| 摘要 |
PURPOSE:To enable highly accurate alignment of a wafer so as to prevent futile baking of the wafer by finding the offset quantity between the image position of a reticle mark and wafer mark detecting position by utilizing a position calibrating mark on the surface of a water chuck and positioning the wafer based on the offset quantity. CONSTITUTION:The position of a reticle mark 4b on the surface of a reticle 4 is detected by means of a reticle mark detecting section 6 and the reticle 4 is positioned to a position fixed against a projecting optical system 5. Then, a position calibrating mark 3 on a wafer chuck 1 is detected by means of a wafer mark detecting section 7 and a wafer 2 is positioned. When the chuck 1 is moved so that the mark 3 is projected and image of the mark 3 is formed in the vicinity of a position A at which another reticle mark 4a is projected and image of the mark 4a is formed on the surface of the wafer 2 and the marks 4a and 3 are made coincident with each other by means of a position calibrating end detecting section 9, highly accurate alignment is performed and the then moving quantity A becomes the offset quantity between the position A and the detecting section 7. Based on the offset quantity, the wafer is exposed to exposure light through the reticle pattern and futile baking of the wafer can be prevented. |
