Characteristic evaluation of Ga-Sn-O thin films fabricated using RF magnetron sputtering

We have evaluated characteristics of Ga-Sn-O (GTO) thin films deposited by RF magnetron sputtering with changing composition ratios of sputtering targets and deposition pressure. The optical transmittance is more than 80%, and the sheet resistance decreases as the deposition pressure increase for the thin films for Ga:Sn=3:1, On the other hand, for the thin films for Ga:Sn=3:1, both the transmittance and sheet resistance decreases as the deposition pressure increases. We analyze the composition ratio and find that for the thin films for Ga:Sn=3:1, the composition ratios in the thin films are similar to that in the sputtering target, whereas for the thin films for Ga:Sn=3:1, the composition ratios in the thin films change as the deposition pressure changes, namely, the ratio of Ga decreases and the ratio of Sn increases as the deposition pressure increases. It is expected that GTO thin films are utilized for future device applications by controlling the composition ratios of Ga and Sn and deposition conditions.