US 12,405,538 B2
Calibration method, detection system, exposure apparatus, article manufacturing method, and non-transitory computer-readable storage medium
Hironobu Fujishima, Saitama (JP); and Wataru Yamaguchi, Tochigi (JP)
Assigned to CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Apr. 6, 2023, as Appl. No. 18/296,418.
Claims priority of application No. 2022-070268 (JP), filed on Apr. 21, 2022.
Prior Publication US 2023/0341786 A1, Oct. 26, 2023
Int. Cl. G03F 7/00 (2006.01); G03F 9/00 (2006.01)
CPC G03F 7/706845 (2023.05) [G03F 7/706849 (2023.05); G03F 7/706851 (2023.05); G03F 7/70725 (2013.01); G03F 9/7019 (2013.01); G03F 9/7088 (2013.01)] 12 Claims
OG exemplary drawing
 
10. A detection system for detecting a position of a detection target, comprising:
an illumination system configured to illuminate the detection target;
an imaging system configured to form an image of light from the detection target on a photoelectric conversion element; and
a processing unit configured to perform a process of calibrating the detection system, wherein
the illumination system includes a plurality of first apertures selectively arranged in a pupil plane of the illumination system and having different openings,
the imaging system includes a plurality of second apertures selectively arranged in a pupil plane of the imaging system and having different openings, and
the processing unit obtains, for each of at least two combinations of first apertures and second apertures, each of which is formed by selecting one first aperture and one second aperture from the plurality of first apertures and the plurality of second apertures, a first defocus characteristic indicating a shift amount of the image on the photoelectric conversion element with respect to a defocus amount of the detection target in a state in which each of the first aperture and the second aperture is positioned in a first position shifted from a reference position, and
performs position adjustment on each of the first aperture and the second aperture such that each of the first aperture and the second aperture is positioned in the reference position, based on a reference defocus characteristic indicating a shift amount of the image on the photoelectric conversion element with respect to a defocus amount of the detection target in a state in which each of the first aperture and the second aperture is positioned in the reference position, and on the first defocus characteristic,
wherein in the position adjustment performed by the processing unit, a driving amount of each of the first aperture and the second aperture required for the position adjustment is obtained from a difference between the first defocus characteristic and the reference defocus characteristic, and from a fluctuation amount of the reference defocus characteristic when the first aperture and the second aperture are fluctuated by a unit amount in the pupil plane of the illumination system and the pupil plane of the imaging system.