Patents by Inventor Bill Liu

Bill 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: 20100261418
    Abstract: A method for manufacturing a magnetic disk is provided that includes the steps: forming a layer of a lubricant material on a surface of a magnetic storage medium, the layer of lubricant material also being located on an interior and/or exterior edge of the medium; and removing at least some of the lubricant material from the edge 160 of the medium.
    Type: Application
    Filed: March 23, 2010
    Publication date: October 14, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Thuan Luu, Walter Crofton, Bill Liu, David Spaulding, Kwang Kon Kim
  • Patent number: 7772591
    Abstract: Integrated circuit antifuse circuitry is provided. A metal-oxide-semiconductor (MOS) transistor serves as an electrically-programmable antifuse. The antifuse transistor has source, drain, gate, and substrate terminals. The gate has an associated gate oxide. In its unprogrammed state, the gate oxide is intact and the antifuse has a relatively high resistance. During programming, the gate oxide breaks down, so in its programmed state the antifuse transistor has a relatively low resistance. The antifuse transistor can be programmed by injecting hot carriers into the substrate of the device in the vicinity of the drain. Because there are more hot carriers at the drain than at the substrate, the gate oxide is stressed asymmetrically, which enhances programming efficiency. Feedback can be used to assist in turning the antifuse transistor on to inject the hot carriers.
    Type: Grant
    Filed: November 10, 2006
    Date of Patent: August 10, 2010
    Assignee: Altera Corporation
    Inventors: Chih-Ching Shih, Cheng H. Huang, Hugh Sung-Ki O, Yow-Juang (Bill) Liu
  • Patent number: 7682653
    Abstract: A method for manufacturing a magnetic disk is provided that includes the steps: (a) forming a layer 128 of a lubricant material on a surface of a magnetic storage medium 300, the layer 128 of lubricant material also being located on an interior and/or exterior edge of the medium 300; and (b) removing at least some of the lubricant material from the edge 160 of the medium.
    Type: Grant
    Filed: June 17, 2005
    Date of Patent: March 23, 2010
    Assignee: Seagate Technology LLC
    Inventors: Thuan Luu, Walter Crofton, Bill Liu, David Spaulding, Kwang Kon Kim
  • Patent number: 7671416
    Abstract: A device for providing electrostatic discharge (ESD) protection is provided. The device includes a semiconductor substrate having a drain, a source, and a gate formed therein. The drain contains a region having a resistance that is higher than the resistance of the remainder of the drain and the source. The gate region is in contact with this higher resistance region and the source. In one embodiment, the higher resistance is lacking silicide in order to provide the higher resistance. A method of forming a device for providing ESD protection is included.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: March 2, 2010
    Assignee: Altera Corporation
    Inventors: Hugh Sungki O, Chih-Ching Shih, Cheng-Hsiung Huang, Yow-Juang Bill Liu
  • Patent number: 7638847
    Abstract: An ESD protection structure includes, in part, a NMOS transistor having a source and drain in a well in a substrate and a gate on the substrate with the source and drain being connected between ground and a series diode, and the gate being connected to ground. The structure further includes a diode having a cathode connected to the input pad and an anode connected to the well so that the diode is reverse-biased in the event of a positive voltage ESD event on the input pad. As a result, in a positive voltage ESD event, the avalanche effect rapidly injects current into the substrate and therefore into the base of the parasitic bipolar transistor so as to trigger the transistor into conduction and discharge the ESD pulse. Alternatively, the diode is a Zener diode and the current is generated by the Zener effect. A complementary structure provides protection against a negative ESD pulse.
    Type: Grant
    Filed: January 25, 2006
    Date of Patent: December 29, 2009
    Assignee: Altera Corporation
    Inventors: Hugh Sungki O, Chih-Ching Shih, Cheng-Hsiung Huang, Yow-Juang Bill Liu
  • Patent number: 7514758
    Abstract: The invention provides a transistor having low leakage currents and methods of fabricating the transistor on a semiconductor substrate. The transistor has a gate and a nonuniform gate oxide under the gate.
    Type: Grant
    Filed: June 8, 2005
    Date of Patent: April 7, 2009
    Assignee: Altera Corporation
    Inventors: Peter John McElheny, Yowjuang (Bill) Liu
  • Patent number: 7511533
    Abstract: Circuits, methods, and apparatus for output devices having parasitic transistors for a higher output current drive. One such MOS output device includes a parasitic bipolar transistor that assists output voltage transitions. The parasitic transistor may be inherent in the structure of the MOS device. Alternately, one or more regions, such as implanted or diffused regions, may be added to the MOS device to form or enhance the parasitic bipolar device. The parasitic transistor is turned on when during an appropriate output transition and turned off once the transition is complete. The parasitic device may be turned on by injecting current into the bulk of a pull-down device, by pulling current out of the bulk of a pull-up device, or by tying the bulk of the output device to an appropriate voltage, such as VCC for a pull-down device or ground for a pull-up device.
    Type: Grant
    Filed: February 27, 2006
    Date of Patent: March 31, 2009
    Assignee: Altera Corporation
    Inventors: Hugh Sungki O, Chih-Ching Shih, Cheng-Hsiung Huang, Yow-Juang Bill Liu
  • Patent number: 7470630
    Abstract: An integrated circuit includes a semiconductor substrate and multiple dielectric layers stacked on the substrate. Multiple interconnect metal lines and dummy metals are embedded in the dielectric layers. At least one of the dummy metals is substantially thinner than the interconnect metal lines. To form this structure, first and second pluralities of trenches are formed in the dielectric layer. At least one of the second plurality of trenches is shallower than the first plurality of trenches. The first and second pluralities of trenches are filled with a conductive layer and then planarized.
    Type: Grant
    Filed: April 14, 2005
    Date of Patent: December 30, 2008
    Assignee: Altera Corporation
    Inventors: Shuxian Chen, Yow-Juang (Bill) Liu
  • Patent number: 7471493
    Abstract: A pair of SCR devices connected in antiparallel between first and second nodes. Each SCR device comprises an NPN and a PNP bipolar transistor. Reverse-biased Zener diodes are used for triggering the NPN bipolar transistor in each SCR device when it breaks down in an ESD event. Advantageously, additional Zener diodes are provided for pre-charging the PNP transistor of each SCR device at the same time, thereby reducing the delay time for turning on the PNP bipolar transistor. In addition, the breakdown current of the Zener diodes is preferably maximized by reducing the P-well and N-well resistance of the SCRs. This is achieved by connecting external resistances between the base of each bipolar transistor and the node to which the emitter of the transistor is connected.
    Type: Grant
    Filed: February 28, 2006
    Date of Patent: December 30, 2008
    Assignee: Altera Corporation
    Inventors: Cheng-Hsiung Huang, Chih-Ching Shih, Hugh Sung-Ki O, Yowjuang (Bill) Liu
  • Patent number: 7463057
    Abstract: Integrated circuits such as programmable logic device integrated circuits are provided with adjustable configuration random-access-memory cell power supply circuitry. The adjustable configuration random-access-memory cell power supply circuitry powers configuration random-access-memory cells on an integrated circuit. During operation of the integrated circuit, the configuration random-access-memory cells provide static output signals that turn on and off associated pass transistors. The adjustable power supply circuitry can be configured to produce different power supply voltages on different portions of an integrated circuit. The different power supply voltages accommodate circuit design constraints while minimizing power consumption due to pass transistor leakage.
    Type: Grant
    Filed: March 29, 2006
    Date of Patent: December 9, 2008
    Assignee: Altera Corporation
    Inventors: Irfan Rahim, Jeffrey T. Watt, Yowjuang (Bill) Liu
  • Patent number: 7408754
    Abstract: The present invention provides an ESD device for protecting thin oxide layers in transistors or capacitors in an integrated circuit. In one embodiment, the ESD device includes a silicon-controlled rectifier (SCR), the SCR including a PNP bipolar transistor and a NPN bipolar transistor. The ESD device further includes first and second trigger devices coupled to the SCR and configured to simultaneously turn on the PNP bipolar transistor and the NPN bipolar transistor in response to an ESD pulse on the ESD device. The base of the NPN bipolar transistor is floating to allow a first external resistor to be connected between the base and emitter of the NPN bipolar transistor. A second external resistor can be connected between the base and emitter of the PNP bipolar transistor.
    Type: Grant
    Filed: November 18, 2004
    Date of Patent: August 5, 2008
    Assignee: Altera Corporation
    Inventors: Hugh Sung-Ki O, Chih-Ching Shih, Yow-Juang Bill Liu, Cheng-Hsiung Huang, Wei-Guang Wu, Billy Jow-Tai Kwong, Yu-Cheng Richard Gao
  • Patent number: 7361961
    Abstract: An integrated circuit having an enhanced on-off swing for pass gate transistors is provided. The integrated circuit includes a core region that includes core transistors and pass gate transistors. The core transistors have a gate oxide associated with a first thickness, the pass transistors having a gate oxide associated with a thickness that is less than the first thickness. In one embodiment, the material used for the gate oxide of the pass gate transistors has a dielectric constant that is greater than four, while the material used for the gate oxide of the core transistors has a dielectric constant that is less than or equal to four. A method for manufacturing an integrated circuit is also provided.
    Type: Grant
    Filed: April 25, 2005
    Date of Patent: April 22, 2008
    Assignee: Altera Corporation
    Inventors: Irfan Rahim, Yow-Juang Bill Liu, Jeffrey Watt
  • Patent number: 7333312
    Abstract: An ESD device invention comprises first and second transistors formed in a substrate, each having a source, a drain and a gate, the source and drain of the first transaction being connected between ground and an I/O pin or input, the gate of the first transistor being connected to ground and the source and drain of the second transistor being connected between the substrate of the first transistor and the I/O pin or input; first and second capacitors connected in series between ground and the I/O pin or input; and at least a third transistor connected between ground and a node between the first and second capacitors to which the gate of the second transistor is also connected.
    Type: Grant
    Filed: July 1, 2005
    Date of Patent: February 19, 2008
    Assignee: Altera Corporation
    Inventors: Hugh Sungki O, Chih-Ching Shih, Cheng-Hsiung Huang, Yow-Juang Bill Liu
  • Patent number: 7326998
    Abstract: An integrated circuit is disclosed comprising at least one I/O pull-down device for protecting I/O logic circuits from electrostatic discharge (ESD). The turn-on voltage of the parasitic bipolar transistor in the I/O pull-down device is lowered by forming under a portion of the lightly doped drain (LDD) region of a first conductivity type of a conventional MOS transistor a second region of a second conductivity type. A P-N junction is formed between the second region and the source/drain regions. The turn-on voltage of the parasitic bipolar transistor in the I/O pull-down device can be reduced by at least 3 volts from that of a comparable device that does not practice the invention and can be varied by varying the concentration of the dopant. A method for forming the circuit including a process for recovering the current of the I/O pull-down device and its advantages are also disclosed.
    Type: Grant
    Filed: July 19, 2005
    Date of Patent: February 5, 2008
    Assignee: Altera Corporation
    Inventors: Hugh Sungki O, Chih-Ching Shih, Cheng-Hsiung Huang, Yow-Juang Bill Liu
  • Publication number: 20070243492
    Abstract: A first high resolution pattern is defined in a first layer of photoresist on a work surface and portions of the first layer are removed to expose the pattern on the work surface. The exposed portions of the work surface and the remaining portions of the first layer are then covered by a second layer of photoresist. A second lower resolution pattern is then defined in the second layer and portions of the second layer are removed to expose on the work surface a third pattern that is a subset of the first pattern. Standard (non-custom) masks may be used to define the first pattern while custom but lower resolution masks are used to define the second pattern.
    Type: Application
    Filed: February 23, 2007
    Publication date: October 18, 2007
    Inventors: Peter J. McElheny, Yowjuang (Bill) Liu
  • Patent number: 7279753
    Abstract: The present invention includes a bipolar ESD device for protecting an integrated circuit from ESD damage. The bipolar ESD device includes a collector connected to a terminal of the integrated circuit, a floating base, and a grounded emitter. When an ESD pulse hits the terminal of the integrated circuit, the PN junction between the emitter and the base becomes forward biased. The forward biasing of the emitter-base PN junction in turn causes carriers to be injected into the collector-base junction, triggering the bipolar ESD device to turn on to discharge the ESD pulse. The trigger voltage of the bipolar ESD device is a fraction of a breakdown voltage of the collector-base PN junction and can be modified by adjusting a base length of the bipolar ESD device, a junction depth of the collector, or a dopant concentration in the base.
    Type: Grant
    Filed: December 17, 2004
    Date of Patent: October 9, 2007
    Assignee: Altera Corporation
    Inventors: Hugh Sung-Ki O, Chih-Ching Shih, Yowjuang Bill Liu, Cheng-Hsiung Huang
  • Patent number: 7279952
    Abstract: A voltage converter includes a first N-channel MOSFET transistor, an inverter, a plurality of serially-connected diodes and a second N-channel MOSFET transistor. The inverter is coupled to the gate of the first N-channel MOSFET transistor to turn on/off the voltage converter. The anode of the diodes is coupled to the source of the first N-channel MOSFET transistor and the cathode of the diodes are coupled to the drain of the second N-channel MOSFET transistor. Since the source of the second N-channel MOSFET transistor is ground, the voltage clamped at the source of the first N-channel MOSFET transistor is not higher than 3.4V when a high voltage applied to the gate of the second N-channel MOSFET transistor turns it on.
    Type: Grant
    Filed: September 9, 2005
    Date of Patent: October 9, 2007
    Assignee: Altera Corporation
    Inventors: Hugh Sungki O, Chih-Ching Shih, Cheng-Hsiung Huang, Yow-Juang (Bill) Liu
  • Patent number: 7210115
    Abstract: Methods and apparatus for designing and producing programmable logic devices are provided. A logic design system may be used to analyze various implementations of a desired logic design for a programmable logic device integrated circuit. The logic design system may be used to produce configuration data for the programmable logic device in accordance with an optimized implementation. A logic circuit for a programmable logic device can be analyzed by taking into account the effects of hotspots, power supply voltage drops, and signal congestion on device performance. By modeling the performance of transistors and other components using position-dependent and signal-dependent variables such as temperature, voltage, and capacitance, the effects of congestion on device performance can be characterized and an optimum implementation of the logic design in a programmable logic device can be obtained.
    Type: Grant
    Filed: July 2, 2004
    Date of Patent: April 24, 2007
    Assignee: Altera Corporation
    Inventors: Irfan Rahim, Yow-Juang (Bill) Liu
  • Patent number: 7195958
    Abstract: The present invention provides a novel ESD structure for protecting an integrated circuit (IC) from ESD damage and a method of fabricating the ESD structure on a semiconductor substrate. The ESD structure of the present invention has lower trigger voltage and lower capacitance, and takes smaller substrate area than prior art ESD structures. The low trigger voltage is provided by a small N+P diode or a P+N diode which has a PN junction with a much lower breakdown voltage than a PN junction between a N+ (or P+) source/drain region and a P-well (or N-well). All of the diffusion regions in the ESD device of the present invention can be formed using ordinary process steps for fabricating the MOS devices in the IC and does not require extra masking steps in addition to those required to fabricate the IC.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: March 27, 2007
    Assignee: Altera Corporation
    Inventors: Cheng Huang, Yowjuang (Bill) Liu
  • Patent number: 7186610
    Abstract: The present invention includes a circuit structure for ESD protection and methods of making the circuit structure. The circuit structure can be used in an ESD protection circuitry to protect certain devices in an integrated circuit, and can be fabricated without extra processing steps in addition to the processing steps for fabricating the ESD protected devices in the integrated circuit.
    Type: Grant
    Filed: August 13, 2004
    Date of Patent: March 6, 2007
    Assignee: Altera Corporation
    Inventors: Yowjuang (Bill) Liu, Cheng Huang