Hostname: page-component-76fb5796d-45l2p Total loading time: 0 Render date: 2024-04-26T09:24:57.574Z Has data issue: false hasContentIssue false
  • English
  • Français

Study of the Structural Transformation of Ge2Sb2Te5 Induced by Current Pulse in Phase Change Memory

Published online by Cambridge University Press:  01 February 2011

Rong Zhao ,
Tow Chong Chong ,
Lu Ping Shi ,
Pik Kie Tan ,
Hao Meng ,
Xiang Hu ,
Ke Bin Li  and
An Yan Du
Rong Zhao
Affiliation:
Data Storage Institute, A*Star, Singapore117608
Tow Chong Chong
Affiliation:
Data Storage Institute, A*Star, Singapore117608
Lu Ping Shi
Affiliation:
Data Storage Institute, A*Star, Singapore117608
Pik Kie Tan
Affiliation:
Data Storage Institute, A*Star, Singapore117608
Hao Meng
Affiliation:
Department of Electrical & Computer Engineering, University of Minnesota, MN 55455, USA
Xiang Hu
Affiliation:
Data Storage Institute, A*Star, Singapore117608
Ke Bin Li
Affiliation:
Data Storage Institute, A*Star, Singapore117608
An Yan Du
Affiliation:
Institute of Microelectronics, A*Star, Singapore117685
Get access

Abstract

The electrical induced structural transformation of Ge2Sb2Te5 thin film in phase change memory device was investigated using micro-Raman spectroscopy and transmission electronic microscopy (TEM). Selected area electron diffraction (SAD) pattern showed that the electrical-induced Ge2Sb2Te5 film was crystallized into a face-centered cubic structure. Micro-Raman spectra show that the Ge2Sb2Te5 active layer at the high resistance state exhibited two minor peaks superposed on the broad peak after several switch cycles, which is identical to those of the Ge2Sb2Te5 active layer at the low resistance state. This is most likely due to the accumulation of segregated crystallites. TEM results suggest that the existence of nano-sized nuclei clusters resulted in the reduced resistance for the Ge2Sb2Te5 active layer at the high resistance state after first several switches. The dependence of resistance on the cycle number indicates that the deterioration of the Ge2Sb2Te5 active layer is resulted from the incomplete amorphization process, which is consistent with the micro-Raman results.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 803: Symposia GG/HH – Advanced Characterization Techniques for Data Storage Materials – Phase Change and Nonmagnetic Materials for Data Storage , 2003 , HH1.5
Copyright
Copyright © Materials Research Society 2004

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. Friedrich, I., Weidenhof, V, Lenk, S., Wuttig, M., “Morphology and Structure of Laser-modified Ge2Sb2Te5 Films Studied by Transmission Electron Microscopy”, Thin Solid Films 389, 239–244 (2001)Google Scholar
2. Weidenhof, V., Friedrich, I., Ziegler, S. and Wuttig, M., “Atomic Force Microacopy Study of Laser Induced Phase Transitions in Ge2Sb2Te5 ”, J. Appl. Phys. 86, 5879–5887 (1999)Google Scholar
3. Tominaga, J. and Atoda, N., “Study of the Crystallization of GeSbTe films by Raman Spectroscopy”, Jpn. J. Appl. Phys. 38, L322–L323 (1999)Google Scholar
4. Ohkawa, H., Matsubara, M. and Yoshida, N., “Information Recording Medium”, US patent 5652037Google Scholar
5. Tsunetomo, K, Sugishima, T., Imura, T. and Osaka, Y., “Stability of Metastable Ge2SbTe in Thin Films”, J. of Non-crystalline Solids 95 & 96, 509–516 (1987)Google Scholar
6. Nakayama, K., Kitagawa, T., Ohmura, M. and Suzuki, M., “Nonvolatile Memory Based on Phase Transition in Chalcogenide Thin Film”, Jpn. J. Appl. Phys. 32, 564–569 (1993)Google Scholar
7. Friedrich, I., Weidenhof, V., Njoroge, W., Franz, P. and Wuttig, M., “Structural Transformations of Films Studied by Electrical Resistance Measurement”, J. Appl. Phys. 87, 4130–4134 (2000)Google Scholar
8. Cohen, M. H., Neale, R. G. and Paskin, A., “A model for an amorphous semiconductor memory device”, J. Non-Crystalline Solids 8–10, 885–891 (1972)Google Scholar