Stage and supporting mechanism for supporting movable mirror on stage
AssigneeNikon Corporation
InventorsToshiya Ohtomo, Yutaka Hayashi
Life of this patent
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Abstract
A movable mirror supporting mechanism for supporting a movable mirror forming a part of an interferometric measurement system and having a rectangular cross-section onto an object, with a reflecting surface of said movable mirror being arranged normal to a measuring direction. The movable mirror supporting mechanism includes at least two fixtures for securing the movable mirror from above onto respective movable mirror supporting portions provided on the object. Positions on the movable mirror at which the movable mirror is secured onto the measuring object by the fixtures are defined to be out of that area of the reflecting surface of the movable mirror which is utilized for interferometric measurement.
Claims8
A stage including a movable stage body for carrying a material piece thereon and a movable mirror secured onto said movable stage body and used for interferometric measurement of position of said stage body, wherein:
- said movable mirror is made of a material consisting mainly of a first ceramic material;
- and
- said stage body is made of a material consisting mainly of a second ceramic material having a higher porosity than said first ceramic material.
Dependencies are inferred from the claim text.