| 摘要 |
PURPOSE:To improve the image quality of a TV monitor by providing a means for adjusting quantity of light in an optical path of an illuminating system. CONSTITUTION:The alignment light in a linearly polarized state emitted from an illuminating source 1 such as laser passes through a polarizing plate 3 and is then irradiated via a beam splitter 4 and a mirror 5 freely insertable and removable into and from the optical path for illuminating on the specified region of a mask 7 on a mask holding base 6. A mark (not shown) for positioning with a wafer 10 is provided in the specified region of the mask 7 and the alignment light 2 passed the mask 7 is irradiated on the positioning mark provided in the scribing area of the wafer 10 via a projecting lens 8. The light reflected therefrom passes through a scale-down projecting lens 8 and the same path as the path of the incident light and is detected via a beam splitter 11 by a TV camera 12' which is a means 12 for observing the mask 7 and the wafer 10 and a detector 13 which detects the positioning deviation between the mask 7 and the wafer 10. |
