Densification and Grain Growth of Indium-Tin-Oxide and Indium Oxide Thin Films Fabricated by Dip Coating Process

Abstract

Indium oxide and tin-doped indium oxide (ITO) films were fabricated by repeating dip coating and heating at various temperatures in air for 30 minutes before annealed in N₂-0.1%H₂ at 600℃ for 30 minutes. The heating at 300℃ resulted in porous nanostructure composed of small grains and crystallite size. Densification and growth of grain and crystallite size were remarkable when heated at 800℃. Resistivity of the film decreased by increasing the heating temperature until at 500-700℃. The resistivity increase at the higher heating temperature was attributed to the crack formation of the films. The lowest resistivity (5.5×10^-3 ohm cm) was obtained when the ITO film was prepared at 500℃.