Concurrent delamination propagation and deformation localization in semiconductor devices

In semiconductor devices, metals and polymers are often integrated as electrical conductors and insulators. Fabrication and operation of the devices cause stress in such an integrated structure. The stress can delaminate the metals and polymers, as well as deform them plastically. Here we show that the delamination can localize the deformation in the metals, which form necks to rupture the metals and sever electrical conduction. We simulate the coevolution of delamination propagation and deformation localization. The metals and polymers are modeled as elastic-plastic materials, and their adhesion is represented by a cohesive zone model. The simulation highlights that extensive delamination is a prerequisite for the metals to form necks, and that necking causes delamination to propagate further. Also highlighted are the impact of corners in the structure. Preexisting defects make the structure particularly vulnerable to concurrent delamination and necking. It is hoped that this study will draw renewed attention to the mechanical behavior of materials in the development of the semiconductor industry.