Patents by Inventor Thomas L. Duft

Thomas L. Duft 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: 4980896
    Abstract: An x-ray lithography system is disclosed in which x-rays are generated by directing a high energy laser beam against a metal target to form an x-ray emitting plasma. The x-rays from the plasma are then directed through a mask towards a resist covered wafer to cause a patterned exposure on the wafer resist coating. The mask, the portion of the target which the laser beam strikes and the portion of the wafer to be exposed are all within an evacuated chamber. The laser, prior to entering the chamber, is split into two separate beams, each of which are focused and directed through a window in the side of the chamber towards the same spot on the target. Apparatus, including an air bearing, seal and positioner, is provided to move the target at periodic intervals. Similar apparatus is provided to move the wafer from exposure section to exposure section.
    Type: Grant
    Filed: November 20, 1989
    Date of Patent: December 25, 1990
    Assignee: Hampshire Instruments, Inc.
    Inventors: James M. Forsyth, Joseph A. Abate, Thomas L. Duft, Malcolm M. Drummond, Lisa Gregorka, John F. Hoose, Robert G. Zambelli
  • Patent number: 4870668
    Abstract: A step and repeat mechanism is used with an X-ray lithography system for moving a wafer to be exposed from position to position beneath the source of x-rays. The step and repeat mechanism includes, means for moving the wafer to be exposed with six degrees of freedom. Conventional drive motor means move the step and repeat mechanism, and wafer held thereby, in the X, Y and Z linear directions, as well as rotates, tip and tilt the wafer in the planar direction. In addition, the system includes, three fine Z motor assemblies for moving the wafer in fine increments in the Z direction, which motor assemblies are used to tip and tilt the plane of the wafer. Sensors are included for determining the plane of the mask and the plane of each of the various sections of wafer to be exposed, so that appropriate tip and tilt adjustments by the three fine Z motor assemblies can be made to cause the average plane of each section of the wafer to be exposed to be parallel to the plane of the mask.
    Type: Grant
    Filed: December 30, 1987
    Date of Patent: September 26, 1989
    Assignee: Hampshire Instruments, Inc.
    Inventors: Robert D. Frankel, Marc J. Martin, David G. Baker, Thomas L. Duft