AN ELLIPSOMETRIC STUDY OF NI, MO AND NIXN FILMS DEPOSITED ON SI

The results of spectral and angle-dependent ellipsometric measurements of r.f. magnetron-sputtered very thin nickel, molybdenum and nickel n itride films deposited onto [100] oriented silicon substrates have bee n reported. Ellipsometric data were taken over the spectral range of 3 48-806 nm. The parameters of the films, namely, film thicknesses and v olume fractions for the constituents have been calculated from the ell ipsometric data by the best fitting procedure using one-layer (air/Met al/Si), two-layer (air/Metal/SiO2/Si) and three-layer (air/Metal oxide /Metal/SiO2/Si) optical models. We have estimated the roughness on the film surfaces and contamination of the films by Si and SiO2 using the Maxwell-Garnett and Bruggeman effective medium approximations. We hav e also used a model with an inhomogeneous silicon dioxide interface (a mixture of SiO2 and a-Si). The ellipsometric measurements along with computer data processing will be useful for quality control during the manufacturing of the films, which have applications in soft X-roy opt ical systems. (C) 1998 Elsevier Science S.A.