Photoresist Removal after Plasma Etching of Metal Film using TiW as Antireflective Coating or as a Barrier Metal

Removal of photoresist after plasma metal etch becomes more difficult as the metal etch requirement and metallization systems become more complicated. We have found that the most effective method to remove the damaged metal oxide surface caused by oxygen plasma ash is to use a patented (USP 5,279,771) buffered hydroxylamine reducing solution (EKC-265). Auger analysis indicated the complete removal of the damaged metal oxide surface. This resulted in at least a 25% improvement on the metal continuity and 50% reduction of via resistance after processing through the hydroxylamine buffer solution when compared to the standard photoresist removal processes, consisting of oxygen plasma ash and solvent chemistries.