Patent ID: 8592306

Claim:
A method of forming a semiconductor structure comprising: providing a dielectric material having a dielectric constant of about 4.0 or less located above a substrate, the dielectric material having at least one opening located therein; forming a diffusion barrier within the at least one opening; forming a redundant diffusion barrier layer on the diffusion barrier within the at least one opening, wherein said redundant diffusion barrier layer is a bilayer structure comprising a top layer of Ru and a bottom layer comprising at least a Co-containing material; filling the remaining portion of the at least one opening with a conductive material; and planarizing the diffusion barrier, the redundant diffusion barrier layer, and the conductive material to provide a structure in which the diffusion barrier, redundant diffusion barrier layer and the conductive material each has an upper surface that is co-planar to an upper surface of the dielectric material.