Patents Assigned to Alpha and Omega Semiconductor Incorporated
  • Patent number: 9929076
    Abstract: The invention relates to a semiconductor package of a flip chip and a method for making the semiconductor package. The semiconductor chip comprises a metal-oxide-semiconductor field effect transistor. On a die paddle including a first base, a second base and a third base, half-etching or punching is performed on the top surfaces of the first base and the second base to obtain plurality of grooves that divide the top surface of the first base into a plurality of areas comprising multiple first connecting areas, and divide the top surface of the second base into a plurality of areas comprising at least a second connecting area. The semiconductor chip is connected to the die paddle at the first connecting areas and the second connecting area.
    Type: Grant
    Filed: June 7, 2013
    Date of Patent: March 27, 2018
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Yan Xun Xue, Yueh-Se Ho, Hamza Yilmaz, Jun Lu
  • Publication number: 20180082993
    Abstract: A transient-voltage suppressing (TVS) device disposed on a semiconductor substrate including a low-side steering diode, a high-side steering diode integrated with a main Zener diode for suppressing a transient voltage. The low-side steering diode and the high-side steering diode integrated with the Zener diode are disposed in the semiconductor substrate and each constituting a vertical PN junction as vertical diodes in the semiconductor substrate whereby reducing a lateral area occupied by the TVS device. In an exemplary embodiment, the high-side steering diode and the Zener diode are vertically overlapped with each other for further reducing lateral areas occupied by the TVS device.
    Type: Application
    Filed: September 30, 2017
    Publication date: March 22, 2018
    Applicant: Alpha and Omega Semiconductor Incorporated
    Inventor: Madhur Bobde
  • Patent number: 9911840
    Abstract: A transistor device includes a doped semiconductor substrate having one or more electrically insulated gate electrodes formed in trenches in the substrate. One or more body regions are formed in a top portion of the substrate proximate each gate trench. One or more source regions are formed in a self-aligned fashion in a top portion of the body regions proximate each gate trench. One or more thick insulator portions are formed over the gate electrodes on a top surface of the substrate with spaces between adjacent thick insulator portions. A metal is formed on top of the substrate over the thick insulator portions. The metal forms a self-aligned contact to the substrate through the spaces between the thick insulator portions. An integrated diode is formed under the self-aligned contact.
    Type: Grant
    Filed: March 2, 2015
    Date of Patent: March 6, 2018
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Sik Lui, Anup Bhalla
  • Patent number: 9911728
    Abstract: A low capacitance transient voltage suppressor with snapback control and a reduced voltage punch-through breakdown mode includes an n+ type substrate, a first epitaxial layer on the substrate, a buried layer formed within the first epitaxial layer, a second epitaxial layer on the first epitaxial layer, and an implant layer formed within the first epitaxial layer below the buried layer. The implant layer extends beyond the buried layer. A set of source regions is formed within a top surface of the second epitaxial layer. Implant regions are formed in the second epitaxial layer, with a first implant region located below the first source region.
    Type: Grant
    Filed: February 28, 2017
    Date of Patent: March 6, 2018
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Ning Shi, Lingpeng Guan, Madhur Bobde
  • Patent number: 9899931
    Abstract: A flyback converter implements a Forced Zero Voltage Switching (ZVS) timing control by detecting a positive current excursion of the secondary winding current as the synchronous rectifier turn off trigger. The synchronous rectifier switch is turned on near the end of the switching cycle or the on duration is extended to develop a current ripple on the secondary winding current. The control circuit of the flyback converter detects a positive current excursion on the secondary winding current to turn off the synchronous rectifier and to start the next switching cycle. At this point, the voltage across the primary switch has been discharged and the primary switch can be turned on with zero drain-to-source voltage. In other embodiments, zero voltage switching for the off-transition of the primary switch is realized by coupling a capacitor across the primary switch or by coupling a capacitor across the primary winding, or both.
    Type: Grant
    Filed: October 25, 2016
    Date of Patent: February 20, 2018
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Kuang Ming Chang, Lin Chen, Qihong Huang
  • Patent number: 9899471
    Abstract: An integrated circuit uses a compact CMOS device isolation scheme which forms a ring of N-well housing PMOS devices to encircle the P-well housing NMOS devices in a circuit block. An N-type buried layer is formed under the P-well and extends partially under the surrounding N-well. The compact CMOS device isolation scheme eliminates the use of a deep N-well ring around the circuit block. Therefore, the circuit blocks of the integrated circuit can be formed with reduced silicon area and the die size for implementing the integrated circuit is reduced.
    Type: Grant
    Filed: December 8, 2016
    Date of Patent: February 20, 2018
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventor: Shekar Mallikarjunaswamy
  • Patent number: 9893209
    Abstract: A cascoded junction field transistor (JFET) device comprises a first stage high voltage JFET cascoded to a second stage low voltage JFET wherein one of the first and second stages JFET is connected to a drain electrode of another JFET stage.
    Type: Grant
    Filed: May 13, 2014
    Date of Patent: February 13, 2018
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventor: Hideaki Tsuchiko
  • Patent number: 9887283
    Abstract: This invention discloses a semiconductor power device disposed in a semiconductor substrate. The semiconductor power device comprises a plurality of trenches each having a trench endpoint with an endpoint sidewall perpendicular to a longitudinal direction of the trench and extends vertically downward from a top surface to a trench bottom surface. The semiconductor power device further includes a trench bottom dopant region disposed below the trench bottom surface and a sidewall dopant region disposed along the endpoint sidewall wherein the sidewall dopant region extends vertically downward along the endpoint sidewall of the trench to reach the trench bottom dopant region and pick-up the trench bottom dopant region to the top surface of the semiconductor substrate.
    Type: Grant
    Filed: May 10, 2013
    Date of Patent: February 6, 2018
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Yongping Ding, Lei Zhang, Hong Chang, Jongoh Kim, John Chen
  • Patent number: 9882049
    Abstract: This invention discloses a semiconductor power device disposed in a semiconductor substrate. The semiconductor power device includes trenched gates each having a stick-up gate segment extended above a top surface of the semiconductor substrate surrounded by sidewall spacers. The semiconductor power device further includes slots opened aligned with the sidewall spacers substantially parallel to the trenched gates. The stick-up gate segment further includes a cap composed of an insulation material surrounded by the sidewall spacers. A layer of barrier metal covers a top surface of the cap and over the sidewall spacers and extends above a top surface of the slots. The slots are filled with a gate material same as the gate segment for functioning as additional gate electrodes for providing a depletion layer extends toward the trenched gates whereby a drift region between the slots and the trenched gate is fully depleted at a gate-to-drain voltage Vgs=0 volt.
    Type: Grant
    Filed: October 6, 2014
    Date of Patent: January 30, 2018
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: François Hébert, Madhur Bobde, Anup Bhalla
  • Publication number: 20180026025
    Abstract: A transient voltage suppressing (TVS) device formed in an epitaxial layer of a first conductivity type supported on a semiconductor substrate. The TVS device further comprises a plurality of contact trenches opened and extended to a lower part of the epitaxial layer filled with a doped polysilicon layer of a second conductivity type wherein the trenches are further surrounded by a heavy dopant region of the second conductivity type. The TVS device further includes a metal contact layer disposed on a top surface of the epitaxial layer electrically connected to a Vcc electrode wherein the metal contact layer further directly contacting the doped polysilicon layer and the heavy dopant region of the second conductivity type.
    Type: Application
    Filed: September 30, 2017
    Publication date: January 25, 2018
    Applicant: Alpha and Omega Semiconductor Incorporated
    Inventors: MADHUR BOBDE, WENJIANG ZENG, LIMIN WENG
  • Patent number: 9876073
    Abstract: This invention discloses a method for manufacturing a semiconductor power device in a semiconductor substrate comprises an active cell area and a termination area.
    Type: Grant
    Filed: April 5, 2017
    Date of Patent: January 23, 2018
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Lingpeng Guan, Anup Bhalla, Madhur Bobde, Tinggang Zhu
  • Patent number: 9876072
    Abstract: This invention discloses a semiconductor power device disposed in a semiconductor substrate and the semiconductor substrate has a plurality of deep trenches. The deep trenches are filled with an epitaxial layer thus forming a top epitaxial layer covering areas above a top surface of the deep trenches covering over the semiconductor substrate. The semiconductor power device further includes a plurality of transistor cells disposed in the top epitaxial layer whereby a device performance of the semiconductor power device is dependent on a depth of the deep trenches and not dependent on a thickness of the top epitaxial layer. Each of the plurality of transistor cells includes a trench DMOS transistor cell having a trench gate opened through the top epitaxial layer and filled with a gate dielectric material.
    Type: Grant
    Filed: June 14, 2016
    Date of Patent: January 23, 2018
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventor: François Hébert
  • Patent number: 9876096
    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: October 27, 2016
    Date of Patent: January 23, 2018
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Madhur Bobde, Sik Lui, Hamza Yilmaz, Jongoh Kim, Daniel Ng
  • Patent number: 9865694
    Abstract: A plurality of gate trenches is formed into a semiconductor substrate in an active cell region. One or more other trenches are formed in a different region. Each gate trench has a first conductive material in lower portions and a second conductive material in upper portions. In the gate trenches, a first insulating layer separates the first conductive material from the substrate, a second insulating layer separates the second conductive material from the substrate and a third insulating material separates the first and second conductive materials. The other trenches contain part of the first conductive material in a half-U shape in lower portions and part of the second conductive material in upper portions. In the other trenches, the third insulating layer separates the first and second conductive materials. The first insulating layer is thicker than the third insulating layer, and the third insulating layer is thicker than the second.
    Type: Grant
    Filed: January 23, 2017
    Date of Patent: January 9, 2018
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Yeeheng Lee, Lingpeng Guan, Hongyong Xue, Yiming Gu, Yang Xiang, Terence Huang, Sekar Ramamoorthy, Wenjun Li, Hong Chang, Madhur Bobde, Paul Thorup, Hamza Yilmaz
  • Patent number: 9865678
    Abstract: A semiconductor device includes a semiconductor substrate and epitaxial layer of a first conductivity type with the epitaxial layer on a top surface of the substrate. A body region of a second conductivity type opposite the first conductivity type is disposed near a top surface of the epitaxial layer. A first conductivity type source region is inside the body region and a drain is at a bottom surface of the substrate. An inslated gate overlaps the source and body regions. First and second trenches in the epitaxial layer are lined with insulation material and filled with electrically conductive material. Second conductivity type buried regions are positioned below the trenches. Second conductivity type charge linking paths along one or more walls of the first trench electrically connect a first buried region to the body region. A second buried region is separated from the body region by portions of the expitaxial layer.
    Type: Grant
    Filed: August 12, 2016
    Date of Patent: January 9, 2018
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Anup Bhalla, Hamza Yilmaz, Madhur Bobde, Lingpeng Guan, Jun Hu, Jongoh Kim, Yongping Ding
  • Publication number: 20180005959
    Abstract: A trench-type metal-oxide-semiconductor field-effect transistor (MOSFET) device and a fabrication method are disclosed. The trench MOSFET device comprises a semiconductor substrate of a first conductivity type. The semiconductor substrate has a plurality of first trenches arranged side by side in a first preset area of the semiconductor substrate extending along a first direction and a plurality of second trenches arranged side by side in a second preset area of the semiconductor substrate extending along a second direction perpendicular to the first direction. A control gate is formed in each of the pluralities of first and second trenches. A body region of a second conductivity type is formed at a top portion of the semiconductor substrate near sidewalls of the pluralities of first and second trenches. A source region of the first conductivity type is formed on a top portion of the body region.
    Type: Application
    Filed: June 30, 2016
    Publication date: January 4, 2018
    Applicant: Alpha and Omega Semiconductor Incorporated
    Inventors: Xiaobin Wang, Madhur Bobde, Paul Thorup
  • Patent number: 9853143
    Abstract: A closed cell lateral MOSFET device includes minimally sized source/body contacts formed in source cells with silicided source and body diffusion regions formed therein. In this manner, the cell pitch of the cellular transistor array is kept small while the ruggedness of the transistor is ensured. In other embodiments, a closed cell lateral MOSFET device is formed using silicided source and body diffusion regions and self-aligned contacts or borderless contacts as the source/body contacts. The polysilicon gate mesh can be formed using minimum polysilicon-to-polysilicon spacing to minimize the cell pitch of the cellular transistor array.
    Type: Grant
    Filed: April 11, 2016
    Date of Patent: December 26, 2017
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventor: Shekar Mallikarjunaswamy
  • Patent number: 9853548
    Abstract: A current detection circuit for detecting a current in a Switch Mode Power Supply (SMPS) having a first switch and a second switch coupled in series and an output filter including an inductor and a capacitor coupled to a switch node formed by the first and second switches, has a current sensing circuit for sensing a current across the second switch and generating a current sensing signal indicating current information of the second switch, and a current emulation circuit for emulating current information of the first switch. The current emulation circuit includes an inductance sensing circuit for acquiring a real-time rate of change in inductor current and an AC emulation circuit for computing the AC portion of the current information of the first switch based on the real-time rate of change in inductor current.
    Type: Grant
    Filed: February 6, 2017
    Date of Patent: December 26, 2017
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventor: Zhiye Zhang
  • Patent number: 9846469
    Abstract: A fault tolerant power supply system includes at least one load switch circuit configured to connect, using a main switch, an input voltage to an output node of the load switch circuit when the load switch circuit is turned on and at least one power channel coupled to the load switch circuit to receive the input voltage. The power channel is configured as a buck converter and includes at least a high-side power switch and a low-side power switch. The fault tolerant power supply system is configured to measure a current flowing through the main switch of the load switch circuit, to determine that the current flowing through the main switch of the load switch circuit has exceeded a current limit threshold, and to disable the main switch of the load switch circuit and the low-side power switch of the power channel in response to the determination that the current flowing in the main switch has exceeded the current limit threshold.
    Type: Grant
    Filed: May 16, 2016
    Date of Patent: December 19, 2017
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Mark Tomas, Zhiye Zhang, Allen Chang, Kuang Ming Chang, Gilbert Lee, Son Tran
  • Patent number: 9837386
    Abstract: A power conversion device including a low-side MOSFET, a high-side MOSFET and an integrated control IC chip is disclosed. The power conversion device further includes a substrate comprising a first mounting area having a first group of welding discs and a second mounting area having a second group of welding discs; a first chip flipped and attached to the first mounting area; a second chip flipped and attached to the second mounting area; a metal clip; and a molding body covering a front surface of the substrate, the first chip, the second chip and the metal clip. Metal pads on a front side of the first chip is attached to the first group of welding discs. Metal pads on a front side of the second chip is attached to the second group of welding discs. The metal clip connects a connection pad to a back metal layer of the first chip.
    Type: Grant
    Filed: January 12, 2016
    Date of Patent: December 5, 2017
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Xiaotian Zhang, Shekar Mallikarjunaswamy, Zhiqiang Niu, Cheow Khoon Oh, Yueh-Se Ho