| 摘要 |
PURPOSE: To contrive to make an image surface in a projection optical system coincide accurately with a wafer surface by a method wherein a focusing position on a detection region in the projection optical system is detected on the basis of the quantity of received light and the lighting region of a lighting means is moved according to a change of the detection region. CONSTITUTION: A pattern on a reticle 7, which is positioned on a detection region within the image plane region of a reduction lens 8 in a projection optical system, is illuminated by a lamp 1. Light from the illuminated pattern is made to incide in a reflective surface mirror 27 via the lens 8 and the reflected light is received by a reference plane mirror 17 via the pattern on the reticle 7 and the lens 8. A focusing position on the detection region in the lens 8 is detected by a detection optical system 12 of an automatic focusing control system 19 on the basis of the quantity of this received light. Moreover, a lighting region of a lighting means is moved by a lighting region variable mechanism 25 according to a change of the detection region to control an exposure on a wafer 9. Thereby, a high-integration circuit can be manufactured. |
