Patent ID: 7315366

Claim:
A defect-inspecting apparatus comprising: a stage on which an object to be inspected is mounted; an illumination optical system including: a high-angle illumination system which illuminates light on a surface of the object to be inspected with desired luminous flux from a high-angle relative to the surface of the object; and a low-angle illumination system which illuminates light on the surface of the object to be inspected with desired luminous flux from a low-angle relative to said high-angle illumination system; a detection optical system including: a condensing optical system which condenses light scattered from the surface of the object by the illumination of the high-angle illumination system and/or the low-angle illumination system; and a light receiving optical unit which detects the scattered light condensed by said condensing optical system and converts the detected light into a first signal corresponding to said light illuminated by said high-angle illumination optical system and/or a second signal corresponding to said light illuminated by said low-angle illumination optical system; and a classification unit which utilizes the first and second signal and classifies defects on the object to be inspected, wherein a defect size is estimated by changing a correction coefficient of the defect size on a basis of a concave-convex level (b/a), where the concavo-convex level (b/a) of a defect is indicated by a ratio of a size b of a first direction of the defect to a size a of a second direction of the defect, where the second direction is lateral to the first direction.