Optical proximity correction method and method of fabricating a semiconductor device using the same

A method of fabricating a semiconductor device is disclosed. The method includes performing an optical proximity correction (OPC) on design patterns of a layout to generate a corrected layout, and forming a photoresist pattern on a substrate using a photomask manufactured based on the corrected layout. The OPC comprises generating develop targets for the design patterns, respectively, choosing first object patterns based on distances between the develop targets, performing a first OPC operation on the design patterns based on a mask rule to generate first correction patterns, choosing second object patterns by considering distances between the first correction patterns and a target error of each of the first correction patterns, and performing a second OPC operation on the first and second object patterns to generate second correction patterns, the performing the second OPC not based on the mask rule.