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A Statistical Characterization of Electromigration-Induced Open Failures in 2-Level Metal Structures

Published online by Cambridge University Press:  15 February 2011

H. Kahn  and
C. V. Thompson
H. Kahn
Affiliation:
Massachusetts Institute of Technology, Department of Materials Science and Engineering, Cambridge, MA 02139
C. V. Thompson
Affiliation:
Massachusetts Institute of Technology, Department of Materials Science and Engineering, Cambridge, MA 02139
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Abstract

A new electromigration test structure has been designed and fabricated which allows statistical characterization of current-induced open failures at vias, under varying current flow geometries. Results for a 2-level Al-Cu metallization system with W-filled 1.0 μm vias reveal no differences in via lifetimes for parallel, anti-parallel, or perpendicular current flows. However, a factor of 7 improvement in the total average via resistance produces an order of magnitude improvement in lifetimes. Line reliability remains superior to the reliability of the vias, indicating that the vias are the “weak links” in the system.

A model for evaluating temperature and current density effects which incorporates the atomic flux equation has been developed and used to make reliability predictions for extrapolations to operating conditions. The model suggests that the median time to failure of a 2-level ietal structure with an average via resistance of two ohms will be 2.7×1017 hours for operating conditions of 2×105 A/cm2 and 125°C.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 225: Symposium G – Materials Reliability Issues in Microelectronics , 1991 , 15
Copyright
Copyright © Materials Research Society 1991

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References

REFERENCES

1. Blech, I.A., J. Appl. Phys., 47, 1203 (1976).Google Scholar
2. English, A.T. and Kinsbron, E., J. Appl. Phys., 54, 268 (1983).Google Scholar
3. Prokop, C.S. and Joseph, R.R., J. Appl. Phys., 43, 2595 (1972).Google Scholar
4. Kahn, H. and Thompson, C.V., unpublished.Google Scholar
5. Gargini, P.A., Tseng, C., and Woods, M.H., IEEE/Proc. IRPS, 66 (1982).Google Scholar
6. Chern, J.G.J., Oldham, W.G., and Cheung, N., IEEE Trans. Elec. Dev., ED–33, 1256 (1986).Google Scholar
7. Black, J.R., IEEE Trans. Elec. Dev., ED–16, 338 (1969).Google Scholar
8. Pimbley, J.M. and Brown, D.M., IEEE Trans. Elec. Dev., ED–33, 1399 (1986).Google Scholar
9. Enver, A. and Clement, J.J., IEEE/Proc. V-MIC Conf., 149 (1990).Google Scholar
10. Lee, K., Voorde, P. Vande, Varon, M., and Nishi, Y., IEEE/Proc. IEDM, 510 (1987).Google Scholar
11. Kwok, T., Nguyen, T., Ho, P., and Yip, S., IEEE/Proc. IRPS, 130 (1987).Google Scholar
12. Matsuoka, F., Hama, K., Itoh, H., Nakata, R., Iwai, H., and Kanzaki, K., IEEE/Proc. V-MIC Conf., 491 (1988).Google Scholar
13. Thompson, C.V. and Cho, J., IEEE Elec. Dev. Lett., EDL–7, 667 (1986).Google Scholar
14. CRC Handbook of Chemistry and Physics, 63rd ed., edited by Weast, R.C. (CRC Press, Boca Raton, FL, 1982), p. F-52.Google Scholar
15. Black, J.R., IEEE/Proc. IRPS, 148 (1967).Google Scholar
16. Huntington, H.B., in Diffusion, edited by Aaronson, H.I. (American Society for Metals, Metals Park, OH, 1972), pp. 155–184.Google Scholar
17. Penney, R.V., J. Phys. Chem. Solids, 25, 335 (1964).Google Scholar