US Patent 7341943 Post etch copper cleaning using dry plasma

A method for post-etch copper cleaning uses a hydrogen plasma with a trace gas additive constituting about 3-10 percent of the plasma by volume to clean a copper surface exposed by etching. The trace gas may be atomic nitrogen or other species having an atomic mass of 15 or greater. The trace gas adds a sputtering aspect to the plasma cleaning and removes polymeric etch by-products and polymeric and other residuals formed during the deposition of dielectric materials or etch stop layers over the copper surface. An anti-corrosion solvent may be used to passivate the copper surface prior to formation of the dielectric materials or etch stop layers.