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

SnO_x 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, SnO_x 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 SnO_x thin film while controlling structural defects by chemical reaction between tin and oxygen. The effects of oxygen contents and annealing on various properties of SnO_x 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. SnO_x thin films at P_O2 = 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.