Effects of post-thermal treatment on the properties of rf reactive sputtered ITO films

Indium tin oxide (ITO) thin film prepared by rf sputtering at various Ar–O2 mixtures, were annealed at several temperatures. The electrical, optical and structural properties of the film were systematically investigated before and after post-thermal treatment. The influence of a reactive gas (O2) on the sputtering rate of a metallic (indium/tin) alloy target was also investigated. The films were characterized by X-ray diffraction (XRD) measurement, scanning electron microscopy, and transmittance as a function of wavelength. The resistivity of 8.3×10−4 Ω cm has been achieved for the film thickness of 250 nm, deposited in pure Ar at room temperature (RT).