1. Substrate-Influenced Thermo-Mechanical Fatigue of Copper Metallizations: Limits of Stoney's Equation.
- Author
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Bigl, Stephan, Wurster, Stefan, Cordill, Megan J., and Kiener, Daniel
- Subjects
MICROELECTRONICS ,MICROSTRUCTURE ,THIN films ,FINITE element method ,DEFORMATIONS (Mechanics) - Abstract
Rapid progress in the reduction of substrate thickness for silicon-based microelectronics leads to a significant reduction of the device bending stiffness and the need to address its implication for the thermo-mechanical fatigue behavior of metallization layers. Results on 5 μm thick Cu films reveal a strong substrate thickness-dependent microstructural evolution. Substrates with h
s = 323 and 220 µm showed that the Cu microstructure exhibits accelerated grain growth and surface roughening. Moreover, curvature-strain data indicates that Stoney's simplified curvature-stress relation is not valid for thin substrates with regard to the expected strains, but can be addressed using more sophisticated plate bending theories. [ABSTRACT FROM AUTHOR]- Published
- 2017
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