Patent ID: 8203706
Filing Date: 2012-06-19
Classification: G01N,G03F

Abstract:
1. A method that detects defects of a specimen, comprising the steps of: scanning a stage that carries a specimen with a circuit pattern formed on it in a horizontal plane; illuminating the specimen surface with a plurality of illumination lights each having a different wavelength while keeping a predetermined angle to the normal of the specimen surface; capturing scattered light radiated from the specimen surface that is illuminated by the illumination lights with an objective lens; shielding a part of the scattered light that was captured by a spatial filtering device in the form of an array; branching the scattered light that was not shielded by the spatial filtering device into at least one or more optical paths by spectral splitting or polarization splitting; detecting images on image planes on respective optical paths that are branched; and determining a defect candidate on the specimen by performing comparison processing on each of the detected images, wherein the spatial filtering device comprises a plurality of optical shutters, each of the plurality of optical shutter using a MEMS and the spatial filtering device has a structure in which the optical shutters are arranged in the form of a two-dimensional array that can electrically control transmitted light of the device; wherein: in the comparison processing, first defect determination is performed using a plurality of images that differ from one another in at least one condition of a wavelength condition and a polarization condition; when the plurality of images are determined as defect candidates in the first defect determination, a result of the first defect determination and the images that were subjected to the defect determination are stored; with respect to the images that were not determined as the defect candidates, images in the identical spaces as those of the defect candidates are stored; and second defect determination or defect sorting is performed by comparing feature quantities of the images that were stored and are under the different condition in the identical spaces.