| 摘要 |
PURPOSE:To reduce an error on measurement due to thermal expansion and contraction, and to measure the quantity of movement with high accuracy by connecting a target as a measuring means and a moving base by using fluid pressure or a resilient member. CONSTITUTION:Unlike conventional devices, the left end of a plate 28 is fixed to the holding base 25 of a reflecting mirror 24, and the right end is brought into contact with the upper surface of a base plate 23 for a mask 1. A vacuum chuck 28a is formed to a contact section, and the chuck 28a is changed over to a vacuum pump VAC or a breezer 33 by operating a solenoid valve 32. The chuck 28a is changed over to the breezer to release adsorption, the mask 1 is adjusted, and the chuck is changed over to the vacuum pump to adsorb the base 23. Accordingly, the reflecting mirror 24 of the target as the measuring means and the mask base plate 23 are connected mutually by the plate 28, and an optical axis does not get out of order due to measurement by a laser interferometer 26. Even when an X base 4, a theta base 19 and the mask base 25 are elongated in the B direction due to thermal expansion, the mirror 24 and the base 23 move integrally, and no error on measurement is generated. When the target and the moving base are connected by using fluid pressure, control is facilitated. |
