Effect of metal line geometry on electromigration lifetime in Al-Cu submicron interconnects

The dependence of electromigration lifetime on the metal line geometry in Al-Cu submicron lines was investigated. Results indicated that as the linewidth decreases, the lifetime initially decreases and then increases below a crucial width. The lifetime also decreases with increasing film thickness. Those Al-Cu submicron lines with line width comparable to or smaller than film thickness have longer electromigration lifetime than other Al-Cu fine lines. The effect of line length on electromigration lifetime was found to be small.<>