Patent ID: 7345755
Filing Date: 2008-03-18
Classification: G01N,G03F

Abstract:
1. A defect inspecting apparatus comprising: an illumination optical system configured to illuminate a mask having a patterned surface with an illumination optical beam; an optical splitter configured to split the optical beam passing through the mask into two beam components, which is substantially arranged in an imaging plane on which the optical beam passing through the mask forms an image of the mask; first and second image pickup sensors each having an array of pixels arranged on a longitudinal direction thereof and first and second pickup fields on the patterned surface, respectively, configured to pick up first and second parts of the mask image in the first and second pickup fields, the first and second pickup fields being parallel to each other and displaced from each other by (2n+1)×d/2 in the longitudinal direction thereof, where d denotes a longitudinal dimension of each pixel image in the first and second pick up fields and n denotes an integer equal to or larger than 0; image merging part configured to merge the first and second parts of the mask image to form a pattern image, and a defect detector configured to detect a defect in the mask on the basis of the pattern image.