Patents by Inventor Fred E. Mitchel

Fred E. Mitchel 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: 6056632
    Abstract: A carrier head for a semiconductor wafer polishing apparatus includes a rigid plate which has a major surface with a plurality of open fluid channels. A flexible wafer carrier membrane has a perforated wafer contact section for contacting the semiconductor wafer, and a bellows extending around the wafer contact section. A retaining member is secured to the rigid plate with a flange on the bellows sandwiched between the plate's major surface and the retaining ring, thereby defining a cavity between the wafer carrier membrane and the rigid plate. A fluid conduit is coupled to the rigid plate allowing a source of vacuum and a source of pressurized fluid alternately to be connected to the cavity. An additional wafer carrier membrane is internally located with respect to the cavity formed by the wafer carrier membrane, and forms another cavity with respect to the rigid plate.
    Type: Grant
    Filed: October 9, 1998
    Date of Patent: May 2, 2000
    Assignee: SpeedFam-IPEC Corp.
    Inventors: Fred E. Mitchel, John A. Adams, Thomas Frederick A. Bibby
  • Patent number: 5851140
    Abstract: A carrier head for a semiconductor wafer polishing apparatus includes a rigid plate which has a major surface with a plurality of open fluid channels. A flexible wafer carrier membrane has a perforated wafer contact section for contacting the semiconductor wafer, and a bellows extending around the wafer contact section. A retaining ring is secured to the rigid plate with a flange on the bellows sandwiched between the plate's major surface and the retaining ring, thereby defining a cavity between the wafer carrier membrane and the rigid plate. A fluid conduit is coupled to the rigid plate allowing a source of a vacuum and a source of pressurized fluid alternately to be connected to the cavity.
    Type: Grant
    Filed: February 13, 1997
    Date of Patent: December 22, 1998
    Assignee: Integrated Process Equipment Corp.
    Inventors: Chris E. Barns, Malek Charif, Kenneth D. Lefton, Fred E. Mitchel