Patent ID: 7643137

Claim:
A defect inspection apparatus for inspecting a defect of repeated patterns formed as a top layer of a substrate on which a plurality of layers of repeated patterns are formed, comprising: an illumination optical system for illuminating the repeated patterns formed as the top layer of the substrate on which a plurality of layers of repeated patterns are formed; and a receiving optical system for receiving diffracted light from the substrate; wherein a first polarizing element is provided in the illumination optical system and a second polarizing element is provided in the receiving optical system such that the second polarizing element forms a crossed Nicols relation with the first polarizing element; and the first polarizing element disposed so that an intersection line of a plane of oscillation of polarized light exited from the first polarizing element with the substrate is made substantially parallel or perpendicular to a direction of repetition of patterns of a layer that is lower than the repeated patterns.