Patents Examined by Rita Leypkin
  • Patent number: 6281655
    Abstract: 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).
    Type: Grant
    Filed: December 23, 1999
    Date of Patent: August 28, 2001
    Assignee: Nikon Corporation
    Inventors: Alex Ka Tim Poon, Douglas Watson