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Void evolution and its dependence on segment length in Cu interconnects

Published online by Cambridge University Press:  01 November 2004

R. Leon
Affiliation:
Jet Propulsion Laboratory, Pasadena, California 91109
J.A. Colon
Affiliation:
California State University, Northridge, California 91330
K.C. Evans
Affiliation:
Jet Propulsion Laboratory, Pasadena, California 91109
D.T. Vu
Affiliation:
Jet Propulsion Laboratory, Pasadena, California 91109
V. Blaschke
Affiliation:
International SEMATECH, Austin, Texas 78741
B. Bavarian
Affiliation:
California State University, Northridge, California 91330
E.T. Ogawa
Affiliation:
University of Texas, Austin, Texas 78712
P.S. Ho
Affiliation:
University of Texas, Austin, Texas 78712
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Abstract

Void evolution during electromigration was studied by recording void nucleation, growth, and displacements at various intervals during thermal (240 °C) and electrical stress tests (2 × 106 amps/cm2) of Cu interconnects. Structural data was collected for various serially arranged line segment lengths and correlated with resistance and increases in resistance due to electromigration-induced thinning and voiding. These results allowed determination of void growth rates in Cu interconnects. Void nucleation and growth show a clear dependence on segment length. Void formation did not occur at the via/interconnect interface, which improved interconnect reliability by allowing extensive voiding before catastrophic failure.

Type
Rapid Communications
Copyright
Copyright © Materials Research Society 2004

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References

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