Effects of simultaneous ultraviolet and thermal treatments on physical and chemical properties of RF-sputtered p-type SnO thin-films

Abstract

In this study, simultaneous ultraviolet and thermal (SUT) treatment is proposed as an effective post-deposition treatment technique to lower the annealing temperature required for the formation of p-type SnO thin-films. The chemical, electrical, and optical properties of the radio-frequency (RF)-sputtered SnOX thin-films subjected to the conventional thermal and SUT treatments at different temperatures (as-deposited, 125 °C, 150 °C, 175 °C, and 200 °C) were investigated using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, Hall measurements, and ultraviolet-visible-near infrared spectroscopy. The experimental results revealed that the p-type SnO was the dominant phase of the SnOX thin-film after SUT treatment at 150 °C, which is considerably lower than the annealing temperature of 200 °C required for the formation of the p-type SnO thin-film using the conventional thermal annealing process. The observed phenomenon can be attributed to the reactive oxygen radicals produced by ultraviolet irradiation during the SUT treatment. The proposed post-deposition SUT treatment technique in this work may be useful in various applications that require the formation of p-type SnO thin-films using a low-temperature process.