Post-Annealing Effects on ITO Thin Films RF Sputtered at Different Thicknesses on Si and Glass

Abstract

We report on electrical, optical and surface morphological characteristics of indium tin oxide (ITO) thin films. The ITO was deposited by radio frequency (RF) magnetron sputtering on Si and glass substrates at different thicknesses of 125 nm and 239 nm. Post-annealing treatment was conducted on the samples at temperature of 500°C and 600°C. From Hall Effect measurement, the lowest resistivity was measured as 4.4 × 10-4 Ωcm and 4.5 × 10-4 Ωcm corresponding to the 239 nm and 125 nm ITO sample, respectively, after post-annealed at 600°C. Using UV-Vis spectrophotometer, the highest transmittance of ~84% at 470 nm was observed with respect to the 125 nm ITO thin films after post-annealed at 500°C. Furthermore, the 500°C post-annealed 125 nm thin film shows highest carrier concentrations of more than 1021 cm-3 and smoothest surface morphology of 0.5 nm root-mean-square, RMS. It is clearly shown that post-annealing treatment on ITO thin films is able to enhance the electrical and optical transmittance properties as compared to the as deposited films.