A method for manufacturing an interconnect structure includes providing a substrate structure including a substrate and a first dielectric layer on the substrate and having an opening for a first interconnect layer extending to the substrate, forming a first mask layer on a portion of the first dielectric layer spaced apart from the opening, forming a first metal layer filling the opening and covering a portion of the first dielectric layer not covered by the first mask layer, removing the first mask layer, forming a second dielectric layer on the first dielectric layer and on the first metal layer and having a trench for a second interconnect layer, the trench exposing a portion of the first metal layer; and forming a second metal layer filling the trench and in contact with the exposed portion of the first metal layer.