Abstract: In an X-ray mask for X-ray lithography, a Ta--Ge alloy is employed as the X-ray absorber to form a mask pattern on a membrane, which transmits X-rays, such as a SiC membrane. Ta--Ge is sufficiently high in absorption coefficient. The mask pattern is formed by depositing a Ta--Ge film on the membrane by sputtering and patterning the deposited film. Since the sputter-deposited Ta--Ge film is amorphous, sidewalls of the mask pattern become smooth even when the pattern is finer than 0.1 .mu.m. The Ta--Ge film is high in chemical stability, and this film is relatively small in the dependence of internal stress on the pressure of the sputtering gas so that the stress can easily be controlled.