Abstract: The present invention is to provide a fluorine-containing polymer having excellent light transmission in the vacuum ultraviolet region of not more than 193 nm, a monomer favorably used for preparing the fluorine-containing polymer, a process for preparing the fluorine-containing polymer, and uses of the fluorine-containing polymer. The fluorine-containing polymer has at least a repeated unit structure represented by the following formula (1) and has an absorption coefficient of not more than 3.0 ?m?1 at 157 nm of ultraviolet rays. wherein R1 to R12 are each fluorine, a fluorine-containing alkyl group of 1 to 20 carbon atoms, or the like; X1 is —CRaRb—, —NRa— or —PRa— (Ra and Rb are each fluorine, a fluorine-containing alkyl group of 1 to 20 carbon atoms, hydrogen, —O—, —S—, an alkyl group of 1 to 20 carbon atoms, or the like); at least one of R1 to R12 and X1 is fluorine or a fluorine-containing group; and n is 0 or an integer of 1 to 3.

Abstract: The atmosphere surrounding a photomask provided with a pellicle (2), particularly, an organic pellicle is replaced for purging with a mixed gas prepared by mixing an inert gas and a small amount of an active gas. The atmosphere in a space (8) between a mask base (1) and a pellicle (2) in a photomask is replaced for purging with a mixed gas prepared by mixing an inert gas and a small amount of an active gas.

Abstract: The present invention is to provide a fluorine-containing polymer having excellent light transmission in the vacuum ultraviolet region of not more than 193 nm, a monomer favorably used for preparing the fluorine-containing polymer, a process for preparing the fluorine-containing polymer, and uses of the fluorine-containing polymer. The fluorine-containing polymer has at least a repeated unit structure represented by the following formula (1) and has an absorption coefficient of not more than 3.0 &mgr;m−1 at 157 nm of ultraviolet rays.

Abstract: A pellicle that excellently transmits ultraviolet rays and, particularly, vacuum ultraviolet rays, does not lose the film thickness thereof that stems from the photolysis and, hence, exhibits excellent light resistance. The pellicle is obtained by using, as a material of pellicle film, an impurity-free organic polymer obtained by treating an organic polymer to remove at least a portion of at least any one of, preferably, a majority portion of trace amount-metal components, high molecular components and incomplete molecular structure components contained in the organic polymer. The invention further provides a method of preparing a pellicle.

Abstract: Disclosed in this invention are optical recording media comprising a substrate, a recording layer formed on the substrate and a protective layer formed on the recording layer, in which the recording layer is irradiated with a beam of energy, thereby causing the change of optical properties at the irradiated portions on the recording layer so as to record information,wherein said recording layer is a thin film containing Te and N, and further Pd, if necessary, and producing methods thereof.