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: 20080069167Abstract: 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: ApplicationFiled: May 19, 2005Publication date: March 20, 2008Inventors: Stephen Gorton, Gary Ternent, Christopher Humby, Xuefeng Liu, John Marsh
-
Publication number: 20080067623Abstract: 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: ApplicationFiled: November 26, 2007Publication date: March 20, 2008Inventors: Douglas Coolbaugh, Jeffrey Johnson, Xuefeng Liu, Bradley Orner, Robert Rassel, David Sheridan
-
Patent number: 7335927Abstract: 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: GrantFiled: January 30, 2006Date of Patent: February 26, 2008Assignee: Internatioanl Business Machines CorporationInventors: Douglas Duane Coolbaugh, Jeffrey Bowman Johnson, Xuefeng Liu, Bradley Alan Orner, Robert Mark Rassel, David Charles Sheridan
-
Publication number: 20080036029Abstract: 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: ApplicationFiled: October 11, 2007Publication date: February 14, 2008Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Xuefeng LIU, Rober Rassel, Steven Voldman
-
Patent number: 7329940Abstract: 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: GrantFiled: November 2, 2005Date of Patent: February 12, 2008Assignee: International Business Machines CorporationInventors: Douglas D. Coolbaugh, Alvin J. Joseph, Seong-dong Kim, Louis D. Lanzerotti, Xuefeng Liu, Robert M. Rassel
-
Patent number: 7323948Abstract: 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: GrantFiled: August 23, 2005Date of Patent: January 29, 2008Assignee: International Business Machines CorporationInventors: Hanyi Ding, Kai D. Feng, Zhong-Xiang He, Xuefeng Liu
-
Publication number: 20080012091Abstract: 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: ApplicationFiled: September 24, 2007Publication date: January 17, 2008Inventors: Hanyi Ding, Kai Feng, Zhong-Xiang He, Xuefeng Liu
-
Patent number: 7317215Abstract: 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: GrantFiled: September 21, 2004Date of Patent: January 8, 2008Assignee: International Business Machines CorporationInventors: Peter J. Geiss, Alvin J. Joseph, Rajendran Krishnasamy, Xuefeng Liu
-
Publication number: 20070287243Abstract: 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: ApplicationFiled: June 7, 2006Publication date: December 13, 2007Inventors: Xuefeng Liu, Robert M. Rassel, Steven H. Voldman
-
Publication number: 20070278614Abstract: 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: ApplicationFiled: June 5, 2006Publication date: December 6, 2007Inventors: David S. Collins, Jeffrey B. Johnson, Xuefeng Liu, Bradley A. Orner, Robert M. Rassel, David C. Sheridan
-
Publication number: 20070278618Abstract: 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: ApplicationFiled: June 2, 2006Publication date: December 6, 2007Inventors: David S. Collins, Hanyi Ding, Kai Di Feng, Zhong-Xiang He, Xuefeng Liu
-
Patent number: 7288417Abstract: 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: GrantFiled: January 6, 2005Date of Patent: October 30, 2007Assignee: International Business Machines CorporationInventors: Hanyi Ding, Kai D. Feng, Zhong-Xiang He, Xuefeng Liu
-
Publication number: 20070241421Abstract: 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: ApplicationFiled: April 17, 2006Publication date: October 18, 2007Inventors: Xuefeng Liu, Robert Rassel, Steven Voldman
-
Patent number: 7271693Abstract: 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: GrantFiled: April 7, 2006Date of Patent: September 18, 2007Assignee: International Business Machines CorporationInventors: Hanyi Ding, Kai Di Feng, Zhong-Xiang He, Xuefeng Liu
-
Publication number: 20070176252Abstract: 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: ApplicationFiled: January 30, 2006Publication date: August 2, 2007Inventors: Douglas Duane Coolbaugh, Jeffrey Bowman Johnson, Xuefeng Liu, Bradley Alan Orner, Robert Mark Rassel, David Charles Sheridan
-
Patent number: 7242071Abstract: 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: GrantFiled: July 6, 2006Date of Patent: July 10, 2007Assignee: International Business Machine CorporationInventors: Xuefeng Liu, Robert M. Rassel, Steven H. Voldman
-
Publication number: 20070105354Abstract: 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: ApplicationFiled: November 10, 2005Publication date: May 10, 2007Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Douglas Coolbaugh, Xuefeng Liu, Robert Rassel, David Sheridan
-
Publication number: 20070096257Abstract: 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: ApplicationFiled: November 2, 2005Publication date: May 3, 2007Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Douglas Coolbaugh, Alvin Joseph, Seong-dong Kim, Louis Lanzerotti, Xuefeng Liu, Robert Rassel
-
Publication number: 20070052062Abstract: 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: ApplicationFiled: August 23, 2005Publication date: March 8, 2007Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Hanyi Ding, Kai Feng, Zhong-Xiang He, Xuefeng Liu
-
Publication number: 20070038968Abstract: 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: ApplicationFiled: August 10, 2005Publication date: February 15, 2007Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Florian Braun, Hanyi Ding, Kai Feng, Zhong-Xiang He, Howard Landis, Xuefeng Liu, Geoffrey Woodhouse