Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-05T04:51:20.033Z Has data issue: false hasContentIssue false

In-Situ UHV Electromigration in CU Films

Published online by Cambridge University Press:  15 February 2011

R. W. Vook
Affiliation:
Physics Department, Syracuse University, Syracuse, NY [email protected]. syr. edu
B. H. Jo
Affiliation:
Physics Department, Syracuse University, Syracuse, NY [email protected]. syr. edu
Get access

Abstract

Copper stripes, current stressed under UHV, clean surface conditions, have an activation energy Q for electromigration (EM) of 0.5 eV, significantly lower than the 0.8 eV reported when the surface has been exposed to air. Application of positive or negative potentials to the stripes during EM testing raises or lowers the clean surface Q in a linear relationship in the range of 0.2 to 1. 0 eV. These results were obtained from in-situ electrical resistance measurements during which potentials up to +/− 800 volts were applied to the stripe. Thus the rate at which surface EM takes place is influenced by the sign and magnitude of the applied potential. The low Q for the in-situ clean surface studies also implies that surface diffusion is the dominant physical mechanism whereby EM damage occurs. Ex-situ SEM studies support this conclusion. This work has important implications for ULSI since numerous recent studies have indicated that surface and/or interface diffusion are present during current stressing of passivated and unpassivated fine line stripes.

Type
Research Article
Copyright
Copyright © Materials Research Society 1996

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. Vook, R. W., Mater. Chem. Phys. 36, 199(1994).Google Scholar
2. Hu, C.-K. and Luther, B., Mater. Chem. Phys. 41, 1(1995).Google Scholar
3. Thompson, C. V. and Lloyd, J. R., MRS Bulletin 18, 19(1993).Google Scholar
4. Lloyd, J. R. and Clement, J. J., Thin Solid Films 262, 135(1995).Google Scholar
5. Jo, B. H. and Vook, R. W., Thin Solid Films 262, 129(1995).Google Scholar
6. Rosenberg, R. and Ohring, M., J. Appl. Phys. 42, 5677(1971).Google Scholar
7. Kellogg, G. L., Phys. Rev. Lett. 70, 1631(1993).Google Scholar
8. Kellogg, G. L., Surf. Sci. 290, 295(1993).Google Scholar
9. Kellogg, G. L., Appl. Surf. Sci. 76/77, 115(1994).Google Scholar
10. d'Heurle, F. M. and Ho, P. S., in Thin Films: Interdiffusion and Reactions, edited by Poate, J. M., Tu, K. N., and Mayer, J. W. (Wiley Publishers, New York, 1978) p. 243.Google Scholar
11. Jo, B. H. and Vook, R. W., Appl. Surf. Sci. 89 237(1995).Google Scholar
12. Park, C. W. and Vook, R. W., Appl. Phys. Lett. 59, 175(1991).Google Scholar
13. Feibelman, P. J., Phys. Rev. Lett. 65, 729(1990).Google Scholar
14. Chang, C. Y. and Vook, R. W., Thin Solid Films 228, 205(1993).Google Scholar
15. Park, C. W. and Vook, R. W., Appl. Surf. Sci. 70/71, 639(1993).Google Scholar
16. Chang, C. Y. and Vook, R. W., Thin Solid Films 223, 23(1993).Google Scholar
17. Lobotka, P. and Vavra, I., Phys. Stat. Solidi a63, 655(1981).Google Scholar
18. Chang, C. Y. and Vook, R. W., in Materials Reliability Issues in Microelectronics, edited by Lloyd, J. R., Ho, P. S., Yost, F. (Mater. Res. Soc. Proc. 225, Pittsburgh, PA 1991) p. 125.Google Scholar