Patent ID: 7034921

Claim:
A scanning exposure apparatus for exposing a substrate to light via a reticle, said apparatus comprising: a reticle stage configured to hold the reticle and to scan the reticle; a substrate stage configured to hold the substrate and to scan the substrate; a light source configured to emit pulse light; a light deflector configured to move in a motion cycle in accordance with a scan speed of said reticle stage and said substrate stage and to deflect the pulse light in the motion cycle; a projection optical system configured to project a pattern of the reticle onto the substrate with the deflected pulse light; a direction optical system configured to direct the deflected pulse light to a mark on one of said reticle stage and said substrate stage; a storage-type position sensor configured to receive the deflected pulse light directed by said direction optical system via the mark; and a controller configured to determine a pulse frequency of the pulse light emitted by said light source and a storage time of said storage-type position sensor in accordance with the motion cycle of said light deflector and a number of the pulse lights to be stored by said storage-type position sensor.