Patent ID: 8149423
Filing Date: 2012-04-03
Classification: G03B,G03F

Abstract:
1. A position detection apparatus that detects a position of an object to be detected based on a position of an image of a mark, the apparatus comprising: an imaging system configured to form an image of the mark formed on the object; an illumination system configured to illuminate the mark with illumination light emitted by a light source via a part of said imaging system, said illumination system including a rotary table having a first aperture stop for said illumination system and a second aperture stop for said illumination system, both of which can be positioned on a pupil plane of said illumination system in an optical path of the illumination light between an aperture stop for said imaging system and the light source by rotating said rotary table; a first image sensor configured to detect the image of the mark formed by said imaging system; a second image sensor configured to sense an image of the aperture stop for said imaging system and an image of said first aperture stop; and a controller, wherein said controller causes said second image sensor to sense an image of the aperture stop for said imaging system using the illumination light having passed through said second aperture stop positioned on the pupil plane, positions said first aperture stop on the pupil plane by rotating said rotary table and causes said second image sensor to sense an image of said first aperture stop using the illumination light having passed through said first aperture stop, and performs, a process of correcting said first aperture stop so as to reduce an adverse influence of a displacement of said first aperture stop with respect to the aperture stop for said imaging system, based on the sensed image of the aperture stop for said imaging system and the sensed image of said first aperture stop, and the position detection apparatus detects the position of the object using the illumination light having passed through said first aperture stop having undergone the correcting process.