Patent ID: 8227153

Claim:
A method of correcting light exposure used in pattern transfer, onto a target object for pattern transfer, of a mask pattern of a photomask under light exposure repeated multiple number of times to thereby form a transferred pattern, comprising the steps of: calculating, for each and every one of a plurality of shot regions having a transferred pattern formed by a single time of light exposure through a mask pattern and each and every one of a plurality of chip regions comprised in one of said shot regions, a numerical aperture of said mask pattern corresponding to said transferred pattern onto said target object based on an exposure layout of the plurality of shot regions while considering a first flare due to influence from the peripherals of said each shot region and a second flare due to influence from the peripherals of said each chip region; calculating an irradiation energy distribution of exposure light in said each shot region necessary for obtaining said transferred pattern of a predetermined dimension, using said calculated numerical aperture; and adjusting the irradiation energy distribution of the exposure light in said each shot region, based on said irradiation energy distribution calculated in the above; wherein said calculating said numerical aperture includes, calculating an average numerical aperture for said plurality of shot regions and chip regions, correcting a design value of said numerical aperture for said plurality of shot regions and chip regions for said calculating using said average numerical aperture, and calculating an effective value of said numerical aperture for said shot regions and chip regions for the calculation.