| 摘要 |
PURPOSE:To allow the execution of inspection with always high accuracy without impairing the high-speediness and small-size characteristic of the surface state inspecting device of a beam scanning type and without being affected by the arrangement of chips on a reticule. CONSTITUTION:Two luminous fluxes varied in incident angle are made incident on a polygonal mirror 106 for scanning and while the same positions of the same shape patterns A, B on the reticule 109 are simultaneously illuminated by the reflected two luminous fluxes, the beam scanning according to the rotation of the polygonal mirror is executed. The light rays from the respective irradiation points are separately detected and compared and the presence of foreign matter, etc., is inspected. The spacing J between the irradiation points PA and PB is changed by the operation an actuator 400 to deal with the change and error of the inter-pattern spacings of every reticule. |
