Patents by Inventor William Schluchter

William Schluchter has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20070171426
    Abstract: An interferometer is provided that minimizes the introduction of non-linear errors into displacement measurements. In one embodiment, non-linear errors are reduced by isolating reference and measurement beams over most of their respective optical paths leading to the detector, and by employing a separate amplitude-splitting non-polarizing optical beam splitter for each beam input into the interferometer. Additionally, the interferometer is scalable to an arbitrary number of optical axes or inputs.
    Type: Application
    Filed: April 29, 2005
    Publication date: July 26, 2007
    Inventors: William Schluchter, Robert Belt
  • Publication number: 20070041022
    Abstract: An interferometer provides a large dynamic range for perpendicular displacement measurements. In operation, a measurement reflector on an object reflects a measurement beam to an overlying Porro prism, and a reference reflector on the object returns a reference beam to the interferometer. A second Porro prism in the interferometer can return the reference beam for a second pass to the reference reflector, while the measurement beam complete only one pass. Reductions in beam walk-off result from retroreflections in the Porro prisms and the matching effects that some object rotations have on measurement and reference beams. Perpendicular motion of the object relative to the first Porro prism causes a Doppler shift only in the measurement beam. Accordingly, a beat frequency found when combining the measurement and reference beams can indicate a residual Doppler shift associated with the motion in the perpendicular direction.
    Type: Application
    Filed: August 16, 2005
    Publication date: February 22, 2007
    Inventor: William Schluchter
  • Publication number: 20060274322
    Abstract: A method for non-linearity compensating interferometer position data generated from a measurement signal includes generating a first set of non-linearity parameters based on received digital position values. The method includes sensing whether a low velocity condition exists. A first one of the non-linearity parameters is updated based on an estimated magnitude of the measurement signal if the low velocity condition exists. At least one digital position value is compensated based on the updated non-linearity parameter if the low velocity condition exists.
    Type: Application
    Filed: June 1, 2005
    Publication date: December 7, 2006
    Inventors: David Chu, Lee Kalem, William Schluchter
  • Publication number: 20060245071
    Abstract: A lens assembly is provided that has an index-of-refraction invariant structure. In one embodiment, a void between two lenses or lens elements in a lens assembly is filled with a desired gas, liquid or vacuum, the gas, liquid or vacuum having a pre-determined index of refraction. Once the void has been filled with the desired gas or liquid or been drawn down to a complete vacuum, the void is sealed by any of numerous appropriate means to render it leaktight. The lens assembly may then be tested or calibrated to ensure an appropriate level of optical performance prior to subsequent deployment under actual field conditions. Because the vacuum or filled void disposed in the lens assembly provides optical performance that is index-of-refraction invariant, the lens assembly may be employed successfully under widely varying atmospheric conditions and yet still provide the same high quality results.
    Type: Application
    Filed: April 29, 2005
    Publication date: November 2, 2006
    Inventors: David George, William Schluchter, Robert Belt
  • Publication number: 20050185193
    Abstract: A system and method for acquiring position information of a movable apparatus relevant to a specific axis is disclosed. In one embodiment, an interferometer generates first and second beams and various beam-steering members are located to define beam path segments for the two beams, but no beam path segment varies in length in unity with displacements of the movable apparatus along the specific axis. In another or the same embodiment, each beam path segment in which the first beam either impinges or has been reflected from the movable apparatus is symmetrical to a corresponding beam path segment of the second beam. The movable apparatus may be a wafer stage in which the “specific axis” is the exposure axis of a projection lens, but with all optical members which cooperate with the stage being located beyond the ranges of the wafer stage in directions perpendicular to the lithographic exposure axis.
    Type: Application
    Filed: February 20, 2004
    Publication date: August 25, 2005
    Inventors: William Schluchter, Louis Mueller, Douglas Woolverton, Jeffrey Young, Alan Ray, David Chu
  • Publication number: 20050175217
    Abstract: The position of a stage is determined. Images of a plurality of targets located on the stage are captured. The captured images of the plurality of targets are compared with stored images to determine displacement coordinates for each target. The displacement coordinates for the targets are translated into position coordinates for the stage.
    Type: Application
    Filed: February 5, 2004
    Publication date: August 11, 2005
    Inventors: Louis Mueller, David Chu, Michael Brosnan, William Schluchter, Jeffrey Young, Alan Ray, Douglas Woolverton