Stress and surface studies of SILAR grown ZnS thin films on (100)GaAs substrates

Zinc sulfide thin films were grown on (100)GaAs by the successive ionic lay er adsorption and reaction (SILAR) technique from dilute aqueous precursor solutions. The stress of thin films was characterized by means of laser int erferometry, crystallinity by X-ray diffraction, refractive index by ellips ometry and by fitting the reflectance spectrum, composition by electron spe ctroscopy and morphology by atomic force microscopy. A clear correlation be tween the growth mode and the residual stress level is demonstrated. The ch anges from three-dimensional to two-dimensional growth of the him results i n the change of the residual stress from tensile to compressive. The films were polycrystalline and cubic with rather low crystallinity. The crystalli te size and the refractive index of the films increased when the him thickn ess increased. (C) 2000 Elsevier Science S.A. All rights reserved.