Transparent SnOx thin films fabricated by radio frequency reactive sputtering with a SnO/Sn composite target

SnOx thin films are potentially excellent conductive material with large hole mobility and have attracted ever-increasing attention for next generation electronic applications. In this study, SnOx thin films were deposited on a borosilicate glass substrate by radio frequency (rf) reactive sputtering using a SnO/Sn (9:1 mol% ratio) composite target. The composite target was used to produce a chemically stable composition of SnOx thin film while controlling structural defects by chemical reaction between tin and oxygen. The effects of oxygen contents and annealing on various properties of SnOx thin films were studied. The structural analysis was carried out using X-ray photoelectron spectroscopy and X-ray diffraction. The electrical and optical analyses were performed by the Van der Pauw Hall effect measurement and UV/VIS spectrometer, respectively. SnOx thin films at PO2 = 0% (annealed) and 3% (as deposited) exhibited a p-type conductivity of 0.09-0.11 Ω− 1 cm− 1, a hole mobility of 0.2-1.2 cm2 V− 1 s− 1, and a hole concentration of ~ 1018 cm− 3. Also, these thin films showed the transmittance of about 70% and an optical bandgap of 2.75-3.01 eV.