| 摘要 |
PURPOSE:To realize a high-speed and high-resolution detection by a position detection apparatus for an alignment mark and to control an X-ray aligner with high accuracy by a method wherein images of alignment marks on two objects are detected simultaneously by an image sensing device composed of a linear sensor by using a detection optical system. CONSTITUTION:Alignment marks on a wafer 1 and a mask 2 as two objects arranged to be away from each other by keeping a very small distance are reflected obliqueIy upward to the right by a plane 3a of a reflective prism 3 arranged at the upper part near the mask 2; their images are formed individually on an identical image-forming point P after they have passed through a reflecting mirror 5, a relay lens 6 and a cylindrical lens 7 by using a chromatic aberration objective 4. This cylindrical lens 7 may be arranged behind the image-forming point P as shown by a chain line, if circumstances require. An image formed at this image-forming point P passes through a relay lens 8 and a pattern barrier filter 9 and forms on an image-forming plane of a linear sensor 10. By this setup, the resolution of an A/D converter can be enhanced; accordingly, the detection accuracy can be increased furthermore when the linear sensor of many picture elements is used. |
