| 摘要 |
PURPOSE:To obtain a signal having a good S/N by a method wherein a reference mark is constituted of a shadow mark, which interrupts part of the image of a mark put on a second object, the ralative position between this reference mark and the mark put on such the second object as a wafer is detected to align. CONSTITUTION:The image of a mask put on a wafer is transmitted a window W of a reference mark BM and is incided in an objective L1. A reference mark part of the mark BM is a transparent part, such as an aperture opened in the mark BM, a reference mark illuminating light is transmitted the reference mark part to be turned into a reference mark image and the image is incided in the objective 11. The position of a reticle is monitored by detecting systems OB1 and OB2 at the same time during the alignment operation of the wafer and an arithmetic control system ART applies a feedback to a driving system MOL in such a way that the reticle always keeps a prescribed position. That is, the position of the reticle is monitored and in case the reticle is shifted from the prescribed position, the reticle is driven. Thereby, the position of the reticle is always guaranteed. Moreover, instead of driving the reticle, the amount of position shifting of the reticle can be reflected on the side of the wafer. |
