Patents by Inventor William G. Callahan

William G. Callahan 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: 7663125
    Abstract: An ion beam current uniformity monitor, ion implanter and related method are disclosed. In one embodiment, the ion beam current uniformity monitor includes an ion beam current measurer including a plurality of measuring devices for measuring a current of an ion beam at a plurality of locations; and a controller for maintaining ion beam current uniformity based on the ion beam current measurements by the ion beam current measurer.
    Type: Grant
    Filed: March 29, 2007
    Date of Patent: February 16, 2010
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: William G. Callahan, Morgan D. Evans, George M. Gammel, Norman E. Hussey, Gregg A. Norris, Joseph C. Olson
  • Publication number: 20080245957
    Abstract: An approach that tunes an ion implanter for optimal performance is described. In one embodiment, there is a system for tuning an ion implanter having multiple beamline elements to generate an ion beam having desired beam properties. In this embodiment, the system comprises a beamline element settings controller configured to provide beamline element settings for generating the desired beam properties. A tuning model correlates the beamline element settings with beam properties. A calibration component is configured to calibrate the tuning model in response to a determination that beam properties measured from using the tuned beamline element settings differs from the determined tuned beamline element settings.
    Type: Application
    Filed: April 3, 2007
    Publication date: October 9, 2008
    Inventors: Atul Gupta, Jay Scheuer, Daniel Distaso, Antonella Cucchetti, William G. Callahan
  • Publication number: 20080073584
    Abstract: An ion beam current uniformity monitor, ion implanter and related method are disclosed. In one embodiment, the ion beam current uniformity monitor includes an ion beam current measurer including a plurality of measuring devices for measuring a current of an ion beam at a plurality of locations; and a controller for maintaining ion beam current uniformity based on the ion beam current measurements by the ion beam current measurer.
    Type: Application
    Filed: March 29, 2007
    Publication date: March 27, 2008
    Inventors: William G. Callahan, Morgan D. Evans, George M. Gammel, Norman E. Hussey, Gregg A. Norris, Joseph C. Olson
  • Patent number: 6374144
    Abstract: A method and apparatus for controlling complex systems includes hierarchically coupled subsystems representing operative functions of the system. The hierarchically coupled subsystems are coupled to collect command data from a user and signal data from the system. Each subsystem may include one or more state machines and one or more digital signal processing and conditioning unit (DSPCU) objects. The DSCPU objects accept process commands and convert control system signals into states for further processing by the state machines. Associated with the DSPCUs of each subsystem is a data flow diagram for dictating an order of flow of commands and signals at the DSPCUs. A method of controlling the system represented by the hierarchically coupled subsystems schedules the execution of the subsystems according to an execution protocol.
    Type: Grant
    Filed: December 22, 1998
    Date of Patent: April 16, 2002
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Gary L. Viviani, Nick A. Parisi, William G. Callahan
  • Patent number: 4645227
    Abstract: A bracket is described which is adapted to be detachably mounted to the rear crossmember of the frame of a truck tractor. The bracket includes a horizontal base member, first and second depending legs, and securement means which is adapted to secure the bracket to the rear crossmember. A pintle hook is secured to the second leg member.
    Type: Grant
    Filed: September 9, 1985
    Date of Patent: February 24, 1987
    Inventor: William G. Callahan