Plasma Enhanced Nitriding Process of Titanium Oxide Films Using Reactive Plasma Assisted Deposition

We attempted to deposit nitrogen-contained titanium oxide films by exposing titanium surfaces to a reactive plasma discharge produced by a multi-capillary plasma source in nitrogen monoxide (NO) gas diluted by a carrier gas. The optical absorption spectra of the resulting films exhibited a band at higher energy associated with undoped titanium oxide, and a band at lower energy attributed to nitrogen-containing titanium oxide. In the corresponding X-ray photoelectron spectroscopy (XPS) spectra, the optical absorption edge positions were found to decrease with increasing TiNO/Ti4＋ area ratio, indicating band narrowing due to oxygen substitution of nitrogen atoms. This method of simultaneously nitriding and oxidizing titanium is expected to be an effective approach for plasma-assisted formation of titanium oxy-nitride films.