Patent ID: 7904851

Claim:
A semiconductor device manufacturing method comprising: preparing a photomask in which, based on pattern data, a mask pattern is formed on a transparent substrate; generating a mask pattern dimensional map by measuring a mask in-plane distribution of pattern dimensions of the mask pattern; generating a transmittance correction coefficient map by dividing a formation region of the pattern data into a plurality of subregions and determining a transmittance correction coefficient for each subregion in accordance with a size of a pattern of said each subregion; calculating a plurality transmittance correction values each corresponding to one of said plurality of subregions on the basis of the mask pattern dimensional map and the transmittance correction coefficient map; changing a transmittance of the transparent substrate corresponding to said each subregion on the basis of the corresponding transmittance correction value; and transferring the mask pattern of the photomask onto a wafer using the photomask whose transmittance of the transparent substrate is changed.