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Relaxation of Thermal Stress by Dislocation Motion in Passivated Metal Interconnects

Published online by Cambridge University Press:  03 March 2011

Lucia Nicola
Affiliation:
The Netherlands Institute for Metals Research/Department of Applied Physics, University of Groningen, 9747 AG Groningen, The Netherlands
Erik Van der Giessen
Affiliation:
The Netherlands Institute for Metals Research/Department of Applied Physics, University of Groningen, 9747 AG Groningen, The Netherlands
Alan Needleman
Affiliation:
Division of Engineering, Brown University, Providence, Rhode Island 02912
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Abstract

The development and relaxation of stress in metal interconnects strained by their surroundings (substrate and passivation layers) is predicted by a discrete dislocation analysis. The model is based on a two-dimensional plane strain formulation, with deformation fully constrained in the line direction. Plastic deformation occurs by glide of edge dislocations on three slip systems in the single-crystal line. The substrate and passivation layers are treated as elastic materials and therefore impenetrable for the dislocations. Results of the simulations show the dependence of the stress evolution and of the effectiveness of plastic relaxation on the geometry of the line. The dependence of stress development on line aspect ratio, line size, slip plane orientation, pitch length, and passivation layer thickness are explored.

Type
Articles
Copyright
Copyright © Materials Research Society 2004

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References

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