Modeling crack propagation for advanced 4-point bending testing, of metal-dielectric thin film stacks

摘要

For monitoring and improving mechanical properties of BEoL (back-end of line) intercon nect structures in microprocessor technology, it is crucial to analyze their adhesion and crack propagation properties. In the present investigation, a camera assisted 4-point bend ing beam technique has been used to obtain fast and reliable adhesion measurements including locally resolved crack length information. To interpret the obtained crack prop agation data, a finite-element modeling approach has been utilized. The combination of local measurement of the crack energy release rate and modeling enables to evaluate mea surement curves for both symmetric and asymmetric crack propagation modes and to describe the crack propagation properties of the involved film stacks not attainable in such detail by conventional 4-point bending technique.