Effect of controlled operating pressure on physical optical and electrical properties of AZO thin film by DC magnetron sputtering technique

Abstract

The study aimed to research the controlled operating pressure in the range of 1.10 × 10–2 − 2.60 × 10–3 mbar with the adjustment position of plate valve (40 – 100%) using DC pulsed magnetron sputtering system. The AZO films were prepared onto n-type silicon (100) and glass slide substrates. A comparison, all samples were assigned 400 nm of AZO film thickness and then the prepared AZO films were investigated by field-emission scanning electron microscope (FE-SEM) for surface morphologies, X-ray diffraction (XRD) for crystallinity, UV-Vis-NIR spectrophotometry for optical property, Four-point probe and Hall effect instrument for electrical properties, respectively. The results from FE-SEM image showed that the AZO film was columnar structure. The XRD patterns of AZO films demonstrated the crystal growth direction which preferred AZO growth was indicated the (polycrystalline) hexagonal wurtzite structure. For the optical property, the transmittance (%T) clearly showed transparent film, indicating good average value which was 81.54 – 83.28% in visible region (380 to 780 nm of wavelength). Furthermore, the sheet resistivity, high mobility and carrier concentration displayed 91.48 Ohm sq−1, 3.40 cm2 Vs–1 and 7.00 × 1020 cm–3, respectively. These results were decided that the position of plate valve of 85% with operating pressure of 2.70 × 10–3 mbar was the optimal condition. Finally, the excellent electrical and good optical properties of AZO film is mainly applied in several application for optoelectronic device and solar cell.