Patent ID: 9368314
Filing Date: 2016-06-14
CPC Classification: G01N,H01J,H01L

Claim Text:
1. An inspection system for inspecting a sample, comprising: an electro-optical system comprising: a beam generator for generating either of charged particles or electromagnetic waves as a beam; a stage device for mounting the sample thereon; a primary electro-optical system for guiding and irradiating a surface of the sample mounted on the stage device with the beam from the beam generator as a primary beam; and a secondary electro-optical system for guiding charged particles emitted from the sample surface when irradiating the sample surface with the primary beam; and a detector for detecting the charged particles to output an electric signal as image data corresponding to an intensity of the charged particles; and a controller for controlling the inspection system and processing the image data to determine whether a defect exists on the sample surface, the controller comprising: means for storing a reference image data of a predetermined inspection region; means for controlling the primary electro-optical system to irradiate a plurality of areas with the primary beam in a manner of area-by-area, wherein each area includes at least a part of a predetermined inspection region of the sample surface and has the same size as that of the predetermined inspection region; means for comparing a detected image formed from the image data of each area outputted from the detector with a reference image formed from the reference image data, and calculating a distance value between the detected image and the reference image, wherein the distance value corresponds to a similarity level therebetween; and means for determining that a defect exists on the predetermined inspection region if the distance values of all the areas are larger than a predetermined threshold value, and no defects exists on the predetermined inspection region if the distance value of one of the areas is smaller than or equal to the predetermined threshold value.