“…However, the path to establish the EUVL is not without technical difficulties, e.g., lack of sufficient light-source power, particle-free mask handling, defect-free and flat mask blanks, [1][2][3][4] and resist material development, and need to be resolved. From the viewpoint of EUV mask fabrication, mask pattern defect inspection [5][6][7] and repair [8][9][10][11][12][13] are some of the most demanding tasks to be addressed. The reason is that for EUVL generation, the device pattern feature size happens to be exceedingly small and calls for higher repairing accuracy than would be required in optical lithography.…”