Patents by Inventor Daniel Ng

Daniel Ng 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: 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: 9570404
    Abstract: A semiconductor power device comprises a plurality of power transistor cells each having a trenched gate disposed in a gate trench wherein the trenched gate comprising a shielding bottom electrode disposed in a bottom portion of the gate trench electrically insulated from a top gate electrode disposed in a top portion of the gate trench by an inter-electrode insulation layer. At least one of the transistor cells includes the shielding bottom electrode functioning as a source-connecting shielding bottom electrode electrically connected to a source electrode of the semiconductor power device and at least one of the transistor cells having the shielding bottom electrode functioning as a gate-connecting shielding bottom electrode electrically connected to a gate metal of the semiconductor power device.
    Type: Grant
    Filed: April 1, 2014
    Date of Patent: February 14, 2017
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Ji Pang, Daniel Ng, Anup Bhalla, Xiaobin Wang
  • 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: 20160322459
    Abstract: This invention discloses a semiconductor power device disposed in a semiconductor substrate and the semiconductor substrate has a plurality of trenches. Each of the trenches is filled with a plurality of epitaxial layers of alternating conductivity types constituting nano tubes functioning as conducting channels stacked as layers extending along a sidewall direction with a “Gap Filler” layer filling a merging-gap between the nano tubes disposed substantially at a center of each of the trenches. The “Gap Filler” layer can be very lightly doped Silicon or grown and deposited dielectric layer. In an exemplary embodiment, the plurality of trenches are separated by pillar columns each having a width approximately half to one-third of a width of the trenches.
    Type: Application
    Filed: May 1, 2015
    Publication date: November 3, 2016
    Inventors: Hamza Yilmaz, Daniel Ng, Lingping Guan, Anup Bhalla, Wilson Ma, Moses Ho, 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: 20160315053
    Abstract: A semiconductor power device comprises a plurality of power transistor cells each having a trenched gate disposed in a gate trench wherein the trenched gate comprising a shielding bottom electrode disposed in a bottom portion of the gate trench electrically insulated from a top gate electrode disposed in a top portion of the gate trench by an inter-electrode insulation layer. At least one of the transistor cells includes the shielding bottom electrode functioning as a source-connecting shielding bottom electrode electrically connected to a source electrode of the semiconductor power device and at least one of the transistor cells having the shielding bottom electrode functioning as a gate-connecting shielding bottom electrode electrically connected to a gate metal of the semiconductor power device.
    Type: Application
    Filed: April 1, 2014
    Publication date: October 27, 2016
    Inventors: Ji Pan, Daniel Ng, Anup Bhalla, Xiaobin Wang
  • Publication number: 20160260814
    Abstract: This invention discloses semiconductor power device that includes a plurality of top electrical terminals disposed near a top surface of a semiconductor substrate. Each and every one of the top electrical terminals comprises a terminal contact layer formed as a silicide contact layer near the top surface of the semiconductor substrate. The trench gates of the semiconductor power device are opened from the top surface of the semiconductor substrate and each and every one of the trench gates comprises the silicide layer configured as a recessed silicide contact layer disposed on top of every on of the trench gates slightly below a top surface of the semiconductor substrate surround the trench gate.
    Type: Application
    Filed: January 5, 2016
    Publication date: September 8, 2016
    Inventors: Hamza Yilmaz, John Chen, Daniel Ng, Wenjun Li
  • Publication number: 20160247899
    Abstract: This invention discloses a new switching device supported on a semiconductor that includes a drain disposed on a first surface and a source region disposed near a second surface of said semiconductor opposite the first surface. The switching device further includes an insulated gate electrode disposed on top of the second surface for controlling a source to drain current. The switching device further includes a source electrode interposed into the insulated gate electrode for substantially preventing a coupling of an electrical field between the gate electrode and an epitaxial region underneath the insulated gate electrode. The source electrode further covers and extends over the insulated gate for covering an area on the second surface of the semiconductor to contact the source region. The semiconductor substrate further includes an epitaxial layer disposed above and having a different dopant concentration than the drain region.
    Type: Application
    Filed: February 23, 2015
    Publication date: August 25, 2016
    Inventors: Anup Bhalla, Daniel Ng, Tiesheng Li, Sik K. Lui
  • Publication number: 20160190309
    Abstract: A semiconductor power device may include a lightly doped layer formed on a heavily doped layer. One or more devices are formed in the lightly doped layer. Each device may include a body region, a source region, and one or more gate electrodes formed in corresponding trenches in the lightly doped region. Each of the trenches has a depth in a first dimension, a width in a second dimension and a length in a third dimension. The body region is of opposite conductivity type to the lightly and heavily doped layers. The source region is formed proximate the upper surface. One or more deep contacts are formed at one or more locations along the third dimension proximate one or more of the trenches. The contacts extend in the first direction from the upper surface into the lightly doped layer and are in electrical contact with the source region.
    Type: Application
    Filed: March 4, 2016
    Publication date: June 30, 2016
    Inventors: Hamza Yilmaz, Daniel Ng, Daniel Calafut, Madhur Bobde, Anup Bhalla, Ji Pan, Yeeheng Lee, Jongoh Kim
  • 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
  • Patent number: 9356132
    Abstract: A semiconductor device includes a plurality of trenches including active gate trenches in an active area and gate runner/termination trenches and shield electrode pickup trenches in a termination area outside the active area. The gate runner/termination trenches include one or more trenches that define a mesa located outside an active area. A first conductive region is formed in the plurality of trenches. An intermediate dielectric region and termination protection region are formed in the trenches that define the mesa. A second conductive region is formed in the portion of the trenches that define the mesa. The second conductive region is electrically isolated from the first conductive region by the intermediate dielectric region. A first electrical contact is made to the second conductive regions and a second electrical contact to the first conductive region in the shield electrode pickup trenches. One or more Schottky diodes are formed within the mesa.
    Type: Grant
    Filed: June 27, 2014
    Date of Patent: May 31, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Yi Su, Daniel Ng, Anup Bhalla, Hong Chang, Jongoh Kim, John Chen
  • 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
  • Patent number: 9318603
    Abstract: The invention relates to a power semiconductor device and its preparation methods thereof. Particularly, the invention aims at providing a method for reducing substrate contribution to the Rdson (drain-source on resistance) of power MOSFETs, and a power MOSFET device made by the method. By forming one or more bottom grooves at the bottom of Si substrate, the on resistance of the power MOSFET device attributed to the substrate is effectively reduced. A matching lead frame base complementary to the substrate with bottom grooves further improves the package of the power MOSFET device.
    Type: Grant
    Filed: March 8, 2014
    Date of Patent: April 19, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Yi Su, Daniel Ng, Anup Bhalla, Jun Lu
  • Patent number: 9281394
    Abstract: A semiconductor power device may include a lightly doped layer formed on a heavily doped layer. One or more devices are formed in the lightly doped layer. Each device may include a body region, a source region, and one or more gate electrodes formed in corresponding trenches in the lightly doped region. Each of the trenches has a depth in a first dimension, a width in a second dimension and a length in a third dimension. The body region is of opposite conductivity type to the lightly and heavily doped layers. The source region is formed proximate the upper surface. One or more deep contacts are formed at one or more locations along the third dimension proximate one or more of the trenches. The contacts extend in the first direction from the upper surface into the lightly doped layer and are in electrical contact with the source region.
    Type: Grant
    Filed: July 11, 2014
    Date of Patent: March 8, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Hamza Yilmaz, Daniel Ng, Daniel Calafut, Madhur Bobde, Anup Bhalla, Ji Pan, Yeeheng Lee, Jongoh Kim
  • Patent number: 9252239
    Abstract: This invention discloses semiconductor power device that includes a plurality of top electrical terminals disposed near a top surface of a semiconductor substrate. Each and every one of the top electrical terminals comprises a terminal contact layer formed as a silicide contact layer near the top surface of the semiconductor substrate. The trench gates of the semiconductor power device are opened from the top surface of the semiconductor substrate and each and every one of the trench gates comprises the silicide layer configured as a recessed silicide contact layer disposed on top of every on of the trench gates slightly below a top surface of the semiconductor substrate surround the trench gate.
    Type: Grant
    Filed: May 31, 2014
    Date of Patent: February 2, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Hamza Yilmaz, John Chen, Daniel Ng, Wenjun Li
  • Patent number: 9252264
    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 and 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. 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: December 10, 2014
    Date of Patent: February 2, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Madhur Bobde, Hamza Yilmaz, Sik Lui, Daniel Ng
  • Publication number: 20160027771
    Abstract: A semiconductor power device supported on a semiconductor substrate comprising a plurality of transistor cells each having a source and a drain with a gate to control an electric current transmitted between the source and the drain. The semiconductor further includes a gate-to-drain (GD) clamp termination connected in series between the gate and the drain further includes a plurality of back-to-back polysilicon diodes connected in series to a silicon diode includes parallel doped columns in the semiconductor substrate wherein the parallel doped columns having a predefined gap. The doped columns further include a U-shaped bend column connect together the ends of parallel doped columns with a deep doped-well that is disposed below and engulfing the U-shaped bend.
    Type: Application
    Filed: July 26, 2014
    Publication date: January 28, 2016
    Inventors: Yi Su, Anup Bhalla, Daniel Ng
  • Publication number: 20160005853
    Abstract: A semiconductor device includes a plurality of trenches including active gate trenches in an active area and gate runner/termination trenches and shield electrode pickup trenches in a termination area outside the active area. The gate runner/termination trenches include one or more trenches that define a mesa located outside an active area. A first conductive region is formed in the plurality of trenches. An intermediate dielectric region and termination protection region are formed in the trenches that define the mesa. A second conductive region is formed in the portion of the trenches that define the mesa. The second conductive region is electrically isolated from the first conductive region by the intermediate dielectric region. A first electrical contact is made to the second conductive regions and a second electrical contact to the first conductive region in the shield electrode pickup trenches. One or more Schottky diodes are formed within the mesa.
    Type: Application
    Filed: June 27, 2014
    Publication date: January 7, 2016
    Applicant: Alpha and Omega Semiconductor Incorporated
    Inventors: Yi Su, Daniel Ng, Anup Bhalla, Hong Chang, Jongoh Kim, John Chen
  • Publication number: 20150349091
    Abstract: This invention discloses semiconductor power device that includes a plurality of top electrical terminals disposed near a top surface of a semiconductor substrate. Each and every one of the top electrical terminals comprises a terminal contact layer formed as a silicide contact layer near the top surface of the semiconductor substrate. The trench gates of the semiconductor power device are opened from the top surface of the semiconductor substrate and each and every one of the trench gates comprises the silicide layer configured as a recessed silicide contact layer disposed on top of every on of the trench gates slightly below a top surface of the semiconductor substrate surround the trench gate.
    Type: Application
    Filed: May 31, 2014
    Publication date: December 3, 2015
    Inventors: Hamza Yilmaz, John Chen, Daniel Ng, Wenjun Li
  • Patent number: 9136370
    Abstract: A trench formed in a body layer and epitaxial layer of a substrate is lined with a dielectric layer. A shield electrode formed within a lower portion of the trench is insulated by the dielectric layer. A gate electrode formed in the trench above the shield electrode is insulated from the shield electrode by another dielectric layer. One or more source regions formed within the body layer is adjacent a sidewall of the trench. A source pad formed above the body layer is electrically connected to the source regions and insulated from the gate electrode and shield electrode. The source pad provides an external contact to the source region. A gate pad provides an external contact to the gate electrode. A shield electrode pad provides an external contact to the shield electrode. A resistive element is electrically connected between the shield electrode pad and a source lead.
    Type: Grant
    Filed: June 3, 2014
    Date of Patent: September 15, 2015
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Sik Lui, Yi Su, Daniel Ng, Daniel Calafut, Anup Bhalla