Patent Number: 
Section: claims

1. An X-ray exposure method comprising: supporting an X-ray mask unit in which a patterned X-ray absorber is formed on a membrane, said patterned X-ray absorber containing one of an element having a density/atomic weight of not less than 0.085 [g/cm 3 ] and an L-shell absorption edge at a wavelength of 0.75 to 1.6 nm and an element having a density/atomic weight of not less than 0.04 [g/cm 3 ] and an M-shell absorption edge at a wavelength of 0.75 to 1.6 nm; and  applying synchrotron radiation having maximum light intensity at a wavelength of 0.6 to 1 nm onto said X-ray mask unit. 2. A method according to  claim 1 , wherein said patterned X-ray absorber is a material containing at least one element selected from the group of Co, Ni, Cu, Zn, Ga, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. claim 1 3. A method according to  claim 1 , wherein said patterned X-ray absorber is a material containing at least one element selected from the group of Cu, Ni, and Zn. claim 1 4. A method according to  claim 1 , wherein a patterned transparent film different from the patterned X-ray absorber is further formed on said membrane. claim 1 5. A method according to  claim 4 , wherein said patterned transparent film is a material containing at least one selected from the group of SiO 2 , SiC, Si, SrO, and SiON. claim 4 6. An X-ray exposure method comprising: supporting an X-ray mask unit in which a patterned X-ray absorber is formed on a membrane, said patterned X-ray absorber being formed of one of an alloy and a multi-layer film, which comprises a first material containing an element having an L-shell absorption edge or an M-shell absorption edge at a wavelength of 0.75 to 1.6 nm and a second material containing an element having an M-shell absorption edge at a wavelength of 0.5 to 0.75 nm; and  applying synchrotron radiation having maximum light intensity at a wavelength of 0.6 to 1 nm onto said X-ray mask unit. 7. A method according to  claim 6 , wherein said first material contains at least one element selected from the group of lanthanoid rare-earth elements of atomic numbers 57 to 71 and, Co, Ni, Cu, Zn, and Ga, and said second material contains at least one element selected from the group of Hf, Ta, W, Re, Os, Ir, Pt, Au, and Hg of atomic numbers 72 to 80. claim 6 8. A method according to  claim 6 , wherein a patterned transparent film different from the patterned X-ray absorber is further formed on said membrane. claim 6 9. A method according to  claim 8 , wherein said patterned transparent film is a material containing at least one element selected from the group of SiO 2 , SiC, Si, SrO, and SION. claim 8 10. An X-ray exposure method comprising: supporting an X-ray mask unit in which a patterned X-ray absorber is formed on a membrane, said patterned X-ray absorber being a material containing as a major constituent an element having all L- and M-shell absorption edges in a region shorter than the shortest wavelength or longer than the longest wavelength of an exposure wavelength region having an intensity not less than {fraction (1/10)} the light intensity at a wavelength of maximum light intensity of synchrotron radiation to be incident; and  applying the synchrotron radiation onto said X-ray mask unit. 11. A method according to  claim 10 , wherein the synchrotron radiation has maximum light intensity at a wavelength of 0.6 to 1 nm, and all the L- and M-shell absorption edges of the element exist in a region of not more than 0.65 nm and not less than 1.02 nm. claim 10 12. A method according to  claim 11 , wherein said patterned X-ray absorber is a material containing as a major constituent at least one element selected from the group of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, La, Ce, Pr, Nd, Pm, Sm, Eu, and Gd. claim 11 13. A method according to  claim 11 , wherein said patterned X-ray absorber is a material containing as a major constituent at least one element selected from the group of Cu, Ni, and Zn. claim 11 14. A method according to  claim 10 , wherein a patterned transparent film different from the patterned X-ray absorber is further formed on said membrane. claim 10 15. A method according to  claim 14 , wherein said patterned transparent film is a material containing at least one element selected from the group of SiO 2 , SiC, Si, SrO, and SiON. claim 14 16. A method according to  claim 14 , wherein a material, which makes the ratio of a deviation of maximum an minimum phase shift difference between the absorber and the transparent material with arbitrary thickness for the wavelength of the exposure wavelength from an average phase shift difference in the exposure wavelength region smaller than that of a deviation of maximum and minimum phase shift of the absorber with arbitrary thickness for the wavelength of the exposure wavelength from an average phase shift difference in the exposure wavelength region, is used as the material of said transparent film. claim 14