X-RAY-DIFFRACTION MEASUREMENT OF PARTIALLY CORRELATED INTERFACIAL ROUGHNESS IN MULTILAYERS

The existence of partially correlated roughness in multilayer thin fil ms is demonstrated using x-ray diffraction diffuse-intensity distribut ion measurements. The method is generally applicable and produces, in addition to values of magnitudes of interfacial roughness and its late ral correlation length, a measure of the cross correlation between int erfaces separated by intermediate ones. A simple phenomenological mode l can describe roughness in W/C multilayers prepared under standard co nditions. A cumulative roughness function is used to show that the wav elength range in which the interfacial roughness predominates in these layers lies between 50 angstrom and 2000 angstrom and that the long-w avelength roughness replicates better than the short-wavelength roughn ess.