OPTICAL SYSTEM

To provide metrology tools and method improving measurement accuracy by estimating the effect of topographic phases corresponding to different diffraction orders resulting from light scattering on periodic targets, and adjusting the measurement conditions.SOLUTION: In imaging, overlay error magnific...

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Bibliographic Details
Main Authors VLADIMIR LEVINSKI, YONI SHALIBO, AMNON MANASSEN, YURI PASKOVER
Format Patent
LanguageEnglish
Japanese
Published 02.09.2021
Subjects
APPARATUS SPECIALLY ADAPTED THEREFOR
CINEMATOGRAPHY
ELECTROGRAPHY
HOLOGRAPHY
MATERIALS THEREFOR
MEASURING
MEASURING ANGLES
MEASURING AREAS
MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS
ORIGINALS THEREFOR
PHOTOGRAPHY
PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES,e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTORDEVICES
PHYSICS
TESTING
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Summary:To provide metrology tools and method improving measurement accuracy by estimating the effect of topographic phases corresponding to different diffraction orders resulting from light scattering on periodic targets, and adjusting the measurement conditions.SOLUTION: In imaging, overlay error magnification may be reduced by selecting appropriate measurement conditions based on analysis of a contrast function behavior, changing illumination conditions (reducing spectrum width and illumination NA), using polarizing targets and/or optical systems, using multiple defocusing positions, etc. On-the-fly calibration of measurement results may be carried out in imaging or scatterometry using additional measurements or additional target cells.SELECTED DRAWING: Figure 6 【課題】周期性ターゲット上での光散乱による諸次回折に対応するトポグラフィック位相の影響を推定し、計測条件を調整することで計測の正確性を高める計量ツール及び方法を提供する。【解決手段】イメージングでは、コントラスト関数挙動の分析を踏まえ適正な計測条件を選択すること、照明条件を変更すること（スペクトル幅の縮小及び照明ＮＡの低減）、偏向性のターゲット及び／又は光学システムを用いること、複数通りの焦点ずれ位置を利用すること等々により、オーバレイ誤差拡大を軽減することができる。イメージングでもスキャタロメトリでも、更なる計測又は更なるターゲットセルを利用し計測結果のオンザフライ校正を実行することができる。【選択図】図６
Bibliography:Application Number: JP20210077243