Titanium-doped indium oxide films prepared by d.c. magnetron sputtering using ceramic target

Polycrystalline thin films of Ti-doped indium oxide (indium–titanium-oxide, ITiO) were prepared by d.c. magnetron sputtering and their electrical and optical properties were investigated. Doping of Ti was effective in improvement of the electroconductivity of the indium oxide: the electrical resistivity of 1.7 · 10–3 W cm of non-doping decreased to minimum value of 1.8 · 10–4 W cm at 2.4 at.% Ti-doping when the films were deposited at 300 C. The polycrystalline ITiO films of 0.8–1.6 at. % Ti-doping showed the high Hall mobilitiy (82–90 cm2 V–1 s–1) and the relatively low carrier density (2.4–3.5 · 1020 cm–3) resulting in characteristics of both low resistivity (2.1–3.0 · 10–4 W cm) and high transmittance in the near-infrared region (over 80% at 1550 nm), which cannot be shown in the conventional Sn-doped indium oxide (ITO) films.