US Patent 10163786 Method of forming metal interconnection

A device includes a first conductive feature disposed over a substrate; a second conductive feature disposed directly on and in physical contact with the first conductive feature; a dielectric layer surrounding sidewalls of the second conductive feature; and a first barrier layer interposed between the second conductive feature and the dielectric layer and in physical contact with both the second conductive feature and the dielectric layer. The first barrier layer and the dielectric layer comprise at least two common elements.