Patents by Inventor Wil{acute over (h)}elmus Petrus De Boeij

Wil{acute over (h)}elmus Petrus De Boeij 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).

  • Lithographic apparatus, device manufacturing method
    Patent number: 7245353
    Abstract: To compensate for birefringence of a mask in a lithographic projection apparatus, the birefringence of a mask is measured and stored as birefringence data in a data storage device. A birefringent compensation element is disposed in the optical path of the lithographic projection apparatus. Appropriate adjustments of the compensation element are determined as those optimally reducing impact of the mask birefringence on the state of polarization at substrate level.
    Type: Grant
    Filed: October 12, 2004
    Date of Patent: July 17, 2007
    Assignee: ASML Netherlands B.V.
    Inventors: Johannes Catharinus Hubertus Mulkens, Wil{acute over (h)}elmus Petrus De Boeij, Carsten Andreas Kohler