Finite element solutions to problems of electromigration and stress-driven diffusion are presented. The numerical procedures are based on a formulation that assumes bulk diffusion, so that diffusion along grain boundaries and interfaces is not explicitly taken into account. Two cases are considered: (1) a tungsten via/aluminum line junction, and; (2) a one-dimensional case with a blocking boundary at one end of the line. The results show that lime geometry can significantly affect the magnitude of the stresses that develop, although in each case the maximum hydrostatic stress in the line was proportional to the square root of time.
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