IMAGING OVERLAY TARGETS USING MOIRÉ ELEMENTS AND ROTATIONAL SYMMETRY ARRANGEMENTS

A metrology target may include a first rotationally symmetric working zone with one or more instances of a first pattern and a second rotationally-symmetric working zone with one or more instances of a second pattern, where at least one of the first pattern or the second pattern is a Moiré pattern f...

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Bibliographic Details
Main Authors Gurevich, Evgeni, Shaphirov, Diana, Levinski, Vladimir, Feler, Yoel, Ghinovker, Mark
Format Patent
LanguageEnglish
Published 27.06.2024
Subjects
APPARATUS SPECIALLY ADAPTED THEREFOR
CALCULATING
CINEMATOGRAPHY
COMPUTING
COUNTING
ELECTROGRAPHY
HOLOGRAPHY
IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
MATERIALS THEREFOR
ORIGINALS THEREFOR
PHOTOGRAPHY
PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES,e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTORDEVICES
PHYSICS
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Summary:A metrology target may include a first rotationally symmetric working zone with one or more instances of a first pattern and a second rotationally-symmetric working zone with one or more instances of a second pattern, where at least one of the first pattern or the second pattern is a Moiré pattern formed from a first grating structure with a first pitch along a measurement direction on a first sample layer and a second grating structure with a second pitch different than the first pitch along the measurement direction on a second sample layer. Centers of rotational symmetry of the first and second working zones may overlap by design when an overlay error between the first sample layer and the second layer is zero. A difference between the centers of rotational symmetry of the first and second working zones may indicate an overlay error between the first and second sample layers.
Bibliography:Application Number: US202217675912