Oxidation of thin Ti films and its simultaneous hydrogenation by water vapor plasma

In this study we investigated the use of low-pressure water vapor plasma for oxidation and simultaneous hydrogenation of 0.4–0.6 μm thick Ti films deposited by magnetron sputter-deposition technique as a function of the power dissipated in the plasma and the plasma exposure time at room temperature. A double-layer film, in which about 100 nm thick upper layer was a hydrogenated TiO2, was formed within 5 min of treatment time. The film oxidation state gradually increases as the treatment time lengthens until it is completely transformed after 60 min for 200 W into the hydrogenated nanocrystalline Ti3O5. It is concluded, that fast H transients because of their high mobility may be responsible for oxygen diffusion enhancement.

► Simultaneous Ti films oxidation and hydrogenation during water plasma treatment. ► Hydrogenated nanocrystalline TiO2 forms in the shallow near surface region. ► Plasma induced reduction of oxidized Ti enhances the chemical activity of surface.