A Study on the Fabrication and Characteristics of ITO Thin Film Deposited by Magnetron Sputtering Method

Indium-Tin Oxide (ITO) films were prepared on the commercial glass substrate by the Magnetron Sputtering method. The target was a 90wt.% In₂O₃-10wt.% SnO₂ with 99.99 % purity. The ITO films deposited by changing the partial pressure of oxygen gas (O₂/(Ar+O₂)) of 2, 3 and 5% as well as by changing the substrate temperature of 300℃ or 500℃. The influence of substrate pre-annealing and pre-cleaning on the quality of ITO film were examined, in which the substrate temperature was 500℃ and oxygen partial pressure was 3%. The characteristics of films were examined by the 4-point probe, Hall effect measurement system, SEM, AFM, Spectrophotometer, and X-ray diffraction. The optimum ITO films have been obtained when the substrate temperature is 500℃ and oxygen partial pressure is 3%. At optimum condition, the film showed transmittance of 81%, sheet resistivity of 2260Ω/㎠, resistivity(ρ) of 5.4×10-³Ωcm, carrier concentration of 1.0×1019cm-³, and carrier mobility of 150cm²/Vsec. From XRD spectrum, c(222) plane was dominant in the case of substrate temperature at 300℃ without regarding to oxygen partial pressure. However, in the case of substrate temperature at 500℃ c(400) plane was grown together with c(222) plane, only for oxygen partial pressure of 2 and 3%. In both case of chemical and ultrasonic cleaning without pre-annealing the substrate, it showed much almost same sheet resistivity, resistivity(ρ), transmittance, carrier concentration, and carrier mobility. In case of 500℃/60min pre-annealing before ITO film deposited, both transmittance and carrier mobility are better than no pre-annealing, because preannealing is supposed to remove alkari ions diffusion from substrate. ITO film deposited on the Corning 0080 substrate showed a little bit better sheet resistivity, resistivity(ρ), transmittance, carrier concentration than the film deposited on commercial glass. But no differences between Corning substrate