Ellipsometric characterization and influence of relative humidity on TiO2 layers optical properties

We present spectroscopic ellipsometric measurements of TiO2 thin films depo sited on BK7 glass by electron beam reactive evaporation. The columnar morp hology of the TiO2 films has been observed with SEM. It has ken modelled by means of three layers structures of porous TiO2 of different thickness and filled in with various void/water concentrations. The agreement between me asured ellipsometer parameters, tan Psi and cos Delta, and the values deriv ed from our model is almost complete. Finally, we have characterized the in fluence of relative humidity on TiO2 thin films optical properties, variati ons in cos Delta and refractive index at different wavelengths are presente d. (C) 1999 Elsevier Science S.A. All rights reserved.