Characteristics of a carbon/nickel multilayer structure for soft x-ray optics deposited by rf magnetron sputtering

In order to make X-ray-UV interference mirrors, we tried to obtain a periodic multilayer structure with thin films of two materials, a high absorption material (Ni) and a low absorption material (C) on a quartz substrate. We present theoretical approaches to determine the optimum values of the thicknesses of each thin film and the number of periods required for maximum reflectivity at normal incidence of a soft X-ray mirror working at (lambda) equals 50 angstroms. We also describe the experimental procedures used for obtaining the multilayer structure and the microscopically investigations.