Patents by Inventor Graham J. Siddall

Graham J. Siddall 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).

  • Patent number: 4694477
    Abstract: An apparatus for micropositioning an X-ray lithography mask has but a single stage plate for supporting the mask, three piezoelectric transducers for moving the stage plate in the X-Y plane, and three flexure assemblies located equiangularly around the stage plate for supporting the stage plate and for moving the stage plate in the Z-axis. The flexure assemblies each include a single piezoelectric transducer and various flex strips to allow relative motion of the stage plate to occur smoothly in all six of the possible degrees of freedom.
    Type: Grant
    Filed: December 21, 1983
    Date of Patent: September 15, 1987
    Assignee: Hewlett-Packard Company
    Inventor: Graham J. Siddall
  • Patent number: 4613981
    Abstract: An X-ray lithography apparatus permits the successive exposure of each of four quadrants of a semiconductor wafer through a single mask. The mask overlays one quadrant of the wafer at a time and the wafer is rotated through 90 degrees after exposure of a quadrant to allow exposure of succeeding wafer quadrants; each wafer quadrant is independently aligned to the mask prior to exposure. In an alternative preferred embodiment, a rotatable diaphragm is used to select a single mask quadrant from a mask which overlays the entire surface of the semiconductor wafer. Both the wafer and the diaphragm may be rotated to allow various exposure combinations of mask and wafer quadrants.
    Type: Grant
    Filed: January 24, 1984
    Date of Patent: September 23, 1986
    Assignee: Varian Associates, Inc.
    Inventors: Graham J. Siddall, Steven G. Eaton, James B. Kruger, Garrett A. Garrettson, Armand P. Neukermans
  • Patent number: 4592081
    Abstract: Provided is an apparatus for improving alignment accuracy by distorting in a controlled manner an X-ray lithographic mask to compensate for mask distortions induced primarily by thermally induced clamping effects in E-beam and X-ray exposure systems. A system of additional alignment sensors is used to provide localized misalignment information. This information is then used to provide feedback to a servo system which in turn activates electromechanically translatable clamps which distort the X-ray mask so as to minimize misalignment over the exposure field.
    Type: Grant
    Filed: February 10, 1984
    Date of Patent: May 27, 1986
    Assignee: Varian Associates, Inc.
    Inventors: Steven G. Eaton, Graham J. Siddall
  • Patent number: 4506184
    Abstract: A deformable vacuum pin chuck includes a thin silicon chuck for supporting a semiconductor wafer during lithographic processing and a number of piezoelectric transducers for selectively deforming the chuck. Chuck deformation caused by application of electric potentials to selected transducers may be used to correct flatness deviations in the wafer and, thereby, a desired degree of flatness of the semiconductor wafer may be obtained.
    Type: Grant
    Filed: January 10, 1984
    Date of Patent: March 19, 1985
    Assignee: Varian Associates, Inc.
    Inventor: Graham J. Siddall