Patents Assigned to Transphorm, Inc.
  • Patent number: 10535763
    Abstract: A III-N enhancement-mode transistor includes a III-N structure including a conductive channel, source and drain contacts, and a gate electrode between the source and drain contacts. An insulator layer is over the III-N structure, with a recess formed through the insulator layer in a gate region of the transistor, with the gate electrode at least partially in the recess. The transistor further includes a field plate having a portion between the gate electrode and the drain contact, the field plate being electrically connected to the source contact. The gate electrode includes an extending portion that is outside the recess and extends towards the drain contact. The separation between the conductive channel and the extending portion of the gate electrode is greater than the separation between the conductive channel and the portion of the field plate that is between the gate electrode and the drain contact.
    Type: Grant
    Filed: July 6, 2018
    Date of Patent: January 14, 2020
    Assignee: Transphorm Inc.
    Inventor: Rakesh K. Lal
  • Patent number: 10319648
    Abstract: Techniques for improving reliability of III-N devices include holding the III-N devices at a first temperature less than or equal to 30° for a first period of time while applying a first gate-source voltage lower than a threshold voltage of the III-N devices and a first drain-source voltage greater than 0.2 times a break down voltage of the III-N devices; and holding the III-N devices at a second temperature greater than the first temperature for a second period of time while applying a second gate-source voltage lower than a threshold voltage of the III-N devices and a second drain-source voltage greater than 0.2 times a breakdown voltage of the III-N devices. After holding the III-N devices at the first and second temperatures, screening the III-N devices based on electrical performance of one or more parameters of the III-N devices.
    Type: Grant
    Filed: April 17, 2018
    Date of Patent: June 11, 2019
    Assignee: Transphorm Inc.
    Inventors: Kurt Vernon Smith, Likun Shen, David Michael Rhodes, Ronald Avrom Barr, James Leroy McKay
  • Patent number: 10224401
    Abstract: A III-N device includes a III-N layer structure including a III-N channel layer, a III-N barrier layer over the III-N channel layer, and a graded III-N layer over the III-N barrier layer having a first side adjacent to the III-N barrier layer and a second side opposite the first side; a first power electrode and a second power electrode; and a gate between the first and second power electrodes, the gate being over the III-N layer structure. A composition of the graded III-N layer is graded so the bandgap of the graded III-N layer adjacent to the first side is greater than the bandgap of the graded III-N layer adjacent to the second side. A region of the graded III-N layer is (i) between the gate and the second power electrode, and (ii) electrically connected to the first power electrode and electrically isolated from the second power electrode.
    Type: Grant
    Filed: May 31, 2017
    Date of Patent: March 5, 2019
    Assignee: Transphorm Inc.
    Inventors: Umesh Mishra, Rakesh K. Lal, Geetak Gupta, Carl Joseph Neufeld, David Rhodes
  • Patent number: 10200030
    Abstract: A circuit includes first and second half bridges, a first inductor, a second inductor, and a main inductor. The half bridges each include a high side switch, a low side switch, and a gate driver configured to apply switching signals to the high side switch and the low side switch. The first inductor has one side electrically connected to an output node of the first half bridge between the high side switch and the low side switch. The second inductor has one side electrically connected to an output node of the second half bridge between the high side switch and the low side switch. The main inductor is coupled to a node between the other sides of the first and second inductors. The main inductor has a greater inductance than each of the first and second inductors, and the first and second inductors are inversely coupled to one another.
    Type: Grant
    Filed: March 11, 2016
    Date of Patent: February 5, 2019
    Assignee: Transphorm Inc.
    Inventor: Zhan Wang
  • Patent number: 10199217
    Abstract: Group III-nitride devices are described that include a stack of III-nitride layers, passivation layers, and conductive contacts. The stack includes a channel layer with a 2DEG channel, a barrier layer and a spacer layer. One passivation layer directly contacts a surface of the spacer layer on a side opposite to the channel layer and is an electrical insulator. The stack of III-nitride layers and the first passivation layer form a structure with a reverse side proximate to the first passivation layer and an obverse side proximate to the barrier layer. Another passivation layer is on the obverse side of the structure. Defected nucleation and stress management layers that form a buffer layer during the formation process can be partially or entirely removed.
    Type: Grant
    Filed: October 7, 2016
    Date of Patent: February 5, 2019
    Assignee: Transphorm Inc.
    Inventors: Rongming Chu, Umesh Mishra, Rakesh K. Lal
  • Patent number: 10063138
    Abstract: A power factor correction circuit comprises a pair of III-N based switches coupled to a first reference ground, and an inductive component connected in series with a current sensing resistor. A first side of the current sensing resistor is coupled to a second reference ground which is electrically isolated from the first reference ground, and a second side of the current sensing resistor is coupled to a control circuit. The control circuit is also coupled to the second reference ground and is configured to measure current flowing through the inductive component during operation of the power factor correction circuit.
    Type: Grant
    Filed: February 9, 2017
    Date of Patent: August 28, 2018
    Assignee: Transphorm Inc.
    Inventors: Liang Zhou, Yifeng Wu
  • Patent number: 10043898
    Abstract: A III-N enhancement-mode transistor includes a III-N structure including a conductive channel, source and drain contacts, and a gate electrode between the source and drain contacts. An insulator layer is over the III-N structure, with a recess formed through the insulator layer in a gate region of the transistor, with the gate electrode at least partially in the recess. The transistor further includes a field plate having a portion between the gate electrode and the drain contact, the field plate being electrically connected to the source contact. The gate electrode includes an extending portion that is outside the recess and extends towards the drain contact. The separation between the conductive channel and the extending portion of the gate electrode is greater than the separation between the conductive channel and the portion of the field plate that is between the gate electrode and the drain contact.
    Type: Grant
    Filed: February 23, 2017
    Date of Patent: August 7, 2018
    Assignee: Transphorm Inc.
    Inventor: Rakesh K. Lal
  • Patent number: 10043896
    Abstract: A transistor includes a III-N layer structure including a III-N channel layer between a III-N barrier layer and a III-N depleting layer, where the III-N channel layer includes a 2DEG channel formed adjacent an interface between the III-N channel layer and the III-N barrier layer; a source and a drain, each of which being directly connected to the III-N channel layer; a gate between the source and the drain, the gate being over the III-N layer structure, where the III-N depleting layer includes a first portion that is disposed in a device access region between the gate and the drain; and where the source electrically contacts the first portion of the III-N depleting layer, and the drain is electrically isolated from the first portion of the III-N depleting layer.
    Type: Grant
    Filed: December 8, 2017
    Date of Patent: August 7, 2018
    Assignee: Transphorm Inc.
    Inventors: Umesh Mishra, Rakesh K. Lal, Stacia Keller, Srabanti Chowdhury
  • Patent number: 9991884
    Abstract: A circuit includes an electronic component package that comprises at least a first lead, a III-N device in the electronic component package, a gate driver, and a ferrite bead. The III-N device comprises a drain, gate, and source, where the source is coupled to the first lead. The gate driver comprises a first terminal and a second terminal, where the first terminal is coupled to the first lead. The ferrite bead is coupled between the gate of the III-N transistor and the second terminal of the gate driver. When switching, the deleterious effects of the parasitic inductance of the circuit gate loop are mitigated by the ferrite bead.
    Type: Grant
    Filed: April 19, 2017
    Date of Patent: June 5, 2018
    Assignee: Transphorm Inc.
    Inventors: Zhan Wang, Yifeng Wu, James Honea
  • Patent number: 9941399
    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: August 19, 2016
    Date of Patent: April 10, 2018
    Assignee: Transphorm Inc.
    Inventors: Umesh Mishra, Robert Coffie, Likun Shen, Ilan Ben-Yaacov, Primit Parikh
  • Patent number: 9935190
    Abstract: A method of fabricating a III-N device includes forming a III-N channel layer on a substrate, a III-N barrier layer on the channel layer, an insulator layer on the barrier layer, and a trench in a first portion of the device. Forming the trench comprises removing the insulator layer and a part of the barrier layer in the first portion of the device, such that a remaining portion of the barrier layer in the first portion of the device has a thickness away from a top surface of the channel layer, the thickness being within a predetermined thickness range, annealing the III-N device in a gas ambient including oxygen at an elevated temperature to oxidize the remaining portion of the barrier layer in the first portion of the device, and removing the oxidized remaining portion of the barrier layer in the first portion of the device.
    Type: Grant
    Filed: March 9, 2016
    Date of Patent: April 3, 2018
    Assignee: Transphorm Inc.
    Inventors: Mo Wu, Rakesh K. Lal, Ilan Ben-Yaacov, Umesh Mishra, Carl Joseph Neufeld
  • Patent number: 9899998
    Abstract: A half bridge is described with at least one transistor having a channel that is capable in a first mode of operation of blocking a substantial voltage in at least one direction, in a second mode of operation of conducting substantial current in one direction through the channel and in a third mode of operation of conducting substantial current in an opposite direction through the channel. The half bridge can have two circuits with such a transistor.
    Type: Grant
    Filed: November 12, 2014
    Date of Patent: February 20, 2018
    Assignee: Transphorm Inc.
    Inventors: James Honea, Yifeng Wu
  • Patent number: 9866210
    Abstract: A half bridge is described with at least one transistor having a channel that is capable in a first mode of operation of blocking a substantial voltage in at least one direction, in a second mode of operation of conducting substantial current in one direction through the channel and in a third mode of operation of conducting substantial current in an opposite direction through the channel. The half bridge can have two circuits with such a transistor.
    Type: Grant
    Filed: November 12, 2014
    Date of Patent: January 9, 2018
    Assignee: Transphorm Inc.
    Inventors: James Honea, Yifeng Wu
  • Patent number: 9865719
    Abstract: A method of fabricating a semiconductor device can include forming a III-N semiconductor layer in a reactor and injecting a hydrocarbon precursor into the reactor, thereby carbon doping the III-N semiconductor layer and causing the III-N semiconductor layer to be insulating or semi-insulating. A semiconductor device can include a substrate and a carbon doped insulating or semi-insulating III-N semiconductor layer on the substrate. The carbon doping density in the III-N semiconductor layer is greater than 5×1018 cm?3 and the dislocation density in the III-N semiconductor layer is less than 2×109 cm?2.
    Type: Grant
    Filed: January 8, 2016
    Date of Patent: January 9, 2018
    Assignee: Transphorm Inc.
    Inventors: Stacia Keller, Brian L. Swenson, Nicholas Fichtenbaum
  • Patent number: 9842922
    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: Grant
    Filed: August 3, 2016
    Date of Patent: December 12, 2017
    Assignee: Transphorm Inc.
    Inventors: Umesh Mishra, Rakesh K. Lal, Stacia Keller, Srabanti Chowdhury
  • Patent number: 9831315
    Abstract: A III-N device is described with a III-N material layer, an insulator layer on a surface of the III-N material layer, an etch stop layer on an opposite side of the insulator layer from the III-N material layer, and an electrode defining layer on an opposite side of the etch stop layer from the insulator layer. A recess is formed in the electrode defining layer. An electrode is formed in the recess. The insulator can have a precisely controlled thickness, particularly between the electrode and III-N material layer.
    Type: Grant
    Filed: June 14, 2016
    Date of Patent: November 28, 2017
    Assignee: Transphorm Inc.
    Inventors: Rongming Chu, Robert Coffie
  • Patent number: 9818686
    Abstract: Electronic modules, and methods of forming and operating modules, are described. The modules include a capacitor, a first switching device, and a second switching device. The electronic modules further include a substrate such as a DBC substrate, which includes an insulating layer between a first metal layer and a second metal layer, and may include multiple layers of DBC substrates stacked over one another. The first metal layer includes a first portion and a second portion isolated from one another by a trench formed through the first metal layer between the two portions. The first and second switching devices are over the first metal layer, a first terminal of the capacitor is electrically connected to the first portion of the first metal layer, and a second terminal of the capacitor is electrically connected to the second portion of the first metal layer, with the capacitor extending over the trench.
    Type: Grant
    Filed: April 26, 2016
    Date of Patent: November 14, 2017
    Assignee: Transphorm Inc.
    Inventors: Yifeng Wu, Sung Hae Yea
  • Patent number: 9819336
    Abstract: A half bridge is described with at least one transistor having a channel that is capable in a first mode of operation of blocking a substantial voltage in at least one direction, in a second mode of operation of conducting substantial current in one direction through the channel and in a third mode of operation of conducting substantial current in an opposite direction through the channel. The half bridge can have two circuits with such a transistor.
    Type: Grant
    Filed: November 12, 2014
    Date of Patent: November 14, 2017
    Assignee: Transphorm Inc.
    Inventors: James Honea, Yifeng Wu
  • Patent number: 9741702
    Abstract: An electronic component is described which includes a first transistor encased in a first package, the first transistor being mounted over a first conductive portion of the first package, and a second transistor encased in a second package, the second transistor being mounted over a second conductive portion of the second package. The component further includes a substrate comprising an insulating layer between a first metal layer and a second metal layer. The first package is on one side of the substrate with the first conductive portion being electrically connected to the first metal layer, and the second package is on another side of the substrate with the second conductive portion being electrically connected to the second metal layer. The first package is opposite the second package, with at least 50% of a first area of the first conductive portion being opposite a second area of the second conductive portion.
    Type: Grant
    Filed: November 24, 2015
    Date of Patent: August 22, 2017
    Assignee: Transphorm Inc.
    Inventor: Yifeng Wu
  • Patent number: 9690314
    Abstract: Power switching circuits including an inductive load and a switching device are described. The switches devices can be either low-side or high-side switches. Some of the switches are transistors that are able to block voltages or prevent substantial current from flowing through the transistor when voltage is applied across the transistor.
    Type: Grant
    Filed: July 16, 2014
    Date of Patent: June 27, 2017
    Assignee: Transphorm Inc.
    Inventors: James Honea, Yifeng Wu