PHOTOMASK AND MANUFACTURING METHOD THEREFOR

摘要

A photomask (13) for ultraviolet light with a contrast ratio 10 or more can be fabricated by generating color centers. These are obtained by irradiating a calcium fluoride crystal substrate with e.g. a KrF excimer laser (wavelength of 248 nm) at an energy of 10 J/cm<2> through an original photomask P2 formed by a chromium film on a quartz substrate, and forming a pattern constituted by color centers in regions corresponding to an original photomask pattern. In the same way, a similar photomask can be fabricated by irradiating a calcium fluoride crystal substrate with the X-ray having the wavelength of 0.5 to 1.0 nm through an original photomask formed by gold film on a silicon substrate.