Effects of O2 addition on microstructure and electrical property for ITO films deposited with several kinds of ITO targets

Indium tin oxide (ITO) films were deposited on nonalkali glass substrate by dc magnetron sputtering using various ITO targets, which are commercial, improved conductivity, and improved density target, without substrate heating. In the case of high-conductive ITO target, relatively low resistivity film was obtained by wider rage of oxygen addition ratios (0.1–0.7%) and the lowest resistivity was 2.9×10−4 Ω cm, which could be attributed to not only the decrease of micro-arcing but also the decrease of plasma impedance. As a result, high-conductive ITO target was confirmed to have high stability in electrical property with an addition ratio of O2.On the other hand, decrease of carrier density was observed with increasing O2 ratio which could be due to the exhaust of oxygen vacancy. X-ray diffraction (XRD) patterns revealed that all the ITO films deposited at room temperature were of amorphous structure.