Position detection apparatus, alignment apparatus and methods therefor, and exposure apparatus and device manufacturing method

摘要

A position detection apparatus for detecting a position of a pattern includes a first sensing system which senses a first image of the pattern at a first magnification, a second sensing system which senses a second image of the pattern at a second magnification higher than the first magnification, and a determination system which determines whether a relative position between the second sensing system and the pattern is valid for detecting a position of the pattern based on the first image sensed by the first sensing system.