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EP-4738013-A1 - DETECTION APPARATUS, LITHOGRAPHY APPARATUS, AND ARTICLE MANUFACTURING METHOD

EP4738013A1EP 4738013 A1EP4738013 A1EP 4738013A1EP-4738013-A1

Abstract

A detection apparatus for detecting a surface position of a detection surface includes a mask with slits, a projection optical system configured to form an image on the detection surface by irradiating the detection surface with light having passed through the slits, an image sensor, and a light-receiving optical system configured to form, on the image sensor, an image of light reflected from the detection surface, wherein β 1 = tanθ 2 /tanθ 1 , 70° < θ 1 < 85°, θ 2 < 70°, and 0.03 < β 1 < 0.40 are satisfied, where θ 1 represents an incident angle of the light to the detection surface, θ 2 represents an incident angle of the light to the image sensor, and β 1 represents an optical magnification of the light-receiving optical system.

Inventors

  • SAITO, YUKI
  • MIURA, SEIYA

Assignees

  • Canon Kabushiki Kaisha

Dates

Publication Date
20260506
Application Date
20250925

Claims (9)

  1. A detection apparatus (100) for detecting a surface position of a detection surface (300), characterized by comprising: a mask (112) with a plurality of slits formed; a projection optical system (113) configured to form an image on the detection surface by irradiating, from an oblique direction, the detection surface with light having passed through the plurality of slits; an image sensor (121); and a light-receiving optical system (122) configured to form, on the image sensor, an image of light reflected from the detection surface, wherein β 1 = tan θ 2 / tan θ 1 , 70 ° < θ 1 < 85 ° , θ 2 < 70 ° , and 0.03 < β 1 < 0.40 are satisfied, where θ 1 represents an incident angle, to the detection surface, of the light irradiated by the projection optical system, θ 2 represents an incident angle, to the image sensor, of the light irradiated by the light-receiving optical system, and β 1 represents an optical magnification of the light-receiving optical system.
  2. The apparatus according to claim 1, characterized in that β 2 = tan θ 1 / tan θ 3 is satisfied, where θ 3 represents an angle formed by an optical axis of the projection optical system and a normal to a surface of the mask and β 2 represents an optical magnification of the projection optical system.
  3. The apparatus according to claim 1, characterized in that in a state in which β 1 = tanθ 2 /tanθ 1 is satisfied, the mask and the detection surface have a relationship satisfying a Scheimpflug condition with respect to the projection optical system.
  4. The apparatus according to claim 2, characterized in that in a state in which β 2 = tanθ 1 /tanθ 3 is satisfied, the detection surface and the image sensor have a relationship satisfying a Scheimpflug condition with respect to the light-receiving optical system.
  5. The apparatus according to any one of claims 1 to 4, characterized in that pixel sensitivity of the image sensor to a surface position variation of the detection surface is not less than 0.1 µm/pixel.
  6. The apparatus according to any one of claims 1 to 5, characterized in that pixel sensitivity of the image sensor to a surface position variation of the detection surface is not more than 100 µm/pixel.
  7. The apparatus according to any one of claims 1 to 6, characterized in that the plurality of slits of the mask are formed so as to form a plurality of pattern images on the detection surface.
  8. A lithography apparatus for forming a pattern on a substrate using an original, characterized by comprising: a stage configured to hold the substrate; a detection apparatus defined in any one of claims 1 to 7 and configured to detect a surface position of the substrate held by the stage; and a controller configured to control a position of the stage based on a detection result of the detection apparatus.
  9. An article manufacturing method characterized by comprising: forming a pattern on a substrate using a lithography apparatus defined in claim 8; processing the substrate on which the pattern has been formed in the forming; and manufacturing an article from the substrate processed in the processing.

Description

TECHNICAL FIELD The present disclosure relates to a detection apparatus, a lithography apparatus, and an article manufacturing method. BACKGROUND Japanese Patent No. 3204406 discloses a surface position detection apparatus in which an object and a light-receiving optical system satisfy a Scheimpflug relationship and a diffraction grating for tilt correction is arranged on the image plane of the light-receiving optical system. Japanese Patent Laid-Open No. 10-004054 discloses a surface position detection apparatus in which an object and a light-receiving optical system satisfy a Scheimpflug relationship and a diffuser is arranged on the image plane of the light-receiving optical system. Japanese Patent No. 3271720 discloses a surface position detection apparatus in which an object and a light-receiving optical system satisfy a Scheimpflug relationship and a prism for tilt correction is arranged on the image plane of the light-receiving optical system. SUMMARY However, in the conventional surface position detection apparatuses, it is necessary to use, in the middle of the light-receiving optical system, a deflection optical element for changing an incident angle to an image sensor. In this case, it is necessary to provide an optical system that forms an image on the deflection optical element from a detection surface and an optical system that forms an image on the deflection optical element and the image sensor. Therefore, the cost for the optical systems increases, and the apparatus size also increases. In addition, the cost for the deflection optical element increases. A diffraction grating that increases diffracted light intensity to a specific angle is particularly expensive. The present disclosure provides a technique advantageous in balancing surface position detection accuracy and cost. The present disclosure in its first aspect provides a detection apparatus as specified in claims 1. Optional features are specified in claims 2 to 7. The present disclosure in its second aspect provides a lithography apparatus as specified in claim 8. The present disclosure in its third aspect provides an article manufacturing method as specified in claim 9. Features of the present disclosure will become apparent from the following description of embodiments with reference to the attached drawings. The following description of embodiments is described by way of example. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present disclosure, and together with the description, serve to explain the principles of the embodiments. Fig. 1 is a view showing the configuration of a surface position detection apparatus;Fig. 2 is a graph showing the relationship between an incident angle and a surface reflectance;Fig. 3 is a view showing the relationship of a Scheimpflug optical system;Fig. 4 is a view showing the relationship of the Scheimpflug optical system in a projection optical system;Fig. 5 is a view showing the relationship of the Scheimpflug optical system in a light-receiving optical system;Fig. 6 is a graph exemplifying light receiving sensitivity to the incident angle to an image sensor;Fig. 7 is a view showing an image of a projection pattern on a detection surface;Fig. 8 is a graph showing the relationship among the optical magnification of an imaging optical system, the incident angle to the image sensor, and pixel sensitivity to a surface position variation;Fig. 9 is a view showing an example of an image of a projection pattern on the image sensor;Fig. 10 is a view showing the configuration of a surface position detection apparatus; andFig. 11 is a view showing the configuration of an exposure apparatus. DESCRIPTION OF THE EMBODIMENTS Hereinafter, embodiments will be described in detail with reference to the attached drawings. Note, the following embodiments are not intended to limit the scope of the claims. Multiple features are described in the embodiments, but it is not the case that all such features are required, and multiple such features may be combined as appropriate. Furthermore, in the attached drawings, the same reference numerals are given to the same or similar configurations, and redundant description thereof is omitted. The present disclosure relates to a detection apparatus that detects the surface position of a detection surface. The detection apparatus according to the present disclosure can be applied to control (for example, focus control) of the surface position of a substrate in a lithography apparatus such as an exposure apparatus or an imprint apparatus, and can also be applied to other apparatuses such as a processing apparatus, an inspection apparatus, and a microscope. <First Embodiment> The configuration of a surface position detection apparatus 100 (detection apparatus) according to this embodiment will be described with reference to Fig. 1. The surface position detection appara