Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-12-01T01:04:41.876Z Has data issue: false hasContentIssue false

Local Electron Beam Induced Reduction and Crystallization in Electrochemically Deposited Amorphous TiO2 Films

Published online by Cambridge University Press:  01 February 2011

Philippe Kern
Affiliation:
[email protected], Empa, Materials Science Technology, Feuerwerkerstrasse 39, Thun, 3602, Switzerland, +41 33 228 36 26, +41 33 228 39 46
Johann Michler
Affiliation:
[email protected], Empa, Materials Science Technology, Feuerwerkerstrasse 39, Thun, 3602, Switzerland
Get access

Abstract

Contrary to crystalline titanium oxide (TiO2), electrochemically deposited amorphous thin TiO2 films are found significantly more sensitive towards electron beam (e-beam) exposure. E-beam irradiation experiments were performed under scanning electron microscope conditions at 20 keV with well controlled beam current (IP), current density and exposure dose. As shown by atomic force microscopy and Micro-Raman spectroscopy, even moderate e-beam exposure immediately leads to oxide reduction due to electron stimulated oxygen desorption, while exposure with IP>1 micro-A and J>1 A/cm2 triggers localized crystallization into anatase phase already after seconds of irradiation. The mechanisms for oxide reduction and beam heating induced crystallization are discussed, and a temperature estimation in the beam center indicates that crystallization occurs at less than 150 °C. The well-defined volume loss upon oxygen desorption is shown to be attractive for precise topographical surface patterning, while the triggering local structural changes within a semi-conductive amorphous matrix opens interesting possibilities for tailoring of its local electrical or catalytic properties.

Type
Research Article
Copyright
Copyright © Materials Research Society 2007

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. Lee, W. G., Woo, S. I., Kim, J. C., Choi, S. H. and Oh, K. H., Thin Solid Films 237, 105 (1994).Google Scholar
2. Kim, J. W., Kim, D. O. and Hahn, Y. B., Korean J. Chem. Eng. 15 (2), 217 (1998).Google Scholar
3. Zhang, W., Li, Y. and Wang, F., J. Mater. Sci. Technol. 18 (2), 101 (2002).Google Scholar
4. Wang, L. Q., Baer, D. R. and Engelhard, M. H., Surf. Sci. 320, 295. (1994).Google Scholar
5. McCartney, M. R., Crozier, P. A., Weiss, J. K. and Smith, D. J., Vacuum 42 (4), 301 (1991).Google Scholar
6. McCartney, M. R. and Smith, D. J., Surf. Sci. 250, 169 (1991).Google Scholar
7. Su, D. S., Anal. Bional. Chem. 374, 732 (2002).Google Scholar
8. Aladjem, A., Brandon, D. G., Yahalom, J. and Zahavi, J., Electrochim. Acta 15, 663 (1970).Google Scholar
9. Kern, P., Jäggi, C., Utke, I., Friedli, V. and Michler, J., Appl. Phys. Lett. 89, 021902 (2006).Google Scholar
10. Kern, P., Müller, Y., Patscheider, J. and Michler, J., J. Phys. Chem. B 110 23660 (2006).Google Scholar
11. Kern, P., Schwaller, P., and Michler, J., Thin Solid Films 494, 279 (2006).Google Scholar
12. Egerton, R. F., Li, P. and Malac, M., Micron, 35, 399 (2004).Google Scholar
13. Pells, G. P., Radiation Effects, 64, 71 (1982).Google Scholar
14. Knotek, M. L. and Feibelman, P. J., Phys. Rev. Lett. 40 (14), 964 (1978).Google Scholar
15. Knotek, M. L. and Feibelman, P. J., Surf. Sci. 90, 78 (1979).Google Scholar
16. Zhang, W., Li, Y. and Wang, F., J. Mater. Sci. Technol. 18 (2), 101 (2002).Google Scholar
17. Reimer, L., Scanning Electron Microscopy, second ed., Springer, Berlin 1998, pp.117118.Google Scholar
18. Zhitomirsky, I. and Gal-Or, L., J. Europ. Ceram. Soc. 16, 819 (1996).Google Scholar
19. Kopfstad, P., “Nonstoichiometry, diffusion and electrical conductivity in binary oxides”, Wiley-Interscience, New York 1972.Google Scholar
20. Pino, A. P. del, Serra, P. S. and Morenza, J. L., Appl. Surf. Sci. 197–198, 887 (2002).Google Scholar
21. Afanas'ev, V. V., Stesmans, A., Chen, F., Li, M. and Campbell, S. A., J. Appl. Phys. 95 (12), 7936 (2004).Google Scholar
22. Ohmori, A., Park, K. C., Inuzuka, M., Arata, Y., Inoue, K. and Iwamoto, N., Thin Solid Films, 201, 1 (1991).Google Scholar