US 9,811,003 B2
Metrology method and apparatus, substrate, lithographic system and device manufacturing method
Martin Jacobus Johan Jak, Eindhoven (NL); Armand Eugene Albert Koolen, Nuth (NL); and Hendrik Jan Hidde Smilde, Veldhoven (NL)
Assigned to ASML Netherlands B.V., Veldhoven (NL)
Filed by ASML Netherlands B.V., Veldhoven (NL)
Filed on Nov. 18, 2016, as Appl. No. 15/355,334.
Application 15/355,334 is a division of application No. 14/403,010, granted, now 9,535,338, previously published as PCT/EP2013/059061, filed on May 1, 2013.
Claims priority of provisional application 61/652,552, filed on May 29, 2012.
Prior Publication US 2017/0068173 A1, Mar. 9, 2017
Int. Cl. G03B 27/54 (2006.01); G03F 7/20 (2006.01)
CPC G03F 7/70625 (2013.01) [G03F 7/70483 (2013.01); G03F 7/70633 (2013.01); G03F 7/70683 (2013.01)] 19 Claims
OG exemplary drawing
 
1. An inspection apparatus for measuring a property of a lithographic process using a composite target structure including a plurality of component structures that have been formed by the lithographic process on a substrate, the apparatus comprising:
a support for the substrate having the composite target structure formed thereon;
an optical system configured to illuminate the composite target structure under predetermined illumination conditions and for forming and detecting an image of the composite target structure using a predetermined portion of radiation diffracted by the plurality of component structures under the illumination conditions;
a processor configured to:
identify one or more regions in the detected image, each region corresponding to a respective one of the plurality of component structures,
process pixel values within the one or more regions to obtain a measurement of the property of the lithographic process, and
identify the one or more regions such that their boundaries fall within image regions corresponding to separation zones between the plurality of component structures within the composite target structure.