a method of generating data for a mask in fabricating a semiconductor device is disclosed in the present application . the method includes the steps of determining original mask data for a mask hole pattern on the mask , the hole pattern being formed in at least three rows , defining the mask hole pattern as first , second , and third hole patterns , wherein the first , second , and third hole patterns have first , second , and third distances between holes in first , second , and third rows , respectively , determining a degree of distortion in each row , and calculating adjusted mask data by calibrating a size of the second and third hole patterns in accordance with the distance and the degree of distortion in each row for generating a photoresist hole pattern to be the same as the mask hole pattern .