Selective metal residue and liner cleanse for post-subtractive etch

Abstract

Structures in semiconductor devices, and methods for forming the structures, are described. In one embodiment, a hard mask layer of a deposition stack can be etched to pattern a hard mask. An interconnect layer of the deposition stack can be etched using the hard mask to pattern a plurality of metal lines. The hard mask can be removed. A liner layer of the deposition stack can be etched to remove a portion of the liner layer deposited directly on a dielectric layer of the deposition stack. In response to etching the liner layer, a remaining portion of the liner layer can be deposited between the metal lines and the dielectric layer.