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

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.

This is a preview of subscription content, access via your institution.

References

  1. 1

    J. J. Estabil, H. S. Rathore, and E. N. Levine, “Electromigration Improvements with Titanium Underlay and Overlay in AlCu Metallurgy,” in Proceedings of the 8th International VLSI Multilevel Interconnection Conference, 1991, pp. 242–248

    Google Scholar 

  2. 2

    C. K. Hu, M. B. Small, and P. S. Ho, “Electromigration in Al(Cu) Two-Level Structures: Effect of Cu and Kinetics of Damage Formation,” J. Appl. Phys. 74(2), 1993, pp. 969–978.

    CAS  Article  Google Scholar 

  3. 3

    R. G. Filippi, H. S. Rathore, R. A. Wachnik, and D. Kruger, ‘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. 359–365.

    Google Scholar 

  4. 4

    C. K. Hu and M. B. Small, “Electromigration Failure of Bamboo Structured Lines by Interfacial Transport,” in Proceedings of the 10th International VLSI Multilevel Interconnection Conference, 1993, pp. 265–270.

    Google Scholar 

  5. 5

    L. M. Ting and C. D. Graas, “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. 6

    W. Zhang, Z. G. Li, Y. H. Cheng, W. L. Guo, Y. H. Sun, and X. X. Li, “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. 365–370.

    Google Scholar 

  7. 7

    C. D. Graas, H. A. Le, J. W. McPherson, and R. H. Havemann, “Electromigration Reliability Improvement of W-Plug Vias by Titanium Layering,” in Proceedings of the 32rd Annual International Reliability Physics Symposium. IEEE, 1994, pp. 173–177.

    Google Scholar 

  8. 8

    T. Yamaha, M. Naitou, and T. Hotta, “Three Kinds of Via Electromigration Failure Mode in Multilevel Interconnections,” in Proceedings of the 30rd Annual International Reliability Physics Symposium. IEEE, 1992, pp. 349–355.

    Google Scholar 

  9. 9

    H. Y. Lieu, “Quantitative Study of Al/W Interaction in Si/SiO2/W-Ti/Al Thin Film System,” in Proceedings of Mat. Res. Soc. Symp. 1988, pp. 153–158.

    Google Scholar 

Download references

Author information

Affiliations

Authors

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Ting, L.M., Dixit, G., Jain, M. et al. Effect of Via Etch Profile and Barrier Metal on Electromigration Performance of W-Filled Via Structure in TiN/AlCu/TiN Metallization. MRS Online Proceedings Library 391, 453 (1995). https://doi.org/10.1557/PROC-391-453

Download citation