Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-27T01:21:16.672Z Has data issue: false hasContentIssue false

Microstructural Mechanism of Electromigration Failure In Narrow Interconnects

Published online by Cambridge University Press:  21 February 2011

Choongun Kim
Affiliation:
Center for Advanced Materials, Lawrence Berkeley Laboratory and Department of Materials Science, University of California, Berkeley
S. I. Selister
Affiliation:
Center for Advanced Materials, Lawrence Berkeley Laboratory and Department of Materials Science, University of California, Berkeley
J. W. Morris Jr.
Affiliation:
Center for Advanced Materials, Lawrence Berkeley Laboratory and Department of Materials Science, University of California, Berkeley
Get access

Abstract

Microstructural studies of electromigration failure were performed on A1-2Cu-1Si interconnects with 1.3 μm width. The lines were tested to failure under controlled conditions after pre-aging for various times at three different temperatures. Examination of the microstructure of the failure sites suggests that the lines fail at the bamboo grains that terminate the longest polygranular segments in the line. Transgranular slit voids form after Cu has been swept from the grain that fails. Hence, pre-aging lines to create a more stable distribution of Cu lengthens the time required to sweep Cu and significantly increases the time to failure. The optimal microstructure has a maximum intragranular density of stable θ precipitates. In this case transgranular slit failure is suppressed, and the bamboo grain fails by diffuse thinning to rupture.

Type
Research Article
Copyright
Copyright © Materials Research Society 1993

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. Cho, I. and Thompson, C. V., Appl. Phys. Lett. 54, 2577 (1989).Google Scholar
2. Rose, J. H., Appl. Phys. Lett. 61, 2170 (1992).Google Scholar
3. Sanchez, J. E. Jr., Kraft, O., and Arzt, E., Appl. Phys. Lett. 61, 3121 (1992)Google Scholar
4. Sanchez, J. E. Jr, McKnelly, L. T., and Morris, J. W. Jr., J. Appl. Phys. 72, 3201 (1992)Google Scholar
5. Kim, C. and Morris, J. W. Jr., J. Appl. Phys. 72, 1837 (1992)Google Scholar
6. Kim, C. and Morris, J. W. Jr., J. Appl. Phys. 73,4885 (1993)Google Scholar
7. Nix, W. D. and Artz, E., Metall. Trans. 23, 2007 (1992).Google Scholar
8. Lloyd, J. R., Appl. Phys. Lett. 57, 1167 (1990).CrossRefGoogle Scholar
9. English, A. T. and Kinsborn, E., J. Appl. Phys. 54,268 (1983).CrossRefGoogle Scholar
10. Blech, I. A., J. Appl. Phys. 47, 1203 (1976).Google Scholar
11. Shingubara, S., Nakasaki, Y., and Kaneko, H., Appl. Phys. Lett. 58, 42 (1991).Google Scholar
12. Ho, P. S., Phys. Rev. B5, 4534 (1973).Google Scholar