Patent ID: 7863196

Claim:
A method comprising: providing a substrate with a layer having at least a first region and a second region, wherein the first region comprises a first dielectric material and the second region comprises copper; treating the substrate in a reduced-oxygen environment to remove oxides of copper that may be in the second region; and forming a cap layer over the substrate, wherein the cap comprises a second dielectric material and is selectively formed only over the second region of the substrate such that substantially no second dielectric material is formed over the first region of the substrate, wherein the second dielectric material comprises a material selected from a group consisting of silicon nitride, silicon carbide, and silicon carbon nitride, and wherein the forming comprises using plasma enhanced chemical vapor deposition in an atmosphere comprising a silane and a precursor gas, the silane selected from the group consisting of SiH 4 , Si 2 H 6 , and Si 3 H 8 , the precursor gas selected from a group consisting of CH 4 , C 2 H 6 , C 3 H 8 , N 2 , NH 3 , and N 2 NH 3 .