Patents by Inventor Umesh Mishra

Umesh Mishra has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9171836
    Abstract: An electronic component includes a depletion-mode transistor, an enhancement-mode transistor, and a resistor. The depletion-mode transistor has a higher breakdown voltage than the enhancement-mode transistor. A first terminal of the resistor is electrically connected to a source of the enhancement-mode transistor, and a second terminal of the resistor and a source of the depletion-mode transistor are each electrically connected to a drain of the enhancement-mode transistor. A gate of the depletion-mode transistor can be electrically connected to a source of the enhancement-mode transistor.
    Type: Grant
    Filed: September 5, 2014
    Date of Patent: October 27, 2015
    Assignee: Transphorm Inc.
    Inventors: Rakesh K. Lal, Robert Coffie, Yifeng Wu, Primit Parikh, Yuvaraj Dora, Umesh Mishra, Srabanti Chowdhury, Nicholas Fichtenbaum
  • Patent number: 9171730
    Abstract: A III-N semiconductor HEMT device includes an electrode-defining layer on a III-N material structure. The electrode-defining layer has a recess with a first sidewall proximal to the drain and a second sidewall proximal to the source, each sidewall comprising a plurality of steps. A portion of the recess distal from the III-N material structure has a larger width than a portion of the recess proximal to the III-N material structure. An electrode is in the recess, the electrode including an extending portion over the first sidewall. A portion of the electrode-defining layer is between the extending portion and the III-N material structure. The first sidewall forms a first effective angle relative to the surface of the III-N material structure and the second sidewall forms a second effective angle relative to the surface of the III-N material structure, the second effective angle being larger than the first effective angle.
    Type: Grant
    Filed: February 13, 2014
    Date of Patent: October 27, 2015
    Assignee: Transphorm Inc.
    Inventors: Srabanti Chowdhury, Umesh Mishra, Yuvaraj Dora
  • Publication number: 20150287785
    Abstract: An N-polar III-N transistor includes a III-N buffer layer, a first III-N barrier layer, and a III-N channel layer, the III-N channel layer having a gate region and a plurality of access regions on opposite sides of the gate region. The compositional difference between the first III-N barrier layer and the III-N channel layer causes a conductive channel to be induced in the access regions of the III-N channel layer. The transistor also includes a source, a gate, a drain, and a second III-N barrier layer between the gate and the III-N channel layer. The second III-N barrier layer has an N-face proximal to the gate and a group-III face opposite the N-face, and has a larger bandgap than the III-N channel layer. The lattice constant of the first III-N barrier layer is within 0.5% of the lattice constant of the buffer layer.
    Type: Application
    Filed: June 19, 2015
    Publication date: October 8, 2015
    Inventors: Umesh Mishra, Srabanti Chowdhury, Carl Joseph Neufeld
  • Patent number: 9147760
    Abstract: A transistor device is described that includes a source, a gate, a drain, a semiconductor material which includes a gate region between the source and the drain, a plurality of channel access regions in the semiconductor material on either side of the gate, a channel in the semiconductor material having an effective width in the gate region and in the channel access regions, and an isolation region in the gate region. The isolation region serves to reduce the effective width of the channel in the gate region without substantially reducing the effective width of the channel in the access regions. Alternatively, the isolation region can be configured to collect holes that are generated in the transistor device. The isolation region may simultaneously achieve both of these functions.
    Type: Grant
    Filed: April 24, 2014
    Date of Patent: September 29, 2015
    Assignee: Transphorm Inc.
    Inventors: Umesh Mishra, Srabanti Chowdhury
  • Patent number: 9096939
    Abstract: An electrolysis transistor for providing high-density electrochemistry and products utilizing the same, and high-efficiency electrolysis and electrochemical processes is disclosed. The electrolysis transistor may comprise an electrolyte, one or more working electrodes for transferring charge to or from said electrolyte, and one or more gate structures for altering electrode over-voltage and modifying the barrier at the electrode-electrolyte interface, reducing the voltage necessary for electrolysis. An electrochemical or photo-electrochemical cell may incorporate one or more of these electrolysis transistors.
    Type: Grant
    Filed: May 29, 2008
    Date of Patent: August 4, 2015
    Assignee: Transphorm, Inc.
    Inventors: Umesh Mishra, Rakesh Lai, Likun Shen, Lee McCarthy, Primit Parikh
  • Patent number: 9093366
    Abstract: An N-polar III-N transistor includes a III-N buffer layer, a first III-N barrier layer, and a III-N channel layer, the III-N channel layer having a gate region and a plurality of access regions on opposite sides of the gate region. The compositional difference between the first III-N barrier layer and the III-N channel layer causes a conductive channel to be induced in the access regions of the III-N channel layer. The transistor also includes a source, a gate, a drain, and a second III-N barrier layer between the gate and the III-N channel layer. The second III-N barrier layer has an N-face proximal to the gate and a group-III face opposite the N-face, and has a larger bandgap than the III-N channel layer. The lattice constant of the first III-N barrier layer is within 0.5% of the lattice constant of the buffer layer.
    Type: Grant
    Filed: April 9, 2013
    Date of Patent: July 28, 2015
    Assignee: Transphorm Inc.
    Inventors: Umesh Mishra, Srabanti Chowdhury, Carl Joseph Neufeld
  • Patent number: 9041065
    Abstract: Planar Schottky diodes for which the semiconductor material includes a heterojunction which induces a 2DEG in at least one of the semiconductor layers. A metal anode contact is on top of the upper semiconductor layer and forms a Schottky contact with that layer. A metal cathode contact is connected to the 2DEG, forming an ohmic contact with the layer containing the 2DEG.
    Type: Grant
    Filed: August 22, 2013
    Date of Patent: May 26, 2015
    Assignee: Transphorm Inc.
    Inventors: Yifeng Wu, Umesh Mishra, Primit Parikh, Rongming Chu, Ilan Ben-Yaacov, Likun Shen
  • Patent number: 9041064
    Abstract: A multiple field plate transistor includes an active region, with a source, drain, and gate. A first spacer layer is between the source and the gate and a second spacer layer between the drain and the gate. A first field plate on the first spacer layer and a second field plate on the second spacer layer are connected to the gate. A third field plate connected to the source is on a third spacer layer, which is on the gate and the first and second field plates and spacer layers. The transistor exhibits a blocking voltage of at least 600 Volts while supporting current of at least 2 or 3 Amps with on resistance of no more than 5.0 or 5.3 m?-cm2, respectively, and at least 900 Volts while supporting current of at least 2 or 3 Amps with on resistance of no more than 6.6 or 7.0 m?-cm2, respectively.
    Type: Grant
    Filed: April 12, 2012
    Date of Patent: May 26, 2015
    Assignee: Cree, Inc.
    Inventors: Yifeng Wu, Primit Parikh, Umesh Mishra
  • Publication number: 20150054117
    Abstract: Semiconductor devices with guard rings are described. The semiconductor devices may be, e.g., transistors and diodes designed for high-voltage applications. A guard ring is a floating electrode formed of electrically conducting material above a semiconductor material layer. A portion of an insulating layer is between at least a portion of the guard ring and the semiconductor material layer. A guard ring may be located, for example, on a transistor between a gate and a drain electrode. A semiconductor device may have one or more guard rings.
    Type: Application
    Filed: October 31, 2014
    Publication date: February 26, 2015
    Inventors: Umesh Mishra, Srabanti Chowdhury, Yuvaraj Dora
  • Publication number: 20150041861
    Abstract: A III-N device is described with a III-N layer, an electrode thereon, a passivation layer adjacent the III-N layer and electrode, a thick insulating layer adjacent the passivation layer and electrode, a high thermal conductivity carrier capable of transferring substantial heat away from the III-N device, and a bonding layer between the thick insulating layer and the carrier. The bonding layer attaches the thick insulating layer to the carrier. The thick insulating layer can have a precisely controlled thickness and be thermally conductive.
    Type: Application
    Filed: October 23, 2014
    Publication date: February 12, 2015
    Inventors: Primit Parikh, Yuvaraj Dora, Yifeng Wu, Umesh Mishra, Nicholas Fichtenbaum, Rakesh K. Lal
  • Publication number: 20150021552
    Abstract: A transistor includes a III-N layer structure comprising a III-N channel layer between a III-N barrier layer and a p-type III-N layer. The transistor further includes a source, a drain, and a gate between the source and the drain, the gate being over the III-N layer structure. The p-type III-N layer includes a first portion that is at least partially in a device access region between the gate and the drain, and the first portion of the p-type III-N layer is electrically connected to the source and electrically isolated from the drain. When the transistor is biased in the off state, the p-type layer can cause channel charge in the device access region to deplete as the drain voltage increases, thereby leading to higher breakdown voltages.
    Type: Application
    Filed: July 9, 2014
    Publication date: January 22, 2015
    Inventors: Umesh Mishra, Rakesh K. Lal, Stacia Keller, Srabanti Chowdhury
  • Publication number: 20140377930
    Abstract: An electronic component includes a depletion-mode transistor, an enhancement-mode transistor, and a resistor. The depletion-mode transistor has a higher breakdown voltage than the enhancement-mode transistor. A first terminal of the resistor is electrically connected to a source of the enhancement-mode transistor, and a second terminal of the resistor and a source of the depletion-mode transistor are each electrically connected to a drain of the enhancement-mode transistor. A gate of the depletion-mode transistor can be electrically connected to a source of the enhancement-mode transistor.
    Type: Application
    Filed: September 5, 2014
    Publication date: December 25, 2014
    Inventors: Rakesh K. Lal, Robert Coffie, Yifeng Wu, Primit Parikh, Yuvaraj Dora, Umesh Mishra, Srabanti Chowdhury, Nicholas Fichtenbaum
  • Publication number: 20140361309
    Abstract: A III-N semiconductor device that includes a substrate and a nitride channel layer including a region partly beneath a gate region, and two channel access regions on opposite sides of the part beneath the gate. The channel access regions may be in a different layer from the region beneath the gate. The device includes an AlXN layer adjacent the channel layer wherein X is gallium, indium or their combination, and a preferably n-doped GaN layer adjacent the AlXN layer in the areas adjacent to the channel access regions. The concentration of Al in the AlXN layer, the AlXN layer thickness and the n-doping concentration in the n-doped GaN layer are selected to induce a 2DEG charge in channel access regions without inducing any substantial 2DEG charge beneath the gate, so that the channel is not conductive in the absence of a switching voltage applied to the gate.
    Type: Application
    Filed: August 20, 2014
    Publication date: December 11, 2014
    Inventors: Umesh Mishra, Robert Coffie, Likun Shen, Ilan Ben-Yaacov, Primit Parikh
  • Publication number: 20140362536
    Abstract: A circuit substrate has one or more active components and a plurality of passive circuit elements on a first surface. An active semiconductor device has a substrate with layers of material and a plurality of terminals. The active semiconductor device is flip-chip mounted on the circuit substrate and at least one of the terminals of the device is electrically connected to an active component on the circuit substrate. The active components on the substrate and the flip-chip mounted active semiconductor device, in combination with passive circuit elements, form preamplifiers and an output amplifier respectively. In a power switching configuration, the circuit substrate has logic control circuits on a first surface. A semiconductor transistor flip-chip mounted on the circuit substrate is electrically connected to the control circuits on the first surface to thereby control the on and off switching of the flip-chip mounted device.
    Type: Application
    Filed: July 23, 2014
    Publication date: December 11, 2014
    Inventors: UMESH MISHRA, PRIMIT PARIKH, YIFENG WU
  • Patent number: 8901604
    Abstract: Semiconductor devices with guard rings are described. The semiconductor devices may be, e.g., transistors and diodes designed for high-voltage applications. A guard ring is a floating electrode formed of electrically conducting material above a semiconductor material layer. A portion of an insulating layer is between at least a portion of the guard ring and the semiconductor material layer. A guard ring may be located, for example, on a transistor between a gate and a drain electrode. A semiconductor device may have one or more guard rings.
    Type: Grant
    Filed: September 6, 2011
    Date of Patent: December 2, 2014
    Assignee: Transphorm Inc.
    Inventors: Umesh Mishra, Srabanti Chowdhury, Yuvaraj Dora
  • Patent number: 8895421
    Abstract: A III-N device is described with a III-N layer, an electrode thereon, a passivation layer adjacent the III-N layer and electrode, a thick insulating layer adjacent the passivation layer and electrode, a high thermal conductivity carrier capable of transferring substantial heat away from the III-N device, and a bonding layer between the thick insulating layer and the carrier. The bonding layer attaches the thick insulating layer to the carrier. The thick insulating layer can have a precisely controlled thickness and be thermally conductive.
    Type: Grant
    Filed: December 11, 2013
    Date of Patent: November 25, 2014
    Assignee: Transphorm Inc.
    Inventors: Primit Parikh, Yuvaraj Dora, Yifeng Wu, Umesh Mishra, Nicholas Fichtenbaum, Rakesh K. Lal
  • Publication number: 20140342512
    Abstract: A III-N device is described has a buffer layer, a first III-N material layer on the buffer layer, a second III-N material layer on the first III-N material layer on an opposite side from the buffer layer and a dispersion blocking layer between the buffer layer and the channel layer. The first III-N material layer is a channel layer and a compositional difference between the first III-N material layer and the second III-N material layer induces a 2DEG channel in the first III-N material layer. A sheet or a distribution of negative charge at an interface of the channel layer and the dispersion blocking layer confines electrons away from the buffer layer.
    Type: Application
    Filed: April 25, 2014
    Publication date: November 20, 2014
    Applicant: Transphorm Inc.
    Inventors: Umesh Mishra, Lee McCarthy, Nicholas Fichtenbaum
  • Patent number: 8860495
    Abstract: An electronic component includes a depletion-mode transistor, an enhancement-mode transistor, and a resistor. The depletion-mode transistor has a higher breakdown voltage than the enhancement-mode transistor. A first terminal of the resistor is electrically connected to a source of the enhancement-mode transistor, and a second terminal of the resistor and a source of the depletion-mode transistor are each electrically connected to a drain of the enhancement-mode transistor. A gate of the depletion-mode transistor can be electrically connected to a source of the enhancement-mode transistor.
    Type: Grant
    Filed: October 31, 2013
    Date of Patent: October 14, 2014
    Assignee: Transphorm Inc.
    Inventors: Rakesh K. Lal, Robert Coffie, Yifeng Wu, Primit Parikh, Yuvaraj Dora, Umesh Mishra, Srabanti Chowdhury, Nicholas Fichtenbaum
  • Publication number: 20140299940
    Abstract: An electronic component includes a high-voltage depletion-mode transistor and a low-voltage enhancement-mode transistor. A source electrode of the high-voltage depletion-mode transistor is electrically connected to a drain electrode of the low-voltage enhancement-mode transistor, and a gate electrode of the high-voltage depletion-mode transistor is electrically coupled to the source electrode of the low-voltage enhancement-mode transistor. The on-resistance of the enhancement-mode transistor is less than the on-resistance of the depletion-mode transistor, and the maximum current level of the enhancement-mode transistor is smaller than the maximum current level of the depletion-mode transistor.
    Type: Application
    Filed: June 23, 2014
    Publication date: October 9, 2014
    Inventors: Yifeng Wu, Umesh Mishra, Srabanti Chowdhury
  • Patent number: 8841702
    Abstract: A III-N semiconductor device that includes a substrate and a nitride channel layer including a region partly beneath a gate region, and two channel access regions on opposite sides of the part beneath the gate. The channel access regions may be in a different layer from the region beneath the gate. The device includes an AlXN layer adjacent the channel layer wherein X is gallium, indium or their combination, and a preferably n-doped GaN layer adjacent the AlXN layer in the areas adjacent to the channel access regions. The concentration of Al in the AlXN layer, the AlXN layer thickness and the n-doping concentration in the n-doped GaN layer are selected to induce a 2DEG charge in channel access regions without inducing any substantial 2DEG charge beneath the gate, so that the channel is not conductive in the absence of a switching voltage applied to the gate.
    Type: Grant
    Filed: July 30, 2013
    Date of Patent: September 23, 2014
    Assignee: Transphorm Inc.
    Inventors: Umesh Mishra, Robert Coffie, Likun Shen, Ilan Ben-Yaacov, Primit Parikh