Deposition of aluminium oxide thin films by reactive magnetron sputtering

Aluminium oxide thin films were deposited by direct current (d.c.) reactive magnetron sputtering on glass-slide, silicon wafer, stainless-steel and polycarbonate substrates. The thicknesses of the films were between 200 nm and 3.0 mu m. The deposition was controlled by the target voltage to obtain stoichiometric thin films with a high deposition rate. The deposition process was studied in terms of target power, I-U characteristics of the target, sputtering gas pressure and substrate bias voltage. The him properties of interest were O/Al ratio, density, nanohardness, intrinsic stress, crystallographic structure and surface roughness. The deposition rate obtained for stress-free and transparent aluminium oxide thin film was 215 nm min(-1), 77% of the rate of metallic aluminium. (C) 1999 Elsevier Science S.A. All rights reserved.