A method of optical proximity correction (OPC) in extreme ultraviolet lithography (EUV) lithography includes providing a patterned layout design including first and second design polygons that correspond with the pre-pattern opening, wherein the first and second design polygons are separated by a separation distance, and correcting the patterned layout design using OPC by generating (1) a third polygon that has dimensions corresponding to a combination of the first and second design polygons and the separation distance and (2) and filled polygon within the third polygon, thereby generating an OPC-corrected patterned layout design. EUV photomasks may be manufactured from the OPC-corrected patterned layout design, and integrated circuits may be fabricated using such EUV photomasks.