Hostname: page-component-77c89778f8-gq7q9 Total loading time: 0 Render date: 2024-07-19T08:47:35.509Z Has data issue: false hasContentIssue false

Plasma Etching of Copper Thin Film over a Dielectric Step and Electromigration Failure Mechanism

Published online by Cambridge University Press:  30 July 2012

Chi-Chou Lin
Affiliation:
Thin Film Nano & Microelectronics Research Laboratory, Texas A&M University, College Station, TX 77843-3122, U.S.A.
Yue Kuo
Affiliation:
Thin Film Nano & Microelectronics Research Laboratory, Texas A&M University, College Station, TX 77843-3122, U.S.A.
Get access

Abstract

Process and electromigration issues of the copper line over a dielectric step etched with a new plasma-based process have been studied. The N2 and CF4 additive gas effects on the line profile, undercut, and “neck” formation at the cusp area were investigated with respect to changes of the plasma phase chemistry and ion bombardment energy. The sidewall passivation layer hindered the excessive attack of the cusp region. The undercut of the photoresist pattern caused the residue formation. The lifetime of the etched copper was related to the line shape and the film topography, which directly affected the local current density and stress. With the proper control the plasma phase chemistry and ion bombardment energy, the Cu film over a topographic surface can be etched into fine lines with a long electromigration lifetime.

Type
Articles
Copyright
Copyright © Materials Research Society 2012

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. Kuo, Y., Procs. 6th Intl. Conf. On Reactive Plasmas and 23rd Symp. Plasma Processing, p. 29, 2006.Google Scholar
2. Steigerwald, J. M., Murarka, S. P., Gutmann, R. J., Chemical Mechanical Planarization of Microelectronic Materials, Wiley Publishers, 1997.Google Scholar
3. Kuo, and Lee, S., Appl. Phys. Lett., vol. 78, p. 1002, 2001.Google Scholar
4. Lee, S. and Kuo, Y., J. Electrochem. Soc., vol. 148, p. G524, 2001.Google Scholar
5. Lee, S. and Kuo, Y., Thin Solid Films, vol. 457, p. 326, 2004.Google Scholar
6. Lee, S. and Kuo, Y., Jpn. J. Appl. Phys., vol. 41, p. 7345, 2002.Google Scholar
7. Kuo, Y. and Lee, S., Vacuum, vol. 74, p. 473, 2004.Google Scholar
8. Yang, J. Y., Ahn, Y. K., Bang, J. H., Ryu, W. S., Kim, J. O., Kang, Y. K., Yang, M. S., Kang, I. B., and Cung, I. J., ECS Trans. Thin Film Transistors 9, vol. 16, p. 13, 2008.Google Scholar
9. Kuo, Y., Nominanda, H., and Liu, G., J. Korean Phys. Soc., vol. 48, p. S92, 2006.Google Scholar
10. Tisone, T. C. and Bindell, J. B., J. Vac. Sci. Technol., vol. 11, p. 72, 1974.Google Scholar
11. Maa, J. S. and Halon, B., J. Vac. Sci. Technol. B, vol. 4, p. 4, 1986.Google Scholar
12. Vossen, J. L., Appl. Phys. Lett., vol. 23, p. 287, 1973.Google Scholar
13. Poulsen, R. G., Nentwich, H., Ingrey, S., Electron Devices Meeting, p. 205, 1976.Google Scholar
14. Lin, C. C. and Kuo, Y., J. Vac. Sci. Technol. B, vol. 30, p. 021204, 2012.Google Scholar
15. Lee, S., A Study of Plasma-Based Copper Etching Reaction Process, Texas A&M University, College Station, TX, 2001.Google Scholar
16. Coburn, J. W. and Chen, M., J. Appl. Phys., vol. 51, p. 3134, 1980.Google Scholar
17. Liu, G. and Kuo, Y., J. Electrochem. Soc., vol. 155, p. H97, 2008.Google Scholar
18. Kuo, Y., J. Vac. Sci. Technol. A, vol. 8, p. 1702, 1990.Google Scholar
19. Kerr, A. in CRC Handbook of Chemistry and Physics, CRC Press, 1995.Google Scholar
20. Han, K., Kim, J., Jang, W. H., J. Appl. Polym. Sci, vol. 79, p. 176, 2000.Google Scholar
21. Liu, G., Process and Reliability Assessment of Plasma-Based Copper Etch Process, Texas A&M University, College Station, TX, 2008.Google Scholar
22. Jung, J. K. and Lee, W. J., Jpn. J. Appl. Phys., Part 1, vol. 40, p. 1408, 2001.Google Scholar
23. Sesselmann, W. and Chuang, T. J., Surf. Sci, vol. 176, p. 67, 1986.Google Scholar
24. Min, J. H., Hwang, S. W, Lee, G. R., Moon, S. H., J. Vac. Sci. Technol. A, vol. 20, p. 1574, 2002.Google Scholar
25. Hu, C. K., Lee, K. Y., Gignac, L. and Carruthers, R., Thin Solid Films, vol. 308, p. 443, 1997.Google Scholar
26. Hu, C. K., Rosenberg, R. and Lee, K. Y., Appl. Phys. Lett., vol. 74, p. 2945, 1999.Google Scholar