Patents by Inventor Joao L G Ferreira

Joao L G Ferreira 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).

  • Electrostatic clamping method and apparatus
    Patent number: 9793149
    Abstract: A method of electrostatically clamping a dielectric wafer to a processing table during plasma processing is described. The table has interdigitated electrodes embedded therein. The method comprises applying respective voltages of opposite first and second polarities to adjacent electrodes wherein polarization charges are induced in the wafer with opposite polarity to the respective underlying electrodes thereby electrostatically clamping the wafer to the table; and, after a predetermined time (ton), reversing the polarities of the voltages so that the polarization charges and electrostatic clamping continues.
    Type: Grant
    Filed: November 18, 2014
    Date of Patent: October 17, 2017
    Assignee: Oxford Instruments Nanotechnology Tools Limited
    Inventors: Yiping Song, Joao L G Ferreira, Michael Cooke
  • ELECTROSTATIC CLAMPING METHOD AND APPARATUS
    Publication number: 20150162234
    Abstract: A method of electrostatically clamping a dielectric wafer to a processing table during plasma processing is described. The table has interdigitated electrodes embedded therein. The method comprises applying respective voltages of opposite first and second polarities to adjacent electrodes wherein polarisation charges are induced in the wafer with opposite polarity to the respective underlying electrodes thereby electrostatically clamping the wafer to the table; and, after a predetermined time (ton), reversing the polarities of the voltages so that the polarisation charges and electrostatic clamping continues.
    Type: Application
    Filed: November 18, 2014
    Publication date: June 11, 2015
    Inventors: Yiping Song, Joao L G Ferreira, Michael Cooke