Patent ID: 8922764

Claim:
A defect inspection method performed by a processing unit constructed at least in part by hardware, the defect inspection method comprising: an illumination step of illuminating an area on surface of a specimen as a test object under a specified illumination condition; a specimen scan step of translating and rotating the specimen; a scattering light detection step of separating each of a plurality of scattering lights scattered in a plurality of directions from the illuminated area on the specimen into a two dimensional plurality of pixels, to be detected according to both a scan direction at the specimen scan step and a direction approximately orthogonal to the scan direction; and a process step of performing an addition process on scattering lights that are detected by plural pixels of the two dimensional plurality of pixels corresponding to a radial direction of the specimen, determining presence or absence of a defect based on scattering light treated by the addition process, and computing a size of the determined defect using at least one of the scattering lights corresponding to the determined defect.