To improve the optical performance of EUV multilayer mirror working at 30.4nm wavelength

a series of SiC/Mg multilayer mirrors were fabricated with DC magnetron sputtering at different base pressure before depositing. The measured results of x-ray diffraction (XRD) shows that the multilayers fabricated at different base pressure differ from each other. The reflectivities of these multilayer mirrors were measured by synchrotron radiation light. The measured reflectivity of the multilayer prepared at the base pressure of 6.0E-5Pa is as high as 43%

but

for the multilayer prepared at the base pressure of 5.0E-4Pa

the reflectivity in only 30%. By analyzing the reflectance curve and scattering curve measured in the synchrotron radiation

the decrease of reflectivity of SiC/Mg multilayer was relative to the content of magnesium oxide in the layers.