Interconnect structure with an electromigration and stress migration enhancement liner

摘要

An electromigration and stress migration enhancement liner is provided for use in an interconnect structure. The liner includes a metal that has a thickness at a bottom of the at least one via opening and on an exposed portion of an underlying conductive feature that is greater than a remaining thickness that is located on exposed sidewalls of the interconnect dielectric material. The thinner portion of the electromigration and stress migration enhancement liner is located between the interconnect dielectric material and an overlying diffusion barrier. The thicker portion of the electromigration and stress migration enhancement liner is located between the underlying conductive feature and the diffusion barrier as well as between an adjacent dielectric capping layer and the diffusion barrier. The remainder of the at least one via opening is filled with an adhesion layer and a conductive material.