Temperature effect on structure and surface morphology of indium tin oxide films deposited by reactive ion-beam sputtering

Indium tin oxide (ITO) films were deposited by reactive ion-beam sputtering. The relationship among the surface morphology, the resistivity rho of the films, the substrate temperature T-S and the film thickness t(F) was investigated. The heat power from the ion source during the sputtering was 265 W. T-S increased from 30 to 145 degrees C with an increase of t(F). The films thinner than 187 nm at T-S lower than 120 degrees C were amorphous, the film surface was as smooth as the substrate. The films deposited at T-S in the range between 135 and 145 degrees C were polycrystal line. So, the films thicker than 375 nm were in a multilayer structure of a polycrystalline layer on an amorphous layer. The surface of the polycrystalline films became rough. rho of the films suddenly decreased at t(F) of 375 run, where the structure of the films changed. Next, the amorphous films with t(F) of 39 nm were annealed in the atmosphere. The film structure changed to a polycrystalline structure at annealing temperature T-A of 350 degrees C. However, the surface roughness of all the films was almost same. As a result, the substrate temperature during the sputtering was important for the deposition of the films with a very smooth surface. (c) 2005 Elsevier Ltd. All rights reserved.