MICROSTRUCTURAL STUDIES OF MOLYBDENUM SILICIDE THIN-FILMS BY SPECTROSCOPIC ELLIPSOMETRY

Thin films of compositions Mo25Si75 and Mo36Si64 were co-sputtered ont o p-type silicon substrates and annealed using a rapid thermal anneali ng system. The spectroscopic ellipsometric studies were performed on s amples which crystallized into the most stable MoSi2 tetragonal phase. The Bruggeman effective medium theory in a multiphase-multilayer mode was used to determine the microstructural details of these films. The microstructural modelling results indicated varied fractions of silic on and voids randomly mixed in the matrix of MoSi2. It was also observ ed that the composition of the SiO2 overlayer also varied with changes in the annealing temperature and was found to. depend on the starting composition.