Scanning scatterometry overlay metrology

US12422363B2 · kind B2 · utility

Assignee

• KLA Corporation · US

Inventors

• Amnon Manassen · Haifa, IL
• Andrew V. Hill · Chino Hills, US
• Yuri Paskover · Or Akiva, IL
• Itay Gdor · Elyachin, IL
• Yonatan Vaknin · Yoqneam Illit, IL
• Yuval Lubashevsky · Haifa, IL

Key dates

• Filing date: Mar 30, 2022
• Grant date: Sep 23, 2025
• Expiry date: Feb 10, 2044

Classification

• Technology area (CPC G): Physics
• CPC primary: G01B2210/56
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An overlay metrology system may include an illumination an illumination source to generate an illumination beam, one or more illumination optics to direct the illumination beam to an overlay target on a sample as the sample is scanned relative to the illumination beam along a scan direction, the target including one or more cells having Moiré structures. The system may also include two photodetectors at locations of a pupil plane associated with Moiré or overlapping diffraction orders from the Moiré structures. The system may then generate overlay measurements based on time-varying interference signals captured by the detector as the sample is scanned.