METHOD FOR MANUFACTURING GLASS SUBSTRATE FOR MASK BLANK, METHOD FOR MANUFACTURING MASK BLANK, AND METHOD FOR MANUFACTURING MASK FOR EXPOSURE

摘要

PROBLEM TO BE SOLVED: To manufacture a defect-free product by reliably detecting inner defects in the whole region inside a glass substrate including a region close to the surface.

SOLUTION: The method for manufacturing the glass substrate for mask blank includes: a primary shaping step of processing a sheet glass into a shape of a glass substrate for a mask blank; a defect inspection step of polishing one end face of the glass substrate into a mirror face, introducing an inspection beam at a wavelength of not more than 200 nm into the glass to inspect whether fluorescent light emitting from an inner defect is present or not, and selecting a glass substrate with no detection of fluorescent light; and a secondary shaping step of grinding and polishing the selected glass substrate. The width in a direction across both of the main surfaces of a region, where the inspection beam at an intensity necessary to emit fluorescent light from an inner defect in the glass substrate can reach in the defect inspection step, is larger than the thickness between both of the main surfaces of the glass substrate after the secondary shaping step.

COPYRIGHT: (C)2011,JPO&INPIT