Correction of overlay offset between inspection layers

摘要

A method for determining between at least three origins of a coordinate system used for at least three different defect inspection spaces. The method comprises: collecting multiple sets of data spanning defect inspection spaces; filtering the data sets to remove points that introduce noise into correlation calculations; determining whether different data sets show correlation; selecting pairs of data sets showing correlation greater than or equal to a metric; and calculating coordinate offsets of at least three origins based on the selected pairs of data sets.