Evaluation of Electromigration Coupling Different Physics Fields in Numerical Simulation

With the minimization trend of component size, electromigration is becoming an increasingly important concern. Current studies mainly focused on predicting the EM time to failure (TTF) based on Black’s equation. By simulating the current and temperature, TTF of test structures can be calculated. However, the current distribution is not considered in Black’s equation and this method may not be able to describe the current redistribution and current crowding effects. Some numerical models have been developed to simulate the current redistribution and joule heating influence. Still, electromigration is a Multiphysics phenomenon that couples not only electric and thermal fields but also includes atomic diffusion and stress migration. To simulate the actual migration behavior, the influence of different physic fields needs to be considered. In this paper, we employed different physics fields on test vehicle simulations: electrical-diffusion, electrical-thermal-diffusion and structural-thermal-electric-diffusion. The results of EM behavior as well as the computational time are compared.