Patents Assigned to Alpha and Omega Semiconductor Incorporated
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Patent number: 10224411Abstract: A lateral bipolar transistor includes trench emitter and trench collector regions to form ultra-narrow emitter regions, thereby improving emitter efficiency. The same trench process is used to form the emitter/collector trenches as well as the trench isolation structures so that no additional processing steps are needed to form the trench emitter and collector. In embodiments of the present invention, the trench emitter and trench collector regions may be formed using ion implantation into trenches formed in a semiconductor layer. In other embodiments, the trench emitter and trench collector regions may be formed by out-diffusion of dopants from heavily doped polysilicon filled trenches.Type: GrantFiled: May 30, 2017Date of Patent: March 5, 2019Assignee: Alpha and Omega Semiconductor IncorporatedInventors: Shekar Mallikarjunaswamy, Francois Hebert
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Patent number: 10205017Abstract: A low voltage transient voltage suppressing (TVS) device supported on a semiconductor substrate supporting an epitaxial layer to form a bottom-source metal oxide semiconductor field effect transistor (BS-MOSFET) that comprises a trench gate surrounded by a drain region encompassed in a body region disposed near a top surface of the semiconductor substrate. The drain region interfaces with the body region constituting a junction diode. The drain region on top of the epitaxial layer constituting a bipolar transistor with a top electrode disposed on the top surface of the semiconductor functioning as a drain/collector terminal and a bottom electrode disposed on a bottom surface of the semiconductor substrate functioning as a source/emitter electrode. The body regions further comprises a surface body contact region electrically connected to a body-to-source short-connection thus connecting the body region to the bottom electrode functioning as the source/emitter terminal.Type: GrantFiled: September 25, 2013Date of Patent: February 12, 2019Assignee: Alpha and Omega Semiconductor IncorporatedInventor: Madhur Bobde
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Patent number: 10199492Abstract: A trench MOSFET device includes a body, region and source region that undulate along a channel width direction of the MOSFET device such that the body region and source region have variations in depth along the channel width direction. The undulations increase a channel width of the MOSFET device.Type: GrantFiled: November 30, 2016Date of Patent: February 5, 2019Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATEDInventor: Sik Lui
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Patent number: 10199455Abstract: A method of manufacturing an insulated gate bipolar transistor (IGBT) device comprising 1) preparing a semiconductor substrate with an epitaxial layer of a first conductivity type supported on the semiconductor substrate of a second conductivity type; 2) applying a gate trench mask to open a first trench and second trench followed by forming a gate insulation layer to pad the trench and filling the trench with a polysilicon layer to form the first trench gate and the second trench gate; 3) implanting dopants of the first conductivity type to form an upper heavily doped region in the epitaxial layer; and 4) forming a planar gate on top of the first trench gate and apply implanting masks to implant body dopants and source dopants to form a body region and a source region near a top surface of the semiconductor substrate.Type: GrantFiled: May 21, 2017Date of Patent: February 5, 2019Assignee: Alpha and Omega Semiconductor IncorporatedInventors: Jun Hu, Madhur Bobde, Hamza Yilmaz
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Patent number: 10192982Abstract: 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 includes a body region, a source region, and one or more gate electrodes formed in corresponding trenches in the lightly doped region. Each trench has a first dimension (depth), a a second dimension (width) and a third dimension (length). The body region is of opposite conductivity type to the lightly and heavily doped layers. An opening is formed between first and second trenches through an upper portion of the source region and a body contact region to the body region. A deep implant region of the second conductivity type is formed in the lightly doped layer below the body region. The deep implant region is vertically aligned to the opening and spaced away from a bottom of the opening.Type: GrantFiled: August 18, 2017Date of Patent: January 29, 2019Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATEDInventors: Hamza Yilmaz, Daniel Ng, Daniel Calafut, Madhur Bobde, Anup Bhalla, Ji Pan, Yeeheng Lee, Jongoh Kim
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Patent number: 10177221Abstract: 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: GrantFiled: January 23, 2018Date of Patent: January 8, 2019Assignee: Alpha and Omega Semiconductor IncorporatedInventors: Lingpeng Guan, Anup Bhalla, Madhur Bobde, Tinggang Zhu
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Patent number: 10170563Abstract: This invention discloses a gallium nitride based semiconductor power device disposed in a semiconductor substrate. The power device comprises a termination area disposed at a peripheral area of the semiconductor power device comprises a termination structure having at least a guard ring disposed in a trench filled with doped gallium-based epitaxial layer therein.Type: GrantFiled: February 9, 2013Date of Patent: January 1, 2019Assignee: Alpha and Omega Semiconductor IncorporatedInventor: Tinggang Zhu
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Patent number: 10157984Abstract: 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: GrantFiled: December 14, 2015Date of Patent: December 18, 2018Assignee: Alpha & Omega Semiconductor IncorporatedInventor: Hideaki Tsuchiko
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Publication number: 20180323282Abstract: This invention discloses a semiconductor power device disposed in a semiconductor substrate including an active cell areas and a termination area. The semiconductor power device further comprises a plurality of gate trenches formed at a top portion of the semiconductor substrate in the active cell area wherein each of the gate trenches is partially filled with a conductive gate material with a top portion of the trenches filled by a high density plasma (HDP) insulation layer. The semiconductor power device further comprises mesa areas of the semiconductor substrate disposed between the gate trenches wherein the mesa areas are recessed and having a top mesa surface disposed vertically below a top surface of the HDP insulation layer wherein the HDP insulation layer covering over the conductive gate material constituting a stick-out boundary-defining layer surrounding the recessed mesa areas in the active cell areas between the gate trenches.Type: ApplicationFiled: June 27, 2018Publication date: November 8, 2018Applicant: Alpha & Omega Semiconductor, IncorporatedInventors: Wenjun Li, Paul Thorup, Hong Chang, Yeeheng Lee, Yang Xiang, Jowei Dun, Hongyong Xue, Yiming Gu
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Publication number: 20180323155Abstract: A trench-type metal-oxide-semiconductor field-effect transistor (MOSFET) device and a fabrication method are disclosed. A semiconductor substrate of a first conductivity type is provided. A plurality of first trenches arranged side by side in a first stripe layout extending along a first direction in a first preset area of the semiconductor substrate are formed. A plurality of second trenches arranged side by side in a second stripe layout extending along a second direction perpendicular to the first direction in a second preset area of the semiconductor substrate are formed. The plurality of first trenches and the plurality of second trenches are filled with a conductive material so as to form a plurality of control gates.Type: ApplicationFiled: June 21, 2018Publication date: November 8, 2018Applicant: Alpha and Omega Semiconductor IncorporatedInventors: Xiaobin Wang, Madhur Bobde, Paul Thorup
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Patent number: 10121857Abstract: 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: GrantFiled: May 1, 2015Date of Patent: November 6, 2018Assignee: Alpha and Omega Semiconductor IncorporatedInventors: Hamza Yilmaz, Daniel Ng, Lingping Guan, Anup Bhalla, Wilson Ma, Moses Ho, John Chen
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Patent number: 10115814Abstract: 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: GrantFiled: January 19, 2018Date of Patent: October 30, 2018Assignee: Alpha and Omega Semiconductor IncorporatedInventors: Yongping Ding, Lei Zhang, Hong Chang, Jongoh Kim, John Chen
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Patent number: 10103240Abstract: A lateral super junction JFET is formed from stacked alternating P type and N type semiconductor layers over a P-epi layer supported on an N+ substrate. An N+ drain column extends down through the super junction structure and the P-epi to connect to the N+ substrate to make the device a bottom drain device. N+ source column and P+ gate column extend through the super junction but stop at the P-epi layer. A gate-drain avalanche clamp diode is formed from the bottom the P+ gate column through the P-epi to the N+ drain substrate.Type: GrantFiled: February 10, 2013Date of Patent: October 16, 2018Assignee: Alpha and Omega Semiconductor IncorporatedInventors: Madhur Bobde, Lingpeng Guann, Anup Bhalla, Hamza Yilmaz
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Patent number: 10103140Abstract: A switch circuit includes a first MOS transistor and a second MOS transistor of a same conductivity type connected in parallel between a first terminal and a second terminal of the switch circuit, the first and second MOS transistors having respective gate terminals coupled to the control terminal to receive a control signal to turn the first and second MOS transistors on or off. The first MOS transistor is characterized by a first reverse gate-to-drain capacitance (Crss) and the second MOS transistor is characterized by a second Crss that is greater than the first Crss.Type: GrantFiled: October 14, 2016Date of Patent: October 16, 2018Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATEDInventors: Ji Pan, Sik Lui
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Patent number: 10096588Abstract: 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: GrantFiled: September 30, 2017Date of Patent: October 9, 2018Assignee: Alpha and Omega Semiconductor IncorporatedInventors: Madhur Bobde, Wenjiang Zeng, Limin Weng
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Publication number: 20180269293Abstract: 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: ApplicationFiled: December 16, 2017Publication date: September 20, 2018Applicant: Alpha and Omega Semiconductor IncorporatedInventors: Hamza Yilmaz, John Chen, Daniel Ng, Wenjun Li
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Patent number: 10069005Abstract: The present disclosure describes a termination structure for a high voltage semiconductor transistor device. The termination structure is composed of at least two termination zones and an electrical disconnection between the body layer and the edge of the device. A first zone is configured to spread the electric field within the device. A second zone is configured to smoothly bring the electric field back up to the top surface of the device. The electrical disconnection prevents the device from short circuiting the edge of the device. 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: GrantFiled: February 6, 2017Date of Patent: September 4, 2018Assignee: Alpha and Omega Semiconductor IncorporatedInventors: Lingpeng Guan, Anup Bhalla, Hamza Yilmaz
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Patent number: 10062755Abstract: Semiconductor devices are formed using a thin epitaxial layer (nanotube) formed on sidewalls of dielectric-filled trenches. In one embodiment, a termination structure is formed in the termination area and includes an array of termination cells formed in the termination area, the array of termination cells including a first termination cell at an interface to the active area to a last termination cell, each termination cell in the array of termination cells being formed in a mesa of the first semiconductor layer and having a first width; and an end termination cell being formed next to the last termination cell in the termination area, the end termination cell being formed in an end mesa of the first semiconductor layer and having a second width greater than the first width.Type: GrantFiled: January 10, 2018Date of Patent: August 28, 2018Assignee: Alpha and Omega Semiconductor IncorporatedInventors: Hamza Yilmaz, Xiaobin Wang, Anup Bhalla, John Chen, Hong Chang
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Patent number: 10062685Abstract: 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: GrantFiled: June 14, 2017Date of Patent: August 28, 2018Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATEDInventors: Sik Lui, Ji Pan
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Patent number: 10056461Abstract: Aspects of the present disclosure discloses a method for fabricating a trench MOSFET device comprising simultaneously forming a narrow trench and a wide trench into a semiconductor substrate using a mask to defines the narrow trench and the wide trench, forming an insulating layer over the semiconductor substrate with a first portion that fills up the narrow trench and a second portion that partially fills the wide trench, removing the second portion from the wide trench completely and leaving the narrow trench filled with the first portion, forming a gate electrode, forming a body region in a top portion of the semiconductor substrate, forming a source region in a portion of the body region, removing the first portion of nitride from the narrow trench, and forming a contact plug by filling a second conductive material in the narrow trench.Type: GrantFiled: September 30, 2016Date of Patent: August 21, 2018Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATEDInventors: Sik Lui, Hong Chang