Patent ID: 8781758

Claim:
An optical inspection apparatus comprising: a stage which rotates a sample and continuously moves the sample in one direction; a light irradiator which irradiates a surface of the sample which is rotated and continuously moved in one direction by the stage, with illumination light which is incident in a direction obliquely to the surface of the sample; a first detector which detects an image of light formed by a forward scattering light around an optical axis of regular-reflection light while excluding the regular-reflection light which is reflected from the surface of the sample irradiated with the illumination light from the light irradiator; a second detector which condenses and detects lateral scattering light which scatters laterally from the surface of the sample with respect to an incidence direction of the illumination light from the light irradiator; and a defect extractor which processes signals detected by the first and the second detector to extract one or more scratch defects in an arbitrary direction in the surface of the sample, wherein a shallow defect is extracted from the scratch defects when one of the scratch defect is determined to have a size less than 100 μm and is only detected by the first detector.