Finite Elements for Electromigration Analysis

A finite element analysis of the electromigration process in metal interconnects can now be performed using the ANSYS program. The analysis is based on the model that includes all the driving forces of electromigration-diffusion gradient, electric current, stress, and temperature gradients. The electromigration model is implemented in the framework of 2-D and 3-D coupled-field elements. Diffusion, electric, structural, and thermal degrees of freedom are fully (matrix) coupled and solved for simultaneously. Matrix coupling ensures robust convergence of the highly nonlinear electromigration analysis. The finite element solution is validated using 1-D analytical and numerical models of the electromigration process in metal lines. A model of a solder joint illustrates a 3-D electromigration analysis.