IMPROVEMENT FOR DEFECT DETECTION SYSTEM

PROBLEM TO BE SOLVED: To provide a surface inspection method capable of determining presence of anomalies in an inside of a surface or on the surface, on inspection of a wafer formed with a pattern.SOLUTION: Scattered light from a sample surface 20a is collected by collectors 38, 52 that collects light substantially symmetrically about a line perpendicular to the surface 20a. The collected light is directed to channels at different azimuthal angles so that information related to relative azimuthal angle positions of the collected scattered light about the line is stored. The collected light is converted into respective signals representing light scattered at the different azimuthal angles about the perpendicular line. Presence and/or characteristics of anomalies are determined from the signals. Alternatively, the light collected by the collectors 38, 52 is filtered by a spatial filter having a circular gap of an angle related to angle difference of expected pattern scattering, and the signals obtained from a narrow angle and a wide angle collection channels may be compared to distinguish between micro-scratches and particles.