METHOD AND DEVICE FOR INSPECTING DEFECT OF GRAY TONE MASK AND THOSE FOR INSPECTING DEFECT OF PHOTO MASK

摘要

PROBLEM TO BE SOLVED: To provide a defect inspecting method and a device for it capable of securing transmittance in a gray tone part in a gray tone mask. SOLUTION: By this defect inspecting method, a defect is inspected for the gray tone mask having a light shielding part, a light transmitting part, and a gray tone part, which is a transmittance-regulated area reducing an amount of light transmitted through it for selectively changing a film thickness of a photoresist. Using a transmittance signal obtained by scanning a pattern inside the mask, threshold values 8a and 8b of a transmittance defect in the gray tone part are set on the transmittance signal 7, and when transmittance exceeds the threshold values 8a and 8b, the occurrence of a transmittance defect is determined in the gray tone part.