The effect of annealing treatment on microstructure and properties of indium tin oxides films

Indium tin oxide (ITO) thin films were prepared by radio frequency (r.f.) magnetron sputtering system with high-density ITO target (90 wt.% In2O3 and 10 wt.% SnO2). The microstructure of the thin films at various processing parameters was measured using an X-ray diffractometer (XRD) method. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to observe the microstructure and surface morphology of the thin films. The composition of the thin films was measured by energy dispersive X-ray (EDX). The result shows that the as-deposited ITO film is amorphous-like and includes some round shaped particles in the matrix. The transformed temperature of amorphous to crystal is the range of 150–250 °C. The resistivity is increased sharply at 250 °C with the film fine grain and minimum optical band gap. We could get the minimum resistivity of 3.5 × 10−4 Ω cm and over 80% of the average transmittance in a visible region at the optimum condition of our deposition technique.