Detection apparatus, lithography apparatus, and article manufacturing method

An article manufacturing method comprising:

• transferring a pattern of an original onto a substrate using a lithography apparatus;
• and
• obtaining an article from the substrate onto which the pattern has been transferred,
• wherein the lithography apparatus is configured to transfer a pattern of an original onto a substrate, and comprises a detection apparatus provided for alignment between the original and the substrate, and a control unit configured to control the alignment between the original and the substrate based on an output of the detection apparatus, and
• wherein the detection apparatus comprises:
• an image sensing device having an image sensing plane including a first periodic structure;
• and
• an optical system configured to illuminate a detection target on the substrate, including a second periodic structure different from the first periodic structure, and form an image of light from the detection target on the image sensing plane,
• wherein light having entered the image sensing plane generates a plurality of diffracted light beams of different orders in accordance with the first periodic structure, and
• wherein a normal of the image sensing plane is tilted with respect to an optical axis of the optical system such that the optical axis is located between diffracted light beams of adjacent orders not less than a first order among the plurality of diffracted light beams,
• wherein the optical system includes an illumination optical system configured to illuminate the detection target, and an imaging optical system configured to form the image of light from the detection target on the image sensing plane, and
• wherein the normal of the image sensing plane is tilted with respect to an optical axis of the imaging optical system such that the optical axis of the imaging optical system is located between diffracted light beams of adjacent orders not less than the first order among the plurality of diffracted light beams.