DEVICE AND METHOD FOR INSPECTING PHASE SHIFT MASK

摘要

PROBLEM TO BE SOLVED: To securely detect the local phase defect of a phase shift mask by an inexpensive inspecting device. SOLUTION: The whole inspection area of a phase shift mask being the object of inspection is irradiated by an illumination system 20 with almost uniform light quantity. The image of the phase shift mask is image-picked up by an image pickup optical system 8 having the resolution limit of Rayleigh where a pattern being the object of inspection on the phase shift mask is not resolved and by a CCD camera 4, and a picture processor 3 analyzes the light intensity distribution of the image. Thus, the local phase defect of the phase shift mask is inspected.