US Patent 8242600 Redundant metal barrier structure for interconnect applications

A redundant metal diffusion barrier is provided for an interconnect structure which improves the reliability and extendibility of the interconnect structure. The redundant metal diffusion barrier layer is located within an opening that is located within a dielectric material and it is between a diffusion barrier layer and a conductive material which are also present within the opening. The redundant diffusion barrier includes a single layered or multilayered structure comprising Ru and a Co-containing material including pure Co or a Co alloy including at least one of N, B and P.