Properties of Germanium-Doped Indium Oxide Thin Films Prepared by DC Magnetron Sputtering

Ge-doped indium oxide (In 2 O 3 ) thin films were prepared by dc magnetron sputtering. The electrical resistivity, 1.6×10 -4 Ω·cm, of the film deposited at 200°C was obtained at 5.5% Ge doping. This was comparable with that of ITO (tin-doped In 2 O 3 ) films. Furthermore, amorphous films with Ge content higher than 5.0% were obtained when the substrate temperature was 20°C, while they were obtained with Ge content higher than 7.0% when the substrate temperature was 200°C. The electrical resistivity of 6.0% Ge-doped amorphous In 2 O 3 film deposited at 20°C is 4.1×10 -4 Ω·cm. The etching rate of the film by 5% HCl is 1400 Å/min and is nine times as high as that of ITO films.