AVS 53rd International Symposium
    Thin Film Tuesday Sessions
       Session TF-TuP

Paper TF-TuP11
Transparent Conductive Oxide Films of In2O3-ZnO with Additional Ga2O3 Impurities

Tuesday, November 14, 2006, 6:00 pm, Room 3rd Floor Lobby

Session: Thin Film Poster Session
Presenter: K. Tominaga, The University of Tokushima, Japan
Authors: K. Tominaga, The University of Tokushima, Japan
D. Takada, The University of Tokushima, Japan
H. Suketa, The University of Tokushima, Japan
K. Takita, The University of Tokushima, Japan
K. Shimomura, The University of Tokushima, Japan
K. Inoue, The University of Tokushima, Japan
K. Murai, The University of Tokushima, Japan
T. Moriga, The University of Tokushima, Japan
Correspondent: Click to Email
In2O3-ZnO films have amorphous phase. These films are expected as a transparent conductive oxide (TCO) film in optoelectronics. We deposited In2O3-ZnO films with additional Ga2O3 impurities and investigated the influence of Ga2O3 on TCO film properties. Using a facing target sputtering system of ZnO:Ga and In2O3 targets, two targets were sputtered simultaneously in Ar gas at 1 mTorr, and electric current ratio @delta@=IZn/(IZn+IIn) was adopted as a deposition parameter to change film composition. Discharge current of each target was changed from 0 to 80 mA in order to change the contents of Zn and In in the film. Compositional ratios of Zn/(Zn+In) in films were nearly equal to @delta@ value according to the data estimated by X-ray fluorescence analysis. Four ZnO:Ga targets containing 0,4.5,6 and 7.5 wt% Ga2O3 were used for Ga adding in the films. In2O3-ZnO films in amorphous phase were deposited between Zn/Zn+In=0.27-0.57. The lowest resistivity in amorphous In2O3-ZnO was 2.7x10-4 Ωcm. The resistivity for the amorphous film was low between @delta@=0.27 and 0.5, but the resistivity for homologous film increased rapidly between @delta@=0.5. and 0.8. For amorphous films at @delta@=0.33 and 0.5, optical bandgap energy for the film of @delta@=0.33 shifted to higher energy side for that of @delta@=0.5. Similarly, with increasing the Ga2O3 content, optical bandgap energy shifted to a higher energy side.