Patent ID: 7949178
Filing Date: 2011-05-24
Classification: G06T

Abstract:
1. A method of inspecting a pattern by using an inspection apparatus, comprising the steps of: illuminating, with a light, a specimen placed on a stage; imaging, with an image sensor, corresponding areas of two patterns formed on the specimen, which are originally formed so as to have an identical shape, to obtain a reference image and an inspection image; correcting a positional difference between the reference image and the inspection image; correcting a first brightness difference of a corresponding area between the reference image and the inspection image whose positional difference is corrected at the step of correcting a positional difference with a first corrector, the first corrector being specifically adapted to correct the first brightness difference which is caused by at least one of a difference in a sensitivity of each pixel of the imagine sensor, a difference in the amount of accumulated light due to unevenness of the speed of movement of the stage, and fluctuation in an illumination light; correcting a second brightness difference of the corresponding area between the reference image and the inspection image whose first brightness difference is corrected at the step of correcting a first brightness difference, with a second corrector which is different from the first corrector, the second corrector being specifically adapted to correct the second brightness difference which is caused by the specimen, and a factor which causes said second brightness difference being a slight difference of thin film among chips formed on the specimen; detecting a defect of the pattern formed on the specimen by using the reference image and the inspection image whose second brightness difference is corrected, wherein said corresponding area in the step of correcting a first brightness difference and said corresponding area in the step of correcting a second brightness difference are different in size from a processing unit area.