MANUFACTURING METHOD OF SUBSTRATE FOR MASK BLANK, MANUFACTURING METHOD OF MASK BLANK, MANUFACTURING METHOD OF PHOTO MASK, AND MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE

摘要

A before-chucking main surface shape is measured in an actual measurement region of a main surface of a substrate which has been precision-polished and, based on the before-chucking main surface shape of the substrate and a shape of a mask stage (1), an after-chucking main surface shape of the substrate when a photomask (2) manufactured from the substrate is set in an exposure apparatus is obtained through simulation. A selection is made of the substrate in which the after-chucking main surface shape has a flatness of a first threshold value or less in a virtual calculation region thereof. For the selected substrate, a calculation is made of a first approximate curve approximate to a cross-sectional shape along a first direction in a correction region of the after-chucking main surface shape. Correction is performed by calculating an approximate curved surface from the first approximate curve and subtracting the approximate curved surface from the after-chucking main surface shape to calculate an after-correction main surface shape. A selection is made of the substrate in which the after-correction main surface shape has a flatness of a second threshold value or less in the correction region.