Patent ID: 6222624
Filing Date: 2001-04-24
Classification: G01N

Abstract:
An apparatus for inspecting a defect on an object having repeated patterns on the basis of comparison between a pattern at a first position on the object and another pattern at a second position on the object, said apparatus comprising:an imaging optical system having an image pick-up element for obtaining an image of substantially overall surface or a divided surface of said object to be inspected;moving means for relatively moving said object with respect to said imaging optical system;movement controlling means for controlling said moving means so that a positional relationship of said pattern at said first position with respect to pixels of said image pick-up element before movement is substantially identical to a positional relationship of said pattern at said second position with respect to pixels of said image pick-up element after said movement; anddefect detecting means for detecting a defect on the basis of comparison between at least two image data obtained by said image pick-up element before and after said movement controlled by said movement controlling means.