DETECTOR, LITHOGRAPHIC APPARATUS AND ARTICLE MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a detector which is advantageous in improving measuring accuracy.SOLUTION: A detector is used to detect a mark 2 having a periodic structure and comprises: an illumination optical system for emitting light to the mark 2; a light receiving optical system 11 for receiving diffraction light from the mark 2 when a relative position between the illumination optical system and the mark 2 are being changed in a measurement direction; and a light receiving element 16 for detecting diffraction light from the light receiving optical system 11. Here, the number of openings in the measurement direction on the light receiving optical system 11 is greater than the number of openings on the light receiving optical system in a non-measurement direction on a plane provided with the mark 2.