Study on Fluorine-Doped Indium Oxide Films Deposited by RF Magnetron Sputtering

Fluorine-doped In 2 O 3 films were deposited by rf magnetron sputtering using an In 2 O 3 target at substrate temperatures from RT to 300°C under Ar gas pressure of 1.0 Pa. The fluorine doping was carried out by the following two methods, (1) placing InF 3 pellets on the erosion area of the In 2 O 3 target, and (2) introducing CF 4 gas into the sputtering chamber. In both cases a systematic increase in carrier density ( n ) was observed, i.e. in case (1): n increased from 3.1×10 19 to 2.9×10 20 cm -3 by placing optimum number of InF 3 pellets and in case (2): n increased from 3.1×10 19 to 1.1×10 20 cm -3 by introducing CF 4 gas at CF 4 /Ar flow ratio of 4%. The fluorine content of the fluorine-doped films was estimated by electron probe microanalysis (EPMA) and X-ray photoelectron spectroscopy (XPS), where the inclusion of fluorine was observed to increase by about 30% (F/In at.%) in both cases.