Influence of stress-induced void formation on electromigration endurance in quarter-micron aluminum interconnects

Abstract

A study to characterize the electromigration behavior in quarter-micron lines is discussed. An increase of activation energy (E/sub a/) with reduction of line width has been experimentally observed. It was also found that there is a region where the lifetime degrades in spite of an increase in E/sub a/ as line width is reduced. This degradation is caused by current crowding and joule-heating around voids that exist before current stressing. According to the electromigration model, a larger grain size and higher