Temperature dependence of the microstructure and resistivity of indium zinc oxide films deposited by direct current magnetron reactive sputtering

Indium zinc oxide (lZO) films were deposited as a function of the deposition temperature using a sintered indium zinc oxide target (In,03: ZnO=90: 10 wt.%) by direct current (DC) magnetron reactive sputtering method. The influence of the substrate temperature on the microstructure, surface roughness and electrical properties was studied. With increasing the temperature up to 200 degrees C, the characteristic properties of amorphous IZO films were improved and the specific resistivity was about 3.4 x 10(-4) Omega CM. Change of structural properties according to the deposition temperature was also observed with X-ray diffraction patterns, transmission electron microscopy, X-ray photoelectron spectroscopy, and atomic force microscopy. IZO films deposited above 300 degrees C showed polycrystalline phases evolved on the amorphous IZO layer. Very flat surface roughness could be obtained at lower than 200 degrees C of the substrate temperature, while surface roughness of the films was increased due to the formation of grains over 300 degrees C. Consequently, high quality IZO films could be prepared by DC magnetron sputtering with O-2/Ar of 0.03 and deposition temperature in range of 150-200 degrees C; a specific resistivity of 3.4 x 10(-4) Omega cm, and the values of peak to valley roughness and root-mean-square roughness are less than 4 nm and 0.5 nm, respectively. (c) 2007 Elsevier B.V All rights reserved.