| 摘要 |
PROBLEM TO BE SOLVED: To enable highly precise alignment capable of position detection in the course of exposure, by arranging a second observation optical system which has a different magnification and forms the image of a light reflected by a partial reflection mirror, on the optical axis of a first observation optical system which forms images of lights scattered from a wafer and a mask. SOLUTION: When a wafer mark and a mask mark formed on a wafer 11 and a mask 12 have edges, illumination light is scattered by the edges. Out of the scattered light, a light entering a lens 22 is converged in a lens 22, and a part of the light passes half mirrors 23 and 26A, and forms an image on the imaging surface 29A of an image detecting equipment 21A. The imaging magnification on the imaging surface 29A is e.g. 20. Out of the scattered lights, a light reflected by the half mirror 26A is reflected by a mirror 26B, converged by a relay lens 28, and forms an image on the imaging surface 29B of an image detecting equipment 21B. The imaging magnification on the imaging surface 29B is, e.g. 80-100. Two observation optical systems different in magnification are arranged in the above manner. |
