The properties of reactively-sputtered, stoichiometry-controlled and optimum-conductivity transparent indium oxide films as a function of their titanium, aluminium and zinc content; comparisons with the use of tin as a dopant

Indium films doped with controlled amounts of original dopants of aluminium , titanium and zinc have been made with their stoichiometry controlled to g ive optimum electrical and optical properties. This was made possible by a technique where they were deposited by the successive sputtering of a thin metal film followed by the anodisation of it, using the plasma created by a n unbalanced magnetron. The processes involved transportation between stage s with medium-frequency (40 kHz) power used to suppress any arcing at the t arget, when it was operated in a high concentration of oxygen in the atmosp here. These simply controlled processes gave high rate deposition of doped indium oxide films with resistivities of around 4 mu Ohm m and a film/glass substrate transmittance of around 80%. In particular it was found that dop ing with titanium was more successful than with tin, giving less blue absor ption and a wider process window in the pressure of oxygen used with the pr ocess. (C) 1999 Elsevier Science S.A. All rights reserved.