With the evolution of semiconducting industries, thermomechanical
failure induced in a multilayered structure with a high aspect ratio
during manufacturing and operation has become one of the critical
reliability issues. In this work, the effect of thermomechanical stress
on the failure of multilayered thin films on Si substrates was studied
using analytical calculations and various thermomechanical tests.
The residual stress induced during material processing was calculated
based on plate bending theory. The calculations enabled the prediction
of the weakest region of failure in the thin films. To verify our
prediction, additional thermomechanical stress was applied to induce
cracking and interfacial delamination by various tests. We assumed
that, when accumulated thermomechanical-residual and externally applied
mechanical stress becomes larger than a critical value the thin-film
cracking or interfacial delamination will occur. The test results
agreed well with the prediction based on the analytical calculation
in that the film with maximum tensile residual stress is the most
vulnerable to failure. These results will provide useful analytical
and experimental prediction tools for the failure of multilayered
thin films in the device design stage.