AVS 56th International Symposium & Exhibition
    Thin Film Thursday Sessions
       Session TF-ThP

Paper TF-ThP5
Spatial Resistivity Distribution of Transparent Conducting Impurity-doped ZnO Thin Films Deposited on Substrates by DC Magnetron Sputtering

Thursday, November 12, 2009, 6:00 pm, Room Hall 3

Session: Aspects of Thin Films Poster Session
Presenter: J. Oda, Kanazawa Institute of Technology, Japan
Authors: J. Oda, Kanazawa Institute of Technology, Japan
J. Nomoto, Kanazawa Institute of Technology, Japan
M. Konagai, Kanazawa Institute of Technology, Japan
T. Miyata, Kanazawa Institute of Technology, Japan
T. Minami, Kanazawa Institute of Technology, Japan
Correspondent: Click to Email
In this paper, we describe and discuss the relationship between two techniques developed for improving the spatial resistivity distribution of transparent conducting impurity-doped ZnO thin films deposited on glass substrates at 200oC by dc magnetron sputtering (dc-MS) with various sintered impurity-doped ZnO targets. One improvement method superimposes an rf component onto dc-MS. The other improvement method uses conventional dc-MS with a low resistivity target prepared under optimized conditions. It was found that decreasing the resistivity of the targets used improved the resistivity distribution in both Al- and Ga-doped ZnO (AZO and GZO) thin films deposited using dc-MS either with or without superimposing rf power. The use of rf-superimposing dc-MS with lower resistivity targets did not result in a sufficient improvement in spatial resistivity distribution over that found in impurity-doped ZnO thin films deposited by conventional dc-MS with the same targets. With rf-superimposed dc-MS, the resistivity distribution in thin films only improved when using targets with a resistivity higher than around 1X10-3 Ωcm. In addition, the sintered targets optimized for preparing transparent conducting AZO and GZO thin films with lower resistivity as well as more uniform resistivity distribution on the substrate surface were found to exhibit a tendency for lower resistivity than around 1X10-3 Ωcm. Consequently, the observed improvement of resistivity distribution on the substrate surface when using the two deposition techniques was achieved by suppressing the amount and/or activity of oxygen reaching the substrate surface during the deposition, resulting from a deposition using either a lower dc sputter voltage or a lower resistivity impurity-doped ZnO target with a lower oxygen content.