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Thermal strains in passivated aluminum and copper conductor lines

Published online by Cambridge University Press:  09 March 2011

Hongqing Zhang ,
G. Slade Cargill III  and
Antoinette M. Maniatty
Hongqing Zhang
Affiliation:
Department of Materials Science & Engineering, Lehigh University, Bethlehem, Pennsylvania 18105
G. Slade Cargill III*
Affiliation:
Department of Materials Science & Engineering, Lehigh University, Bethlehem, Pennsylvania 18105
Antoinette M. Maniatty
Affiliation:
Department of Mechanical, Aerospace & Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180
*
a)Address all correspondence to this author. e-mail: gsc3@lehigh.edu
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Abstract

Line width and line thickness thermal strain components in passivated Al and Cu lines were observed to relax much more than the line length strain component. Although the width-to-thickness ratios were large, 3.5 and 4.4 for Al and Cu lines, respectively, the behaviors of the thermal stresses were far from the equibiaxial. Observed changes in deviatoric strains between room temperature and 190 °C for Al and 300 °C for Cu were consistent with a model in which the changes in line width and line thickness strains were simply related to changes in line length strains by the uniaxial Poisson’s ratio. Changes in line length strains were determined by the differences in metal and substrate thermal expansion coefficients and the magnitudes of temperature changes through retained elastic strain coefficients for Al of 30% for heating and for Cu of 60% for heating and 80% for cooling, with the balance accommodated by relaxation.

Keywords

Stress/strain relationshipThermal stressesx-Ray diffraction
Type
Articles
Information
Journal of Materials Research , Volume 26 , Issue 5 , 14 March 2011 , pp. 633 - 639
Copyright
Copyright © Materials Research Society 2011

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References

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