US 10,707,175 B2Granted

Asymmetric overlay mark for overlay measurement

AssigneeGlobalfoundries Inc.

InventorsWei Zhao, Minghao Tang, Rui Chen, Dongyue Yang, Haiting Wang, Erik Geiss, Scott Beasor

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Abstract

One illustrative example of an overlay mark disclosed herein includes four quadrants (I-IV). Each quadrant of the mark contains an inner periodic structure and an outer periodic structure. Each of the outer periodic structures includes a plurality of outer features. Each of the inner periodic structures includes a plurality of first inner groups, each of the first inner groups having a plurality of first inner features, each first inner group being oriented such that there is an end-to-end spacing relationship between each first inner group and a selected one of the outer features.

Claims19

Dependent claims

An overlay mark comprising four quadrants referenced with numerals I, II, III and IV respectively, said overlay mark comprising:

a first centerline that extends in a first direction, wherein quadrants I and II, considered collectively, and quadrants III and IV, considered collectively, are positioned on opposite sides of said first centerline;
a second center line that extends in a second direction that is orthogonal to said first direction, wherein quadrants I and IV, considered collectively, and quadrants II and III, considered collectively, are positioned on opposite sides of said second centerline;
and
four inner periodic structures and four outer periodic structures,
wherein each of said four quadrants includes one of the four inner periodic structures and one of the four outer periodic structures, and wherein each of said outer periodic structures comprises a plurality of outer features, wherein each of said inner periodic structures comprises a plurality of first inner groups, each of said first inner groups comprising a plurality of first inner features, each of said first inner groups being oriented such that there is an end-to-end spacing relationship between each of said first inner groups and one of said outer features.

2 more elements

An overlay mark comprising four quadrants that will be referenced with numerals I, II, III and IV respectively, said overlay mark comprising:

a first centerline that extends in a first direction, wherein quadrants I and II, considered collectively, and quadrants III and IV, considered collectively, are positioned on opposite sides of said first centerline;
a second centerline that extends in a second direction that is orthogonal to said first direction, wherein quadrants I and IV, considered collectively, and quadrants II and III, considered collectively, are positioned on opposite sides of said second centerline;
and
four inner periodic structures and four outer periodic structures, wherein each of said four quadrants includes one of the four inner periodic structures and one of the four outer periodic structures, and wherein each of said outer periodic structures comprises a plurality of outer features, wherein each of said inner periodic structures comprises a plurality of first inner groups, each of said first inner groups comprising a plurality of first inner features and wherein said inner periodic structures in quadrants II and IV are positioned asymmetrically relative to said first centerline of said overlay mark, and said inner periodic structures in quadrants I and III are positioned asymmetrically relative to said second centerline of said overlay mark.

1 more element

Dependencies are inferred from the claim text.