Spectroscopic study of the effect of annealing temperature and atmosphere on the opto-electrical properties of sputtered ITO thin films

The effect of annealing temperature and atmosphere on structural, optical and electrical properties of indium tin oxide (ITO) thin films with a nanoscale thickness, grown on glass substrates by radio frequency sputtering, was investigated. X-ray diffraction, grazing incidence X-ray reflectivity, scanning electron microscopy, energy dispersive X-ray spectroscopy, optical transmission and electrical resistivity measurements were performed to study the prepared films. Under both, air and vacuum atmospheres, the films start crystallization from a temperature of 100°C, and show an average transmittance of 83%. From the figure of merit, which takes into account the optical and electrical properties, it is found that the films annealed under vacuum generally show much better performance than those annealed in air.