| 摘要 |
PURPOSE:To converge scattered light efficiently and to evade the detection of unnecessary light by allowing to inspection light to impinge on the 1st focus of a body to be inspected and condensing the scattered light from a 1st focus part by a reflecting mirror. CONSTITUTION:The 1st focus P1 is formed on the inspection surface of a wafer 2 at its top surface side, and an elliptic reflector 28 as the reflecting mirror which forms a 2nd focus P2 at the side of a photodetector 6 as a photodetecting means is installed. This beam-shaped laser light 36 emitted by a laser light source 6 is projected on the 1st focus P1 from one window 32. The scattered light 38 from foreign matter such as dust and a flaw present at the 1st focus P1 is reflected by the reflecting mirror 30 and condensed on the 2nd focus P2, and the light is guided into a dark box 14 through the window 15 of the dark box 14 and detected by the photodetector 16. Consequently, the scattered light 38 is condensed efficiently and the detection of the unnecessary light is evaded.
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