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Published June 2008 | metadata_only
Journal Article

Some Practical Issues of Curvature and Thermal Stress in Realistic Multilevel Metal Interconnect Structures


This paper presents the results of a systematic study of curvature and stress evolution during thermal loading in single- and multilevel interconnect line structures which have been deposited on a much thicker substrate. Effects of line aspect ratio, passivation geometry, and metal density within a metalization level on thermal stress evolution in the lines are addressed. The current analytical stress model enables us to predict that interaction between lines on the same level, i.e., in the lateral direction, is so strong that it cannot be neglected. A two-dimensional (2-D) finite element method has been used to verify the accuracy of the current model, while available experimental data have been compared with theory. In order to capture the exact variation of the thermal stresses at different metalization levels, and to investigate the effect of the upper level line arrangements on the stress states at the lower level, a three-dimensional (3-D) finite element analysis was employed. It can be seen that the interaction between levels in the vertical direction is quite weak when the thickness of the interlevel dielectric (ILD) layer becomes comparable to that of the metal layer.

Additional Information

© 2008 TMS. Received August 27, 2007; accepted February 12, 2008; published online March 18, 2008. We acknowledge support of the Defense University Research Initiative on Nano Technology (DURINT) on "Damage- and Failure-Resistant Nanostructured and Interfacial Materials" which is funded at MIT by the Office of Naval Research under Grant N00014-01-1-0808.

Additional details

August 22, 2023
August 22, 2023