Method of detecting position of mark on substrate, position detection apparatus using this method, and exposure apparatus using this position detection apparatus

An exposure apparatus which exposes an object through a projection optical system, with an exposure beam irradiated on a mask, comprising:

• a mark detecting system of which an illumination system to illuminate a mark on the object and a detecting system to detect the illuminated mark are arranged at a same side as the projection optical system with respect to the object, the illumination system including a first optical system disposed on an optical path through which a first illumination beam having a first wavelength and a second illumination beam having a second wavelength different from the first wavelength pass to irradiate onto the mark the first and second illumination beams along a plane substantially perpendicular to a periodic direction of the mark, and the detecting system including a second optical system optically aligned with the first optical system, on which first diffracted beams of same order generated from the mark with the first illumination beam and second diffracted beams of same order generated from the mark with the second illumination beam are incident through a part of the first optical system and of which a reference grating is illuminated with the first diffracted beams and the second diffracted beams, and receiving beams from the reference grating;
• and
• a stage on which the object is provided, that moves in a predetermined plane substantially perpendicular to an optical axis of the mark detecting system.