Patents by Inventor David Ru-Chen Liu

David Ru-Chen Liu 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).

  • Negative offset bipolar electrostatic chucks
    Patent number: 5835333
    Abstract: A bipolar electrostatic chuck system having a bipolar electrostatic chuck for securely holding a wafer on the surface of the bipolar electrostatic chuck. The bipolar electrostatic chuck system includes a negative-offset power supply for providing a positive potential level and a negative potential level. The positive potential level is positively biased relative to a common reference voltage level by a first magnitude while the negative potential level is negatively biased relative to the same common reference voltage level by a second magnitude, which is larger than the first magnitude. Further, the bipolar electrostatic chuck includes a positive pole, which is coupled to the negative-offset power supply for biasing the positive pole at the positive potential level when the negative-offset power supply is turned on.
    Type: Grant
    Filed: October 30, 1995
    Date of Patent: November 10, 1998
    Assignee: Lam Research Corporation
    Inventors: Edward Ross Castro, Ken Edwin Tokunaga, Boris V. Atlas, David Ru-Chen Liu