Patents by Inventor Robert John Clifford Mitchell

Robert John Clifford Mitchell 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 of detecting the position of a wafer
    Patent number: 6690986
    Abstract: An apparatus for processing wafers one at a time. The apparatus has a vacuum chamber into which wafers are loaded through a pair of loadlocks which are spaced one above the other. A robot within the vacuum chamber has a pair of gripper arms which are moveable along and rotatable about a vertical axis so as to be moveable between the loadlocks and a wafer processing position. Each of the loadlocks has a vertically moveable portion which is moveable away from the remainder of the loadlock to provide access in a horizontal plane for one of the gripper arms. Signals from encoders and optical sensors are used to determine that a handoff position has been reached.
    Type: Grant
    Filed: April 19, 2000
    Date of Patent: February 10, 2004
    Assignee: Applied Materials, Inc.
    Inventors: Robert John Clifford Mitchell, Ian R. Joyce, James Biddle, James Victor Edwards
  • Ion implanter with wafer angle and faraday alignment checking
    Patent number: 6566661
    Abstract: A beam/wafer alignment arrangement has a laser and sensor mounted on the scanning magnet. Direct alignment of the wafer relative to the scanning magnet is determined by reflecting the beam in a specular surface on the wafer holder back to the sensor. Correct alignment of the wafer translation direction is also confirmed from any movement of the reflected light spot on the sensor as the wafer holder is translated up and down. A further sensor is mounted on the beam stop to monitor any misalignment of the process chamber to the collimator magnet, and for checking the location of the travelling Faraday.
    Type: Grant
    Filed: October 11, 2000
    Date of Patent: May 20, 2003
    Assignee: Applied Materials, Inc.
    Inventor: Robert John Clifford Mitchell
  • Ion implanter
    Patent number: 6555825
    Abstract: An ion implanter having a scanning arm which can pass vertically through ion beam, having a wafer loading/unloading position above the beam. The scanning arm also has capability for movement of wafer in its own plane when tilted relative to the beam, and there is also disclosure of a double scanning arm arrangement generating to/from a single wafer loader/unloader.
    Type: Grant
    Filed: April 19, 2000
    Date of Patent: April 29, 2003
    Assignee: Applied Materials, Inc.
    Inventors: Robert John Clifford Mitchell, Keith Relleen, Justin Lowe
  • Ion implanter and beam stop therefor
    Patent number: 6525327
    Abstract: A beam stop (23) has a charge collecting member (40) which extends in the direction of scanning of a scanned beam by less than the total distance scanned, so that variation in the charge signal derived from the collecting member can provide a timing signal for use in monitoring alignment of the scanned beam. In a preferred embodiment, the beam stop plate (42) has slits (65-69) leading to apertures (60-64) containing charge collecting rods (73-75) located within the thickness of the beam stop plate (42).
    Type: Grant
    Filed: October 12, 2000
    Date of Patent: February 25, 2003
    Assignee: Applied Materials, Inc.
    Inventors: Robert John Clifford Mitchell, Michael T. Wauk, John Ruffell, Hilton Glavish, Peter Kindersley