Patents by Inventor Zhiwei (Steve) Xu

Zhiwei (Steve) Xu 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: 7397254
    Abstract: Methods for determining an electrical parameter of an insulating film are provided. One method includes measuring a surface potential of a leaky insulating film without inducing leakage across the insulating film and determining the electrical parameter from the surface potential. Another method includes applying an electrical field across the insulating film. Leakage across the insulating film caused by the electrical field is negligible. The method also includes measuring a surface potential of the specimen and determining a potential of the substrate. In addition, the method includes determining a pure voltage across the insulating film from the surface potential and the substrate potential. The method further includes determining the electrical parameter from the pure voltage. The electrical parameter may be capacitance or electrical thickness of the insulating film.
    Type: Grant
    Filed: March 21, 2006
    Date of Patent: July 8, 2008
    Assignee: KLA-Tencor Technologies Corp.
    Inventors: Xiafang (Michelle) Zhang, Zhiwei (Steve) Xu, Jianou Shi, Quoc-Bao Vu, Thomas G. Miller, Gregory S. Horner
  • Patent number: 7110238
    Abstract: A method and a system for calibrating the work function of a non-contact voltage sensor are provided. The method includes preparing a reference sample to have a stable work function, measuring a voltage of the sample using a non-contact voltage sensor, and determining a work function correction factor of the sensor from the measured voltage. In turn, the calibrated work function may be used to adjust voltages of substrates measured by the sensor. A corona gun which includes a first electrode and one or more conductive rods is provided. In some embodiments, the conductive rods may be angled between 0 and 90 degrees with respect to a first electrode sidewall and/or be concentrically arranged less than 90 degrees from each other. In addition or alternatively, the corona gun may be adapted to alter its length and/or include a second electrode partially inset within a space surrounded by the first electrode.
    Type: Grant
    Filed: June 16, 2005
    Date of Patent: September 19, 2006
    Assignee: KLA-Tencor Technologies Corp.
    Inventors: Zhiwei (Steve) Xu, Jianou Shi, Shiyou Pei, Mahmood Mirzaaghaeian, Jeffrey A. Rzepiela
  • Patent number: 7103484
    Abstract: Non-contact methods for determining a parameter of an insulating film are provided. One method includes measuring at least two surface voltages of the insulating film. The surface voltages are measured after different charge depositions. Measuring the surface voltages is performed in two or more sequences. The method also includes determining individual parameters for the two or more sequences from the surface voltages and the charge depositions. In addition, the method includes determining the parameter of the insulating film as an average of the individual parameters. The parameter is substantially independent of leakage in the insulating film. Another method includes determining a characteristic of nitrogen in an insulating film using two parameters of the insulating film selected from equivalent oxide thickness, optical thickness, and a measure of leakage through the insulating film. The characteristic may be a nitrogen dose, a nitrogen percentage, or a presence of nitrogen in the insulating film.
    Type: Grant
    Filed: October 31, 2003
    Date of Patent: September 5, 2006
    Assignee: KLA-Tencor Technologies Corp.
    Inventors: Jianou Shi, Steve Yifeng Cui, Shiyou Pei, Zhiwei (Steve) Xu, Haiyong (Howard) Wang
  • Patent number: 7075318
    Abstract: Methods for determining an electrical parameter of an insulating film are provided. One method includes measuring a surface potential of a leaky insulating film without inducing leakage across the insulating film and determining the electrical parameter from the surface potential. Another method includes applying an electrical field across the insulating film. Leakage across the insulating film caused by the electrical field is negligible. The method also includes measuring a surface potential of the specimen and determining a potential of the substrate. In addition, the method includes determining a pure voltage across the insulating film from the surface potential and the substrate potential. The method further includes determining the electrical parameter from the pure voltage. The electrical parameter may be capacitance or electrical thickness of the insulating film.
    Type: Grant
    Filed: January 9, 2004
    Date of Patent: July 11, 2006
    Assignee: KLA-Tencor Technologies Corp.
    Inventors: Xiafang (Michelle) Zhang, Zhiwei (Steve) Xu, Jianou Shi, Bao Vu, Thomas G. Miller, Gregory S. Horner
  • Patent number: 6909291
    Abstract: A method and a system for calibrating the work function of a non-contact voltage sensor are provided. The method includes preparing a reference sample to have a stable work function, measuring a voltage of the sample using a non-contact voltage sensor, and determining a work function correction factor of the sensor from the measured voltage. In turn, the calibrated work function may be used to adjust voltages of substrates measured by the sensor. A corona gun which includes a first electrode and one or more conductive rods is provided. In some embodiments, the conductive rods may be angled between 0 and 90 degrees with respect to a first electrode sidewall and/or be concentrically arranged less than 90 degrees from each other. In addition or alternatively, the corona gun may be adapted to alter its length and/or include a second electrode partially inset within a space surrounded by the first electrode.
    Type: Grant
    Filed: June 24, 2003
    Date of Patent: June 21, 2005
    Assignee: KLA-Tencor Technologies Corp.
    Inventors: Zhiwei (Steve) Xu, Jianou Shi, Shiyou Pei, Mahmood Mirzaaghaeian, Jeffrey A. Rzepiela