Electromigration‐induced failure in passivated aluminum‐based metallizations−The dependence on temperature and current density

A new dynamic picture of electromigration‐induced failure in passivated narrow lines allows the prediction of the variation of lifetimes with temperature and current density. According to the model, damage is usually nucleated by thermal stress‐induced voiding. Small voids are trapped and grow at grain and phase boundaries. After reaching a critical size, voids then begin to migrate and coalesce, eventually leading to line severance. In most cases this leads to lifetimes varying approximately as the square of the current density j for low and moderate j, and faster for large j. The temperature dependence is determined by a combination of bulk, surface, and grain boundary diffusivities.