FEM of anodic bonding test structures

The presented work deals with the study of the electro-mechanical phenomena during the anodic bonding process between glass and silicon. Special test structures were designed for the characterisation of the bonding. The test structures consist of a matrix of circular and rectangular cavities defined by reactive ion etching on the silicon piece with different sizes and depths. During anodic bonding the structures deform. In the cavities with lower stiffness, the surfaces of the glass and silicon get into intimate contact and bond. The larger electrostatic pressure the more stiff structures will be bonded, therefore, the bonded structures give information about the electrostatic pressure. In this manuscript different electrostatic models are studied by using finite element modeling (ANSYS). The results are fitted with experimental data to validate the best model.