Transparent conductive indium zinc oxide films prepared by pulsed plasma deposition

Abstract

Transparent conductive indium zinc oxide films were prepared by pulsed plasma deposition from a ceramic target (90 wt. % In2O3 and 10 wt. % ZnO). The dependences of film properties upon the substrate temperature was investigated using characterization methods including x-ray diffraction, atomic force microscope, Hall measurement, ultraviolet-visible spectroscopy, and x-ray photoelectron spectroscopy. The films grown at room temperature had a rather smooth surface due to the amorphous structure, with a root mean square roughness of less than 1 nm. The atomic ratio of Zn/(Zn + In) in these films is 15.3 at. %, which is close to that in the target, and the chemical states of indium and zinc atoms were In3+ and Zn2+, respectively. The films deposited on a substrate with a temperature of 200 °C exhibited polycrystalline structure and a preferred growth orientation along the (222) plane. Here the electrical properties were improved due to the better crystallinity, with the films exhibiting a minimum resistivity value of 4.2 × 10−4 Ω cm, a maximum carrier mobility of 45 cm2 V−1 s−1, and an optical transmittance over 80% in the visible region.