Nitride and oxide film coatings by plasma sputtering process

Abstract

Titanium nitride films can be prepared by sputtering metallic titanium with nitrogen containing plasmas. Injection of water molecules into an argon plasma striking a metal target realizes functional metal oxide films like ZnO. Metal target surface adsorbs reactive gas species like atomic nitrogen and oxygen to release nitrides and oxides of the target material upon irradiation of plasma ions. Some of these surface leaving molecules pick up electrons from the target surface to be accelerated as negative ions across the sheath towards the plasma. The surface produced negative ions traverse the plasma regions with neutral atoms and molecules formed at the sputtering target to constitute a film on the base material to be coated. The discharge schedule as well as the sequence control of the sputtering voltage can be optimized to form the desired film. By properly controlling the discharge condition and the schedule, other elements can be implanted into the formed film. Possibility of injecting carbon into TiO₂ film is discussed.