| 摘要 |
PROBLEM TO BE SOLVED: To provide a foreign object inspecting apparatus that has a reflection type spatial filter in the foreign object inspecting apparatus, shields 80% or more of noise components by diffraction light being generated from the circuit pattern of an inspection area, avoids the S/N ratio for detecting foreign objects, and can detect a minute foreign object. SOLUTION: The reflection type spatial filter 14 is used for a detection means, and a plurality of light-shielding mask patterns for shielding diffraction light being generated from a circuit pattern on an inspection subject 1 are changed to a circuit pattern on the reflection type spatial filter 14, (1) thus obtaining the desired foreign object inspecting apparatus and hence solving problems that light-shielding performance is low in a filter 12 using a liquid crystal although a light-shielding mask pattern that is optimum for each inspection area of the entire surface of the inspection subject 1 is formed on the transmission type spatial filter 12, one portion of the diffraction light is transmitted through the light-shielding mask pattern to become noise components, and scattered light through a part other than the light-shielding mask pattern is transmitted through liquid crystal glass for reducing the quantity of light, and (2) then image-forming characteristics decrease by the aberration of the liquid crystal glass, signal components decrease since the scattered light cannot be condensed easily, S/N ratio decreases, and an improvement in inspection sensitivity by the transmission type spatial filter is limited. COPYRIGHT: (C)2004,JPO
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