Patents Assigned to Alpha & Omega Semiconductor, Ltd.
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Patent number: 11594613Abstract: 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: June 13, 2021Date of Patent: February 28, 2023Assignee: Alpha and Omega Semiconductor, Ltd.Inventors: Madhur Bobde, Lingpeng Guan, Anup Bhalla, Hamza Yilmaz
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Patent number: 8981464Abstract: Power wafer level chip scale package (CSP) and process of manufacture are enclosed. The power wafer level chip scale package includes all source, gate and drain electrodes located on one side of the device, which is convenient for mounting to a printed circuit board (PCB) with solder paste.Type: GrantFiled: May 6, 2014Date of Patent: March 17, 2015Assignee: Alpha and Omega Semiconductor LtdInventors: Tao Feng, François Hébert, Ming Sun, Yueh-Se Ho
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Patent number: 8884406Abstract: A semiconductor device wafer includes a test structure. The test structure includes a layer of material having an angle-shaped test portion disposed on at least a portion of a surface of the semiconductor wafer. A ruler marking on the surface of the semiconductor wafer proximate the test portion is adapted to facilitate measurement of a change in length of the test portion.Type: GrantFiled: September 13, 2011Date of Patent: November 11, 2014Assignee: Alpha & Omega Semiconductor LtdInventors: Yingying Lou, Tiesheng Li, Yu Wang, Anup Bhalla
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Patent number: 8853772Abstract: High-mobility vertical trench DMOSFETs and methods for manufacturing are disclosed. A source region, a drain region or a channel region of a high-mobility vertical trench DMOSFET may comprise silicon germanium (SiGe) that increases the mobility of the charge carriers in the channel region. In some embodiments the channel region may be strained to increase channel charge carriers mobility.Type: GrantFiled: July 22, 2011Date of Patent: October 7, 2014Assignee: Alpha & Omega Semiconductor LtdInventor: François Hébert
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Publication number: 20140239383Abstract: Power wafer level chip scale package (CSP) and process of manufacture are enclosed. The power wafer level chip scale package includes all source, gate and drain electrodes located on one side of the device, which is convenient for mounting to a printed circuit board (PCB) with solder paste.Type: ApplicationFiled: May 6, 2014Publication date: August 28, 2014Applicant: Alpha & Omega Semiconductor, LTDInventors: Tao Feng, FRANÇOIS HÉBERT, Ming Sun, Yueh-Se Ho
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Publication number: 20140225188Abstract: A semiconductor device includes a gate electrode, a top source region disposed next to the gate electrode, a drain region disposed below the bottom of the gate electrode, a oxide disposed on top of the source region and the gate electrode, and a doped polysilicon spacer disposed along a sidewall of the source region and a sidewall of the oxide. Methods for manufacturing such device are also disclosed. 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: ApplicationFiled: April 18, 2014Publication date: August 14, 2014Applicant: Alpha & Omega Semiconductor, LTDInventors: François Hébert, Anup Bhalla
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Patent number: 8729881Abstract: A voltage/current control apparatus and method are disclosed. The apparatus includes a low-side field effect transistor (FET) having a source, a gate and a drain, a high-side field effect transistor (FET) having a source, a gate and a drain, a gate driver integrated circuit (IC), a sample and hold circuit, and a comparator configured to produce a trigger signal at the output when a sum of the first and second input signals is equal to a sum of the third and fourth input signals, wherein the trigger signal is configured to trigger a beginning of a new cycle by turning the gate of the high-side FET “on” and the gate of the low-side FET “off”.Type: GrantFiled: May 17, 2011Date of Patent: May 20, 2014Assignee: Alpha & Omega Semiconductor LtdInventor: Yu Cheng Chang
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Patent number: 8716063Abstract: Power wafer level chip scale package (CSP) and process of manufacture are enclosed. The power wafer level chip scale package includes all source, gate and drain electrodes located on one side of the device, which is convenient for mounting to a printed circuit board (PCB) with solder paste.Type: GrantFiled: January 14, 2011Date of Patent: May 6, 2014Assignee: Alpha & Omega Semiconductor LtdInventors: Tao Feng, François Hébert, Ming Sun, Yueh-Se Ho
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Patent number: 8703563Abstract: A semiconductor device includes a gate electrode, a top source region disposed next to the gate electrode, a drain region disposed below the bottom of the gate electrode, a oxide disposed on top of the source region and the gate electrode, and a doped polysilicon spacer disposed along a sidewall of the source region and a sidewall of the oxide. Methods for manufacturing such device are also disclosed. 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: July 26, 2012Date of Patent: April 22, 2014Assignee: Alpha & Omega Semiconductor LtdInventors: François Hébert, Anup Bhalla
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Patent number: 8558275Abstract: This invention discloses a semiconductor power device formed in a semiconductor substrate. The semiconductor power device further includes rows of multiple horizontal columns of thin layers of alternate conductivity types in a drift region of the semiconductor substrate where each of the thin layers having a thickness to enable a punch through the thin layers when the semiconductor power device is turned on. In a specific embodiment the thickness of the thin layers satisfying charge balance equation q*ND*WN=q*NA*WP and a punch through condition of WP<2*WD*[ND/(NA+ND)] where ND and WN represent the doping concentration and the thickness of the N type layers 160, while NA and WP represent the doping concentration and thickness of the P type layers; WD represents the depletion width; and q represents an electron charge, which cancel out. This device allows for a near ideal rectangular electric field profile at breakdown voltage with sawtooth like ridges.Type: GrantFiled: December 31, 2007Date of Patent: October 15, 2013Assignee: Alpha and Omega Semiconductor LtdInventor: Madhur Bobde
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Patent number: 8441109Abstract: A vertical semiconductor power device includes a top surface and a bottom surface of a semiconductor substrate constituting a vertical current path for conducting a current there through. The semiconductor power device further includes an over current protection layer composed of a material having a resistance with a positive temperature coefficient (PTC) and the over current protection layer constituting as a part of the vertical current path connected to a source electrode and providing a feedback voltage a gate electrode of the vertical semiconductor power device for limiting a current passing there through for protecting the semiconductor power device at any voltage.Type: GrantFiled: May 31, 2008Date of Patent: May 14, 2013Assignee: Alpha and Omega Semiconductor Ltd.Inventor: François Hébert
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Patent number: 8431958Abstract: 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: GrantFiled: October 1, 2008Date of Patent: April 30, 2013Assignee: Alpha and Omega Semiconductor LTDInventor: Madhur Bobde
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Publication number: 20120293144Abstract: A voltage/current control apparatus and method are disclosed. The apparatus includes a low-side field effect transistor (FET) having a source, a gate and a drain, a high-side field effect transistor (FET) having a source, a gate and a drain, a gate driver integrated circuit (IC), a sample and hold circuit, and a comparator configured to produce a trigger signal at the output when a sum of the first and second input signals is equal to a sum of the third and fourth input signals, wherein the trigger signal is configured to trigger a beginning of a new cycle by turning the gate of the high-side FET “on” and the gate of the low-side FET “off”.Type: ApplicationFiled: May 17, 2011Publication date: November 22, 2012Applicant: ALPHA & OMEGA SEMICONDUCTOR, LTD.Inventor: Yu Cheng Chang
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Publication number: 20120286356Abstract: A semiconductor device includes a gate electrode, a top source region disposed next to the gate electrode, a drain region disposed below the bottom of the gate electrode, a oxide disposed on top of the source region and the gate electrode, and a doped polysilicon spacer disposed along a sidewall of the source region and a sidewall of the oxide. Methods for manufacturing such device are also disclosed. 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: ApplicationFiled: July 26, 2012Publication date: November 15, 2012Applicant: Alpha and Omega Semiconductor, LTD.Inventors: François Hébert, Anup Bhalla
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Patent number: 8236653Abstract: A novel integration scheme for forming power MOSFET, particularly forming salicided layers for both gate contact regions and mesa contact regions, as well as using multiple energy contact implants through the salicided layer to form conductive body contacts which short to the source region by the salicided layers.Type: GrantFiled: January 31, 2012Date of Patent: August 7, 2012Assignee: Alpha & Omega Semiconductor, LTDInventors: Yongzhong Hu, Sung-Shan Tai
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Patent number: 8124453Abstract: An electronic package for containing at least a top packaging module vertically stacked on a bottom packaging module. Each of the packaging modules includes a semiconductor chip packaged and connected by via connectors and connectors disposed on a laminated board fabricated with a standard printed-circuit board process wherein the top and bottom packaging module further configured as a surface mountable modules for conveniently stacking and mounting to prearranged electrical contacts without using a leadframe. At least one of the top and bottom packaging modules is a multi-chip module (MCM) containing at least two semiconductor chips. At least one of the top and bottom packaging modules includes a ball grid array (BGA) for surface mounting onto the prearranged electrical contacts. At least one of the top and bottom packaging modules includes a plurality of solder bumps on one of the semiconductor chips for surface mounting onto the prearranged electrical contacts.Type: GrantFiled: November 8, 2010Date of Patent: February 28, 2012Assignee: Alpha & Omega Semiconductor, LtdInventors: Ming Sun, Yueh Se Ho
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Patent number: 8120887Abstract: An electronic device formed as an integrated circuit (IC) wherein the electronic device further includes a transient voltage suppressing (TVS) circuit. The TVS circuit includes a triggering MOS transistor connected between an emitter and a collector of a first bipolar-junction transistor (BJT) coupled to a second BJT to form a SCR functioning as a main clamp circuit of the TVS circuit. The TVS circuit further includes a triggering circuit for generating a triggering signal for the triggering MOS transistor wherein the triggering circuit includes multiple stacked MOS transistors for turning into a conductive state by a transient voltage while maintaining a low leakage current.Type: GrantFiled: February 28, 2007Date of Patent: February 21, 2012Assignee: Alpha & Omega Semiconductor, Ltd.Inventors: Shekar Mallikararjunaswamy, Madhur Bobde
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Patent number: 8120142Abstract: An electronic circuit includes a filtering circuit implemented with a distributed inductor-and-capacitor (LC) network that includes metal oxide effect (MOS) trenches opened in a semiconductor substrate filled with dielectric material for functioning as capacitors for the distributed LC network. The electronic circuit further includes a transient voltage suppressing (TVS) circuit integrated with the filtering circuit that functions as a low pass filter wherein the TVS circuit includes a bipolar transistor triggered by a diode disposed in the semiconductor substrate. The distributed LC network further includes metal coils to function as inductors disposed on a top surface of the semiconductor electrically contacting the MOS trenches.Type: GrantFiled: April 18, 2008Date of Patent: February 21, 2012Assignee: Alpha & Omega Semiconductor, Ltd.Inventor: Madhur Bobde
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Patent number: 8110869Abstract: A semiconductor power device supported on a semiconductor substrate of a first conductivity type with a bottom layer functioning as a bottom electrode and an epitaxial layer overlying the bottom layer with a same conductivity type as the bottom layer. The semiconductor power device includes a plurality of FET cells and each cell further includes a body region of a second conductivity type extending from a top surface into the epitaxial layer. The body region encompasses a heavy body dopant region of second conductivity type. An insulated gate is disposed on the top surface of the epitaxial layer, overlapping a first portion of the body region. A barrier control layer is disposed on the top surface of the epitaxial layer next to the body region away from the insulated gate. A conductive layer overlies the top surface of the epitaxial layer covering a second portion of the body region and the heavy body dopant region extending over the barrier control layer forming a Schottky junction diode.Type: GrantFiled: October 1, 2007Date of Patent: February 7, 2012Assignee: Alpha & Omega Semiconductor, LtdInventor: Anup Bhalla
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Patent number: 8110472Abstract: A semiconductor power device is formed on a semiconductor substrate. The semiconductor power device includes a plurality of transistor cells distributed over different areas having varying amount of ballasting resistances depending on a local thermal dissipation in each of the different areas. An exemplary embodiment has the transistor cells with a lower ballasting resistance formed near a peripheral area and the transistor cells having a higher ballasting resistance are formed near a bond pad area. Another exemplary embodiment comprises cells with a highest ballasting resistance formed in an area around a wire-bonding pad, the transistor cells having a lower resistance are formed underneath the wire-bonding pad connected to bonding wires for dissipating heat and the transistor cells having a lowest ballasting resistance are formed in an areas away from the bonding pad.Type: GrantFiled: August 23, 2011Date of Patent: February 7, 2012Assignee: Alpha and Omega Semiconductor LtdInventors: François Hébert, Anup Bhalla