Patent ID: 7187438

Claim:
A defect-inspecting apparatus comprising: a stage on which an object to be inspected is mounted; an illumination optical system comprising; 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 comprising: 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 comparison and judgment unit which classifies defects on the object to be inspected into scratches, thin film-like foreign materials or convex defects by using the first signal and/or the second signal, which have been converted by the light receiving optical unit of the detection optical system; wherein the comparison and judgment unit is configured to classify foreign materials, which are convex defects, into a small group and a large group on a basis of data in response to a defect size calculated from the first signal and the second signal.