Patent ID: 8779359

Claim:
A defect review apparatus comprising: an electron scanning part which irradiates an observation region of a surface of a sample with an electron beam and which scans the electron beam over the observation region; a plurality of electron detectors which are arranged around an optical axis of the electron beam and which detect electrons emitted from the surface of the sample by the irradiation of the electron beam; a signal processing unit which generates a plurality of pieces of image data of the observation region on the basis of detection signals from the electron detectors, the plurality of pieces of image data respectively taken in different directions; and a defect inspection unit which generates a subtract image by taking a subtract between each two of the plurality of pieces of image data and which detects a defect in the observation region on the basis of the subtract image, wherein when a pattern in the observation region is a line-and-space pattern including a line pattern and a space, the defect inspection unit generates the subtract image by taking the subtract between two pieces of the image data respectively taken in two directions which are parallel to an extending direction of the line pattern and face each other with the optical, axis of the electron beam in between, thereby canceling out images of only the line pattern, and then detects a pattern remaining in the subtract image as a defect.