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Understanding Void Phenomena in Metal Lines: Effects of Mechanical and Electromigration Stress

Published online by Cambridge University Press:  15 February 2011

Paul A. Flinn*
Affiliation:
Intel Corporation, 3065 Bowers Avenue, Santa Clara, CA 95052, and Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305.
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Abstract

As the shrinking of VLSI devices continues, the problem of voids in interconnections becomes of steadily increasing concern. Voids can result from the effects of triaxial tensile stresses produced during fabrication; they can also arise from electromigration. The effects can combine: voids arising from mechanical stress can move and grow under electromigration stress. A detailed understanding of the phenomena requires both knowledge of the properties of the metal and dielectric as functions of time and temperature, and direct observations of the void behavior in real time under varying stress conditions. The material property information can be obtained by a combination of wafer curvature, X-ray diffraction and ultramicro indentation measurements. Void behavior can be inferred from high precision resistivity measurements, and observed directly with Scanning Electron Microscopy. With these data it is possible to evaluate various models for the phenomena.

Type
Research Article
Copyright
Copyright © Materials Research Society 1992

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References

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