Manufacture and performances of rhodium/carbon multilayer x-ray mirrors

Abstract

A diode rf-sputtering technique was used to produce Rh/C multilayers for application in the soft-x-ray domain. In situ kinetic ellipsometry is used to calibrate the deposition rates and to analyze precisely the interface structure formation. Grazing x-ray reflectivity at the Cu-Kα line (1.54 Å), and absolute soft-x-ray reflectivity at the Cu-Lα line (13.33 Å) and at the C-Kα line (44.7 Å) are also measured on the same multilayers. A model which assumes a quasi-sharp C-Rh interface (4 Å thick) and a diffused Rh-C interface (22 Å) in the stack is used to fit the reflectivity curves at the three experimental wavelengths. Reflectivities as high as 22% at 13.3 Å and 24% at 44.7 Å were measured on a 17-period multilayer structure having a period of ≂69 Å.