Patents by Inventor Xiafang Zhang

Xiafang Zhang 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: 9239522
    Abstract: Methods of determining asymmetric properties of structures are described. A method includes measuring, for a grating structure, a first signal and a second, different, signal obtained by optical scatterometry. A difference between the first signal and the second signal is then determined. An asymmetric structural parameter of the grating structure is determined based on a calculation using the first signal, the second signal, and the difference.
    Type: Grant
    Filed: October 8, 2010
    Date of Patent: January 19, 2016
    Assignee: KLA-Tencor Corporation
    Inventors: Meng-Fu Shih, In-Kyo Kim, Xiafang Zhang, Leonid Poslavsky
  • Publication number: 20120086940
    Abstract: Methods of determining asymmetric properties of structures are described. A method includes measuring, for a grating structure, a first signal and a second, different, signal obtained by optical scatterometry. A difference between the first signal and the second signal is then determined. An asymmetric structural parameter of the grating structure is determined based on a calculation using the first signal, the second signal, and the difference.
    Type: Application
    Filed: October 8, 2010
    Publication date: April 12, 2012
    Inventors: Meng-Fu Shih, In-Kyo Kim, Xiafang Zhang, Leonid Poslavsky
  • Patent number: 8004290
    Abstract: A method and apparatus for determining dielectric layer properties are disclosed. Dielectric layer properties such as dielectric thickness, dielectric leakage or other electrical information may be determined for a multilayer film stack on a semiconducting or conducting substrate. The film stack may comprise a first dielectric layer between the substrate and an intermediate layer of semiconducting or conducting material, and a second dielectric layer disposed such that the intermediate layer is between the first and second dielectric layers. The dielectric layer properties may be determined by a) depositing electrical charge at one or more localized regions on an exposed surface of the second dielectric layer; b) performing a measurement of an electrical quantity at the one or more localized regions; and c) determining a property of the second dielectric layer from the one or more measurements.
    Type: Grant
    Filed: April 2, 2008
    Date of Patent: August 23, 2011
    Assignee: KLA-Tencor Corporation
    Inventors: Xiafang Zhang, Nanchang Zhu, Yiping Feng, Min Xiang, Jianou Shi
  • Patent number: 7724003
    Abstract: A measurement system for taking a reading in a test zone on a surface of a substrate. A chamber forms an environment, a surface treatment station dispenses a stabilizing chemical in the test zone, a charge deposition station deposits a charge in the test zone, and a QV measurement station takes a QV based measurement in the test zone. Where the surface treatment station, the charge deposition station, and the QV measurement station all interact with the substrate within the chamber. In this manner, reliable QV measurements are taken on the substrate by controlling charge spreading with the stabilizing chemical. QV measurement stability is also improved by reducing the influence of the time trending on substrates with reactive dielectrics, such as on silicon oxynitride and high-k surfaces.
    Type: Grant
    Filed: November 12, 2007
    Date of Patent: May 25, 2010
    Assignee: KLA-Tencor Corporation
    Inventors: NanChang Zhu, Jainou Shi, Min Xiang, ZiangHua Liu, Goujun Zhang, Xiafang Zhang, Shiyou Pei, Liang-Guo Wang, Joseph R. Laia, Jr.
  • Patent number: 7525304
    Abstract: A method for determining an effective capacitance of a dielectric material, by forming first and second asymmetrical electrodes entirely within a field of the dielectric material, where the first electrode, the second electrode, and the field of the dielectric material are co-planar, neither the first electrode nor the second electrode are either electrically connected to ground or to each other, applying a first charge Q on the first electrode, measuring a first voltage change V1 on the first electrode, measuring a second voltage change V2 on the second electrode, depositing a second charge Q? on the second electrode, measuring a third voltage change V3 on the first electrode, measuring a fourth voltage change V4 on the second electrode, calculating a first ground capacitance Cg1 by Cg1=(V2Q??V4Q)/(V2V3?V1V4), calculating a second ground capacitance Cg2 by Cg2=(V3Q?V1Q?)/(V2V3?V1V4), and calculating an inter-electrode capacitance Cie by Cie=V3Cg1/(V4?V3)=V2Cg2/(V1?V2).
    Type: Grant
    Filed: May 14, 2007
    Date of Patent: April 28, 2009
    Assignee: KLA-Tencor Corporation
    Inventors: Yiping Feng, Jianou Shi, Xiafang Zhang
  • Patent number: 7345306
    Abstract: A method of measuring electrical characteristics of a gate dielectric. The gate dielectric is local annealed by directing a highly localized energy source at the measurement area, such that the measurement area is brought to an annealing temperature while surrounding structures are not significantly heated. While heating the measurement area, a flow of a gas containing a percentage of hydrogen, deuterium, or water vapor at a flow rate is directed to the measurement area. A charge is inducted on the measurement area and the electrical characteristics of the gate dielectric are measured using non contact electrical probing.
    Type: Grant
    Filed: June 2, 2006
    Date of Patent: March 18, 2008
    Assignee: KLA-Tencor Technologies Corporation
    Inventors: Sergio Edelstein, Eric F. Bouche, Jianou Shi, Shiyou Pei, Xiafang Zhang
  • Publication number: 20070109003
    Abstract: Test pads, methods, and systems for measuring properties of a wafer are provided. One test pad formed on a wafer includes a test structure configured such that one or more electrical properties of the test structure can be measured. The test pad also includes a conductive layer formed between the test structure and the wafer. The conductive layer prevents structures located under the test structure between the conductive layer and the wafer from affecting the one or more electrical properties of the test structure during measurement. One method for assessing plasma damage of a wafer includes measuring one or more electrical properties of a test structure formed on the wafer and determining an index characterizing the plasma damage of the test structure using the one or more electrical properties.
    Type: Application
    Filed: August 21, 2006
    Publication date: May 17, 2007
    Applicant: KLA-TENCOR TECHNOLOGIES CORP.
    Inventors: Jianou Shi, Xiafang Zhang, Shiyou Pei, Shu Huang, Dennis Yeh, Jeffrey Rzepiela, Yiping Feng, Ahmad Khan
  • Patent number: 7098050
    Abstract: A method of measuring electrical characteristics of a gate dielectric. The gate dielectric is local annealed by directing a highly localized energy source at the measurement area, such that the measurement area is brought to an annealing temperature while surrounding structures are not significantly heated. While heating the measurement area, a flow of a gas containing a percentage of hydrogen, deuterium, or water vapor at a flow rate is directed to the measurement area. A charge is inducted on the measurement area and the electrical characteristics of the gate dielectric are measured using non contact electrical probing.
    Type: Grant
    Filed: October 27, 2004
    Date of Patent: August 29, 2006
    Assignee: KLA-Tencor Technologies Corporation
    Inventors: Sergio Edelstein, Eric F. Bouche, Jianou Shi, Shiyou Pei, Xiafang Zhang