Adhesion of arbitrary-shaped thin-film microstructures

We develop, implement in a finite element environment, and experimentally validate an approach to model adhesion of a class of arbitrary-shaped thin-film microstructures commonly used in microsystems technology. The modeling approach adopts principles of three-dimensional linear elastic fracture mechanics and extends them to thin-film plate-like microstructures. A companion experimental effort is carried out to measure adhesion energy of polysilicon microcantilevers using interferometry, and then to study the adhesion behavior of a suite of circular and square plates. The finite element approach is validated by comparison with relevant analytical results. It is then applied to the circular and square plate microstructures and good agreement between measurements and predictions is obtained.