US Patent 8735278 Copper etch scheme for copper interconnect structure

The present disclosure is directed to a method of manufacturing an interconnect structure in which a low-k dielectric layer is formed over a semiconductor substrate followed by formation of a copper or copper alloy layer over the low-k dielectric layer. The copper or copper alloy layer is patterned and etched to form a copper body having recesses, which are then filled with a low-k dielectric material. The method allows for formation of a damascene structures without encountering the various problems presented by non-planar features and by porus low-K dielectric damage.