Hostname: page-component-848d4c4894-p2v8j Total loading time: 0.001 Render date: 2024-05-16T07:28:23.205Z Has data issue: false hasContentIssue false

Microstructure and Electromigration Properties of Submicron Al (.5%Cu) Lines

Published online by Cambridge University Press:  15 February 2011

J. A. Prybyla
Affiliation:
AT&T Bell Laboratories, Murray Hill, New Jersey 07974
R. R. Kola
Affiliation:
AT&T Bell Laboratories, Murray Hill, New Jersey 07974
R. Hull
Affiliation:
AT&T Bell Laboratories, Murray Hill, New Jersey 07974
D. J. Eaglesham
Affiliation:
AT&T Bell Laboratories, Murray Hill, New Jersey 07974
H. A. HUGGINS
Affiliation:
AT&T Bell Laboratories, Murray Hill, New Jersey 07974
Get access

Abstract

The evolution of the microstructure of submicron Al (.5wt%Cu) lines has been examined as a function of annealing and electromigration stressing time. We have studied lines of two different thicknesses (4000 and 2000 Å) and a range of widths from 0.2 to 1.0 Μm. Pre- and post- stressing studies of the microstructure have been performed, as well as real-time studies during stressing inside the transmission electron Microscope (TEM). We report the results of temperature cyclings over the range 400–525 C for both passivateci and unpassivated lines. IMprovements in the microstructure were observed in all cases. The Most dramatic improvement occurred for the unpassivated lines when annealed to 450 C and for the passivated lines upon annealing to 525 C. In both cases a true bamboo structure was very nearly achieved for lines of width ≤0.5 Μm. Grain growth was by far the greatest in the pads. In the 2000 Å thick passivated lines, voiding upon temperature cycling is more pronounced than for the thicker lines. Also, the bamboo microstructure is more difficult to obtain compared to the 4000 Å lines. Finally, we report our preliminary results on the microstructural changes which occur as a result of electromigration. Voiding and hillock formation are examined. Microstructure is correlated with electromigration reliability.

Type
Research Article
Copyright
Copyright © Materials Research Society 1994

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. Walton, D.T. and Frost, H.J., Appl. Phys. Lett., 61, 40 (1992).CrossRefGoogle Scholar
2. For a review see: Evolution of Thin Films and Surface Microstructures, Ed: Thompson, C. V., Tsao, J.Y, and Srolovitz, D.S., MRS Proceedings, 202, Pittsburgh, PA (1991).Google Scholar
3. Physics of Thin Films, Ed: Haas, E., Francombe, M.H., and Hoffmann, R. W., (Academic, NY), 1973, 7, 257.Google Scholar
4. Nichols, C.S., Mansuri, C.M., Townsend, S.J., and Smith, D.A., Acta Metall. Mater., 41, 1861 (1993).CrossRefGoogle Scholar
5. Smith, D.A., Kwok, T., Small, M.B., Stanis, C., Mat. Res. Symp. Proc., 265, 73 (1992).CrossRefGoogle Scholar
6. Hu, C.K. et al., Mat. Res. Soc. Proc., 309, 111 (1993).CrossRefGoogle Scholar
7. Frost, H.J., Thompson, C.V., and Walton, D.T., Acta Metall., 40, 779 (1992), and 38, 1445 (1990).CrossRefGoogle Scholar
8. Doerner, M.F., Gardner, D.S., and Nix, W. D., J. Mater. Res., 1 (6), 845 (1986).CrossRefGoogle Scholar
9. Sullivan, T.D. and Miller, L.A., Mat. Res. Soc. Proc., 309, 169 (1993).CrossRefGoogle Scholar
10. Cho, J. ands Thompson, C.V., Appl. Phys. Lett., 54, 2577 (1989).CrossRefGoogle Scholar