Formation of aligned capped metal lines and interconnections in multilevel semiconductor structures

In integrated circuit technology; an electromigration and diffusion sensitive conductor of a metal such as copper and processing procedure therefore is provided, wherein, at a planarized chemical mechanical processed interfacing surface, the conductor metal is positioned in a region of a selectable low K eff dielectric material surrounded by a material selected to be protection from outdiffusion and a source of a film thickness cap that is to form over the conductor metal and/or serve as a catalytic layer for electroless selective deposition of a CoWP capping layer.