Influence of sputtering power on optical, electrical properties and structure of aluminum-doped indium saving indium-tin oxide thin films sputtered on preheated substrates

Abstract

The indium tin oxide (ITO) thin film doped with aluminum oxide with reduced to 50 mass% indium oxide content were fabricated by co-sputtering of the ITO and Al2O3 targets. Thin films were deposited in mixed argon–oxygen atmosphere onto glass substrates preheated at 523 K. The dependence of the electrical, optical and structural properties of the films on radio frequency (RF) power of the Al2O3 target was investigated. The obtained thin films were characterized by means of four-point probe, Ultraviolet-Visible-Infrared (UV–Vis-IR) spectroscopy, x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS). Doping of the ITO thin films by Al2O3 resulted in increasing transmittance of films. It has been found that the film sputtered under optimum condition showed values of volume resistivity 713 µΩcm, electron mobility 30.8 cm2V−1s−1 and carrier density 2.87 × 1020 cm−3.