Patents by Inventor Xuefeng Liu

Xuefeng 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).

  • Patent number: 7538004
    Abstract: A heterojunction bipolar transistor is formed in a semiconductor substrate of a first conductivity type including a collector region. A base region is formed on the substrate and an emitter region is formed over the base region. At least one of the collector, base and emitter regions includes a first region doped with an impurity having a first concentration and a second region doped with the impurity having a second concentration. Noise performance and reliability of the heterojunction bipolar transistor is improved without degrading ac performance.
    Type: Grant
    Filed: November 9, 2007
    Date of Patent: May 26, 2009
    Assignee: International Business Machines Corporation
    Inventors: Peter J. Geiss, Alvin J. Joseph, Rajendran Krishnasamy, Xuefeng Liu
  • Patent number: 7538409
    Abstract: A device comprises a first sub-collector formed in an upper portion of a substrate and a lower portion of a first epitaxial layer and a second sub-collector formed in an upper portion of the first epitaxial layer and a lower portion of a second epitaxial layer. The device further comprises a reach-through structure connecting the first and second sub-collectors and an N-well formed in a portion of the second epitaxial layer and in contact with the second sub-collector and the reach-through structure. The device further comprises N+ diffusion regions in contact with the N-well, a P+ diffusion region in contact with the N-well, and shallow trench isolation structures between the N+ and P+ diffusion regions.
    Type: Grant
    Filed: June 7, 2006
    Date of Patent: May 26, 2009
    Assignee: International Business Machines Corporation
    Inventors: Xuefeng Liu, Robert M. Rassel, Steven H. Voldman
  • Publication number: 20090127652
    Abstract: A structure includes a substrate comprising a region having a circuit or device which is sensitive to electrical noise. Additionally, the structure includes a first isolation structure extending through an entire thickness of the substrate and surrounding the region and a second isolation structure extending through the entire thickness of the substrate and surrounding the region.
    Type: Application
    Filed: November 20, 2007
    Publication date: May 21, 2009
    Inventors: Hanyi Ding, Kai D. Feng, Zhong-Xiang He, Xuefeng Liu
  • Publication number: 20090055790
    Abstract: A design structure is embodied in a machine readable medium for designing, manufacturing, or testing an integrated circuit. The design structure comprises: a conductive structure surrounding and accommodating a circuit or a circuit device arranged on a substrate and at least one feed through capacitor and one transmission line associated with the conductive structure and providing the power supply and signals to the circuit or circuit device respectively. The design structure also comprises a shielding structure surrounding a circuit or a circuit device arranged on a substrate and at least one feed through capacitor or a transmission line arranged on a side of the shielding structure.
    Type: Application
    Filed: March 12, 2008
    Publication date: February 26, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Hanyi DING, Kai D. FENG, Zhong-Xiang HE, Xuefeng LIU
  • Publication number: 20090052153
    Abstract: An electromagnetic shielding structure that includes a conductive structure surrounding and accommodating a circuit or a circuit device arranged on a substrate. At least one feed through device is associated with the conductive structure and provides signals to the circuit or circuit device. The method includes forming a shielding structure so that the shielding structure at least one of is at least partially arranged within the substrate and surrounds the circuit or circuit device and associating at least one feed through device with the shielding structure.
    Type: Application
    Filed: August 24, 2007
    Publication date: February 26, 2009
    Inventors: Hanyi Ding, Kai D. Feng, Zhong-Xiang He, Xuefeng Liu
  • Patent number: 7491632
    Abstract: A method of fabricating a buried subcollector in which the buried subcollector is implanted to a depth in which during subsequent epi growth the buried subcollector remains substantially below the fictitious interface between the epi layer and the substrate is provided. In particular, the inventive method forms a buried subcollector having an upper surface (i.e., junction) that is located at a depth from about 3000 ? or greater from the upper surface of the semiconductor substrate. This deep buried subcollector having an upper surface that is located at a depth from about 3000 ? or greater from the upper surface of the substrate is formed using a reduced implant energy (as compared to a standard deep implanted subcollector process) at a relative high dose. The present invention also provides a semiconductor structure including the inventive buried subcollector which can be used as cathode for passive devices in high frequency applications.
    Type: Grant
    Filed: November 10, 2005
    Date of Patent: February 17, 2009
    Assignee: International Business Machines Corporation
    Inventors: Douglas D. Coolbaugh, Xuefeng Liu, Robert M. Rassel, David C. Sheridan
  • Publication number: 20090039385
    Abstract: A device comprises a first sub-collector formed in an upper portion of a substrate and a lower portion of a first epitaxial layer and a second sub-collector formed in an upper portion of the first epitaxial layer and a lower portion of a second epitaxial layer. The device further comprises a reach-through structure connecting the first and second sub-collectors and an N-well formed in a portion of the second epitaxial layer and in contact with the second sub-collector and the reach-through structure. The device further comprises N+ diffusion regions in contact with the N-well, a P+ diffusion region in contact with the N-well, and shallow trench isolation structures between the N+ and P+ diffusion regions.
    Type: Application
    Filed: September 24, 2008
    Publication date: February 12, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Xuefeng LIU, Robert M. Rassel, Steven H. Voldman
  • Publication number: 20090026912
    Abstract: Method and apparatus for achieving an intensity modulated electron blanker are disclosed. An apparatus includes a cathode exposed to an activation source to generate an electron beam. Cathode control circuitry adjusts a cathode control amplifier to regulate cathode voltage and the potential of the electron beam. In some approaches the electron beam potential is used to control the blanking frequency, switching speeds, and duty cycle. In another approach electron generating beams directed on to the cathode are modulated to control the electron beam.
    Type: Application
    Filed: July 26, 2007
    Publication date: January 29, 2009
    Inventors: Vincenzo Lordi, Kirkwood Rough, Xuefeng Liu, Shem-Tov Levi
  • Publication number: 20090001417
    Abstract: Semiconductor structures and methods of forming semiconductor structures, and more particularly to structures and methods of forming SiGe and/or SiGeC buried layers for SOI/SiGe devices. An integrated structure includes discontinuous, buried layers having alternating Si and SiGe or SiGeC regions. The structure further includes isolation structures at an interface between the Si and SiGe or SiGeC regions to reduce defects between the alternating regions. Devices are associated with the Si and SiGe or SiGeC regions. The invention is also directed to a design structure on which a circuit resides.
    Type: Application
    Filed: October 5, 2007
    Publication date: January 1, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Xuefeng LIU, Robert M. Rassel, Steven H. Voldman
  • Publication number: 20090001414
    Abstract: Semiconductor structures and methods of forming semiconductor structures, and more particularly to structures and methods of forming SiGe and/or SiGeC buried layers for SOI/SiGe devices. An integrated structure includes discontinuous, buried layers having alternating Si and SiGe or SiGeC regions. The structure further includes isolation structures at an interface between the Si and SiGe or SiGeC regions to reduce defects between the alternating regions. Devices are associated with the Si and SiGe or SiGeC regions.
    Type: Application
    Filed: June 29, 2007
    Publication date: January 1, 2009
    Inventors: Xuefeng Liu, Robert M. Rassel, Steven H. Voldman
  • Publication number: 20080277769
    Abstract: An integrated circuit package includes an integrated circuit with one or more on-chip inductors. A package cover covers the integrated circuit. A magnetic material is provided between the integrated circuit and the package cover. The magnetic material may be a soft magnetic thin film. The magnetic material may be affixed to the package cover by an adhesive. The magnetic material may be formed directly on the package cover by one of deposition, sputtering or spraying. The magnetic material may be affixed to the integrated circuit.
    Type: Application
    Filed: May 8, 2007
    Publication date: November 13, 2008
    Inventors: John Michael Cotte, Hanyi Ding, Kai Di Feng, Zhong-Xiang He, Nils D. Hoivik, Xuefeng Liu
  • Publication number: 20080179703
    Abstract: The structure for millimeter-wave frequency applications, includes a Schottky barrier diode (SBD) with a cutoff frequency (FC) above 1.0 THz formed on a SiGe BiCMOS wafer. A method is also contemplated for forming a Schottky barrier diode on a SiGe BiCMOS wafer, including forming a structure which provides a cutoff frequency (Fc) above about 1.0 THz. In embodiments, the structure which provides a cutoff frequency (Fc) above about 1.0 THz may include an anode having an anode area which provides a cutoff frequency (FC) above about 1.0 THz, an n-epitaxial layer having a thickness which provides a cutoff frequency (FC) above about 1.0 THz, a p-type guardring at an energy and dosage which provides a cutoff frequency (FC) above about 1.0 THz, the p-type guardring having a dimension which provides a cutoff frequency (FC) above about 1.0 THz, and a well tailor with an n-type dopant which provides a cutoff frequency (FC) above about 1.0 THz.
    Type: Application
    Filed: September 12, 2007
    Publication date: July 31, 2008
    Inventors: Jeffrey B. Johnson, Xuefeng Liu, Bradley A. Orner, Robert M. Rassel
  • Patent number: 7402890
    Abstract: A structure and associated method for forming a structure. The structure comprises a first doped region, a second doped region, a third doped region, and a first shallow trench isolation structure formed within a substrate. The first doped region comprises a first dopant having a first polarity. The second doped region forms a first electrode of a capacitor. The third doped region forms a second electrode of the capacitor. Each of the second doped region and the third doped region comprises a second dopant having a second polarity. The first shallow trench isolation structure is formed between the second doped region and the third doped region. The capacitor comprises a main capacitance. The structure comprises a first parasitic capacitance and a second parasitic capacitance. The first parasitic capacitance is about equal to the second parasitic capacitance.
    Type: Grant
    Filed: June 2, 2006
    Date of Patent: July 22, 2008
    Assignee: International Business Machines Corporation
    Inventors: David S. Collins, Hanyi Ding, Kai Di Feng, Zhong-Xiang He, Xuefeng Liu
  • Publication number: 20080142861
    Abstract: A structure comprising a first doped region, a second doped region, a third doped region, and a first shallow trench isolation structure formed within a substrate. The first doped region comprises a first dopant having a first polarity. The second doped region forms a first electrode of a capacitor. The third doped region forms a second electrode of the capacitor. Each of the second doped region and the third doped region comprises a second dopant having a second polarity. The first shallow trench isolation structure is formed between the second doped region and the third doped region. The capacitor comprises a main capacitance. The structure comprises a first parasitic capacitance and a second parasitic capacitance. The first parasitic capacitance is about equal to the second parasitic capacitance.
    Type: Application
    Filed: February 12, 2008
    Publication date: June 19, 2008
    Inventors: David S. Collins, Hanyi Ding, Kai Di Feng, Zhong-Xiang He, Xuefeng Liu
  • Patent number: 7381997
    Abstract: A structure and method of fabricating lateral diodes. The diodes include Schottky diodes and PIN diodes. The method of fabrication includes forming one or more doped regions and more trenches in a silicon substrate and forming metal silicides on the sidewalls of the trenches. The fabrication of lateral diodes may be integrated with the fabrication of field effect, bipolar and SiGe bipolar transistors.
    Type: Grant
    Filed: November 26, 2007
    Date of Patent: June 3, 2008
    Assignee: International Business Machines Corporation
    Inventors: Douglas Duane Coolbaugh, Jeffrey Bowman Johnson, Xuefeng Liu, Bradley Alan Orner, Robert Mark Rassel, David Charles Sheridan
  • Publication number: 20080124883
    Abstract: A structure comprises a single wafer with a first subcollector formed in a first region having a first thickness and a second subcollector formed in a second region having a second thickness, different from the first thickness. A method is also contemplated which includes providing a substrate including a first layer and forming a first doped region in the first layer. The method further includes forming a second layer on the first layer and forming a second doped region in the second layer. The second doped region is formed at a different depth than the first doped region. The method also includes forming a first reachthrough in the first layer and forming a second reachthrough in second layer to link the first reachthrough to the surface.
    Type: Application
    Filed: November 16, 2007
    Publication date: May 29, 2008
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION,
    Inventors: Douglas D. COOLBAUGH, Alvin J. Joseph, Seong-dong Kim, Louis D. Laozerotti, Xuefeng Liu, Robert M. Rassel
  • Publication number: 20080124882
    Abstract: A heterojunction bipolar transistor is formed in a semiconductor substrate of a first conductivity type including a collector region. A base region is formed on the substrate and an emitter region is formed over the base region. At least one of the collector, base and emitter regions includes a first region doped with an impurity having a first concentration and a second region doped with the impurity having a second concentration. Noise performance and reliability of the heterojunction bipolar transistor is improved without degrading ac performance.
    Type: Application
    Filed: November 9, 2007
    Publication date: May 29, 2008
    Inventors: Peter J. Geiss, Alvin J. Joseph, Rajendran Krishnasamy, Xuefeng Liu
  • Publication number: 20080099787
    Abstract: A structure comprises a single wafer with a first subcollector formed in a first region having a first thickness and a second subcollector formed in a second region having a second thickness, different from the first thickness. A method is also contemplated which includes providing a substrate including a first layer and forming a first doped region in the first layer. The method further includes forming a second layer on the first layer and forming a second doped region in the second layer. The second doped region is formed at a different depth than the first doped region. The method also includes forming a first reachthrough in the first layer and forming a second reachthrough in second layer to link the first reachthrough to the surface.
    Type: Application
    Filed: October 17, 2007
    Publication date: May 1, 2008
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Douglas Coolbaugh, Alvin Joseph, Seong-dong Kim, Louis Lanzerotti, Xuefeng Liu, Robert Rassel
  • Publication number: 20080092094
    Abstract: The invention relates to noise isolation in semiconductor devices, and a design structure on which a subject circuit resides. A design structure is embodied in a machine readable medium used in a design process. The design structure includes a deep sub-collector located in a first epitaxial layer, and a doped region located in a second epitaxial layer, which is above the first epitaxial layer. The design structure further includes a reach-through structure penetrating from a surface of the device through the first and second epitaxial layers to the deep sub-collector, and a trench isolation structure penetrating from a surface of the device and surrounding the doped region.
    Type: Application
    Filed: November 16, 2007
    Publication date: April 17, 2008
    Applicant: INTERNATIONAL BUSINESS MACHISNES CORPORATION
    Inventors: Douglas D. COOLBAUGH, Xuefeng Liu, Robert M. Rassel, David C. Sheridan, Steven H. Voldman
  • Publication number: 20080087978
    Abstract: A structure and method comprises a deep sub-collector located in a first epitaxial layer and a doped region located in a second epitaxial layer, which is above the first epitaxial layer. The device further comprises a reach-through structure penetrating from a surface of the device through the first and second epitaxial layers to the deep sub-collector, and a trench isolation structure penetrating from a surface of the device and surrounding the doped region.
    Type: Application
    Filed: October 11, 2006
    Publication date: April 17, 2008
    Inventors: Douglas D. Coolbaugh, Xuefeng Liu, Robert M. Rassel, David C. Sheridan, Steven H. Voldman