Hostname: page-component-848d4c4894-sjtt6 Total loading time: 0 Render date: 2024-07-04T22:09:23.464Z Has data issue: false hasContentIssue false

Determination of yielding and debonding in Al–Cu thin films from residual stress measurements via diffraction

Published online by Cambridge University Press:  31 January 2011

C.J. Shute
Affiliation:
Department of Materials Science and Engineering, Robert R. McCormick School of Engineering and Applied Science, Northwestern University, Evanston, Illinois 60208
J.B. Cohen
Affiliation:
Department of Materials Science and Engineering, Robert R. McCormick School of Engineering and Applied Science, Northwestern University, Evanston, Illinois 60208
Get access

Abstract

The yield strength and interfacial bonding are properties of interest for understanding void formation in thin film interconnect and subsequent failure of VLSI devices. A method is presented to examine the mechanical properties of thin polycrystalline films attached to substrates by measuring the change in thermal residual stress, due to the difference in coefficient of expansion between the film and substrate, as a function of decreasing temperature of the sample. The yield strengths of passivated 0.5, 1.0, and 2.0 μm thin films of Al–2% Cu on oxidized Si wafer substrates have been determined with this method to be 325, 170, and 120 MPa, respectively. Unpassivated films of the same thicknesses were also examined, but yielding did not occur for these films even though the residual stress reached a value of over 400 MPa. The lack of yielding in the unpassivated samples and the thickness dependence of the passivated samples is attributed to the grain size of these materials, which is less than the film thickness for the unpassivated case and greater than the film thickness after passivation. Debonding occurred in the 2 μm unpassivated sample but in none of the others, indicating a thickness dependence of the energy for delamination.

Type
Articles
Copyright
Copyright © Materials Research Society 1991

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

1Jones, R. E. and Basehore, M. L., Appl. Phys. Lett. 50 (12), 725727 (1987).CrossRefGoogle Scholar
2Shute, C. J., Cohen, J. B. and Jeannotte, D. A., in Thin Films: Stresses and Mechanical Properties, edited by Bravman, J. C., Nix, W. D., Barnett, D. M., and Smith, D. A. (Mater. Res. Soc. Symp. Proc. 130, Pittsburgh, PA, 1989), pp. 2933.Google Scholar
3Aluminum: Properties and Physical Metallurgy, edited by Hatch, J. E. (American Society for Metals, Metals Park, OH, 1984), p. 227.Google Scholar
4Hardwich, D. A., Thin Solid Films 154, 109124 (1987).CrossRefGoogle Scholar
5Rosenmayer, C. T., Brotzen, F. R. and Gale, R. J., in Thin Films: Stresses and Mechanical Properties, edited by Bravman, J. C., Nix, W. D., Barnett, D. M., and Smith, D. A. (Mater. Res. Soc. Symp. Proc. 130, Pittsburgh, PA, 1989), pp. 7786.Google Scholar
6Griffin, A. J., Brotzen, F. R. and Dunn, C. F., Thin Solid Films 150, 237244 (1987).CrossRefGoogle Scholar
7Doerner, M. F. and Nix, W. D., J. Mater. Res. 1, 601609 (1986).CrossRefGoogle Scholar
8Doerner, M. F., Gardner, D. S. and Nix, W. D., J. Mater. Res. 1, 845851 (1986).CrossRefGoogle Scholar
9Nix, W. D., Metall. Trans. A 20A, 22172245 (1989).CrossRefGoogle Scholar
10Pethica, J. B., Hutchings, R. and Oliver, W. C., Philos. Mag. A 48, 593606 (1983).CrossRefGoogle Scholar
11Hong, S., Weihs, T. P., Bravman, J. C. and Nix, W. D., in Thin Films: Stresses and Mechanical Properties, edited by Bravman, J. C., Nix, W. D., Barnett, D. M., and Smith, D. A. (Mater. Res. Soc. Symp. Proc. 130, Pittsburgh, PA, 1989), pp. 9398.Google Scholar
12Kinosita, K., Thin Solid Films 12, 1728 (1972).CrossRefGoogle Scholar
13Weihs, T. P., Hong, S., Bravman, J. C. and Nix, W. D., (Mater. Res. Soc. Symp. Proc. 130, Pittsburgh, PA, 1989), pp. 8792, 93–98.CrossRefGoogle Scholar
14Murakami, M., Acta Metall. 26, 175183 (1978).CrossRefGoogle Scholar
15Murakami, M., Thin Solid Films 55, 101111 (1978).CrossRefGoogle Scholar
16Kuan, T. S. and Murakami, M., Metall. Trans. A 13A, 383391 (1982).CrossRefGoogle Scholar
17Sheikh, G. and Noyan, I. C., Adv. X-ray Anal. 33, 161169 (1990).Google Scholar
18Noyan, I. C. and Cohen, J. B., Residual Stress: Measurement by Diffraction and Interpretation (Springer-Verlag, New York, 1987).CrossRefGoogle Scholar
19Winholtz, R. A., “Residual Stress and Diffraction Elastic Constants Measurements with a Personal Computer,” O. N. R. Technical Report #27, July 1990.Google Scholar
20Bollenrath, F., Hauk, V. and Müller, E. H., Z. Metallkde. 58, 7680 (1967).Google Scholar
21Simmons, G. and Wang, H., Single Crystal Elastic Constants and Calculated Aggregate Properties: A Handbook (Cambridge: The M. I. T. Press, 1971).Google Scholar
22Carr, R. H., McCammon, R. D. and White, G. K., Philos. Mag. 12, 157163 (1965).CrossRefGoogle Scholar
23Materials at Low Temperatures, edited by Reed, R. P. and Clark, A. F. (American Society for Metals, Metals Park, OH, 1983), p. 95.CrossRefGoogle Scholar
24Materials at Low Temperatures, edited by Reed, R. P. and Clark, A. F. (American Society for Metals, Metals Park, OH, 1983), p. 8.CrossRefGoogle Scholar
25Chaudhari, P., Philos. Mag. A 39 (4), 507516 (1979).CrossRefGoogle Scholar
26Cannon, R. M., Fisher, R. M. and Evans, A. G., in Thin Films — Interfaces and Phenomena, edited by Nemanich, R. J., Ho, P. S., and Lau, S. S. (Mater. Res. Soc. Symp. Proc. 54, Pittsburgh, PA, 1986), pp. 799804.Google Scholar