A method to predict electromigration failure of metal lines

Abstract

A new calculation method of atomic flux divergence (AFDgen) due to electromigration has recently been proposed by considering all the factors on void formation, and AFDgen has been identified as a parameter governing void formation by observing agreement of the numerical prediction of the void with experiment. In this article, a method to predict the electromigration failure of metal lines was proposed by using AFDgen. Lifetime and failure site in a polycrystalline line were predicted by numerical simulation of the processes of void initiation, its growth to line failure, where the change in distributions of current density and temperature with void growth was taken into account. The usefulness of this prediction method was verified by the experiment where the angled aluminum line was treated. The failure location was determined by the line shape and the operating condition. The present simulation accurately predicted the lifetime as well as the failure location of the metal line.