Patent ID: 7171038

Claim:
A method of inspecting and/or characterizing a substrate, comprising: obtaining a first dataset (D A1 ), wherein said first dataset includes data derived from an image collected by a first detector of a first region of said substrate; obtaining a second dataset (D B1 ), wherein said second dataset includes data derived from an image collected by a second detector of at least a portion of said first region of said substrate; obtaining a third dataset (D A2 ), wherein said third dataset includes data derived from an image collected by said first detector from a second region of said substrate, wherein said second region of said substrate is expected to be substantially identical to said first region; obtaining a fourth dataset (D B2 ), wherein said fourth dataset includes data derived from an image collected by said second detector of at least a portion of said second region of said substrate; and processing information derived from said first, second, third and fourth datasets to detect a defect in at least one of said first or second regions using a generalized equation of a form A= ( P ( BD A1 +CD B1 ) M /( SD A1 +TD B1 ) Q +( ED A2 +FD B2 ) N /( UD A2 +VD B2 ) R ) k , where values of B, C, E, F, M, K, P, Q, R, S, T, U, V, and N represent constants and/or functions of other variables, wherein said information processing further includes calculating a first function representing comparison between said first and third datasets and calculating a second function representing comparison between said second and fourth data sets; and classifying the detected defect using output values of the first and second functions.