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

摘要

The shape of a main surface of a substrate which has been precisely ground within an actual measurement area prior to chucking is measured and the shape of the main surface of the substrate after chucking when a photo mask (2) fabricated from the substrate is set in an exposure device is obtained by simulation, on the basis of the shape of the substrate prior to chucking and the shape of a mask stage (1). A substrate having a flatness below a first threshold value within a virtual calculation area of the main surface shape after chucking is selected. For the selected substrate, a first approximate curve approximate to the sectional shape in a first direction within a correction area of the main surface shape after chucking is calculated. A correction is carried out by calculating an approximate curved surface from the first approximate curve and subtracting the same from the main surface shape after chucking, in order to calculate a corrected main surface shape. A substrate having a flatness below a second threshold value within the correction area of the corrected main surface shape is selected.