| 摘要 |
PURPOSE:To keep the gap between the mask and wafer at the specified value by effectively correcting the fluctuation in depth of the mask and wafer. CONSTITUTION:Plural microdisplacement detecting sensors 5 are fixedly provided on a mask holder 1 oppositting to wafer 3. The sensors 5 detect the gap between the upper surface of the wafer fixed on a wafer holder 4 and the outer edges of the sensors 5. With use of this detected result, the level of the mask holder 1 or wafer holder 4 is controlled to keep the gap between the mask and the wafer at the specified value and make them parallel in plane. |
