Patent ID: 6400454
Filing Date: 2002-06-04
Classification: G01N

Abstract:
A defect inspection method comprising the steps of:radiating a Gaussian light beam to an area of detection on a substrate serving as an object of inspection and having a circuit pattern created thereon by using a radiation optical system wherein said Gaussian light beam is shaped to give an illumination-intensity distribution of a Gaussian distribution having a standard deviation about equal to a distance from an optical axis of said area of detection to peripheries of said area of detection; forming an optical image of said area of detection on said substrate serving as an object of inspection by radiating of said shaped Gaussian light beam to a photo-sensitive surface of a detector corresponding to said area of detection and detecting a picture signal corresponding to said area of detection and originating from said detector; and processing so as to judge whether or not a defect exists in said area of detection on the basis of said detected picture signal originating from said detector by a signal processing system.