Thin low-k SiOC(N) dielectric / ruthenium stacked barrier technology

A ruthenium (Ru) film was deposited by physical sputtering in an N2 atmosphere on a low-k SiOC dielectric film. This Ru deposition process modified the surface of the underlying low-k SiOC to a higher density SiOC(N) layer of approximately 3 nm thickness. This combined SiOC(N) / Ru stack showed good barrier properties without the need of any other barrier layer. This new stack structure removes the requirement for any TaN like film previously used to prevent Cu, Cu ion, and moisture diffusion into or from the SiOC film.