Preparation and Properties of Gallium-Indium-Codoped Tin Oxide Sputtering Targets and Sputtered Thin Films

抄録

I report on a new transparent conducting SnO₂-based oxide: Ga-In-codoped SnO₂ (GIT). Sintering was carried out at 1500^oC x 2h in air. The sintered body of GIT including 4wt% Ga₂O₃ and 5wt% In₂O₃ had a high bulk density of 5.9 g/cm³, in comparison with 3.8 g/cm³ for pure SnO₂. Thus, the sintering characteristics of SnO₂ dramatically improve by adding both Ga₂O₃ and In₂O₃. The resistivity of the sintered body was 6x10^-2ohm-cm. This value is low enough to be used as dc sputtering targets. The resistivity of the films deposited by dc sputtering using the target at room temperature was 5.6x10^-3ohm-cm. Moreover, it decreased to less than 2x10^-3ohm-cm on annealing at 250^oC in air. The transmittance of the films was more than 80% in the visible light region. These films show high durability for alkali and acid, even for hydrofluoric acid.