Abstract: A method and system are presented for evaluating a variation of a parameter of a pattern. The method includes processing data indicative of an aerial intensity image of at least a portion of a patterned article, and determining values of a certain functional of the aerial image intensity for predetermined regions within the at least portion of the patterned article. The values of the aerial image intensity functional are indicative of a variation of at least one parameter of the pattern within the at least portion of the patterned article or are indicative of a variation of at least one parameter of a pattern manufactured by utilizing the patterned article.

Abstract: A method for evaluating placement errors within a lithographic mask, the method includes: providing or receiving a reference result that represents a distance between a reference pair of points of a reference element; measuring, for each pair of points out of multiple pairs of points that are associated with multiple spaced apart elements of the lithographic mask, the distance between the pair of points to provide multiple measurement results; wherein differences between a measurement result and the reference result are indicative of relative placement errors; and determining relative placement errors in response to relationships between the reference result and each of the measurement results.

Abstract: A method for evaluating placement errors within a lithographic mask, the method includes: providing or receiving a reference result that represents a distance between a reference pair of points of a reference element; measuring, for each pair of points out of multiple pairs of points that are associated with multiple spaced apart elements of the lithographic mask, the distance between the pair of points to provide multiple measurement results; wherein differences between a measurement result and the reference result are indicative of relative placement errors; and determining relative placement errors in response to relationships between the reference result and each of the measurement results.

Abstract: A method and system are presented for evaluating a variation of a parameter of a pattern, the method includes: processing data indicative of an aerial intensity image of at least a portion of a patterned article, and determining values of a certain functional of the aerial image intensity for predetermined regions within said at least portion of the patterned article, said values of the aerial image intensity functional being indicative of a variation of at least one parameter of the pattern within said at least portion of the patterned article or of a variation of at least one parameter of a pattern manufactured by utilizing the patterned article.