Patent ID: 6985618
Filing Date: 2006-01-10
Classification: G03F,G06K,G06T,Y10S

Abstract:
1. 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, the method comprising: providing a base overlay mark architecture including a plurality of working zones selected from at least first and second working zones that are separately generated patterns on a single or successive layers of a substrate, each of the working zones including a periodic structure positioned therein, each of the periodic structures including a plurality of coarsely segmented elements that are formed from a plurality of finely segmented elements; optimizing the geometry of the working zones of the overlay mark according to a first scale, the first scale corresponding to a metrology kernel scale based on metrology tool limitations, process issues and circuit design criteria; optimizing the geometry of the coarsely segmented elements of the overlay mark according to a second scale, the second scale corresponding to an image resolution scale based on metrology tool limitations and process robustness issues; and optimizing the geometry of the finely segmented elements of the overlay mark according to a third scale, the third scale corresponding to a lithography resolution scale based on circuit design rules, process robustness issues and metrology tool limitations.