Thermomigration as a driving force for instability of electromigration induced mass transport in interconnect lines

Linear instability of electromigration induced mass transport is studied as an intrinsic mechanism of void nucleation and growth in interconnect lines . Heat conduction along the conductor line and between the conductor line a nd surrounding materials is added to a recent model, proposed by Korhonen.e t al. (1993) for electromigration induced stress evolution, to examine the role of thermomigration in linear instability of uniform mass transport. Th e analysis shows that thermomigration is the leading driving force for inst ability of electromigration-induced mass transport in interconnect lines. T his theoretical prediction seems to qualitatively agree with a recent exper imental study. These results suggest that thermomigration, which has been i gnored in most previous studies, could play a significant role in electromi gration failure of interconnect lines. (C) 2000 Kluwer Academic Publishers.