A relationship between the adhesion of a Cu conductor to its surrounding medium, the electromigration drift velocity, and lifetime in a conventional electromigration test was demonstrated. Lifetime measurements demonstrated that the drift velocity and the activation energy for mass transport along an interface correlate with the measured adhesion energy of the interface as determined by a four-point bending test. The results indicated that a linear relationship was expected between the electromigration activation energy and the intrinsic work of adhesion, which was consistent with a simple model relating the two. The data indicated that interfacial cleanliness and bond character at the interface (i.e., metal/dielectric versus metal/metal bonding) have a significant impact on all measured parameters.

Relationship Between Interfacial Adhesion and Electromigration in Cu Metallization. M.W.Lane, E.G.Liniger, J.R.Lloyd: Journal of Applied Physics, 2003, 93[3], 1417-21