Patent ID: 7049609

Claim:
A method of verifying correcting data used for proximity effect correction in an electron beam lithographic machine for irradiating a workpiece having a resist applied thereon with an electron beam to delineate a on a surface of the workpiece by the beam, the machine being capable of irradiating the workpiece by the beam with a variable dwell time for proximity effect correction, said method comprising the steps of: virtually dividing an area that covers a region written by the beam into subfields; finding a correcting value for proximity effect correction for each one of the subfields, taking account of the distribution of pattern elements contained in subfields peripheral to each one subfield and storing in a PEC memory; finding the differences between the correcting value for each subfield of the written region and correcting values for at least two subfields adjacent to that one subfield when the found correcting value is stored in said PEC (proximity effect correction) memory; comparing absolute values of the differences with a reference value; and judging the correcting value to be normal when the differences between the absolute values and the reference value are within a given range.