Patents by Inventor Min-Su Fung

Min-Su Fung 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: 7230443
    Abstract: Corona charges are used to bias a wafer to push down mobile charges and then pull them up during temperature cycles. Mobile charge is measured from the drops in the corona voltage due to the mobile charges. Corrections are made in the measurements for dipole potentials, leakage and silicon band-bending.
    Type: Grant
    Filed: August 23, 2005
    Date of Patent: June 12, 2007
    Assignee: KLA-Tencor Corporation
    Inventors: Min-Su Fung, Roger L. Verkuil, Gregory S. Horner, William H. Howland
  • Patent number: 6937050
    Abstract: Corona charges are used to bias a wafer to push down mobile charges and then pull them up during temperature cycles. Mobile charge is measured from the drops in the corona voltage due to the mobile charges. Corrections are made in the measurements for dipole potentials, leakage and silicon band-bending.
    Type: Grant
    Filed: March 25, 2004
    Date of Patent: August 30, 2005
    Inventors: Min-Su Fung, Roger L. Verkuil, Gregory S. Horner, William H. Howland
  • Patent number: 6771092
    Abstract: Corona charges are used to bias a wafer to push down mobile charges and then pull them up during temperature cycles. Mobile charge is measured from the drops in the corona voltage due to the mobile charges. Corrections are made in the measurements for dipole potentials, leakage and silicon band-bending.
    Type: Grant
    Filed: November 18, 2002
    Date of Patent: August 3, 2004
    Inventors: Min-Su Fung, Roger L. Verkuil, Gregory S. Horner, William H. Howland
  • Patent number: 6522158
    Abstract: Corona charges are used to bias a wafer to push down mobile charges and then pull them up during temperature cycles. Mobile charge is measured from the drops in the corona voltage due to the mobile charges. Corrections are made in the measurements for dipole potentials, leakage and silicon band-bending.
    Type: Grant
    Filed: April 30, 1997
    Date of Patent: February 18, 2003
    Assignee: Keithley Instruments, Inc.
    Inventors: Min-Su Fung, Roger L. Verkuil, Gregory S. Horner, William H. Howland
  • Patent number: 6136669
    Abstract: A semi conductor manufacturing process including uniform negative polarity wafer charging to remove or immobilize alkali ions such that the device becomes immune to their presence. The wafer is charged with a corona discharge at a 1MV/cm-2MV/cm bias field and low temperature (200.degree. C.-300.degree. C.) heating to bring mobile ions to the wafer's surface. Surface mobile ions are removed with a deionized (DI) water rinse or a standard sequential wafer wet cleaning step, immobilized with a normal gate (polysilicon) or metal contact formation step or both, thereby effectively removing mobile ions from the semiconductor structure.
    Type: Grant
    Filed: July 21, 1998
    Date of Patent: October 24, 2000
    Assignee: International Business Machines Corporation
    Inventors: Frederick Albert Flitsch, Min-Su Fung
  • Patent number: 5650731
    Abstract: An apparatus for measuring charge in an oxide layer overlying a silicon substrate containing very high density product chips characterized by thick oxides and high substrate doping levels in the field regions. A specially designed extremely thin conductive probe is pressed against the oxide layer whose charge is to be measured. A bias is applied to the probe for biasing the underlying silicon surface into accumulation or inversion. An intensity modulated light beam is focussed at the point of probe contact. The resulting amplitude modulated photovoltage is detected and applied to a computer to derive the value of the oxide charge therefrom.
    Type: Grant
    Filed: December 12, 1996
    Date of Patent: July 22, 1997
    Assignee: International Business Machines Corporation
    Inventors: Min-Su Fung, Roger Leonard Verkuil, Bob Hong Yun
  • Patent number: 5498974
    Abstract: A method and apparatus comprises heating a wafer to a temperature sufficient to temperature stress the wafer and enable ion motion. The wafer is then initialized in a measurement region with a non-contact corona discharge of a first polarity until a first dielectric field is developed, wherein any mobile ions present in the dielectric layer or at an air/dielectric interface move to a substrate/dielectric interface. A non-contact pulsed corona discharge of a second polarity, opposite the first polarity, is then applied to the wafer until a second dielectric field is developed and an amount of corona discharge Q.sub.MEASURED necessary to change the dielectric field from the first dielectric field to the second dielectric field is measured, wherein any mobile ions present at the dielectric/substrate interface move to the air/dielectric interface. An ideal amount of corona discharge Q.sub.
    Type: Grant
    Filed: December 30, 1994
    Date of Patent: March 12, 1996
    Assignee: International Business Machines Corporation
    Inventors: Roger L. Verkuil, Min-Su Fung
  • Patent number: 4812756
    Abstract: A contactless technique for semiconductor wafer testing comprising: depositing charges on the top surface of an insulator layer over the wafer to create an inverted surface with a depletion region and thereby a field-induced junction therebelow in the wafer, with an accumulated guard ring on the semiconductor surface therearound. The technique further includes the step of changing the depth to which the depletion region extends below the inverted semiconductor wafer surface to create a surface potential transient, and the step of measuring a parameter of the resultant surface potential transient. This technique may be utilized to make time retention and epi doping concentration measurements. It is especially advantageous for reducing the effects of surface leakage on these measurements. In a preferred embodiment, corona discharges are used to effect the charge deposition configuration. Either corona discharge or photon injection are used to change the depletion region depth.
    Type: Grant
    Filed: August 26, 1987
    Date of Patent: March 14, 1989
    Assignee: International Business Machines Corporation
    Inventors: Huntington W. Curtis, Min-Su Fung, Roger L. Verkuil