| 摘要 |
A surface inspection system for projecting a laser beam to a surface of a substrate (5) and for detecting a foreign object by detecting scattered reflection light of the laser beam (2), comprising a light source unit (12) having a plurality of light emitting sources (1a,1b) for emitting the laser beams (2a,2b), and a projecting optical system (7) for projecting the laser beam from each of the light emitting sources to the surface of the substrate. Preferably, laser beam (2a,2b) from at least one light emitting source (1a,1b) is entered at a predetermined angle with respect to the optical axis of an image forming forming lens (4) of said projecting optical system (7). At least one of wavelength, polarization state, or light intensity of said light emitting sources (1a,1b) is adjustable so that a flat reflectivity variation curve can be obtained. <IMAGE> |
