OVERLAY MARKS, METHODS OF OVERLAY MARK DESIGN AND METHODS OF OVERLAY MEASUREMENTS

A method of designing an overlay mark, which is used to determine the relative position between two or more successive layers of a substrate or between two or more separately generated patterns on a single layer of a substrate, is disclosed. The method includes optimizing the geometry of a first element of the mark according to a first scale. The method further includes optimizing the geometry of a second element of the mark according to a second scale. The method additionally includes optimizing the geometry of a third element of the mark according to a third scale.