Method of fabricating copper-based semiconductor devices using a sacrificial dielectric layer

A method is provided for forming a copper interconnect, the method including forming a sacrificial dielectric layer above a structure layer, forming an opening in the sacrificial dielectric layer and forming a copper layer above the sacrificial dielectric layer and in the opening. The method also includes forming the copper interconnect by removing portions of the copper layer above the sacrificial dielectric layer, leaving the copper interconnect in the opening. The method further includes removing the sacrificial dielectric layer above the structure and adjacent the copper interconnect, and forming a low dielectric constant dielectric layer above the structure and adjacent the copper interconnect.