Patent ID: 7446866

Claim:
An apparatus for inspecting defects, comprising: a table for mounting a specimen, on which at least one die having at least one pattern is formed, to be inspected and movable in a plane; an ultraviolet light source for emitting ultraviolet light; an illuminating unit for illuminating the specimen mounted on the table with light emitted from the ultraviolet light source and provided with a first polarization condition; a detecting unit for detecting an image of the at least one pattern of the at least one die on the specimen illuminated by the illuminating unit, the image of the at least one pattern being formed by providing light reflected from the specimen with a second polarization condition, and detecting the image with an image sensor; and an image processing unit for processing the image of the at least one pattern detected by the image sensor by comparison with a reference image of at least one pattern formed in the at least one die or another so as to detect defects having sizes from 20 nm to 50 nm and outputting information about the defects detected on the specimen; wherein the illuminating unit and the detecting unit are disposed in a clean environment supplied with clean gas and separated from outside by a wall.