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Microscopic Estimates for Electromigration Velocities of Intragranular Voids in Thin Aluminum Lines

Published online by Cambridge University Press:  15 February 2011

L. K. Wickham  and
J. P. Sethna
L. K. Wickham
Affiliation:
Laboratory of Atomic and Solid-State Physics, Cornell University, Ithaca, NY 14853-2501
J. P. Sethna
Affiliation:
Laboratory of Atomic and Solid-State Physics, Cornell University, Ithaca, NY 14853-2501
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Abstract

We explore the effect of faceting on possible mechanisms for mass transport around electromigration voids in aluminum interconnects. Motivated by linear response estimates which suggest that particle flux would be much higher along steps than across terraces on a clean aluminum surface, we study step nucleation in the presence of a small driving force along a surface. We find that step nucleation, even on a nearly defect-free void surface, would be slow if the step energy is equal to that calculated for a clean aluminum surface. In the presence of a uniform electromigration force, the creation of new steps between existing ones should not occur unless the free energy cost of a step is much less than thermal energies. We conclude that voids cannot move intragranularly at μm/hr rates without help from other factors such as local heating and impurities.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 428: Symposium L – Materials Reliability in Microelectronics VI , 1996 , 171
Copyright
Copyright © Materials Research Society 1996

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References

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