Defect test method and apparatus for gray-tone mask and defect test method and apparatus for photo mask

摘要

PURPOSE: A method and a device for inspecting defects of a gray tone mask and a method and a device for inspecting defects of a photomask are provided to guarantee the transmissivity of the gray tone part of the gray tone mask and carry out the inspection of the micro pattern of the photomask with a high precision. CONSTITUTION: A method for inspecting defects of a dray tone mask includes the steps of using transmissivity signals(7) obtained by scanning patterns in the mask, setting threshold values(8a,8b) of the transmissivity defect in the gray tone part with respect to the transmissivity signal, and determining the defect of the transmissivity in the gray tone part if the transmissivity signal value exceeds the threshold values.