| 摘要 |
<p>PURPOSE:To inspect the defect of a pattern with high accuracy by providing both of photodetecting parts having a dark visual field and a bright visual field and discriminating exactly the ture defect and the defect owing to a dust or the like. CONSTITUTION:The signals obtd. by amplifying the output signals of photoelectric transducers 26, 28 on one side and the signals obtd. by amplifying the output signals of photoelectric transducers 27, 29 on the other side with amplifiers 32, 34 and inverting the phases thereof with phase inverters 35, 36 by each of a bright visual field part and a dark visual field part are supplied to respectively separate defect discriminating circuits 37, 38. The circuit 37, 38 add both input signals basically and discriminate the defect such as the difference in patterns, flaw, dirt or the like by each of the bright visual field and the dark visual field. Both output signals of the circuits 37, 38 are supplied to a processing circuit 39 of defect detection which gates the visual field output in the case of inspecting a photomask as a specimen 17 and processes the signals conversely in the case of inspecting a wafer so as to discriminate only the true defect excluding the defects by dirt, etc. and outputs the defect signal.</p> |
