Patent ID: 8629979

Claim:
An inspection system for inspecting a surface of an item to be inspected, the inspection apparatus comprising: an irradiation unit that irradiates inspection light onto the item to be inspected; a scattered light observation unit that observes an image of scattered light produced at or near the surface of the item to be inspected; a diffracted light observation unit that observes an image of diffracted light as the Fourier transform of the scattered light produced at or near the surface of the item to be inspected; a spatial filter unit that blocks some of the diffracted light; a detection unit that detects the intensity and position of the scattered light produced at or near the surface of the item to be inspected; a stage unit that can be moved at a variable speed with the item to be inspected mounted thereon; a processing unit that processes information detected by the detection unit; a display unit that displays the information processed by the processing unit; a spatial filter setting unit that observes an intensity profile of the scattered light image and an intensity profile of the diffracted light image simultaneously, and determines a setting condition for a spatial filter for selectively blocking the diffracted light due to a specific pattern on the surface of the item to be inspected on the basis of an observation result; and wherein the spatial filter setting unit scans a diffracted light observation field of view with a single spatial filter unit, and monitors a state change with respect to the intensity profile of the scattered light image and the intensity profile of the diffracted light image in the absence of insertion of the spatial filter unit simultaneously.