Substrate, method for measuring and forming a combined target on said substrate, lithographic apparatus, metrology apparatus, lithographic cell, and computer program system
Disclosed is a substrate comprising a combined target for measurement of overlay and focus. The target comprises: a first layer comprising a first periodic structure; and a second layer comprising a second periodic structure overlaying the first periodic structure. The target has structural asymmetr...
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Main Authors | , |
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Format | Patent |
Language | Chinese English |
Published |
11.04.2018
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Subjects | |
Online Access | Get full text |
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Summary: | Disclosed is a substrate comprising a combined target for measurement of overlay and focus. The target comprises: a first layer comprising a first periodic structure; and a second layer comprising a second periodic structure overlaying the first periodic structure. The target has structural asymmetry which comprises a structural asymmetry component resultant from unintentional mismatch between the first periodic structure and the second periodic structure, a structural asymmetry component resultant from an intentional positional offset between the first periodic structure and the second periodic structure and a focus dependent structural asymmetry component which is dependent upon a focus setting during exposure of said combined target on said substrate. Also disclosed is a method for forming such a target, and associated lithographic and metrology apparatuses. |
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Bibliography: | Application Number: TW20165138642 |