Controlled fabrication of multilayer soft-x-ray mirrors

Multilayer mirrors have been fabricated for various angles of incidence throughout the wavelength range λ=1.5-160 Å. Reflectivity increases by more than a factor 103 over the best single-film reflectors have been obtained. Measured reflectivities are around 10% near normal incidence in the λ=45-160-Å wavelength region and above 50% near grazing incidence (grazing angle 1°-2°) for λ=1.54 Å. The required thickness control has been achieved by monitoring the reflectivity of the films in situ during the deposition.