Extraction of Equivalent Mechanical Properties for Power ICs Metallization

A finite element method analysis using the concepts of representative volume element and periodic boundary conditions is carried out in order to determine the equivalent linear-elastic properties for a multi-level routing metallization typically found in power integrated circuits. Some theoretical aspects regarding homogenization are discussed, a typical metallization structure is presented, a substructure is chosen as a representative volume element and then mechanical loads are applied to it through adequate use of periodic boundary conditions in a stationary mechanical simulation. The resulting stress and strain distributions are analysed and their volume averages are used to calculate the anisotropic linear-elastic properties of the routing metallization. The procedure is repeated at a larger scale to validate the method. Conclusions are drawn regarding the accuracy and the advantages of the method.