Pennie & Edmonds LLP
Alignment method
 In an exposure apparatus, an alignment-detecting light component of a mask and that of a plate are spatially separated from each other, thereby enabling highly accurate alignment with little influence of the light from the plate on detection of the mask position. An alignment optical system comprises a light source means for supplying a luminous flux; a scan beam forming optical system for forming, based on the luminous flux, a scan beam at a visual field area on a first substrate with respect to a predetermined optical system; a scanning means for optically scanning, in a predetermined direction, the scan beam formed on the first substrate; a first detection means for detecting a diffracted and reflected light component from a first mark generated when optically scanned with the scan beam formed on the first substrate; and a second detection means for detecting, by way of the predetermined optical system and through a path different from the path through which the diffracted and reflected light component from the first mark is detected, a diffracted and reflected light component from a second mark generated when optically scanned with the scan beam which is formed on the second substrate by way of the predetermined optical system. 
Nikon Corporation
G G G
G03F G03F G03F
inventional inventional inventional
Kinya Kei Masaki
Kato Nara Kato