[en] Single layers of Cu and Si and Cu/Si multilayers were deposited on glass substrates kept at room temperature, by r.f. sputtering technique in Argon plasma. The films have been characterised by x-ray reflectometry at Cu Kα (1.54 A) radiation and phase modulated ellipsometry in the wavelength range 300-800 nm. It has been found by the small angle x-ray reflectivity measurement that the sputtering system is able to produce high quality layers with very low roughness (∼ 5 A), which is very much needed for the fabrication of x-ray multilayer mirror systems. The multilayer coating, consisting of 10 bilayers of Cu and Si, have showed Bragg peak up to the 3rd order and about 45% reflectivity at the 1st Bragg peak. (author)