Patents by Inventor Tuan M. Ngo

Tuan M. Ngo 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: 6361645
    Abstract: Disclosed is a method and device for compensating a bias voltage on a wafer disposed over an electrostatic chuck in a processing chamber of a plasma processing system. The plasma processing system includes an electrostatic and RF power supplies that are coupled to the electrostatic chuck. The bias compensation device includes a voltage converter, a storage unit, and a voltage adjusting circuitry. The voltage converter is coupled to the electrostatic chuck for detecting a voltage Vpp of the electrostatic chuck. The voltage converter converts the detected voltage to a lower voltage Vref. The storage unit stores a predetermined slope and a predetermined offset of a calibration curve, which is derived by fitting a plurality of wafer bias voltages as a function of electrostatic chuck voltages.
    Type: Grant
    Filed: October 8, 1998
    Date of Patent: March 26, 2002
    Assignee: Lam Research Corporation
    Inventors: Alan M. Schoepp, Robert E. Knop, Christopher H. Olson, Michael S. Barnes, Tuan M. Ngo
  • Patent number: 4507078
    Abstract: A wafer handling method and apparatus insures proper centering of a wafer at a work station and controls the heat transferred to the wafer in a baking operation. The amount of heat transferred and the rate at which the heat is transferred to the wafer are regulated by controlling the distance between the wafer and a hot plate. The hot plate is maintained at a constant temperature higher than the bake out or equilibrium temperature to which the wafer is to be heated.
    Type: Grant
    Filed: March 28, 1983
    Date of Patent: March 26, 1985
    Assignee: Silicon Valley Group, Inc.
    Inventors: Johann Tam, Jalal Ashjaee, Nobuo B. Kuwaki, Tuan M. Ngo, Susan W. Kung