Semiconducting TiO _2-x S _x thin films by atomic layer deposition of TiS ₂ and its oxidation in ambient

The authors describe the atomic layer deposition (ALD) of titanium oxysulfide films (TiO _2-x S _x ). A new ALD chemistry of tetrakis(dimethylamido)titanium and hydrogen sulfide is proposed for fabricating amorphous titanium sulfide layers. They found that the resulting films subsequently underwent oxidation upon reactions under the ambient condition, resulting in TiO _2-x S _x . The resultant structures were analyzed by using x-ray diffraction, transmission electron microscopy, and x-ray photoelectron spectroscopy, indicative of the formation of TiO _2-x S _x . A combined study of Hall effect measurements and Mott-Schottky analysis showed n-type semiconductor behaviors possessing a good conductivity. Optical properties testify that the present system has a moderate bandgap in between the related binary end compounds such as TiS ₂ and TiO ₂ .