Diffusion phenomena in microelectronic metallizations and interconnections

Abstract

Grain boundary diffusion is ubiquitous in the metallization of modern microelectronic devices. As density of these devices increases, stringent demands are placed on their performance where failures occur by grain boundary diffusion-induced mechanisms such as electromigration, hillock growths, creep and fatigue. To suppress grain boundary diffusion, solutes are commonly added and in some situations diffusion barriers are used. We have systematically studied grain boundary diffusion in the Al-Cu and Cu conductors and in β-Ta, CVD-W and TiAl3 diffusion barriers. Grain boundary diffusion studies have also been made in several Pb-based alloys, which are of interest for chip-substrate bonding technology. Finally, the role of grain boundary solute segregation in reducing grain boundary diffusion is illustrated. © 1995 Maney Publishing.