Elecromigration damage in fine Al alloy lines due to interfacial diffusion

Abstract

Both electromigration lifetime experiments and experiments of the drift velocity type have been conducted with the alloys (Al 2% Cu), Al(0.5% Cu, 0.3% Zr), and Al(0.3% pd, 0.3 Nb) also with structures with two wiring levels of Ti/Al (0.5-4% Cu)/Ti interconnected with W studs. The latter structure and these structures in general, are representative of present applications, which contain Al and alloy/W interfaces. In all cases it was found that the mass transport along the line's edges played a role in their damage formation, which was at least as great as grain boundary diffusion.