Patent ID: 11934098
Assignee: CANON KABUSHIKI KAISHA
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 10:
11. A lithography apparatus for forming a pattern on a substrate, the lithography apparatus comprising:
a detection apparatus configured to, using a mark provided on a substrate as a detection target, detect a position of the mark; and
a mechanism configured to position the substrate based on a detection result of the detection apparatus,
wherein the detection apparatus comprises:
an illuminator configured to illuminate the detection target with illumination light including a plurality of wavelengths;
a wavelength selector including an incident surface on which diffracted light from the detection target illuminated by the illuminator is incident, and configured to select light of a specific wavelength from the diffracted light; and
a detector configured to receive the light of the specific wavelength selected by the wavelength selector and detect the position of the detection target,
wherein the wavelength selector includes a plurality of elements, each configured to switch light guide/nonguide of the diffracted light to the detector, two-dimensionally arrayed on the incident surface of the wavelength selector,
wherein diffraction directions of light components of the plurality of wavelengths included in the illumination light on the detection target are different from each other, and positions on the incident surface of the wavelength selector where the light components are incident as the diffracted light are different from each other, and
wherein the wavelength selector:
decides the specific wavelength based on information about a wavelength characteristic representing a relationship between each of the plurality of wavelengths and a detection error in the detector, so that the detection error is reduced; and
selects the light of the decided specific wavelength from the diffracted light and guides the light to the detector, by controlling each of the plurality of elements in accordance with the position on the incident surface where the light of the decided specific wavelength is incident.