A method to predict electromigration failure of metal lines

A new calculation method of atomic flux divergence (AFD(gen)) due to electr omigration has recently been proposed by considering all the factors on voi d formation, and AFD(gen) has been identified as a parameter governing void formation by observing agreement of the numerical prediction of the void w ith experiment. In this article, a method to predict the electromigration f ailure of metal lines was proposed by using AFD(gen). Lifetime and failure site in a polycrystalline line were predicted by numerical simulation of th e processes of void initiation, its growth to line failure, where the chang e in distributions of current density and temperature with void growth was taken into account. The usefulness of this prediction method was verified b y the experiment where the angled aluminum line was treated. The failure lo cation was determined by the line shape and the operating condition. The pr esent simulation accurately predicted the lifetime as well as the failure l ocation of the metal line. (C) 1999 American Institute of Physics. [S0021-8 979(99)08823-4].