Defect inspection apparatus, defect inspection method and program

摘要

A reference image and an inspection image indicating pattern on a substrate are acquired and a specified pixel value range ( 63 ) is set on the basis of a histogram ( 62 a) of pixel values of the reference image. Then, a transfer curve ( 71 ) having a large inclination in the specified pixel value range ( 63 ) is obtained. The inspection image and the reference image are converted in accordance with an LUT having transfer characteristics indicated by the transfer curve ( 71 ), an enhanced differential image between a converted inspection image and a converted reference image is generated and each pixel value of the enhanced differential image is compared with a predetermined threshold value, to thereby perform a detection of defective pixel. With this, a value of pixel in the enhanced differential image which corresponds to a pixel in the reference image (or inspection image) having the pixel value in the specified pixel value range ( 63 ) is enhanced, and appropriate inspection is thereby performed.