Hostname: page-component-848d4c4894-pjpqr Total loading time: 0 Render date: 2024-07-06T19:57:18.141Z Has data issue: false hasContentIssue false

Stresses in Passivated Films

Published online by Cambridge University Press:  16 February 2011

Paul A. Flinn*
Affiliation:
Intel Corporation, 3065 Bowers Avenue, Santa Clara, CA 95052, and Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305.
Get access

Abstract

Although wafer curvature measurement provides a rapid and accurate determination of stress in a uniform thin film, the technique is not applicable to patterned films. To study the stress in metal lines, and the effect of passivation on that stress, it is necessary to use X-ray diffraction. To obtain the sensitivity and precision required, a generalized focusing diffractometer (GFD), that had been developed especially for work on thin films, was used in this study.

The elastic strain tensors for aluminum and aluminum-silicon films and patterned lines were determined by X-ray diffraction. The corresponding stress tensors were calculated with the use of the known elastic constants of aluminum. The effect of various oxide and oxynitride passivations was investigated. Passivation over uniform metal films has very little effect, while passivation over patterned metal results in substantial triaxial tensile stress in the metal. Contrary to the conventional wisdom, high compressive stress in the passivation does not result in additional tensile stress in the metal. A possible explanation for the frequently observed deleterious effect (increased tendency for formation of cracks and voids) of highly compressive silicon nitride and silicon oxynitride passivations will be discussed.

Type
Research Article
Copyright
Copyright © Materials Research Society 1990

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. Klema, J., Pyle, R. and Domangue, E., “Reliability Implications of Nitrogen Contamination During Deposition of Sputtered Aluminum/Silicon Metal Films”, Proceedings of the 22nd Annual International Reliability Symposium, IEEE, 1984, pp. 15.Google Scholar
2. Curry, J., Fitzgibbon, G., Guan, Y., Muollo, R., Nelson, G. and Thomas, A., “New Failure Mechanism in Sputtered Aluminum-Silicon Films”, Proceedings of the 22nd Annual International Reliability Symposium, IEEE, 1984, pp. 68.Google Scholar
3. Yue, J. T., Funsten, W. P. and Taylor, R. V., “Stress Induced Voids in Aluminum Interconnects during IC Processing”, Proceedings of the 23rd Annual International Reliability Symposium, IEEE, 1985, pp. 126137.Google Scholar
4. Sugano, Y., Minegishi, S., Sumi, H. and Itabashi, M., “In-situ Observation and Formation Mechanism of Aluminum Voiding”, Proceedings of the 26th Annual International Reliability Symposium, IEEE, 1988, pp. 3438.Google Scholar
5. Manos, P., Pintchovski, F., Klein, J., Travis, E., Boeck, B., Woo, M., Chen, C., Koenigseder, S., and Dillard, R., “A Submicron Triple-level Metal Gate Array Process Utilizing Tungsten for 1st Level Interconnect”, Proceedings Sixth International IEEE VLSI Multilevel Interconnection Conference, IEEE, 1989, pp. 4046.Google Scholar
6. Flinn, P. A., Gardner, D. S. and Nix, W. D., “Measurement and Interpretation of Stress in Aluminum-Based Metallization as a Function of Thermal History”, IEEE Transactions on Electron Devices, Vol. ED–34, 1987, pp. 689699.Google Scholar
7. Lester, H. H. and Abom, R. H., “The Behavior under Stress of the Iron Crystals in Steel”, Army Ordnance, Vol.6, 1925, pp. 120129,200–207,283–287,364–369.Google Scholar
8. Cullity, B. D., Elements of X-ray Diffraction, Addison-Wesley, Reading,MA, 1978, pp. 451460.Google Scholar
9. James, M. R. and Cohen, J. B., “The Measurement of Residual Stresses by X-Ray Diffraction Techniques”, in Treatise on Materials Science and Technology, Vol 19A, Herman, H., ed., Academic Press, New York, 1980, pp. 162.Google Scholar
10. Segmueller, A. and Murakami, M., “X-Ray Diffraction Analysis of Strains and Stresses in Thin Films”, in Treatise on Materials Science and Engineering, Vol.27, Herman, H., ed., Academic Press, New York, 1988, pp. 143200.Google Scholar
11. Flinn, P. A. and Chiang, C., “X-ray Difraction Determination of the Effect of Various Passivations on Stress in Metal Films and Patterned Lines”, Journal of Applied Physics, Vol.67, 1990, pp. 2927–293 1.Google Scholar
12. Tezaki, A., Mineta, T., Egawa, H. and Noguchi, T., “Measurement of Three Dimensional Stress and Modeling of Stress Induced Migration Failure in Aluminum Interconnects”, Proceedings of the 28th Annual International Reliability Symposium, IEEE, 1990, pp. 221229.Google Scholar
13. Flinn, P. A. and Waychunas, G. A., “A New X-ray Diffractometer Design for Thin-film Texture, Strain, and Phase Characterization”, Journal of Vacuum Science and Technology, Vol. B6, 1988, pp. 17491755.Google Scholar
14. Flinn, P. A., “Principles and Applications of Wafer Curvature Techniques for Stress Measurements in Thin Films”, Thin Films: Stresses and Mechanical Properties. MRS Symposium Proceedings Volume 130., Materials Research Society, 1989, pp. 4151.Google Scholar
15. Sauter, A. I. and Nix, W. D., “Finite Element Calculations of Thermal Stresses in Passivated and Unpassivated Lines Bonded to Substrates”, Elsewhere in this volume..Google Scholar
16. Gasser, R.. Private CommunicationGoogle Scholar
17. Peek, H. L. and Wolters, R. A. M., “Bubble and Cavity Formation in Aluminum-Plasma Silicon Nitride Structures”, Proceedings Third International IEEE VLSI Multilevel Interconnection Conference, IEEE, 1986, pp. 165172.Google Scholar
18. Albrecht, J., Bernstein, I. M., and Thompson, A. W., “Evidence for Dislocation Transport of Hydrogen in Aluminum”, Metallurgical Transactions A, Vol.13A, 1982, pp. 811820.Google Scholar
19. Budhani, R. C., Bunshah, R. F. and Flinn, P. A., “Kinetics of Structural Relaxation and Hydrogen Evolution from Plasma Deposited Silicon Nitride”, Applied Physics Letters, Vol.52, 1988, pp. 284286.Google Scholar