| 摘要 |
PROBLEM TO BE SOLVED: To improve length measurement accuracy of a laser length-measuring system which is used by an electron beam lithography system, at measuring of the position of an X-Y stage by preventing the vibration of a writing chamber from being transmitted to an offset mirror which constitutes a laser optical system. SOLUTION: The offset mirror 11 and a reference mirror 13 are attached to the ceiling section 1a of the wiring chamber. The offset mirror 11 is provided with an offset mirror base 21, which is extended in parallel with the X-axis and is provided with a pair of reflecting surfaces 22 and 23 at both ends. The mirror 11 introduces the laser light emitted from a laser light source to the reference mirror 13, and at the same time, the laser light reflected by the reference mirror 13 to a laser interferometer in reverse, via the same route. The central part of the offset mirror base 21 is fixed to the ceiling section 1a via a flange 27, and at the same time, both end sections of the base 21 are held by the ceiling section 1a via an elastic materials 24. |
