Abstract: The conductivity of nanometer TiO₂ thin films was studied. The dependence of the conductivity of TiO₂ thin films on the thickness of the film and the
substrate materials were educed. The TiO₂ films were deposited by reactive magnetron sputtering of Ti target in an Ar+O₂ mixture in a conventional
sputtering reactor. The thickness of the films varied in the range from 15nm to 225 nm. The electrical resistivity of the films was measured at
room temperature in the air. The results show that the conductivity of TiO₂ thin films varies from metal, semiconductor to nonconductor. This is
attributed to the transfer of the electrons at the interface between the TiO₂ and substrates, and the difference of work function determines the
depth of the transfer of the electrons.

Key words: TiO₂ thin films, conductivity, resistivity, transfer of electrons