Patent ID: 7526119

Claim:
A pattern inspection apparatus which performs die-to-die inspection of comparing detected pattern data of one area with detected pattern data of another area among a plurality of repeated pattern areas, comprising: first imaging optics which forms first optical image of a pattern formed on an inspection target plate on the basis of design pattern data; a detected pattern data generator which detects the first optical image and generates first detected pattern data; second imaging optics which forms second optical image of the pattern, the second imaging optics serving to scan an entire region of the pattern on the inspection target plate with an optical magnification lower than that of the first imaging optics; a low-resolution image data generator which generates second detected pattern data corresponding to the entire region of the pattern on the inspection target plate by using the second optical image; repeated pattern area detector which detects whether candidates for the plurality of repeated pattern areas exist in the second detected pattern data by performing rough search of the second detected pattern data, measures area sizes of the candidates if the candidates exist; and a comparator which sequentially compares the first detected pattern data corresponding to the plurality of repeated pattern areas detected by the repeated pattern area detector through the second imaging optics in accordance with die-to-die comparison, wherein, after the second imaging optics forms the second optical image of the pattern, the low-resolution image data generator generates the second detected pattern data corresponding to the entire pattern region using the second optical image, the repeated pattern generator detects if the candidates exist, the first imaging optics forms the first optical image of the candidates, the detected pattern data generator generates the first detected pattern data of the candidates, and the comparator compares the first detected pattern data with die-to-die comparison.