Patents by Inventor Edward Christopher Stewart

Edward Christopher Stewart 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).

  • Method and apparatus for controlling focus based on a thickness of a layer of photoresist
    Patent number: 6709797
    Abstract: In one illustrative embodiment, a method is provided that controls a stepper to position a focal plane of a light source adjacent a top surface of a layer of photoresist. A metrology tool is used to measure a thickness of the layer of photoresist, and a controller uses the thickness measurement to determine a position of the top surface of the layer of photoresist. The controller delivers a control signal to the stepper, causing the stepper to move the focal plane of the light source adjacent the top surface of the layer of photoresist.
    Type: Grant
    Filed: May 9, 2001
    Date of Patent: March 23, 2004
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Scott Bushman, Anastasia Lynn Oshelski Peterson, Edward Christopher Stewart, Curtis Warren Doss
  • Method and apparatus for controlling optical-parameters in a stepper
    Patent number: 6417912
    Abstract: In one illustrative embodiment, a system is provided for controlling a lens of an optical system of a stepper. The system comprises the stepper, the optical system, and a controller. The stepper has a light source controllably energizable to provide light to a surface of a semiconductor device. The lens of the optical system has a controllable focus. The controller is capable of determining a temperature of the lens, and controllably varying the focus of the lens in response to the temperature of the lens.
    Type: Grant
    Filed: March 21, 2001
    Date of Patent: July 9, 2002
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Scott Bushman, Anthony John Toprac, Richard David Edwards, Edward Christopher Stewart