Patent ID: 8811713

Claim:
A pattern inspection apparatus for inspecting a plurality of photomasks each used to manufacture a same semiconductor device, the photomasks each including a plurality of mutually replaceable unit regions set therein, the apparatus comprising: a redundancy map storage unit storing a redundancy map indicating a disposition of the unit regions; an image capture unit for acquiring optical images of the photomasks; a defect determination unit which: compares an acquired optical image of a first one of the photomasks to a reference image associated with the first one of the photomasks to detect a defect, determines whether a detected defect is a redundancy defect positioned in a first one of the unit regions replaceable with a second one of the unit regions to render usable the first one of the photomasks, updates the redundancy map to record a coordinate of the redundancy defect, and outputs information regarding the detected defect; and a control unit which: identifies, for a second one of the photomasks, one of the unit regions on the second one of the photomasks that includes the coordinate of the detected redundancy defect as a redundancy-relevant region on the second one of the photomasks, and instructs the image capture unit not to inspect the redundancy-relevant region.