Cohesive zone modeling for structural integrity analysis of IC interconnects

Due to the miniaturization of integrated circuits, their thermo-mechanical reliability tends to become a truly critical design criterion. Especially the introduction of copper and low-k dielectric materials cause some reliability problems. Numerical simulation tools can assist developers to meet this challenge. This paper considers the first bond integrity during wire bond qualification testing. During testing, metal peel off may occur. This mechanical failure mode is caused by delamination of several layers of the interconnect structure. An interfacial damage model is employed for simulating delamination. However, the fact that the considered interfaces are brittle triggers some reported numerical difficulties. This paper illustrates the potential of the interface damage mechanics approach for simulating metal peel off and it highlights the computational aspects to be developed to render a practically applicable approach.