2D modelling of mechanical stress evolution and electromigration in confined aluminum interconnects

A complete description for mechanical stress evolution and electromigration in confined Al interconnects, taking into account the microstructure features, is presented in this paper. In the last years there were proposed several 1D models for the time-dependent evolution of the mechanical stress in Al interconnect lines, since the time to failure of the line can be related to the time a critical value of the stress is reached. The present paper extends and improves the existing models in 2D using a two dimensional simulator based on finite element method. Also, the model makes an attempt to relate the stress/vacancy concentration evolution with the early resistance change of the Al line