Patent ID: 7672799

Claim:
A defect inspection apparatus comprising: a stage that runs with an inspecting object mounted thereon, the inspecting object including a circuit pattern having a group of lines parallel to each other formed therein; an illumination optical system that illuminates a surface of the inspecting object with multiple pairs of slit beams, with each of the pairs comprising a first slit beam being a slit light so as to have a first inclined angle formed by the direction of the group of lines and a projection line of an optical axis of the slit beam to the inspecting object and another slit beam from a direction opposite to an incident direction of the slit beam on a plane; a detection optical system that detects reflected and scattered light from the inspecting object by an image sensor; a data processing section that extracts a signal indicating a defect such as a foreign material in response to a signal detected by the image sensor of the detection optical system; and a defect classifying section that classifies the defect according to a difference in distribution of orientation of reflected and scattered light of the inspecting object.