A method of fabricating a metal capping layer having improved etch resistance for copper-based metal regions in semiconductor devices

摘要

A method comprising: forming an opening (221A) in a layer stack (220) formed over a substrate (201) of a semiconductor device (200), the layer stack (220) comprising a conductive cap layer (213) formed on a metal line (212) and a dielectric material (221) formed over the conductive capping layer (213) and wherein the opening (221A) extends into the conductive capping layer (213); selectively forming (232) a protective layer (233) on an exposed one Exposing (213S) at least one of the conductive capping layer (213) in the opening (221A) by performing a chemical vapor deposition process and / or an atomic layer deposition process in which the deposition of metal material on dielectric surface regions is delayed with respect to exposed metal surface regions (213S); andperforming a wet chemical treatment (215) after forming the protective layer (233), wherein the protective layer (233) preserves the integrity of the protective layer (233) Area (213) is substantially preserved when the wet chemical treatment (233) is performed.