| 摘要 |
PURPOSE:To make design and manufacture of a reflection prevention coating for a projection optical system easy, relating to detection of an alignment mark formed on a sensitive substrate through the projection optical system by using alignment light of wave length different from exposure light. CONSTITUTION:In exposure light, a pattern of a reticule 2 is, through a projection optical system 3, projected on a wafer 4. Laser beam emitted, as alignment light, from a laser light source 10 is poured on a reticule mark of the reticule 2, and then the alignment light that has transmitted through the reticule 2 is, through the projection optical system 3, poured on a wafer mark on the wafer 2. Wave length of the laser beam, working as alignment light, is set about three times the exposure light. |
