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).

  • Publication number: 20080069167
    Abstract: Apparatus for implementing a thermal printing technique onto thermally sensitive print media use one or more laser arrays to provide optical heating. A technique for alignment of multiple monolithic arrays onto a common carrier such that the constant pitch of parallel output beams is maintained as described.
    Type: Application
    Filed: May 19, 2005
    Publication date: March 20, 2008
    Inventors: Stephen Gorton, Gary Ternent, Christopher Humby, Xuefeng Liu, John Marsh
  • Publication number: 20080067623
    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: Application
    Filed: November 26, 2007
    Publication date: March 20, 2008
    Inventors: Douglas Coolbaugh, Jeffrey Johnson, Xuefeng Liu, Bradley Orner, Robert Rassel, David Sheridan
  • Patent number: 7335927
    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: January 30, 2006
    Date of Patent: February 26, 2008
    Assignee: Internatioanl Business Machines Corporation
    Inventors: Douglas Duane Coolbaugh, Jeffrey Bowman Johnson, Xuefeng Liu, Bradley Alan Orner, Robert Mark Rassel, David Charles Sheridan
  • Publication number: 20080036029
    Abstract: A design structure embodied in a machine readable medium used in a design process. The design structure includes 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 design structure additionally includes 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. Also, the design structure includes N+ diffusion regions in contact with the N-well, a P+ diffusion region within the N-well, and shallow trench isolation structures between the N+ and P+ diffusion regions.
    Type: Application
    Filed: October 11, 2007
    Publication date: February 14, 2008
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Xuefeng LIU, Rober Rassel, Steven Voldman
  • Patent number: 7329940
    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: Grant
    Filed: November 2, 2005
    Date of Patent: February 12, 2008
    Assignee: International Business Machines Corporation
    Inventors: Douglas D. Coolbaugh, Alvin J. Joseph, Seong-dong Kim, Louis D. Lanzerotti, Xuefeng Liu, Robert M. Rassel
  • Patent number: 7323948
    Abstract: An LC tank structure. The structure, including a set of wiring levels on top of a semiconductor substrate, the wiring levels stacked on top of each other from a lowest wiring level nearest the substrate to a highest wiring level furthest from the substrate; an inductor in the highest wiring level, the inductor confined within a perimeter of a region of the highest wiring level; and a varactor formed in the substrate, the varactor aligned completely under the perimeter of the region of the highest wiring level. The structure may additionally include an electric shield in a wiring level of the set of wiring levels between the lowest wiring level and the highest wiring level. Alternatively, the inductor includes a magnetic core and alternating electrically non-magnetic conductive metal coils and magnetic coils around the core.
    Type: Grant
    Filed: August 23, 2005
    Date of Patent: January 29, 2008
    Assignee: International Business Machines Corporation
    Inventors: Hanyi Ding, Kai D. Feng, Zhong-Xiang He, Xuefeng Liu
  • Publication number: 20080012091
    Abstract: An LC tack structure. The structure, including a set of wiring levels on top of a semiconductor substrate, the wiring levels stacked on top of each other from a lowest wiring level nearest the substrate to a highest wiring level furthest from the substrate; an inductor in the highest wiring level, the inductor confined within a perimeter of a region of the highest wiring level; and a varactor formed in the substrate, the varactor aligned completely under the perimeter of the region of the highest wiring level. The structure may additionally include an electric shield in a wiring level of the set of wiring levels between the lowest wiring level and the highest wiring level. Alternatively, the inductor includes a magnetic core and alternating electrically non-magnetic conductive metal coils and magnetic coils around the core.
    Type: Application
    Filed: September 24, 2007
    Publication date: January 17, 2008
    Inventors: Hanyi Ding, Kai Feng, Zhong-Xiang He, Xuefeng Liu
  • Patent number: 7317215
    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: September 21, 2004
    Date of Patent: January 8, 2008
    Assignee: International Business Machines Corporation
    Inventors: Peter J. Geiss, Alvin J. Joseph, Rajendran Krishnasamy, Xuefeng Liu
  • Publication number: 20070287243
    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: June 7, 2006
    Publication date: December 13, 2007
    Inventors: Xuefeng Liu, Robert M. Rassel, Steven H. Voldman
  • Publication number: 20070278614
    Abstract: A lateral passive device is disclosed including a dual annular electrode. The annular electrodes form an anode and a cathode. The annular electrodes allow anode and cathode series resistances to be optimized to the lowest values at a fixed device area. In addition, the parasitic capacitance to a bottom plate (substrate) is greatly reduced. In one embodiment, a device includes a first annular electrode surrounding a second annular electrode formed on a substrate, and the second annular electrode surrounds an insulator region. A related method is also disclosed.
    Type: Application
    Filed: June 5, 2006
    Publication date: December 6, 2007
    Inventors: David S. Collins, Jeffrey B. Johnson, Xuefeng Liu, Bradley A. Orner, Robert M. Rassel, David C. Sheridan
  • Publication number: 20070278618
    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: Application
    Filed: June 2, 2006
    Publication date: December 6, 2007
    Inventors: David S. Collins, Hanyi Ding, Kai Di Feng, Zhong-Xiang He, Xuefeng Liu
  • Patent number: 7288417
    Abstract: A mixed-signal chip having a signal transformer located between analog circuitry and digital circuitry. The signal transformer includes a primary winding electrically coupled to the analog circuitry and a secondary winding electrically coupled to the digital circuitry. The primary and secondary windings are magnetically coupled with one another via a magnetic core. The magnetic coupling between the primary and secondary windings inhibits the coupling of electrical noise between the analog and digital circuitries.
    Type: Grant
    Filed: January 6, 2005
    Date of Patent: October 30, 2007
    Assignee: International Business Machines Corporation
    Inventors: Hanyi Ding, Kai D. Feng, Zhong-Xiang He, Xuefeng Liu
  • Publication number: 20070241421
    Abstract: A structure comprises a deep subcollector buried in a first region of a dual epitaxial layer and a reachthrough structure in contact with the deep subcollector to provide a low-resistive shunt which prevents CMOS latch-up for a first device. The structure may additionally include a near subcollector formed in a higher region than the deep subcollector and under another device. At least one reachthrough electrically connects the deep subcollector and the near subcollector. The method includes forming a merged triple well double epitaxy/double subcollector.
    Type: Application
    Filed: April 17, 2006
    Publication date: October 18, 2007
    Inventors: Xuefeng Liu, Robert Rassel, Steven Voldman
  • Patent number: 7271693
    Abstract: An inductor formed on an integrated circuit chip including one or more inner layers between two or more outer layers, inductor metal winding turns included in one or more inner layers, and a magnetic material forming the two or more outer layers and the one or more inner layers. In one embodiment, the magnetic material is a photoresist paste having magnetic particles. In another embodiment, the magnetic material is a series of magnetic metallic strips disposed on each of first and second portions of the two or more outer layers and on each of the one or more inner layers. The series of magnetic metallic strips on the first and second portions form a grid pattern. Other embodiments include an adjustable controlled compound deposit and control windings with adjustable electrical currents.
    Type: Grant
    Filed: April 7, 2006
    Date of Patent: September 18, 2007
    Assignee: International Business Machines Corporation
    Inventors: Hanyi Ding, Kai Di Feng, Zhong-Xiang He, Xuefeng Liu
  • Publication number: 20070176252
    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: Application
    Filed: January 30, 2006
    Publication date: August 2, 2007
    Inventors: Douglas Duane Coolbaugh, Jeffrey Bowman Johnson, Xuefeng Liu, Bradley Alan Orner, Robert Mark Rassel, David Charles Sheridan
  • Patent number: 7242071
    Abstract: A structure comprises a deep sub-collector buried in a first epitaxial layer and a near sub-collector buried in a second epitaxial layer. The structure further comprises a deep trench isolation structure isolating a region which is substantially above the deep sub-collector, a reach-through structure in contact with the near sub-collector, and a reach-through structure in contact with the deep sub-collector to provide a low-resistance shunt, which prevents COMS latch-up of a device. The method includes forming a merged triple well double epitaxy/double sub-collector structure.
    Type: Grant
    Filed: July 6, 2006
    Date of Patent: July 10, 2007
    Assignee: International Business Machine Corporation
    Inventors: Xuefeng Liu, Robert M. Rassel, Steven H. Voldman
  • Publication number: 20070105354
    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: Application
    Filed: November 10, 2005
    Publication date: May 10, 2007
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Douglas Coolbaugh, Xuefeng Liu, Robert Rassel, David Sheridan
  • Publication number: 20070096257
    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 2, 2005
    Publication date: May 3, 2007
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Douglas Coolbaugh, Alvin Joseph, Seong-dong Kim, Louis Lanzerotti, Xuefeng Liu, Robert Rassel
  • Publication number: 20070052062
    Abstract: An LC tank structure. The structure, including a set of wiring levels on top of a semiconductor substrate, the wiring levels stacked on top of each other from a lowest wiring level nearest the substrate to a highest wiring level furthest from the substrate; an inductor in the highest wiring level, the inductor confined within a perimeter of a region of the highest wiring level; and a varactor formed in the substrate, the varactor aligned completely under the perimeter of the region of the highest wiring level. The structure may additionally include an electric shield in a wiring level of the set of wiring levels between the lowest wiring level and the highest wiring level. Alternatively, the inductor includes a magnetic core and alternating electrically non-magnetic conductive metal coils and magnetic coils around the core.
    Type: Application
    Filed: August 23, 2005
    Publication date: March 8, 2007
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Hanyi Ding, Kai Feng, Zhong-Xiang He, Xuefeng Liu
  • Publication number: 20070038968
    Abstract: Increase power line noise immunity in an IC is provided by using decoupling capacitor structure in an area of the IC that is typically not used for routing, but filled with unconnected and non-functional metal squares (fills). In one embodiment, a method includes providing a circuit design layout; determining a density of a structure in an area of the circuit design layout; and in response to the density being less than a pre-determined density for the structure in the area, filling in a portion of the area with at least one capacitor structure until a combined density of the structure and the at least one capacitor structure in the area is about equal to the pre-determined density. Power line noise immunity is increased by increasing decoupling capacitance without enlarging the IC's total size by using a (fill) area that would normally be filled with unconnected and non-functional metal shapes.
    Type: Application
    Filed: August 10, 2005
    Publication date: February 15, 2007
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Florian Braun, Hanyi Ding, Kai Feng, Zhong-Xiang He, Howard Landis, Xuefeng Liu, Geoffrey Woodhouse