Patents Assigned to Alpha & Omega Semiconductor Incorporated
  • Patent number: 9214545
    Abstract: A semiconductor device has a plurality of gate electrodes over a gate insulator layer formed in active trenches located in an active region of a semiconductor substrate. A first gate runner is formed in the semiconductor substrate and electrically connected to the gate electrodes. The first gate runner abuts and surrounds the active region. A second gate runner is connected to the first gate runner to make contact to a gate metal. A dielectric filled trench surrounds the first and second gate runners and the active region and a highly doped channel stop region is formed under the dielectric filled trench.
    Type: Grant
    Filed: December 8, 2014
    Date of Patent: December 15, 2015
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Sung-Shan Tai, Sik Lui, Xiaobin Wang
  • Patent number: 9214457
    Abstract: The present invention is directed to a method for forming multiple active components, such as bipolar transistors, MOSFETs, diodes, etc., on a semiconductor substrate so that active components with higher operation voltage may be formed on a common substrate with a lower operation voltage device and incorporating the existing proven process flow of making the lower operation voltage active components. The present invention is further directed to a method for forming a device of increasing operation voltage over an existing device of same functionality by adding a few steps in the early manufacturing process of the existing device therefore without drastically affecting the device performance.
    Type: Grant
    Filed: September 20, 2011
    Date of Patent: December 15, 2015
    Assignee: Alpha & Omega Semiconductor Incorporated
    Inventor: Hideaki Tsuchiko
  • Patent number: 9214417
    Abstract: A combined packaged power semiconductor device includes flipped top source low-side MOSFET electrically connected to top surface of a die paddle, first metal interconnection plate connecting between bottom drain of a high-side MOSFET or top source of a flipped high-side MOSFET to bottom drain of the low-side MOSFET, and second metal interconnection plate stacked on top of the high-side MOSFET chip. The high-side, low-side MOSFET and the IC controller can be packaged three-dimensionally reducing the overall size of semiconductor devices and can maximize the chip's size within a package of the same size and improves the performance of the semiconductor devices. The top source of flipped low-side MOSFET is connected to the top surface of the die paddle and thus is grounded through the exposed bottom surface of die paddle, which simplifies the shape of exposed bottom surface of the die paddle and maximizes the area to facilitate heat dissipation.
    Type: Grant
    Filed: February 21, 2014
    Date of Patent: December 15, 2015
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Yueh-Se Ho, Hamza Yilmaz, Yan Xun Xue, Jun Lu
  • Patent number: 9214534
    Abstract: A lateral bipolar transistor with deep emitter and deep collector regions is formed using multiple epitaxial layers of the same conductivity type. Deep emitter and deep collector regions are formed without the use of trenches. Vertically aligned diffusion regions are formed in each epitaxial layer so that the diffusion regions merged into a contiguous diffusion region after annealing to function as emitter or collector or isolation structures. In another embodiment, a lateral trench PNP bipolar transistor is formed using trench emitter and trench collector regions. In yet another embodiment, a lateral PNP bipolar transistor with a merged LDMOS transistor is formed to achieve high performance.
    Type: Grant
    Filed: November 12, 2014
    Date of Patent: December 15, 2015
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Shekar Mallikarjunaswamy, Francois Hebert
  • Publication number: 20150357267
    Abstract: A combined packaged power semiconductor device includes flipped top source low-side MOSFET electrically connected to top surface of a die paddle, first metal interconnection plate connecting between bottom drain of a high-side MOSFET or top source of a flipped high-side MOSFET to bottom drain of the low-side MOSFET, and second metal interconnection plate stacked on top of the high-side MOSFET chip. The high-side, low-side MOSFET and the IC controller can be packaged three-dimensionally reducing the overall size of semiconductor devices and can maximize the chip's size within a package of the same size and improves the performance of the semiconductor devices. The top source of flipped low-side MOSFET is connected to the top surface of the die paddle and thus is grounded through the exposed bottom surface of die paddle, which simplifies the shape of exposed bottom surface of the die paddle and maximizes the area to facilitate heat dissipation.
    Type: Application
    Filed: August 11, 2015
    Publication date: December 10, 2015
    Applicant: Alpha and Omega Semiconductor Incorporated
    Inventors: Yueh-Se Ho, Hamza Yilmaz, Yan Yun Xue, Jun Lu
  • Patent number: 9209260
    Abstract: Fabricating a semiconductor device includes: forming a gate trench on a semiconductor substrate; forming a spacer inside the gate trench; forming one or more gate electrodes within the gate trench; implanting a body region; implanting a source region; forming a contact trench; disposing dielectric material within the gate trench; removing at least a portion of the dielectric material such that at least a portion of the source region extends above the dielectric material; and depositing a metal layer over at least a portion of a gate trench opening, at least a portion of the source region, and at least a portion of the contact trench.
    Type: Grant
    Filed: November 21, 2013
    Date of Patent: December 8, 2015
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventor: John Chen
  • Publication number: 20150349101
    Abstract: Semiconductor power devices can be formed on substrate structure having a lightly doped semiconductor substrate of a first conductivity type or a second conductivity type opposite to the first conductivity type. A semiconductive first buffer layer of the first conductivity type formed above the substrate. A doping concentration of the first buffer layer is greater than a doping concentration of the substrate. A second buffer layer of the second conductivity type formed above the first buffer layer. An epitaxial layer of the second conductivity type formed above the second buffer layer. A doping concentration of the epitaxial layer is greater than a doping concentration of the second buffer layer. This abstract is provided to allow a searcher or reader to quickly ascertain the subject matter of the disclosure with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
    Type: Application
    Filed: May 30, 2014
    Publication date: December 3, 2015
    Applicant: Alpha and Omega Semiconductor Incorporated
    Inventors: Madhur Bobde, Jun Hu, Lingpeng Guan, Hamza Yilmaz, Lei Zhang, Jongoh Kim
  • Patent number: 9202938
    Abstract: A method for manufacturing a transient voltage suppressing (TVS) array substantially following a manufacturing process for manufacturing a vertical semiconductor power device. The method includes a step of opening a plurality of isolation trenches in an epitaxial layer of a first conductivity type in a semiconductor substrate followed by applying a body mask for doping a body region having a second conductivity type between two of the isolation trenches. The method further includes a step of applying an source mask for implanting a plurality of doped regions of the first conductivity type constituting a plurality of diodes wherein the isolation trenches isolating and preventing parasitic PNP or NPN transistor due to a latch-up between the doped regions of different conductivity types.
    Type: Grant
    Filed: June 8, 2013
    Date of Patent: December 1, 2015
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventor: Madhur Bobde
  • Publication number: 20150340363
    Abstract: A high density trench-gated MOSFET array and method are disclosed. It comprises semiconductor substrate partitioned into MOSFET array area and gate pickup area; epitaxial region, body region and source region; numerous precisely spaced active nitride-capped trench gate stacks (ANCTGS) embedded till the epitaxial region. Each ANCTGS comprises a stack of polysilicon trench gate with gate oxide shell and silicon nitride cap covering top of polysilicon trench gate and laterally registered to gate oxide shell. The ANCTGS forms, together with the source, body, epitaxial region, a MOSFET device in the MOSFET array area. Over MOSFET array area and gate pickup area, a patterned dielectric region atop the MOSFET array and a patterned metal layer atop the patterned dielectric region. Thus, the patterned metal layer forms, with the MOSFET array and the gate pickup area, self-aligned source and body contacts through the inter-ANCTGS separations.
    Type: Application
    Filed: August 6, 2015
    Publication date: November 26, 2015
    Applicant: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Yeeheng - Lee, Jongoh Kim, Hong Chang
  • Patent number: 9196534
    Abstract: A method for preparing semiconductor devices in a flip chip process comprises forming deep grooves surrounding each of the semiconductor chips; depositing a first plastic package material to form a first plastic package layer covering front surface of the semiconductor wafer and filling the deep grooves; depositing a metal layer at back surface of the semiconductor wafer after grinding; grinding an outermost portion of the metal layer thus forming a ring area located at back surface around edge of the semiconductor wafer not covered by the metal layer; cutting the first plastic package layer, the semiconductor wafer, the metal layer and the first plastic package material filled in the deep grooves along a straight line formed by two ends of each of the deep grooves filled with the first plastic package material; and picking up the semiconductor devices and mounting on a substrate without flipping the semiconductor devices.
    Type: Grant
    Filed: February 24, 2013
    Date of Patent: November 24, 2015
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Yan Xun Xue, Ping Huang, Hamza Yilmaz, Yueh-Se Ho, Lei Shi, Liang Zhao, Ping Li Wu, Lei Duan, Yuping Gong
  • Patent number: 9196701
    Abstract: A semiconductor substrate comprises epitaxial region, body region and source region; an array of interdigitated active nitride-capped trench gate stacks (ANCTGS) and self-guided contact enhancement plugs (SGCEP) disposed above the semiconductor substrate and partially embedded into the source region, the body region and the epitaxial region forming the trench-gated MOSFET array.
    Type: Grant
    Filed: March 5, 2014
    Date of Patent: November 24, 2015
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Yeeheng Lee, Jongoh Kim, Hong Chang
  • Patent number: 9190512
    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. Additionally, the active devices may have a two-step gate oxide, wherein a lower portion of the gate oxide has a thickness T2 that is larger than the thickness T1 of an upper 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: January 27, 2015
    Date of Patent: November 17, 2015
    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: 9190478
    Abstract: A method for forming a dual oxide thickness trench gate structure for a power MOSFET includes providing a semiconductor substrate; forming a first trench on a top surface of the substrate; forming a first oxide layer in the first trench where the first oxide layer has a first depth from the bottom of the first trench; forming a dielectric spacer along the sidewall of the first trench and on the first oxide layer; etching the first oxide layer exposed by the dielectric spacer to a second depth from the bottom of the first trench using the dielectric spacer as a mask where the second depth is lower than the first depth; removing the dielectric spacer; and forming a second oxide layer along the sidewall of the first trench above the first oxide layer where the second oxide layer has a thickness thinner than the thickness of the first oxide layer.
    Type: Grant
    Filed: December 22, 2013
    Date of Patent: November 17, 2015
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Daniel Calafut, Madhur Bobde, Yeeheng Lee, Hong Chang
  • Patent number: 9190408
    Abstract: A semiconductor device with multiple transistor devices includes a semiconductor layer of a first conductivity type formed on a substrate; a first trench formed in the semiconductor layer including a first trench gate; a second trench formed in the semiconductor layer and extending into the substrate and including a second trench gate; a first transistor device being an LDMOS transistor formed in the semiconductor layer between the first trench and the second trench; and a second transistor device formed in the semiconductor layer on the other side of the second trench. The first transistor device is electrically isolated from the second transistor device by the second trench.
    Type: Grant
    Filed: March 4, 2014
    Date of Patent: November 17, 2015
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventor: Shekar Mallikarjunaswamy
  • Publication number: 20150325559
    Abstract: The present invention discloses a new embedded package comprising: a pre-mold lead frame with a plurality of chips attached thereon, where the molding material fills the voids of the lead frame, so that the lead frame is entirely solid; a plurality of pins arranged around the lead frame; a metal clip attached on and electrically connecting the chips together; first laminate layer which covers the chips, the lead frame, a metal clip and pins; conductive plug and extension formed to connect an electrode of a chip to a corresponding pin or to connect the chips together. The new embedded package of the invention with a three-dimensional stack capacity improves the thickness, thermal and electrical properties and the flexible power and logic hybrid design.
    Type: Application
    Filed: May 9, 2014
    Publication date: November 12, 2015
    Applicant: Alpha and Omega Semiconductor Incorporated
    Inventors: Zhiqiang Niu, Hua Pan, Ming-Chen Lu, Yueh-Se Ho, Jun Lu
  • Patent number: 9184117
    Abstract: The invention relates to a power semiconductor device and a preparation method, particularly relates to preparation of stacked dual-chip packaging structure of MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) using flip chip technology with two interconnecting plates. The first chip is flipped and attached on the base such that the first chip is overlapped with the third pin; the back metal layer of the first chip is connected to the bonding strip of the first pin through a first interconnecting plate; the second chip is flipped and attached on a main plate portion of the first interconnecting plate such that the second chip is overlapped with the fourth pin; and the back metal layer of the second chip is connected to the bonding strip of the second pin through the second interconnecting plate.
    Type: Grant
    Filed: October 30, 2012
    Date of Patent: November 10, 2015
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Yueh-Se Ho, Yan Xun Xue, Hamza Yilmaz, Jun Lu
  • Publication number: 20150311295
    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: April 23, 2014
    Publication date: October 29, 2015
    Applicant: Alpha and Omega Semiconductor Incorporated
    Inventors: Yeeheng Lee, Sik Lui, Jongoh Kim, Hong Chang, Madhur Bobde, Lingpeng Guan, Hamza Yilmaz
  • Patent number: 9171788
    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: Grant
    Filed: September 30, 2014
    Date of Patent: October 27, 2015
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Yan Xun Xue, Hamza Yilmaz, Yueh-Se Ho, Jun Lu, Ming-Chen Lu, Hongtao Gao
  • Patent number: 9171949
    Abstract: A semiconductor device includes a superjunction structure formed using simultaneous N and P angled implants into the sidewall of a trench. The simultaneous N and P angled implants use different implant energies and dopants of different diffusion rate so that after annealing, alternating N and P thin semiconductor regions are formed. The alternating N and P thin semiconductor regions form a superjunction structure where a balanced space charge region is formed to enhance the breakdown voltage characteristic of the semiconductor device.
    Type: Grant
    Filed: September 24, 2014
    Date of Patent: October 27, 2015
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Karthik Padmanabhan, Madhur Bobde, Lingpeng Guan, Lei Zhang, Hamza Yilmaz
  • Patent number: 9171917
    Abstract: This invention discloses a semiconductor power device disposed in a semiconductor substrate and having an active cell area and an edge termination area wherein the edge termination area comprises a wide trench filled with a field-crowding reduction filler and a buried field plate buried under a top surface of the semiconductor substrate and laterally extended over a top portion of the field crowding field to move a peak electric field laterally away from the active cell area. In a specific embodiment, the field-crowding reduction filler comprises a silicon oxide filled in the wide trench.
    Type: Grant
    Filed: January 23, 2014
    Date of Patent: October 27, 2015
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Madhur Bobde, Sik Lui, Anup Bhalla