摘要 |
A stage assembly (10) for moving and positioning one or more objects (24) for an exposure apparatus (28) is provided herein. The stage assembly (10) includes a fine stage (14) and a coarse stage (18). The fine stage (14) includes a holder (15) that retains the object (24). The stage assembly (10) also includes a fine Y mover (32) and a fine X mover (34) that precisely move the fine stage (14) relative to the coarse stage (18). Uniquely, the fine movers (32), (34) are positioned on only one side of the holder (15). With this design, the resulting stage assembly (10) has a relatively low mass and a relatively high servo bandwidth. Further, with this design, the stage assembly (10) is readily accessible for service and a measurement system (16) can be easily positioned near the fine stage (14). The stage assembly (10) can also include an anti-gravity mechanism (40) that minimizes distortion of a stage base (12) that supports the fine stage (14) as the fine stage (14) moves above the stage base (12). Additionally, the stage assembly (10) can include a reaction assembly (20) that reduces the amount of reaction forces transferred from the coarse stage (18).
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