Halbtonphasenverschiebungsphotomaske, Blankohalbtonphasenverschiebungsmaske und Verfahren zur Herstellung der Blankomaske

摘要

A halftone phase shift photomask having a sufficiently high transmittance for light of short wavelength and usable for high-resolution lithography effected by exposure using deep-ultraviolet + radiation, e.g., krypton fluoride excimer laser light. The halftone phase shift photomask has on a transparent substrate a halftone phase shift layer which includes at least one layer composed mainly of a chromium compound. The chromium compound contains at least fluorine atoms in addition to chromium atoms. A transmittance higher than a predetermined level can be obtained even in exposure carried out at a relatively short wavelength. The photomask can be used for exposure using deep-ultraviolet + radiation, e.g., krypton fluoride excimer laser light (wavelength: 248 nm). Thus, high-resolution lithography can be realized. Since the photomask can be formed by approximately the same method as in the case of the conventional photomasks, it is possible to improve the yield and reduce the cost.