Patent ID: 9057711
Filing Date: 2015-06-16
Classification: G01N

Abstract:
1. An inspection apparatus which determines whether or not there is a defect by irradiating light on to a sample on which a pattern is formed and forming an image of the sample on an image sensor by means of an optical system, the inspection apparatus comprising: an optical image acquiring unit which acquires an optical image of the sample from the image sensor; a first comparing unit which compares the optical image with a reference image which serves as a reference of the determination, and identifies a defect when a difference exceeds a first threshold; a transfer image estimating unit which estimates a transfer image when patterns of the optical image of the sample and the reference image are transferred by a transfer device; a second comparing unit which compares each of the transfer images and identifies a defect when a difference exceeds a second threshold; and a review device which reviews information from the first comparing unit and the second comparing unit, wherein the review device performs review in order of following (1) to (3): (1) when the degree of a defect identified in the first comparing unit is a third threshold or above and an error ratio of a line width or an inter-line distance of a defect corresponding to the defect and identified in the second comparing unit is a fourth threshold or above; (2) when the degree of a defect identified in the first comparing unit is less than the third threshold, and an error ratio of a line width or an inter-line distance of a defect corresponding to the defect and identified in the second comparing unit is the fourth threshold or above; and (3) when the degree of a defect identified in the first comparing unit is the third threshold or above, and an error ratio of a line width or an inter-line distance of a defect corresponding to the defect and identified in the second comparing unit is less than the fourth threshold.