Patents by Inventor Sheau-Suey Li

Sheau-Suey Li 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: 7232717
    Abstract: A method of forming a non-volatile DRAM includes, in part: forming p-well and an n-well between two trench isolation regions formed in a semiconductor substrate, forming a polysilicon control gate of the non-volatile device disposed in the non-volatile DRAM, forming a first oxide spacer above portions of the body region and adjacent said first control gate, forming gate oxide layers of varying thicknesses above the body region, forming the guiding gate of the non-volatile device and the gate of an associated passgate transistor, forming LDD implant regions of the non-volatile device and the associated pass-gate transistor, forming source/drain regions of the non-volatile device and the associated pass-gate transistor, depositing a dielectric layer over the polysilicon guiding gate of the non-volatile device and the polysilicon gate of the associated passgate transistor, forming polysilicon landing pads, and forming polysilicon vertical walls defining capacitor plates of the non-volatile DRAM capacitor.
    Type: Grant
    Filed: May 28, 2003
    Date of Patent: June 19, 2007
    Assignee: O2IC, Inc.
    Inventors: Kyu Hyun Choi, Sheau-suey Li
  • Patent number: 6954377
    Abstract: In accordance with the present invention, a memory cell includes a pair of non-volatile devices and a pair of DRAM cells each associated with a different one of the non-volatile devices. Each DRAM cell further includes an MOS transistor a capacitor. The DRAM cells and their associated non-volatile devices operate differentially and when programmed store and supply complementary data. The non-volatile devices are erased prior to being programmed. Programming of the non-volatile devices may be done via hot-electron injection or Fowler-Nordheim tunneling. When a power failure occurs, the data stored in the DRAM are loaded in the non-volatile devices. After the power is restored, the data stored in the non-volatile devices are restored in the DRAM cells. The differential reading and wring of data reduces over-erase of the non-volatile devices.
    Type: Grant
    Filed: March 19, 2003
    Date of Patent: October 11, 2005
    Assignee: O2IC, Inc.
    Inventors: Kyu Hyun Choi, Sheau-suey Li
  • Publication number: 20050219913
    Abstract: Each non-volatile memory cell of an array of includes a guiding gate extending along a first portion of the cell's channel and a control gate extending along a second portion of the cell's channel. The first and second portions of the channel do not overlap. The guiding gate, which overlays the substrate above the channel, is insulated from the substrate via an oxide layer. The control gate, which also overlays the substrate above the channel region, is insulated from the substrate via an oxide-nitride-oxide layer. Each row of the array has a first terminal coupled to the guiding gates, and a second terminal coupled to the control gates of the cells disposed in that row. Each column of the array has a first terminal coupled to the drain regions, and a second terminal coupled to the source regions of the cells disposed in that column.
    Type: Application
    Filed: April 6, 2004
    Publication date: October 6, 2005
    Applicant: O2IC, Inc.
    Inventors: Kyu Choi, Sheau-suey Li
  • Patent number: 6806148
    Abstract: A method of forming an integrated circuit, includes, in part: forming trench isolation in a semiconductor substrate, forming a first well between the trench isolation, forming a second well above the first well, forming a first oxide layer above a first portion of the second well, forming a first dielectric layer above the first oxide layer, forming a first polysilicon gate layer above the first dielectric layer, forming a second dielectric layer above the first polysilicon layer, forming a first spacer above the body region and adjacent the first polysilicon layer, forming a second oxide layer above a second portion of the second well not covered by the first spacer, forming a second polysilicon gate layer above the second oxide layer, the first spacer and a portion of the second dielectric layer, and forming a second spacer to define source and drain regions.
    Type: Grant
    Filed: May 28, 2003
    Date of Patent: October 19, 2004
    Assignee: O2IC, Inc.
    Inventors: Kyu Hyun Choi, Sheau-suey Li
  • Publication number: 20030231528
    Abstract: In accordance with the present invention, a memory cell includes a pair of non-volatile devices and a pair of DRAM cells each associated with a different one of the non-volatile devices. Each DRAM cell further includes an MOS transistor a capacitor. The DRAM cells and their associated non-volatile devices operate differentially and when programmed store and supply complementary data. The non-volatile devices are erased prior to being programmed. Programming of the non-volatile devices may be done via hot-electron injection or Fowler-Nordheim tunneling. When a power failure occurs, the data stored in the DRAM are loaded in the non-volatile devices. After the power is restored, the data stored in the non-volatile devices are restored in the DRAM cells. The differential reading and wring of data reduces over-erase of the non-volatile devices.
    Type: Application
    Filed: March 19, 2003
    Publication date: December 18, 2003
    Applicant: 021C, Inc.
    Inventors: Kyu Hyun Choi, Sheau-suey Li
  • Patent number: 6645802
    Abstract: An ESD protection circuit includes a bipolar transistor, a resistor, and a zener diode formed on and within a semiconductor substrate. The resistor extends between the base and emitter regions of the transistor so that voltage developed across the resistor can turn on the transistor. The zener diode is formed in series with the resistor and extends between the base and collector regions of the transistor. Thus configured, breakdown current through the zener diode, typically in response to an ESD event, turns on the transistor to provide a nondestructive discharge path for the ESD. The zener diode includes anode and cathode diffusions. The cathode diffusion extends down into the semiconductor substrate in a direction perpendicular to the substrate. The anode diffusion extends down through the cathode diffusion into the semiconductor substrate. The anode diffusion extends down further than the cathode diffusion so that the zener diode is arranged vertically with respect to the substrate.
    Type: Grant
    Filed: June 8, 2001
    Date of Patent: November 11, 2003
    Assignee: Xilinx, Inc.
    Inventors: Sheau-Suey Li, Shahin Toutounchi, Michael J. Hart, Xin X. Wu, Daniel Gitlin
  • Patent number: 6268639
    Abstract: An ESD protection circuit includes a bipolar transistor, a resistor, and a zener diode formed on and within a semiconductor substrate. The resistor extends between the base and emitter regions of the transistor so that voltage developed across the resistor can turn on the transistor. The zener diode is formed in series with the resistor and extends between the base and collector regions of the transistor. Thus configured, breakdown current through the zener diode, typically in response to an ESD event, turns on the transistor to provide a nondestructive discharge path for the ESD. The zener diode includes anode and cathode diffusions. The cathode diffusion extends down into the semiconductor substrate in a direction perpendicular to the substrate. The anode diffusion extends down through the cathode diffusion into the semiconductor substrate. The anode diffusion extends down further than the cathode diffusion so that the zener diode is arranged vertically with respect to the substrate.
    Type: Grant
    Filed: February 11, 1999
    Date of Patent: July 31, 2001
    Assignee: Xilinx, Inc.
    Inventors: Sheau-Suey Li, Shahin Toutounchi, Michael J. Hart, Xin X. Wu, Daniel Gitlin
  • Patent number: 5880620
    Abstract: A pass gate circuit includes a pass transistor and a body bias control circuit for biasing the body of the pass transistor to reduce body effect. The body bias control circuit includes one or more control transistors arranged to selectively connect the substrate (body) of the pass transistor to the drain or gate of the pass transistor when predetermined voltages are applied to the drain and gate of the pass transistor. As a result, the pass transistor exhibits a reduced body effect in the on-state. In one embodiment, the body bias control circuit includes a first control transistor having a drain and gate connected to the gate of the pass transistor, a gate connected to the drain of the pass transistor, and a source. The body bias control circuit also includes a second control transistor having a drain connected to the source of the first control transistor, a source connected to a body of the pass transistor, and a gate connected to the drain of the pass transistor.
    Type: Grant
    Filed: April 22, 1997
    Date of Patent: March 9, 1999
    Assignee: Xilinx, Inc.
    Inventors: Daniel Gitlin, Sheau-Suey Li, Martin L. Voogel, Tiemin Zhao
  • Patent number: 5689133
    Abstract: An ESD protection circuit combines a split bipolar transistor with a transistor layout which exhibits very high tolerance to ESD events. The split bipolar transistor divides current among many segments and prevents the current hogging which often causes an ESD failure. Several splitting structures are disclosed, each combining a resistor in series with each segment to distribute current evenly. The transistor takes advantage of the snap-back effect to increase current carrying capacity. Layout positions metal contacts away from regions of highest energy dissipation. Layout also allows high currents to be dissipated through ESD protection structures and not through circuit devices such as output drivers or through parasitic bipolar transistors not designed for high current. Sharp changes in electron density are avoided by the use of high-diffusing phosphorus in N-regions implanted to both lightly and heavily doped levels. Critical corners are rounded rather than sharp.
    Type: Grant
    Filed: September 9, 1996
    Date of Patent: November 18, 1997
    Assignee: Xilinx, Inc.
    Inventors: Sheau-Suey Li, Randy T. Ong, Samuel Broydo, Khue Duong
  • Patent number: 5623387
    Abstract: An ESD protection circuit combines a split bipolar transistor with a transistor layout which exhibits very high tolerance to ESD events. The split bipolar transistor divides current among many segments and prevents the current hogging which often causes an ESD failure. Several splitting structures are disclosed, each combining a resistor in series with each segment to distribute current evenly. The transistor takes advantage of the snap-back effect to increase current carrying capacity. Layout positions metal contacts away from regions of highest energy dissipation. Layout also allows high currents to be dissipated through ESD protection structures and not through circuit devices such as output drivers or through parasitic bipolar transistors not designed for high current. Sharp changes in electron density are avoided by the use of high-diffusing phosphorus in N-regions implanted to both lightly and heavily doped levels. Critical corners are rounded rather than sharp.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: April 22, 1997
    Assignee: XILINX, Inc.
    Inventors: Sheau-Suey Li, Randy T. Ong, Samuel Broydo, Khue Duong
  • Patent number: 5610790
    Abstract: A method and structure for providing ESD protection for Silicon-On-Insulator (SOI) integrated circuits. The ESD protection circuit includes an electrically conductive pad and first conductor segment fabricated over an insulating layer. The first conductor segment connects the pad directly to a first node, without an intervening input resistor. A first diode is fabricated over the insulating layer and connected between the first node and a first voltage supply rail. Similarly, a second diode is fabricated over the insulating layer and connected between the first node and a second voltage supply rail. Ballast resistors can be included in series with each of the diodes. A cross power supply clamp, also fabricated over the insulating layer, is connected between the first and second voltage supply rails. The first node of the ESD protection circuit is coupled to the SOI integrated circuit to be protected.
    Type: Grant
    Filed: January 20, 1995
    Date of Patent: March 11, 1997
    Assignee: Xilinx, Inc.
    Inventors: David R. Staab, Sheau-Suey Li
  • Patent number: 5477414
    Abstract: An ESD protection circuit combines a split bipolar transistor with a transistor layout which exhibits very high tolerance to ESD events. The split bipolar transistor divides current among many segments and prevents the current hogging which often causes an ESD failure. Several splitting structures are disclosed, each combining a resistor in series with each segment to distribute current evenly. The transistor takes advantage of the snap-back effect to increase current carrying capacity. Layout positions metal contacts away from regions of highest energy dissipation. Layout also allows high currents to be dissipated through ESD protection structures and not through circuit devices such as output drivers or through parasitic bipolar transistors not designed for high current. Sharp changes in electron density are avoided by the use of high-diffusing phosphorus in N-regions implanted to both lightly and heavily doped levels. Critical corners are rounded rather than sharp.
    Type: Grant
    Filed: May 3, 1993
    Date of Patent: December 19, 1995
    Assignee: Xilinx, Inc.
    Inventors: Sheau-Suey Li, Randy T. Ong, Samuel Broydo, Khue Duong