Hostname: page-component-76fb5796d-skm99 Total loading time: 0 Render date: 2024-04-25T11:03:58.268Z Has data issue: false hasContentIssue false

Effect of Via Etch Profile and Barrier Metal on Electromigration Performance of W-Filled Via Structure in TiN/AlCu/TiN Metallization

Published online by Cambridge University Press:  15 February 2011

Larry M. Ting
Affiliation:
Texas Instruments, Dallas, TX
G. Dixit
Affiliation:
Texas Instruments, Dallas, TX
M. Jain
Affiliation:
Texas Instruments, Dallas, TX
K. A. Littau
Affiliation:
Applied Materials, Santa Clara, CA
H. Tran
Affiliation:
Applied Materials, Santa Clara, CA
M. Chang
Affiliation:
Applied Materials, Santa Clara, CA
A. Sdsfha
Affiliation:
Applied Materials, Santa Clara, CA
Get access

Abstract

In this study, we have evaluated electromigration performance of W-plug vias, fabricated with process variations in via hole etching as well as in via barrier deposition, on a TiN(barrier)/AlCu/TiN metallization system. We found that via etch profile scheme as well as deposition conformity for via barrier can significantly affect W-plug via lifetimes. The results indicate that the quality of contact with AlCu layer of bottom level metal is a critical factor in determining via lifetime. Precise control of via etching or by use of conformal via barrier to ensure a good barrier between W-plug and the AlCu of bottom level metal is essential for achieving reliable via structures.

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 Estabil, J. J., Rathore, H. S., and Levine, E. N., “Electromigration Improvements with Titanium Underlay and Overlay in AlCu Metallurgy,” in Proceedings of the 8th International VLSI Multilevel Interconnection Conference, 1991, pp. 242248 Google Scholar
2 Hu, C. K., Small, M. B., and Ho, P. S., “Electromigration in Al(Cu) Two-Level Structures: Effect of Cu and Kinetics of Damage Formation,” J. Appl. Phys. 74(2), 1993, pp. 969978.Google Scholar
3 Filippi, R. G., Rathore, H. S., Wachnik, R. A., and Kruger, D., “The effect of Copper Concentration on the Electromigration Lifetime of Layered Aluminum-Copper (Ti- AlCu-Ti) Metallurgy,” in Proceedings of the 9th International VLSI Multilevel Interconnection Conference, 1992, pp. 359365.Google Scholar
4 Hu, C. K. and Small, M. B., “Electromigration Failure of Bamboo Structured Lines by Interfacial Transport,” in Proceedings of the 10th International VLSI Multilevel Interconnection Conference, 1993, pp. 265270.Google Scholar
5 Ting, L. M. and Graas, C. D., “Impact of Test Structure Design on Electromigration Lifetime Measurements,” to be published in Proceedings of the 33rd Annual International Reliability Physics Symposium. IEEE, 1995.Google Scholar
6 Zhang, W., Li, Z. G., Cheng, Y. H., Guo, W. L., Sun, Y. H., and Li, X. X., “An Increase of the Electromigration Reliability of Ohmic Conatcts by Enhancing Backflow Effects,” in Proceedings of the 33rd Annual International Reliability Physics Symposium. IEEE, 1995, pp. 365370.Google Scholar
7 Graas, C. D., Le, H. A., McPherson, J. W., and Havemann, R. H., “Electromigration Reliability Improvement of W-Plug Vias by Titanium Layering,” in Proceedings of the 32rd Annual International Reliability Physics Symposium. IEEE, 1994, pp. 173177.Google Scholar
8 Yamaha, T., Naitou, M., and Hotta, T., “Three Kinds of Via Electromigration Failure Mode in Multilevel Interconnections,” in Proceedings of the 30rd Annual International Reliability Physics Symposium. IEEE, 1992, pp. 349355.Google Scholar
9 Lieu, H. Y., “Quantitative Study of Al/W Interaction in Si/SiO2/W-Ti/Al Thin Film System,” in Proceedings of Mat. Res. Soc. Symp. 1988, pp. 153158.Google Scholar