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.
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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
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.
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.
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.
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.
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.
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.
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.
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.
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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