| 摘要 |
PURPOSE:To provide X-ray masking material having a high transmission factor for position detector light of a specific wavelength. CONSTITUTION:This X-ray masking material has an X-ray transmission film on a board, and the thickness t1 of the X-ray transmission film is set to t1=m1lambda/(2n1), (where n1 is the refractive index of the X-ray transmission film at a wavelength lambda, m1 is a positive integer, and lambda is the wavelength of alignment detector light.). |
