Patent ID: 8462330

Claim:
A method for detecting a defect, comprising the steps of: irradiating an area on a specimen, on which circuit patterns including repetitive patterns are formed, with light which is formed to irradiate the slit shaped area from an oblique direction; detecting scattered light which is scattered in an upward direction of the irradiation directions area and sideward-oblique detection of the irradiation direction area on the specimen by blocking belt-shaped light scattered from the repetitive patterns, thereby obtaining a detection signal; and processing said detection signal to detect defects, including foreign matter, on the specimen; and displaying said detected defects on a display device; wherein the step of irradiating further comprises a step of setting an azimuth angle at which the specimen is irradiated with the light from said oblique direction during the step of detecting and to detect foreign matter during the step of processing, wherein the sideward-oblique direction scattered light is detected by a linear CCD or TDI sensor, and wherein the sideward-oblique direction scattered light is detected in a direction perpendicular to the longitudinal direction of the slit shaped area.