INDEPENDENT CHARACTERIZATION OF DENSITY AND INTERFACE ROUGHNESS OF MULTILAYERS USING X-RAY STANDING WAVES

X-ray standing waves were used to characterize the density and the interface roughness of multilayers. To include the interface roughness effect into consideration, the X-ray wave amplitude in the multilayers was described in terms of a modified optical matrix. Simulation results show the possibility of determining both roughness and density of multilayers, independently. Analysis of a Ni/C multilayer with a period of about 54.6 Angstrom showed the interface roughness was 10 Angstrom and the density of the nickel layer was equal to the bulk value. The uniqueness of the roughness and the density was confirmed by calculating standing wave profiles for various roughnesses and nickel layer densities.