Hostname: page-component-5c6d5d7d68-lvtdw Total loading time: 0 Render date: 2024-08-15T12:14:48.359Z Has data issue: false hasContentIssue false

Change in Tunneling Spectrum of a Co/AlOx/Co Junction under Constant Voltage Stress

Published online by Cambridge University Press:  01 February 2011

Kouhei Horikiri
Affiliation:
horik@appi.keio.ac.jp, Keio University, Applied Physics and Physico-Informatics, Yokohama, Japan
Kazuo Shiiki
Affiliation:
shiiki@appi.keio.ac.jp, Keio University, Applied Physics and Physico-Informatics, Yokohama, Kanagawa, Japan
Get access

Abstract

To investigate the aging effect of a tunneling junction under constant voltage stress, the tunneling resistance and inelastic electron tunneling (IET) spectra were measured. At a low voltage, up to about 0.5 V, the tunneling resistance of junctions increased gradually over time, while above about 0.6V, it decreased gradually. This change was observed independent of voltage polarity. When the applied voltage was positive, the IET spectrum did not change, whereas when it was negative, the IET spectrum changed—the asymmetric peak became symmetric. X-ray photoelectron spectroscopy (XPS) analysis showed that the junction exhibiting an asymmetric peak contained metallic Al at the AlOx/bottom electrode interface, and the junction exhibiting a symmetric peak contained a homogeneous barrier layer. An increase in the tunneling resistance indicates that the amount of metallic Al decreased in the AlO x barrier layer. Transformation from an asymmetric to a symmetric peak indicates that the metallic Al in the AlOx/bottom electrode interface was oxidized, which led to the AlOx layer becoming homogeneous.

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

REFERENCES

1. Miyazaki, T. and Tezuka, N., J. Magn. Magn. Mater. 139, L231 (1995).Google Scholar
2. Moodera, J. S., Kinder, L. R., Wong, T. M., and Meservey, R., Phys. Rev. Lett. 74, 3273 (1995).Google Scholar
3. Lotkhov, S. V., Tolkacheva, E. M., Balashov, D. V., Khabipov, M. I., Buchholz, F.-I., and Zorin, A. B., Appl. Phys. Lett. 89, 132115 (2006).Google Scholar
4. Oepts, W., Verhagen, H. J., de Mooij, D. B., Zieren, V., Coehoorn, R., and de Jonge, W. J. M., J. Magn. Magn. Mater. 198–199, 164 (1999).Google Scholar
5. Das, J., Degraeve, R., Boeve, H., Duchamps, P., Lagae, L., Groeseneken, G., Borghs, G. and De Boeck, J., J. Appl. Phys. 89, 7350 (2001).Google Scholar
6. Rao, D., Sin, K., Gibbons, M., Funada, S., Mao, M., Chien, C., and Tong, H.-C., J. Appl. Phys. 89, 7362 (2001).Google Scholar
7. Horikiri, K. and Shiiki, K., phys. stat. sol. (c) 4, 12, 4532 (2007).Google Scholar
8. Jacklevic, R. C. and Lambe, J., Phys. Rev. Lett. 17, 1139 (1966).Google Scholar
9. Klein, J. and Leger, A., Phys. Lett. 28A (1968) 134.Google Scholar
10. Bowser, W. M. and Weinberg, W. H., Surface Sci. 64, 377, (1977).Google Scholar
11. Higo, M. and Kamata, S., J. Phys. Chem. 94, 8709, (1990).Google Scholar
12. Bowen, M., Barthéléy, A., Bibes, M., Jacquet, E., Contour, J.-P., Fert, A., Ciccacci, F., Duò, L., and Bertacco, R., Phys. Rev. Lett. 95, 137203 (2005).Google Scholar
13. Arakawa, N., Otaka, Y., and Shiiki, K., Thin Solid Films 505, 67 (2006).Google Scholar
14. Dargis, A. B., Rev. Sci. Instrum. 52, 46 (1981).Google Scholar
15. Horikiri, K., Morizumi, M., and Shiiki, K., Thin Solid Films (submitted).Google Scholar