Detection apparatus, lithography apparatus, and article manufacturing method
By tilting the imaging surface of the detection device to align with diffracted light beams, the device mitigates noise interference, improving the accuracy of relative position measurements between alignment marks.
KR103000167B1Active Publication Date: 2026-08-05CANON KK
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Patent Information
- Application Number
- KR1020230062843
- Authority / Receiving Office
- KR · KR
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2022-05-18
- Filing Date
- 2023-05-16
- Publication Date
- 2026-08-05
- Estimated Expiration
- 2043-05-16
AI Technical Summary
Technical Problem
The periodic structure of imaging elements in detection devices generates diffracted light noise, which reduces detection accuracy.
Method used
The detection device incorporates an imaging element with a first periodic structure and an optical system that illuminates a detection target with a second periodic structure, where the normal of the imaging surface is tilted relative to the optical axis to position the optical axis between diffracted light beams of adjacent orders, preventing interference and improving accuracy.
Benefits of technology
This configuration suppresses the degradation of detection accuracy by minimizing the return of diffracted light beams to the detection optical system, enhancing the precision of relative position measurements between alignment marks.
✦ Generated by Eureka AI based on patent content.
Abstract
The detection device includes an imaging element having an imaging surface having a first periodic structure; and an optical system configured to illuminate a detection target having a second periodic structure different from the first periodic structure and to form an image of light from the detection target on the imaging surface. Light incident on the imaging surface generates a plurality of diffracted light beams of different orders according to the first periodic structure. The normal of the imaging surface is tilted with respect to the optical axis such that the optical axis of the optical system is located between diffracted light beams of at least one order of adjacent orders among the plurality of diffracted light beams.
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