Hostname: page-component-77c89778f8-gq7q9 Total loading time: 0 Render date: 2024-07-23T13:32:39.025Z Has data issue: false hasContentIssue false

Electroplasticity and Electromigration

Published online by Cambridge University Press:  21 February 2011

Shefford P. Baker
Affiliation:
Max-Planck-Institut für Metallforschung, Institut für Werkstoffwissenschaft, Seestr. 92, 70174 Stuttgart, Germany
Michael P. Knauss
Affiliation:
Max-Planck-Institut für Metallforschung, Institut für Werkstoffwissenschaft, Seestr. 92, 70174 Stuttgart, Germany
Ulrich E. Möckl
Affiliation:
Max-Planck-Institut für Metallforschung, Institut für Werkstoffwissenschaft, Seestr. 92, 70174 Stuttgart, Germany
Eduard Arzt
Affiliation:
Max-Planck-Institut für Metallforschung, Institut für Werkstoffwissenschaft, Seestr. 92, 70174 Stuttgart, Germany
Get access

Abstract

It is known that an electric current can interact with dislocations in metals. Recent studies suggest that these interactions include current-induced dislocation motion and multiplication (electroplasticity) through both glide and climb mechanisms. Such interactions might be expected to effect both the mechanical properties and the electromigration behavior of the thin metal conductor lines used in integrated circuits. The mechanical properties would be directly modified through changes in dislocation density and mobility. Changes in microstructure and strength could affect electromigration lifetime and failure morphology. In order to investigate the effects of current-dislocation interactions, we conducted three sets of experiments in unpassivated aluminum conductor lines: First, a nanoindentation device was used to measure the mechanical properties of the lines during application of current densities up to 6 MA/cm2. Second, the mechanical properties of the lines were measured ex situ as a function of time in accelerated electromigration testing conditions. Third, the nanoindentation device was used to damage the lines at specific sites and damage morphology was examined during subsequent electromigration experiments by means of in situ scanning electron microscopy. To date we observe no direct effect of electric current on the mechanical properties of conductor lines and no clear correlation between mechanical damage and electromigration failure characteristics. Based on theoretical calculations and previous experiments on bulk samples, these results were not expected.

Type
Research Article
Copyright
Copyright © Materials Research Society 1995

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

1. Conrad, H. and Sprecher, A.F., in Dislocations in Solids. (Edited by Nabarro, F. R. N.). Vol. 8. North-Holland, Amsterdam (1989) p. 499 Google Scholar
2. Varma, S.K. and Cornwell, L.R., Scripta metall. 14, 1035 (1980).Google Scholar
3. Sprecher, A.F., Mannan, S.L. and Conrad, H., Acta metall. 34, 1145 (1986).Google Scholar
4. Livesay, B.R., Donlin, N.E., Garrison, A.K., Harris, H.M. and Hubbard, J.L., in International Reliability Physics Symposium, IEEE, (1992) p. 217Google Scholar
5. Suo, Z., Acta metall. mater. 42, 3581 (1994).Google Scholar
6. Silveira, V.L.A., Fortes, R.A.F.O. and Mannheimer, W.A., in 7th Int. Am. Conf. Mater. Tech., Mexico (1981) p. 722.Google Scholar
7. Nano Instruments Inc., “Nanoindenter II,” Knoxville, TNGoogle Scholar
8. Tabor, D., The Hardness of Metals, Oxford University Press, London (1951).Google Scholar
9. Bader, S., Flinn, P.A., Arzt, A. and Nix, W.D., J. Mater. Res. 9, 318 (1993).Google Scholar
10. Sanchez, J.E. Jr., McKnelly, L.T. and Moms, J.W., J. Electron. Mater. 19, 1213 (1990).Google Scholar
11. Oliver, W.C. and Pharr, G.M., J. Mater. Res. 7, 1564 (1992).Google Scholar
12. Arzt, E., Kraft, O., Nix, W.D. and Sanchez, J.E. Jr., J. Appl. Phys. 76, 1563 (1994).Google Scholar