Apparatus and method for detecting defect on object

Abstract

In a defect detection apparatus, data of an inspection image and that of a reference image are inputted from an image pickup part (3) to an operation part (50), and a differential image is thereby generated in a differential image generation part (52) and an image representing a defect inclusion area which includes a defect in an area image generation part (51) as an image which has less information on a false defect and shape of a defect than information on those in the differential image. A first evaluation part (53) performs a provisional evaluation on whether a defect candidate in an area of the differential image which corresponds to the defect inclusion area is true or false. A second evaluation part (54) determines the type of feature values to be obtained from the defect candidate in accordance with a result of provisional evaluation performed by the first evaluation part (53) to obtain the feature values of the defect candidate and performs an evaluation on whether the defect candidate is true or false on the basis of the feature values. With this construction, it is possible to detect a defect on a substrate (9) with high accuracy and high efficiency.

Dependencies are inferred from the claim text.