Interconnect with multiple layers of conductive material with grain boundary between the layers

Abstract

An interconnect structure is formed with a plurality of layers of a conductive material with a grain boundary between any two adjacent layers of the conductive material. Such grain boundaries between layers of conductive material act as shunt by-pass paths for migration of atoms of the conductive material to minimize migration of atoms of the conductive material along the interface between a dielectric passivation or capping layer and the interconnect structure. When the interconnect structure is a via structure, each of the layers of the conductive material and each of the grain boundary are formed to be perpendicular to a direction of current flow through the via structure. Such grain boundaries formed between the plurality of layers of conductive material in the via structure minimize charge carrier wind-force along the direction of current flow through the via structure to further minimize electromigration failure of the via structure.