US Patent 7241682 Method of forming a dual damascene structure

An improved method of forming an integrated circuit that includes a dual damascene interconnect is described. A contact via hole is formed in a dielectric layer disposed above a semiconductor substrate. A protective layer is disposed on top of the dielectric layer and in the contact via hole, and subsequently forming as a recessed plug in the via, followed by etching to form a trench to complete formation of a dual damascene opening.