Patent ID: 6992780
Filing Date: 2006-01-31
Classification: G03F

Abstract:
1. A method of determining relative position between a reflective reticle and a substrate, said method comprising: a first detection step of detecting relative position between a transmissive reference mark on a reticle stage and a substrate alignment mark through a reflective optical system which projects a pattern of the reflective reticle onto the substrate with extreme ultraviolet light; a second detection step of detecting relative position between a reflective reference mark on the reticle stage and a reflective alignment mark on the reticle, said second detection step comprising steps of: (i) detecting light reflected from the reflective reference mark with a detector, (ii) detecting light reflected from the reflective alignment mark with the detector, and (iii) changing relative position between the reticle stage and the detector between said step (i) and said step (ii); and a determination step of determining relative position between the reticle and the substrate based on the detection results in said first and second detection steps.