and
Andrew J. Kellock
Simone Raoux
Affiliation:
simone_raoux@almaden.ibm.com, IBM Almaden Research Center, IBM/Qimonda/Macronix PCRAM Joint Project, 650 Harry Road, San Jose, CA, 95120, United States, 408 927 2069
Jean L. Jordan-Sweet
Affiliation:
jljs@us.ibm.com, IBM T. J. Watson Research Center, P. O. Box 218, Yorktown Heights, NY, 10598, United States
Andrew J. Kellock
Affiliation:
kellock@almaden.ibm.com, IBM Almaden Research Center, 650 Harry Road, San Jose, CA, 95120, United States
Get access

Abstract

We have investigated the crystallization behavior of phase change materials as a function of their thickness. Thin films of variable thickness between 1 and 50nm of the phase change materials Ge2Sb2Te5 (GST), N-doped GST (N-GST), Ge15Sb85 (GeSb), Sb2Te, and Ag and In doped Sb2Te (AIST) were deposited by magnetron sputtering, and capped in situ by a 10nm thick Al2O3 film to prevent oxidation. The crystallization behavior of the films was studied using time-resolved X-ray diffraction. For each material we observed a constant crystallization temperature Tx that was comparable to bulk values for films thicker than 10 nm, and an increased Tx when the film thickness was reduced below 10 nm. The thinnest films that showed XRD peaks were 2 nm for GST and N-GST, 1.5 nm for Sb2Te and AgIn-Sb2Te, and 1.3 nm for GeSb. The observed increase in the phase transition temperature with reduced film thickness and the fact that very thin films still show clear phase change properties are indications that Phase Change Random Access Memory technology can be scaled down to several future technology nodes.

Keywords

phase transformationmemorythin film
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1072: Symposium G – Phase-Change Materials for Reconfigurable Electronics and Memory Applications , 2008 , 1072-G05-02
Copyright
Copyright © Materials Research Society 2008

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

REFERENCES

1. Zhou, G.-F., Mater. Sci. Engin. A304-306, 73 (2001).Google Scholar
2. Martens, H. C. F. Vlutters, R. and Prangsma, J. C. J. Appl. Phys. 95, 3977 (2004).Google Scholar
3. Chen, Y. C. Rettner, C. T. Raoux, S. Burr, G. W. Chen, S. H. Shelby, R. M. Salinga, M. Risk, W. P. Happ, T. D. McClelland, G. Breitwisch, M. Schrott, A. Philipp, J. B. Lee, M. H. Cheek, R. Nirschl, T. Lamorey, M. Chen, C. F. Joseph, E. Zaidi, S. Yee, B. Lung, H. L. Bergmann, R. and Lam, C. IEDM Technical Digest, p.777–780 (2006).Google Scholar
4. Zacharias, M. and Streitenberger, P. Phys. Rev. B 62, 8391 (2000).Google Scholar
5. Williams, G. V. M. Bittar, A. and Trodahl, H. J. J. Appl. Phys. 67, 1874 (199).Google Scholar
6. Homma, H. Schuller, I. K. Sevenhans, W. and Bruynseraede, Y. Appl. Phys. Lett. 50, 594 (1987).Google Scholar
7. Wei, X. Shi, L. Chong, T. C. Zhao, R. and Lee, H. K. Jpn. J. Phys. 46, 2211 (2007).Google Scholar
8. Quintero, A. Libera, M. Cabral, C. Jr., Lavoie, C. and Harper, J. M. E. J. Appl. Phys. 98, 4879 (2001)Google Scholar
9. Raoux, S. Rettner, C. T. Jordan-Sweet, J. L., Kellock, A. J. Topuria, T. Rice, P. M. and Miller, D. C. J. Appl. Phys. 102, 094305 (2007).Google Scholar
10. Friedrich, I. Weidenhof, V. Njoroge, W. Franz, P. and Wuttig, M, J. Appl. Phys. 87, 4130 (2000).Google Scholar
11. Sun, X. Yu, B. and Meyyappan, M. Appl. Phys. Lett. 90, 183116 (2007).Google Scholar
12. Lee, S.-H. Jung, Y. and Agarwal, R. Nature Nanotech. 2, 626 (2007)Google Scholar
13. Choi, H. S. Seol, K. S. Takeuchi, K. Fujita, J. and Ohki, Y. Jap. J. Appl. Phys. 44, 7720 (2005).Google Scholar
14. Raoux, S. Rettner, C. T. Jordan-Sweet, J., Deline, V. R. Philipp, J. B. and Lung, H. L. Proc. Europ. Conf. on Phase Change and Ovonic Science, Grenoble, France, 2006.Google Scholar