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).

  • Publication number: 20140231929
    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: Application
    Filed: April 24, 2014
    Publication date: August 21, 2014
    Applicant: Transphorm Inc.
    Inventors: Umesh Mishra, Srabanti Chowdhury
  • Publication number: 20140231823
    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: Application
    Filed: February 13, 2014
    Publication date: August 21, 2014
    Applicant: Transphorm Inc.
    Inventors: Srabanti Chowdhury, Umesh Mishra, Yuvaraj Dora
  • Patent number: 8803313
    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: Grant
    Filed: August 21, 2012
    Date of Patent: August 12, 2014
    Assignee: Cree, Inc.
    Inventors: Umesh Mishra, Primit Parikh, Yifeng Wu
  • Patent number: 8803246
    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: Grant
    Filed: July 16, 2012
    Date of Patent: August 12, 2014
    Assignee: Transphorm Inc.
    Inventors: Yifeng Wu, Umesh Mishra, Srabanti Chowdhury
  • Patent number: 8742459
    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: Grant
    Filed: May 14, 2009
    Date of Patent: June 3, 2014
    Assignee: Transphorm Inc.
    Inventors: Umesh Mishra, Lee McCarthy, Nicholas Fichtenbaum
  • Patent number: 8742460
    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: December 15, 2010
    Date of Patent: June 3, 2014
    Assignee: Transphorm Inc.
    Inventors: Umesh Mishra, Srabanti Chowdhury
  • Publication number: 20140103399
    Abstract: Enhancement mode III-nitride devices are described. The 2DEG is depleted in the gate region so that the device is unable to conduct current when no bias is applied at the gate. Both gallium face and nitride face devices formed as enhancement mode devices.
    Type: Application
    Filed: December 17, 2013
    Publication date: April 17, 2014
    Applicant: Transphorm Inc.
    Inventors: Chang Soo Suh, Umesh Mishra
  • Publication number: 20140099757
    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: December 11, 2013
    Publication date: April 10, 2014
    Applicant: Transphorm Inc.
    Inventors: Primit Parikh, Yuvaraj Dora, Yifeng Wu, Umesh Mishra, Nicholas Fichtenbaum, Rakesh K. Lal
  • Publication number: 20140094010
    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: October 31, 2013
    Publication date: April 3, 2014
    Applicant: Transphorm Inc.
    Inventors: Rakesh L. Lal, Robert Coffie, Yifeng Wu, Primit Parikh, Yuvaraj Dora, Umesh Mishra, Srabanti Chowdhury, Nicholas Fichtenbaum
  • Patent number: 8664695
    Abstract: A transistor comprising a plurality of active semiconductor layers on a substrate, with source and drain electrodes in contact with the semiconductor layers. A gate is formed between the source and drain electrodes and on the plurality of semiconductor layers. A plurality of field plates are arranged over the semiconductor layers, each of which extends from the edge of the gate toward the drain electrode, and each of which is isolated from said semiconductor layers and from the others of the field plates. The topmost of the field plates is electrically connected to the source electrode and the others of the field plates are electrically connected to the gate or the source electrode.
    Type: Grant
    Filed: July 2, 2009
    Date of Patent: March 4, 2014
    Assignee: Cree, Inc.
    Inventors: Yifeng Wu, Primit Parikh, Umesh Mishra, Marcia Moore
  • Publication number: 20140054603
    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: Application
    Filed: August 22, 2013
    Publication date: February 27, 2014
    Applicant: Transphorm Inc.
    Inventors: Yifeng Wu, Umesh Mishra, Primit Parikh, Rongming Chu, Ilan Ben-Yaacov, Likun Shen
  • Publication number: 20140042495
    Abstract: An electronic component includes a high-voltage depletion-mode transistor and a low-voltage enhancement-mode transistor both encased in a single package. A source electrode of the high-voltage depletion-mode transistor is electrically connected to a drain electrode of the low-voltage enhancement-mode transistor, a drain electrode of the high-voltage depletion-mode transistor is electrically connected to a drain lead of the single package, a gate electrode of the low-voltage enhancement-mode transistor is electrically connected to a gate lead of the single package, a gate electrode of the high-voltage depletion-mode transistor is electrically connected to an additional lead of the single package, and a source electrode of the low-voltage enhancement-mode transistor is electrically connected to a conductive structural portion of the single package.
    Type: Application
    Filed: October 18, 2013
    Publication date: February 13, 2014
    Applicant: Transphorm Inc.
    Inventors: Primit Parikh, James Honea, Carl C. Blake, Jr., Robert Coffie, Yifeng Wu, Umesh Mishra
  • Patent number: 8643062
    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: February 2, 2011
    Date of Patent: February 4, 2014
    Assignee: Transphorm Inc.
    Inventors: Primit Parikh, Yuvaraj Dora, Yifeng Wu, Umesh Mishra, Nicholas Fichtenbaum, Rakesh K. Lal
  • Patent number: 8633518
    Abstract: Enhancement mode III-nitride devices are described. The 2DEG is depleted in the gate region so that the device is unable to conduct current when no bias is applied at the gate. Both gallium face and nitride face devices formed as enhancement mode devices.
    Type: Grant
    Filed: December 21, 2012
    Date of Patent: January 21, 2014
    Assignee: Transphorm Inc.
    Inventors: Chang Soo Suh, Umesh Mishra
  • Publication number: 20140015066
    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: July 16, 2012
    Publication date: January 16, 2014
    Applicant: TRANSPHORM INC.
    Inventors: Yifeng Wu, Umesh Mishra, Srabanti Chowdhury
  • Patent number: 8624662
    Abstract: An electronic component includes a high-voltage depletion-mode transistor and a low-voltage enhancement-mode transistor both encased in a single package. A source electrode of the high-voltage depletion-mode transistor is electrically connected to a drain electrode of the low-voltage enhancement-mode transistor, a drain electrode of the high-voltage depletion-mode transistor is electrically connected to a drain lead of the single package, a gate electrode of the low-voltage enhancement-mode transistor is electrically connected to a gate lead of the single package, a gate electrode of the high-voltage depletion-mode transistor is electrically connected to an additional lead of the single package, and a source electrode of the low-voltage enhancement-mode transistor is electrically connected to a conductive structural portion of the single package.
    Type: Grant
    Filed: February 5, 2010
    Date of Patent: January 7, 2014
    Assignee: Transphorm Inc.
    Inventors: Primit Parikh, James Honea, Carl C. Blake, Jr., Robert Coffie, Yifeng Wu, Umesh Mishra
  • Publication number: 20140001557
    Abstract: Transistor devices which include semiconductor layers with integrated hole collector regions are described. The hole collector regions are configured to collect holes generated in the transistor device during operation and transport them away from the active regions of the device. The hole collector regions can be electrically connected or coupled to the source, the drain, or a field plate of the device. The hole collector regions can be doped, for example p-type or nominally p-type, and can be capable of conducting holes but not electrons.
    Type: Application
    Filed: June 27, 2012
    Publication date: January 2, 2014
    Applicant: TRANSPHORM INC.
    Inventors: Umesh Mishra, Srabanti Chowdhury, Ilan Ben-Yaacov
  • Publication number: 20130344687
    Abstract: Semiconductor device structures and methods of fabricating semiconductor devices structures are provided that include a semi-insulating or insulating GaN epitaxial layer on a conductive semiconductor substrate and/or a conductive layer. The semi-insulating or insulating GaN epitaxial layer has a thickness of at least about 4 ?m. GaN semiconductor device structures and methods of fabricating GaN semiconductor device structures are also provided that include an electrically conductive SiC substrate and an insulating or semi-insulating GaN epitaxial layer on the conductive SiC substrate. The GaN epitaxial layer has a thickness of at least about 4 ?m.
    Type: Application
    Filed: August 26, 2013
    Publication date: December 26, 2013
    Applicant: Cree, Inc.
    Inventors: Adam William Saxler, Yifeng Wu, Primit Parikh, Umesh Mishra, Richard Peter Smith, Scott T. Sheppard
  • Patent number: 8598937
    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 7, 2011
    Date of Patent: December 3, 2013
    Assignee: Transphorm Inc.
    Inventors: Rakesh K. Lal, Robert Coffie, Yifeng Wu, Primit Parikh, Yuvaraj Dora, Umesh Mishra, Srabanti Chowdhury, Nicholas Fichtenbaum
  • Publication number: 20130316502
    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: July 30, 2013
    Publication date: November 28, 2013
    Applicant: Transphorm Inc.
    Inventors: Umesh Mishra, Robert Coffie, Likun Shen, Ilan Ben-Yaacov, Primit Parikh