Patent ID: 8023723

Claim:
A mask pattern dimensional inspection method comprising: preparing a sidewall shape correction function by, using an optical method, determining contour position data of a plurality of mask patterns which are different in sidewall shape and formed on a photomask as optical contour position data, obtaining SEM image data of the mask patterns, obtaining a plurality of items of pattern contour position data corresponding to the mask patterns from the SEM image data using a first threshold, determining an offset between the pattern contour position data obtained for each of the mask patterns using the first threshold and the corresponding optical contour position data, obtaining two items of pattern contour position data from the SEM image data for each of the mask patterns using second and third thresholds, obtaining contour position difference data between the two items of pattern contour position data obtained for each of the mask patterns using the second and third thresholds, and determining the sidewall shape correction function representing the correspondence between the offset and the contour position difference data obtained for each mask pattern; obtaining an SEM image of a pattern to be inspected; obtaining pattern contour position data from the SEM image of the pattern to be inspected using the first, second and third thresholds; obtaining position contour position difference data between two items of pattern contour position data obtained from the SEM image of the pattern to be inspected using the second and third thresholds; obtaining an offset corresponding to the pattern contour position difference data by referring to the sidewall shape correction function; determining pseudo-optical contour position data by adding the resulting offset to the pattern contour position data obtained from the SEM image of the pattern to be inspected using the first threshold; and conducting a lithographic simulation of the pattern to be inspected using the pseudo-optical contour position data.