Electrical and optical properties of sputtered ultra-thin indium tin oxide films using xenon/argon gas

In this work we investigate the optical and electrical properties of sub-50 nm thick indium tin oxide (ITO) deposited by Radio Frequency magnetron sputtering technique. The effect of sputtering gas, oxygen concentration and substrate temperature on these properties was studied. ITO films were deposited on glass and silicon substrates using argon or xenon sputtering gases with oxygen flow rate from 0 to 3 sccm. The deposition temperature was 25 or 250 °C. Sub-50 nm ITO films with resistivity record as $9.0\times {10}^{-4}$ Ω cm was achieved with xenon-sputtered films deposited at 250 °C. High optical transmission beyond 90% was observed in the range of 400–800 nm corresponding to the optical bandgap in the range of 3.5–3.8 eV.