A method of making a mask includes receiving an IC design layout from a designer, applying an logic operation (LOP) correction, performing an OPC correction, fracturing the modified data into a plurality of main features in an electron beam format, and sending the electron beam format data to a mask writer for a mask fabrication. An XOR operation is implemented into the method to check and verify if a pattern is lost during OPC modification and/or data fracture. A BACKBONE XOR operation is also implemented into the method for a plurality of main features with a critical dimension (CD) size smaller than the max OPC correction to check and verify if a small pattern feature is lost during OPC modification and/or data fracture for 45 nm and beyond semiconductor technologies.