Patent ID: 6078386
Filing Date: 2000-06-20
Classification: G01N

Abstract:
An inspection system to inspect a first pattern on a specimen for defects a second pattern that is intended to be the same, said inspection system comprising:a monochomatic probe sequentially directed to each point in said first pattern on said specimen;a broadband probe sequentially directed to said each point in said first pattern on said specimen;a monochomatic response detetor positioned to detect a first response from each point of said first pattern on said specimen generated by said monochomatic probe;a broadband response detector positoned a second response from each point of said first pattern on said specimen generated by said broadband probe;a first response comparator coupled to said monochomatic response detector to generate a first response difference signal by comparing the output from said monochromatic response detector for each point of said first pattern with a known first response to a monochromatic probe from each corresponding point on said second pattern to develop a first response difference signal;a second response comparator coupled to said broadband response detector to generate a second response difference signal by comparing the output from said broadband response detector for each point of said first pattern with a known second response to a broadband probe from each corresponding point of said second pattern to develop a second response difference signal; anda difference map generator coupled to said first and second response comparators to receive said first and second response difference signals, respectively, to generate a difference map for said first pattern with values of said first and second difference signals the coordinates of said difference map for each point in said first pattern.