Patent ID: 6654489
Filing Date: 2003-11-25
Classification: G06T

Abstract:
A method of inspecting a sample, the method comprising:providing a test image of the sample, the test image having a plurality of test features each having one or more measurable test characteristic values; providing a baseline image containing an expected pattern of the test image, the baseline image having a plurality of baseline features each having one or more measurable baseline characteristic values, wherein each measurable baseline characteristic value is expected to match a corresponding one of the measurable test characteristic value; comparing at least a first subset and a second subset of the test characteristic values to their corresponding measurable baseline characteristic values such that a plurality of difference values are calculated for each pair of measurable test and baseline characteristic values; and during the comparison, collecting statistical information that is determined from at least a second subset of the measurable test characteristic values or the difference values resulting from the comparison, wherein the statistical information includes a median or average value of the second subset of the measurable test characteristic values.