Metal-filled openings for submicron devices and methods of manufacture thereof

摘要

A method of forming a metal-filled opening in a semiconductor or other submicron device substrate includes forming a conductive bulk layer over the substrate surface and in the opening, wherein the conductive bulk layer has a first grain size. A conductive cap layer is formed over the conductive bulk layer, the conductive cap layer having a second grain size that is substantially smaller than the first grain size. At least one of the conductive bulk and cap layers are then planarized to form a planar surface that is substantially coincident with the substrate surface.