Transparent conducting ZnO thin films deposited by vacuum arc plasma evaporation

Abstract

A high rate deposition of co-doped ZnO:Ga,F and ZnO–In 2O 3 multicomponent oxide thin films on large area substrates has been attained by a vacuum arc plasma evaporation method using oxide fragments as a low-cost source material. Highly transparent and conductive ZnO:Ga,F and ZnO–In 2O 3 thin films were prepared on low temperature substrates at a deposition rate of approximately 375 nm/min with a cathode plasma power of 10 kW. A resistivity of 4.5×10 −4 Ω cm was obtained in ZnO:Ga,F films deposited at 100 °C using ZnO fragments co-doped with 1 wt.% ZnF 2 and 1 wt.% Ga 2O 3 as the source material. In addition, the stability in acid solution of ZnO films was improved by co-doping. It was found that the Zn/(In+Zn) atomic ratio in the deposited ZnO–In 2O 3 thin films was approximately the same as that in the fragments used. The ZnO–In 2O 3 thin films with a Zn/(In+Zn) atomic ratio of approximately 10–30 at.% deposited on substrates at 100 °C exhibited an amorphous and smooth surface as well as a low resistivity of 3–4×10 −4 Ω cm.