| 摘要 |
PURPOSE:To enable to improve an alignment precision by a method wherein a partial variation of a resist layer to result from exposure is detected as a signal from the side of the mask. CONSTITUTION:A wafer stage 2 is put on a base board 1, and a wafer holding plate 3 and a wafer 4 are set up in such a manner as to be able to move at the perpendicular plane to the optical axis of a projection lens 5. The stage 2 is controlled in its moving amount by an optical mirror 6 and a laser interferometer 7. A reticle holding stand and a reticle 9 are disposed in the upper direction of the lens 5. An illumination optical system A is constituted of 1st-3rd condenser lenses 11, 12 and 13 to enable the light from a mercury-arc lamp 10 to transmit and 1st and 2nd mirrors 14 and 15 and a control to exposure is performed by a shutter 16. An alignment optical system C is disposed in such a form that a part thereof is thrusting in between the lens 5 and the wafer 4. The light from a tungsten halogen lamp 22 is condensed by a condenser mirror 23 and a condenser lens 24 and reaches a movable mirror 27 via a half- prism 25 and an objective 26. The light from the movable mirror 27 passes through a relay lens 28 and the image of the wafer is imaged on the face 30 of an image pickup tube 29. |
