METHOD FOR MANUFACTURING PHOTOMASK

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a photomask capable of correcting a defective part in shorter time, in a translucent mask pattern of a photomask blank having light fastness.SOLUTION: A method for manufacturing a photomask includes: a thin film pattern formation process (S2, S3) of forming a thin film pattern by etching a thin film of a photomask blank having a transparent substrate and the thin film formed on the transparent substrate; a metal ion irradiation process (S5) of irradiating an area including a defective part of the thin film pattern with metal ion; and a thin film pattern correction process (S6) of irradiating, with electron beam, the defective part of the thin film pattern irradiated with the metal ion while supplying assist gas to remove the defective part by etching.