Annealing effects on the properties of indium tin oxide films coated on soda lime glasses with a barrier layer of TiO2-SiO2 composite films

The structural, optical, and electrical properties of indium tin oxide (ITO) films coated on soda lime glasses with and without a barrier layer of TiO2-SiO2 composite films before and after annealing in air at 300 and 500 degrees C for 1 h have been systematically investigated using a x-ray diffractometer (XRD), spectrophotometer, and four-point probe, respectively. A TiO2-SiO2 barrier layer and an ITO layer were sequentially deposited onto unheated glass substrates by reactive ion-assisted electron-beam evaporation (IAD) using an advanced plasma source. Correlations between these properties and annealing temperatures and barrier-layer compositions are discussed. The suppression effect of a barrier layer on the outdiffusion of Na atoms from the soda lime glass substrate through the barrier layer into the ITO layer is investigated with secondary-ion mass spectrometry (SIMS). With respect to the optical and electrical requirements of ITO electrodes used in liquid crystal display (LCD) panels, ITO-coated soda lime glasses with a barrier layer of TiO2-SiO2 composite films with TiO2<50 at. % are superior to those with a barrier layer of SiO2. (C) 1997 Society of Photo-Optical Instrumentation Engineers.