METHOD FOR REMOVING ASSIST FEATURES UTILIZED TO IMPROVE PROCESS LATITUDE

摘要

PURPOSE: A method for removing assist features utilized for improving process latitude is provided to effectively remove, from a substrate, unwanted residues in the assist feature to be used for optical proximity compensation when a feature pattern is printed on the substrate by using a lithographic projection system. CONSTITUTION: Which of the features require assist features to be disposed adjacent thereto is determined so as to print the features to be printed on the substrate within the predetermined resolution limit. A mask containing the features to be printed and the assist features thereof is generated. The first illumination process is performed to print the features on the substrate resulting in the partial printing of the assist features on the substrate. The second illumination process with the quadrapole illumination using a mask as the negative mask of the assist feature pattern is performed so as to reduce the amount of the assist features to be printed on the substrate.