Patents Assigned to Alpha and Omega Semiconductor Incorporated
  • Patent number: 9548307
    Abstract: An integrated circuit includes a first well of the first conductivity type formed in a semiconductor layer where the first well housing active devices and being connected to a first well potential, a second well of a second conductivity type formed in the semiconductor layer and encircling the first well where the second well housing active devices and being connected to a second well potential, and a buried layer of the second conductivity type formed under the first well and overlapping at least partially the second well encircling the first well. In an alternate embodiment, instead of the buried layer, the integrated circuit includes a third well of the second conductivity type formed in the semiconductor layer where the third well contains the first well and overlaps at least partially the second well encircling the first well.
    Type: Grant
    Filed: June 30, 2014
    Date of Patent: January 17, 2017
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventor: Shekar Mallikarjunaswamy
  • Patent number: 9548352
    Abstract: This invention discloses a semiconductor power device disposed in a semiconductor substrate comprising a lightly doped layer formed on a heavily doped layer and having an active cell area and an edge termination area. The edge termination area comprises a plurality P-channel MOSFETs. By connecting the gate to the drain electrode, the P-channel MOSFET transistors formed on the edge termination are sequentially turned on when the applied voltage is equal to or greater than the threshold voltage Vt of the P-channel MOSFET transistors, thereby optimizing the voltage blocked by each region.
    Type: Grant
    Filed: July 12, 2014
    Date of Patent: January 17, 2017
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Hamza Yilmaz, Madhur Bobde
  • Patent number: 9543292
    Abstract: One or more Zener diodes and a field effect transistor having a drain connected in series with the one or more Zener diodes are integrally formed by a plurality of doped regions in the same P-type semiconductor substrate and separated by a punch through stop region. An N-type region is formed under the one or more Zener diodes.
    Type: Grant
    Filed: February 27, 2015
    Date of Patent: January 10, 2017
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventor: Hideaki Tsuchiko
  • Patent number: 9543413
    Abstract: A corner layout for a semiconductor device that maximizes the breakdown voltage is disclosed. The device includes first and second subsets of the striped cell arrays. The ends of each striped cell in the first array is spaced a uniform distance from the nearest termination device structure. In the second subset, the ends of striped cells proximate a corner of the active cell region are configured to maximize breakdown voltage by spacing the ends of each striped cell a non-uniform distance from the nearest termination device structure. It is emphasized that this abstract is provided to comply with the 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 28, 2015
    Date of Patent: January 10, 2017
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Lingpeng Guan, Anup Bhalla
  • Publication number: 20160379917
    Abstract: A power semiconductor package device and a method of preparation the device are disclosed. The package device includes a die paddle, a first pin, a second pin, and a semiconductor chip attached to the die paddle. A first electrode, a second electrode and a third electrode of the semiconductor chip are connected to the first pin, the second pin and the die paddle respectively. A plastic package body covers the semiconductor chip, the die paddle, the first pin and the second pin. The first pin and the second pin are located near two adjacent corners of the plastic package body. The bottom surface and two side surfaces of each of the first pin and the second pin are exposed from the plastic package body. Locking mechanisms are constructed to prevent the first pin and the second pin from falling off the power semiconductor package device during a manufacturing cutting process. Portions of the first pin, portions of the second pin, and portions of the plastic package body can be cut off.
    Type: Application
    Filed: May 31, 2016
    Publication date: December 29, 2016
    Applicant: Alpha and Omega Semiconductor Incorporated
    Inventors: Yan Xun Xue, Hamza Yilmaz, Yueh-Se Ho, Jun Lu, De Mei Gong
  • Publication number: 20160379918
    Abstract: A method of manufacturing a semiconductor package having a small gate clip is disclosed. A first and second semiconductor chips, each of which includes a source electrode and a gate electrode at a top surface, are attached on two adjacent lead frame units of a lead frame such that the lead frame unit with the first chip formed thereon is rotated 180 degrees in relation to the other lead frame unit with the second semiconductor chip formed thereon. A first and second clip sets are mounted on the first and second semiconductor chips, wherein the first clip set is connected to the gate electrode of the first chip, the source electrode of the second chip, and their corresponding leads and the second clip set is connected to the gate electrode of the second chip, the source electrode of the first chip and their corresponding leads.
    Type: Application
    Filed: September 9, 2016
    Publication date: December 29, 2016
    Applicant: Alpha and Omega Semiconductor Incorporated
    Inventors: Yan Xun Xue, Hamza Yilmaz, Yueh-Se Ho, Jun Lu, Ming-Chen Lu, Hongtao Gao
  • Patent number: 9530885
    Abstract: In some embodiments, a normally on high voltage switch device (“normally on switch device”) incorporates a trench gate terminal and buried doped gate region. In other embodiments, a surface gate controlled normally on high voltage switch device is formed with trench structures and incorporates a surface channel controlled by a surface gate electrode. The surface gate controlled normally on switch device may further incorporate a trench gate electrode and a buried doped gate region to deplete the conducting channel to aid in the turning off of the normally on switch device. The normally on switch devices thus constructed can be readily integrated with MOSFET devices and formed using existing high voltage MOSFET fabrication technologies.
    Type: Grant
    Filed: June 10, 2015
    Date of Patent: December 27, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Madhur Bobde, Hamza Yilmaz, Daniel Calafut, Karthik Padmanabhan
  • Patent number: 9520464
    Abstract: This invention discloses a semiconductor power device disposed in a semiconductor substrate and having an active cell area and an edge termination area the edge termination area wherein the edge termination area comprises a superjunction structure having doped semiconductor columns of alternating conductivity types with a charge imbalance between the doped semiconductor columns to generate a saddle junction electric field in the edge termination.
    Type: Grant
    Filed: January 4, 2016
    Date of Patent: December 13, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Madhur Bobde, Lingpeng Guan, Anup Bhalla, Hamza Yilmaz
  • Patent number: 9520480
    Abstract: A heterostructure field effect transistor (HFET) gallium nitride (GaN) semiconductor power device comprises a hetero junction structure comprises a first semiconductor layer interfacing a second semiconductor layer of two different band gaps thus generating an interface layer as a two-dimensional electron gas (2DEG) layer. The power device further comprises a source electrode and a drain electrode disposed on two opposite sides of a gate electrode disposed on top of the hetero junction structure for controlling a current flow between the source and drain electrodes in the 2DEG layer.
    Type: Grant
    Filed: June 3, 2015
    Date of Patent: December 13, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Anup Bhalla, Tinggang Zhu
  • Patent number: 9520380
    Abstract: A wafer process for molded chip scale package (MCSP) comprises: depositing metal bumps on bonding pads of chips on a wafer; forming a first packaging layer at a front surface of the wafer to cover the metal bumps; forming an un-covered ring at an edge of the wafer to expose two ends of each scribe line of a plurality of scribe lines; thinning the first packaging layer to expose metal bumps; forming cutting grooves; grinding a back surface of the wafer to form a recessed space and a support ring at the edge of the wafer; depositing a metal seed layer at a bottom surface of the wafer in the recessed space; cutting off an edge portion of the wafer; flipping and mounting the wafer on a substrate; depositing a metal layer covering the metal seed layer; removing the substrate from the wafer; and separating individual chips from the wafer by cutting through the first packaging layer, the wafer, the metal seed layers and the metal layers along the scribe lines.
    Type: Grant
    Filed: November 24, 2015
    Date of Patent: December 13, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Yan Xun Xue, Hamza Yilmaz, Yueh-Se Ho, Jun Lu, Zhiqiang Niu, Guo Feng Lian
  • Patent number: 9508805
    Abstract: A termination structure for a semiconductor power device includes a plurality of termination groups formed in a lightly doped epitaxial layer of a first conductivity type over a heavily doped semiconductor substrate of a second conductivity type. Each termination group includes a trench formed in the lightly doped epitaxial layer of the first conductivity type. All sidewalls of the trench are covered by a plurality of epitaxial layers of alternating conductivity types disposed on two opposite sides and substantially symmetrical with respect to a central gap-filler layer disposed between two innermost epitaxial layers of an innermost conductivity type as the first conductivity type.
    Type: Grant
    Filed: July 28, 2014
    Date of Patent: November 29, 2016
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Lingpeng Guan, Madhur Bobde, Hamza Yilmaz, Karthik Padmanabhan
  • 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
  • Patent number: 9502268
    Abstract: A method to provide a wafer level package with increasing contact pad area comprising the steps of forming a first packaging layer on wafer top surface, grinding the wafer back surface and etch through holes, depositing a metal to fill the through holes and covering wafer backside, cutting through the wafer from wafer backside forming a plurality of grooves separating each chip then depositing a second packaging layer filling the grooves and covering the wafer back metal, reducing the first packaging layer thickness to expose the second packaging layer filling the grooves and forming a plurality of contact pads overlaying the first packaging layer thereafter cutting through the second packaging layer in the grooves to form individual package.
    Type: Grant
    Filed: November 5, 2015
    Date of Patent: November 22, 2016
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventor: Yan Xun Xue
  • Patent number: 9502547
    Abstract: An IGBT device may be formed from a substrate including a bottom semiconductor layer of a first conductivity and an upper semiconductor layer of a second conductivity type located above the bottom semiconductor layer. Trenches for trench gates are formed in the substrate. Each trench extends vertically into the upper semiconductor layer and is provided with a gate insulator on each side of the trench and is filled with polysilicon. A first conductivity type floating body region is formed between two neighboring trenches and over the substrate. A bottom of the floating body region is close in depth to but above a bottom of the polysilicon in the trench. A heavily doped second conductivity type top region is formed over the floating body region. A first conductivity type body region is formed over the top region. The floating body region has a lower doping concentration than the body region.
    Type: Grant
    Filed: August 21, 2015
    Date of Patent: November 22, 2016
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventor: Jun Hu
  • Patent number: 9502503
    Abstract: Semiconductor devices includes a thin epitaxial layer (nanotube) formed on sidewalls of mesas formed in a semiconductor layer. In one embodiment, a semiconductor device includes a first epitaxial layer and a second epitaxial layer formed on mesas of the semiconductor layer. The thicknesses and doping concentrations of the first and second epitaxial layers and the mesa are selected to achieve charge balance in operation. In another embodiment, the semiconductor body is lightly doped and the thicknesses and doping concentrations of the first and second epitaxial layers are selected to achieve charge balance in operation.
    Type: Grant
    Filed: April 12, 2016
    Date of Patent: November 22, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Hamza Yilmaz, Xiaobin Wang, Anup Bhalla, John Chen, Hong Chang
  • Patent number: 9491014
    Abstract: Switching logic receives an input signal and a frequency divided signal and generates switching signals. A delay modulator receives the switching signals and generates a high output when a first node voltage is greater than a second node voltage and low output otherwise. An XOR gate receives the delay modulator's output and the frequency divided signal and produces a final output that is high when one of them is low and the other high and low otherwise. A duty ratio of the final output depends on a ratio of a slope of the first node voltage to a slope of the second node voltage.
    Type: Grant
    Filed: September 23, 2015
    Date of Patent: November 8, 2016
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventor: Gilbert S. Z. Lee
  • 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: 20160315039
    Abstract: A hybrid packaging multi-chip semiconductor device comprises a lead frame unit, a first semiconductor chip, a second semiconductor chip, a first interconnecting structure and a second interconnecting structure, wherein the first semiconductor chip is attached on a first die paddle and the second semiconductor chip is flipped and attached on a third pin and a second die paddle, the first interconnecting structure electrically connecting a first electrode at a front surface of the first semiconductor chip and a third electrode at a back surface of the second semiconductor chip and a second electrode at the front surface of the first semiconductor chip is electrically connected by second interconnecting structure.
    Type: Application
    Filed: July 7, 2016
    Publication date: October 27, 2016
    Applicant: Alpha and Omega Semiconductor Incorporated
    Inventors: Hamza Yilmaz, Yan Xun Xue, Jun Lu, Peter Wilson, Yan Huo, Zhiqiang Niu, Ming-Chen Lu
  • Patent number: 9478646
    Abstract: A method for fabricating an anode-shorted field stop insulated gate bipolar transistor (IGBT) comprises selectively forming first and second semiconductor implant regions of opposite conductivity types. A field stop layer of a second conductivity type can be grown onto or implanted into the substrate. An epitaxial layer can be grown on the substrate or on the field stop layer. One or more insulated gate bipolar transistors (IGBT) component cells are formed within the epitaxial layer.
    Type: Grant
    Filed: July 27, 2011
    Date of Patent: October 25, 2016
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Anup Bhalla, Madhur Bobde, Yongping Ding, Xiaotian Zhang, Yueh-Se Ho