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In-Situ TEM Study of Plastic Stress Relaxation Mechanisms and Interface Effects in Metallic Films

Published online by Cambridge University Press:  01 February 2011

Marc Legros
Affiliation:
CEMES-CNRS, 29 rue J. Marvig, 31055 Toulouse -France
Gerhard Dehm
Affiliation:
Erich Schmid Institute for Materials Science and University of Leoben, Department Materials Physics, Jahnstr. 12, 8700 Leoben - Austria
T. John Balk
Affiliation:
Dept. of Chemical and Materials Engineering, University of Kentucky, Lexington, KY, USA
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Abstract

To investigate the origin of the high strength of thin films, in-situ cross-sectional TEM deformation experiments have been performed on several metallic films attached to rigid substrates. Thermal cycles, comparable to those performed using laser reflectometry, were applied to thin foils inside the TEM and dislocation motion was recorded dynamically on video. These observations can be directly compared to the current models of dislocation hardening in thin films. As expected, the role of interfaces is crucial, but, depending on their nature, they can attract or repel dislocations. When the film/interface holds off dislocations, experimental values of film stress match those predicted by the Nix-Freund model. In contrast, the attracting case leads to higher stresses that are not explained by this model. Two possible hardening scenarios are explored here. The first one assumes that the dislocation/interface attraction reduces dislocation mobility and thus increases the yield stress of the film. The second one focuses on the lack of dislocation nucleation processes in the case of attracting interfaces, even though a few sources have been observed in-situ.

Type
Research Article
Copyright
Copyright © Materials Research Society 2005

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References

1. Freund, L.B., J. Appl. Mech., 54 553 (1987).Google Scholar
2. Nix, W.D., Metall. Trans. A, 20A 22172245 (1989).Google Scholar
3. Matthews, J.W. and Blakeslee, A.E., Journal of Crystal Growth, 29 273280 (1975).Google Scholar
4. Keller, R.-M., Baker, S.P., and Arzt, E., J. Mater. Res., 13 13071317 (1998).Google Scholar
5. Venkatraman, R. and Bravman, J.C., J. Mater. Res., 7 2040 (1992).Google Scholar
6. Venkatraman, R., Bravman, J.C., Nix, W.D., Davies, P.W., Flinn, P.A., and Fraser, D.B., J. Electron. Mater., 19 12311237 (1990).Google Scholar
7. Thompson, C.V., J. Mater. Res., 8 237238 (1993).Google Scholar
8. Dehm, G., Balk, T.J., Edongue, H., and Arzt, E., Microelectronic Engineering, 70 412 (2003).Google Scholar
9. Legros, M., Dehm, G., Balk, T.J., Arzt, E., Bostrom, O., Gergaud, P., Thomas, O., and Kaouache, B.. Plasticity-related phenomena in metallic films on substrates. in Multiscale Phenomena in Materials Experiments and Modeling Related to Mechanical Behavior. (2003). San Francisco, Vol. 779, pp. 6374.Google Scholar
10. Kuan, T.S. and Murakami, M., Metall. Trans. A, 13 383391 (1982).Google Scholar
11. Müllner, P. and Arzt, E.. Observation of dislocation disappearance in aluminum thin films and consequences for thin film properties. in Thin films - Stresse and mechanical properties. (1998). Boston, MA: Mat. Res. Soc. Symp. Proc. 505, Warrendale, PA, Vol. 505, pp. 149–54.Google Scholar
12. Dehm, G., Weiss, D., and Arzt, E., Materials Science and Engineering A, 309-310 468 (2001).Google Scholar
13. Legros, M., Hemker, K.J., Gouldstone, A., Suresh, S., Keller-Flaig, R.M., and Arzt, E., Acta Materialia, 50 3435 (2002).Google Scholar
14. Ovecoglu, M.L., Doerner, M.F., and Nix, W.D., Acta Metallurgica, 35 2947 (1987).Google Scholar
15. Kaouache, B., Gergaud, P., Thomas, O., Bostrom, O., and Legros, M., Microelectronic Engineering, 70 447 (2003).Google Scholar
16. Dehm, G., Inkson, B.J., Balk, T.J., Wagner, T., and Arzt, E.. Influence of film/substrate interface structure on plasticity in metal films. in Dislocations and deformation mechanisms in thin films and small structures. (2001). San Francisco: Mat. Res. Soc. Symp. Proc., Vol. 673, pp. 112.Google Scholar
17. Keller, R.-M., Sigle, W., Baker, S.P., Kraft, O., and Arzt, E.. In situ TEM investigation during thermal cycling of thin copper films. in Mat. Res. Soc. Symp. Proc. (1997). Boston, MA, Vol. 436, pp. 221226.Google Scholar
18. Gao, H., Zhang, L., and Baker, S.P., Journal of the Mechanics and Physics of Solids, 50 21692202 (2002).Google Scholar
19. Blanckenhagen, B. von, Gumbsch, P., and Arzt, E., Modelling and Simulation in Materials Science and Engineering, 9 157169 (2001).Google Scholar
20. Greer, J.R., Oliver, W.C., and Nix, W.D., Acta Materialia, 53 1821 (2005).Google Scholar
21. Swygenhoven, H. Van, Science, 296 6667 (2002).Google Scholar
22. Friedman, L.H. and Chrzan, D.C., Philosophical Magazine A, 77 11851204 (1998).Google Scholar
23. Owusu-Boahen, K. and King, A.H., Acta Materialia, 49 237247 (2001).Google Scholar
24. Lucadamo, G. and Medlin, D.L., Acta Materialia, 50 30453055 (2002).Google Scholar
25. Gao, H., Zhang, L., Nix, W.D., Thompson, C.V., and Arzt, E., Acta Materialia, 47 2865 (1999).Google Scholar
26. Shen, Y.-L. and Suresh, S., Acta Met. Mat., 43 39153926 (1995).Google Scholar
27. Dehm, G., Scheu, C., Ruhle, M., and Raj, R., Acta Materialia, 46 759772 (1998).Google Scholar
28. Couret, A., Crestou, J., Farenc, S., Molenat, G., Clement, N., Coujou, A., and Caillard, D., Microscopy Microanalysis Microstructures, 4 153170 (1993).Google Scholar
29. Legros, M., Hemker, K.J., Gouldstone, A., Suresh, S., Keller-Flaig, R.-M., and Arzt, E., Acta Materialia, 50 34353452 (2002).Google Scholar
30. Kaouache, B., Propriétés mécaniques et microstructures de films minces métalliques, in Laboratoire de Physique des Matériaux. 2002, Université Nancy I: Nancy.Google Scholar
31. Balk, T.J., Dehm, G., and Arzt, E., Acta Materialia, 51 4471 (2003).Google Scholar