Patent ID: 8259310

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