Physical properties of low temperature sputtering-deposited zirconium-doped indium oxide films at various oxygen partial pressures

Abstract

The effects of oxygen content in the sputtering gas on the crystallographic and optoelectronic properties of 210 nm-thick Zr–doped In2O3 (Zr–In2O3) films by rf magnetron sputtering were initially studied. The results of X-ray diffraction show that the Zr–In2O3 films grown on glass substrates exhibit mixed crystallographic orientations. Moreover, the Zr–In2O3 film grown in an Ar atmosphere promotes the appearance of crystallographic orientation of (222). The surface of the Zr–In2O3 film becomes rougher as the oxygen content in the sputtering gas decreases; the current images obtained by conductive atomic force microscopy reveal that the surfaces of the Zr–In2O3 films exhibit a distribution of coexisting conducting and nonconducting regions, and that the area of the nonconducting surface increases with the oxygen content in the sputtering gas. The resistivity is minimized to 3.51×10−4 Ω cm when the Zr–In2O3 film is grown in an Ar atmosphere and the average transmittance in the visible light region is ∼85%. The optical band gap decreases as the oxygen content in the sputtering gas increases.