A new material combination, C/Al, for normal-incidence multilayer mirrors at the wavelength λ=28.5 nm is reported. Compared with Mo/Si, and C/Si multilayers, the C/Al mirrors have the lower second-order peak at the 15.0 nm. The C/Al soft X-ray multilayer, fabricated by magnetron sputtering, was characterized by grazing-incidence X-ray diffraction.