PELLICE FILM AND EXPOSURE METHOD UTILIZING SAME

摘要

PROBLEM TO BE SOLVED: To obtain a pellicle film excellent in transmittance to F2 laser light (157 nm), less liable to its thickness reduction owing to photodegradation and having excellent light resistance and excellent transmittance in a pellicle used for protecting a photomask from dust in lithography using a very short- wavelength light source for exposure such as F2 laser (157 nm). ;SOLUTION: The pellicle film consists of a thin film of an organic polymer selected from a copolymer having units (A) based on a chain olefin and units (B) based on a cyclic olefin and satisfying the relation of 0.05≤n/(m+n)≤0.9 between the number (m) of moles of the unit A and the number (n) of moles of the unit B, polyvinyl acetal and polyvinyl alcohol and having no absorption at 157 nm wavelength.;COPYRIGHT: (C)2001,JPO