Patents by Inventor Sik Lui

Sik Lui 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: 9691863
    Abstract: Embodiments of the present disclosure provide a self-aligned contact for a trench power MOSFET device. The device has a layer of nitride provided over the conductive material in the gate trenches and over portions of mesas between every two adjacent contact structures. Alternatively, the device has an oxide layer over the conductive material in the gate trenches and over portions of mesas between every two adjacent contact structures. It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
    Type: Grant
    Filed: April 8, 2015
    Date of Patent: June 27, 2017
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Hongyong Xue, Sik Lui, Terence Huang, Ching-Kai Lin, Wenjun Li, Yi Chang Yang, Jowei Dun
  • Patent number: 9685435
    Abstract: Aspects of the present disclosure describe MOSFET devices that have snubber circuits. The snubber circuits comprise one or more resistors with a dynamically controllable resistance that is controlled by changes to a gate and/or drain potentials of the one or more MOSFET structures during switching events.
    Type: Grant
    Filed: January 4, 2016
    Date of Patent: June 20, 2017
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Sik Lui, Ji Pan
  • Patent number: 9685523
    Abstract: This invention discloses a semiconductor device disposed in a semiconductor substrate. The semiconductor device includes a first semiconductor layer of a first conductivity type on a first major surface. The semiconductor device further includes a second semiconductor layer of a second conductivity type on a second major surface opposite the first major surface. The semiconductor device further includes an injection efficiency controlling buffer layer of a first conductivity type disposed immediately below the second semiconductor layer to control the injection efficiency of the second semiconductor layer.
    Type: Grant
    Filed: December 17, 2014
    Date of Patent: June 20, 2017
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Madhur Bobde, Harsh Naik, Lingpeng Guan, Anup Bhalla, Sik Lui
  • Publication number: 20170133458
    Abstract: Aspects of the present disclosure provides a device comprising a P-type semiconductor substrate, an N-type tub above the semiconductor substrate, a P-type region provided in the N-type tub isolated by one or more P-type isolation structures, and an N-type punch-through stopper provided under the P-type regions isolated by the isolation structure(s). The punch-through stopper is heavily doped compared to the N-type tub. The P-type region has a width between the two isolation structures that is equal to or less than that of the N-type punch-through stopper.
    Type: Application
    Filed: February 27, 2015
    Publication date: May 11, 2017
    Inventors: Hideaki Tsuchiko, Sik Lui
  • Patent number: 9595587
    Abstract: Embodiments of the present disclosure provide a contact structure in a split-gate trench transistor device for electrically connecting the top electrode to the bottom electrode inside the trench. The transistor device comprises a semiconductor substrate and one or more trenches formed in the semiconductor substrate. The trenches are lined with insulating materials along the sidewalls inside the trenches. Each trench has a bottom electrode in lower portions of the trench and a top electrode in its upper portions. The bottom electrode and the top electrode are separated by an insulating material. A contact structure filled with conductive materials is formed in each trench in an area outside of an active region of the device to connect the top electrode and the bottom electrode. It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure.
    Type: Grant
    Filed: April 23, 2014
    Date of Patent: March 14, 2017
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Yeeheng Lee, Sik Lui, Jongoh Kim, Hong Chang, Madhur Bobde, Lingpeng Guan, Hamza Yilmaz
  • Publication number: 20170047431
    Abstract: A plurality of gate trenches is formed into an epitaxial region of a first conductivity type over a semiconductor substrate. One or more contact trenches are formed into the epitaxial region, each between two adjacent gate trenches. One or more source regions of the first conductivity type are formed in a top portion of the epitaxial region between a contact trench and a gate trench. A barrier metal is formed inside each contact trench. Each gate trench is substantially filled with a conductive material separated from trench walls by a layer of dielectric material to form a gate . A heavily doped well region of a conductivity opposite the first type is provided in the epitaxial region proximate a bottom portion of each of the contact trenches. A horizontal width of a gap between the well region and the gate trench is about 0.05 nm to 0.2 nm.
    Type: Application
    Filed: October 27, 2016
    Publication date: February 16, 2017
    Inventors: Madhur Bobde, Sik Lui, Hamza Yilmaz, Jongoh Kim, Daniel Ng
  • Patent number: 9502554
    Abstract: Aspects of the present disclosure describe a high density trench-based power MOSFETs with self-aligned source contacts and methods for making such devices. The source contacts are self-aligned with spacers. The MOSFETS also may include a depletable shield in a lower portion of the substrate. The depletable shield may be configured such that during a high drain bias the shield substantially depletes. It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
    Type: Grant
    Filed: January 22, 2016
    Date of Patent: November 22, 2016
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Madhur Bobde, Hamza Yilmaz, Sik Lui, Daniel Ng
  • Publication number: 20160329426
    Abstract: Embodiments of the present disclosure provide a contact structure in a split-gate trench transistor device for electrically connecting the top electrode to the bottom electrode inside the trench. The transistor device comprises a semiconductor substrate and one or more trenches formed in the semiconductor substrate. The trenches are lined with insulating materials along the sidewalls inside the trenches. Each trench has a bottom electrode in lower portions of the trench and a top electrode in its upper portions. The bottom electrode and the top electrode are separated by an insulating material. A contact structure filled with conductive materials is formed in each trench in an area outside of an active region of the device to connect the top electrode and the bottom electrode. It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure.
    Type: Application
    Filed: July 19, 2016
    Publication date: November 10, 2016
    Inventors: Yeeheng Lee, Sik Lui, Jongoh Kim, Hong Chang, Madhur Bobde, Lingpeng Guan, Hamza Yilmaz
  • Patent number: 9484453
    Abstract: Aspects of the present disclosure describe a high density trench-based power. The active devices may have a two-step gate oxide. A lower portion may have a thickness that is larger than the thickness of an upper portion of the gate oxide. A lightly doped sub-body layer may be formed below a body region between two or more adjacent active device structures of the plurality. The sub-body layer extends from a depth of the upper portion of the gate oxide to a depth of the lower portion of the gate oxide It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
    Type: Grant
    Filed: September 3, 2015
    Date of Patent: November 1, 2016
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Hamza Yilmaz, Madhur Bobde, Hong Chang, Yeeheng Lee, Daniel Calafut, Jongoh Kim, Sik Lui, John Chen
  • Patent number: 9484452
    Abstract: A plurality of gate trenches is formed into an epitaxial region of a first conductivity type over a semiconductor substrate. One or more contact trenches are formed into the epitaxial region, each between two adjacent gate trenches. One or more source regions of the first conductivity type are formed in a top portion of the epitaxial region between a contact trench and a gate trench. A barrier metal is formed inside each contact trench. Each gate trench is substantially filled with a conductive material separated from trench walls by a layer of dielectric material to form a gate. A heavily doped well region of a conductivity opposite the first type is provided in the epitaxial region proximate a bottom portion of each of the contact trenches. A horizontal width of a gap between the well region and the gate trench is about 0.05 ?m to 0.2 ?m.
    Type: Grant
    Filed: December 10, 2014
    Date of Patent: November 1, 2016
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Madhur Bobde, Sik Lui, Hamza Yilmaz, Jongoh Kim, Daniel Ng
  • Publication number: 20160300917
    Abstract: Embodiments of the present disclosure provide a self-aligned contact for a trench power MOSFET device. The device has a layer of nitride provided over the conductive material in the gate trenches and over portions of mesas between every two adjacent contact structures. Alternatively, the device has an oxide layer over the conductive material in the gate trenches and over portions of mesas between every two adjacent contact structures. It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
    Type: Application
    Filed: April 8, 2015
    Publication date: October 13, 2016
    Inventors: Hongyong Xue, Sik Lui, Terence Huang, Ching-Kai Lin, Wenjun Li, Yi Chang Yang, Jowei Dun
  • Patent number: 9450088
    Abstract: Aspects of the present disclosure describe a high density trench-based power MOSFET with self-aligned source contacts. The source contacts are self-aligned with a first insulative spacer and a second insulative spacer, wherein the first spacer is resistant to an etching process that will selectively remove the material the second spacer is made from. It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
    Type: Grant
    Filed: November 10, 2015
    Date of Patent: September 20, 2016
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Yeeheng Lee, Hong Chang, Jongoh Kim, Sik Lui, Hamza Yilmaz, Madhur Bobde, Daniel Calafut, John Chen
  • Patent number: 9443928
    Abstract: An oxide termination semiconductor device may comprise a plurality of gate trenches, a gate runner, and an insulator termination trench. The gate trenches are located in an active region. Each gate trench includes a conductive gate electrode. The insulator termination trench is located in a termination region that surrounds the active region. The insulator termination trench is filled with an insulator material to form an insulator termination for the semiconductor device.
    Type: Grant
    Filed: December 10, 2015
    Date of Patent: September 13, 2016
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Sik Lui, Anup Bhalla
  • Publication number: 20160254347
    Abstract: Aspects of the present disclosure provides a device comprising a P-type semiconductor substrate, an N-type tub above the semiconductor substrate, a P-type region provided in the N-type tub isolated by one or more P-type isolation structures, and an N-type punch-through stopper provided under the P-type regions isolated by the isolation structure(s). The punch-through stopper is heavily doped compared to the N-type tub. The P-type region has a width between the two isolation structures that is equal to or less than that of the N-type punch-through stopper.
    Type: Application
    Filed: February 27, 2015
    Publication date: September 1, 2016
    Inventors: Hideaki Tsuchiko, Sik Lui
  • Publication number: 20160181391
    Abstract: This invention discloses a semiconductor device disposed in a semiconductor substrate. The semiconductor device includes a first semiconductor layer of a first conductivity type on a first major surface. The semiconductor device further includes a second semiconductor layer of a second conductivity type on a second major surface opposite the first major surface. The semiconductor device further includes an injection efficiency controlling buffer layer of a first conductivity type disposed immediately below the second semiconductor layer to control the injection efficiency of the second semiconductor layer.
    Type: Application
    Filed: December 17, 2014
    Publication date: June 23, 2016
    Inventors: Madhur Bobde, Harsh Naik, Lingpeng Guan, Anup Bhalla, Sik Lui
  • Publication number: 20160172482
    Abstract: A plurality of gate trenches is formed into an epitaxial region of a first conductivity type over a semiconductor substrate. One or more contact trenches are formed into the epitaxial region, each between two adjacent gate trenches. One or more source regions of the first conductivity type are formed in a top portion of the epitaxial region between a contact trench and a gate trench. A barrier metal is formed inside each contact trench. Each gate trench is substantially filled with a conductive material separated from trench walls by a layer of dielectric material to form a gate. A heavily doped well region of a conductivity opposite the first type is provided in the epitaxial region proximate a bottom portion of each of the contact trenches. A horizontal width of a gap between the well region and the gate trench is about 0.05 ?m to 0.2 ?m.
    Type: Application
    Filed: December 10, 2014
    Publication date: June 16, 2016
    Inventors: Madhur Bobde, Sik Lui, Hamza Yilmaz, Jongoh Kim, Daniel Ng
  • Publication number: 20160141411
    Abstract: Aspects of the present disclosure describe a high density trench-based power MOSFETs with self-aligned source contacts and methods for making such devices. The source contacts are self-aligned with spacers. The MOSFETS also may include a depletable shield in a lower portion of the substrate. The depletable shield may be configured such that during a high drain bias the shield substantially depletes. It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
    Type: Application
    Filed: January 22, 2016
    Publication date: May 19, 2016
    Inventors: Madhur Bobde, Hamza Yilmaz, Sik Lui, Daniel Ng
  • Publication number: 20160118380
    Abstract: Aspects of the present disclosure describe MOSFET devices that have snubber circuits. The snubber circuits comprise one or more resistors with a dynamically controllable resistance that is controlled by changes to a gate and/or drain potentials of the one or more MOSFET structures during switching events.
    Type: Application
    Filed: January 4, 2016
    Publication date: April 28, 2016
    Inventors: Sik Lui, Ji Pan
  • Patent number: 9324858
    Abstract: In a trench-gated MIS device contact is made to the gate within the trench, thereby eliminating the need to have the gate material, typically polysilicon, extend outside of the trench. This avoids the problem of stress at the upper corners of the trench. Contact between the gate metal and the polysilicon is normally made in a gate metal region that is outside the active region of the device. Various configurations for making the contact between the gate metal and the polysilicon are described, including embodiments wherein the trench is widened in the area of contact. Since the polysilicon is etched back below the top surface of the silicon throughout the device, there is normally no need for a polysilicon mask, thereby saving fabrication costs.
    Type: Grant
    Filed: November 1, 2010
    Date of Patent: April 26, 2016
    Assignee: Vishay-Siliconix
    Inventors: Anup Bhalla, Dorman Pitzer, Jacek Korec, Xiaorong Shi, Sik Lui
  • Publication number: 20160099308
    Abstract: An oxide termination semiconductor device may comprise a plurality of gate trenches, a gate runner, and an insulator termination trench. The gate trenches are located in an active region. Each gate trench includes a conductive gate electrode. The insulator termination trench is located in a termination region that surrounds the active region. The insulator termination trench is filled with an insulator material to form an insulator termination for the semiconductor device.
    Type: Application
    Filed: December 10, 2015
    Publication date: April 7, 2016
    Inventors: Sik Lui, Anup Bhalla