The deposition of indium zinc oxide (IZO) thin films was carried out on substrate at room temperature by RF magnetron sputtering. The effects of substrate temperature, RF power and deposition pressure were investigated with respect to physical and optical properties of films such as deposition rate, electrical properties, structure, and transmittance. As the RF power increases, the resistivity gradually decreases, and the transmittance slightly decreases. For the variation of deposition pressure, the resistivity greatly increases, and the transmittance is decreased with increasing deposition pressure. As a result, it was demonstrated that an IZO film with the resistivity of 3.89 × 10^-4 Ω·cm, the hole mobility of 51.28 ㎠/Vs, and the light transmittance of 86.89% in the visible spectrum at room temperature can be prepared without post-deposition annealing.

IZO transistors with Al₂O₃ as gate dielectrics have been investigated. To improve permittivity in an ambient dielectric layer, we grew Al₂O₃ by atomic layer deposition directly onto the substrates. Then, we prepared IZO semiconductor solutions with 0.1 M indium nitrate hydrate [In(NO₃)₃·xH₂O] and 0.1 M zinc acetate dehydrate [Zn(CH₃COO)₂·2H₂O] as precursor solutions; the IZO solution made with a molar ratio of 7:3 was then prepared. It has been found that these oxide transistors exhibit low operating voltage, good turn-on voltage, and an average field-effect mobility of 0.90 ㎠/Vs in ambient conditions. Studies of low-voltage driving of IZO transistors with atomic layer-deposited high-k Al₂O₃ as gate dielectric provide data of relevance for the potential use of these materials and this technology in transparent display devices and displays.