Patents by Inventor Loizos Efthymiou

Loizos Efthymiou 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: 11081578
    Abstract: We disclose herein a depletion mode III-nitride semiconductor based heterojunction device, comprising: a substrate; a III-nitride semiconductor region formed over the substrate, wherein the III-nitride semiconductor region comprises a heterojunction comprising at least one two-dimensional carrier gas of second conductivity type; a first terminal operatively connected to the III-nitride semiconductor region; a second terminal laterally spaced from the first terminal in a first dimension and operatively connected to the III-nitride semiconductor region; at least two highly doped semiconductor regions of a first conductivity type formed over the III-nitride semiconductor region, the at least two highly doped semiconductor regions being formed between the first terminal and the second terminal; and a gate terminal formed over the at least two highly doped semiconductor regions; wherein the at least two highly doped semiconductor regions are spaced from each other in a second dimension.
    Type: Grant
    Filed: May 7, 2019
    Date of Patent: August 3, 2021
    Assignee: CAMBRIDGE GAN DEVICES LIMITED
    Inventors: Florin Udrea, Loizos Efthymiou, Giorgia Longobardi, Martin Arnold
  • Publication number: 20210217882
    Abstract: A heterojunction device, includes a substrate; a III-nitride semiconductor region located longitudinally above or over the substrate and including a heterojunction having a two-dimensional carrier gas; first and second laterally spaced terminals operatively connected to the semiconductor; a gate structure of first conductivity type located above or longitudinally over the semiconductor region and laterally spaced between the first and second terminals; a control gate terminal operatively connected to the gate structure, a potential applied to the control gate terminal modulates and controls a current flow through the carrier gas between the terminals, the carrier gas being a second conductivity type; an injector of carriers of the first conductivity type laterally spaced away from the second terminal; and a floating contact layer located over the carrier gas and laterally spaced away from the second terminal and operatively connected to the injector and the semiconductor region.
    Type: Application
    Filed: January 13, 2020
    Publication date: July 15, 2021
    Inventors: Florin Udrea, Loizos Efthymiou, Giorgia Longobardi
  • Publication number: 20200357907
    Abstract: We disclose a III-nitride semiconductor based heterojunction power device, comprising: a first heterojunction transistor formed on a substrate, the first heterojunction transistor comprising: a first III-nitride semiconductor region formed over the substrate, wherein the first III-nitride semiconductor region comprises a first heterojunction comprising at least one two dimensional carrier gas of second conductivity type; a first terminal operatively connected to the first III-nitride semiconductor region; a second terminal laterally spaced from the first terminal and operatively connected to the first III-nitride semiconductor region; a first gate terminal formed over the first III-nitride semiconductor region between the first terminal and the second terminal.
    Type: Application
    Filed: May 7, 2019
    Publication date: November 12, 2020
    Inventors: Florin Udrea, Loizos Efthymiou, Giorgia Longobardi, Martin Arnold
  • Publication number: 20200357909
    Abstract: We disclose a III-nitride semiconductor based heterojunction power device comprising: a first heterojunction transistor formed on a substrate, the first heterojunction transistor comprising: a first III-nitride semiconductor region formed over the substrate, wherein the first III-nitride semiconductor region comprises a first heterojunction comprising at least one two dimensional carrier gas; a first terminal operatively connected to the first III-nitride semiconductor region; a second terminal laterally spaced from the first terminal and operatively connected to the first III-nitride semiconductor region; a first plurality of highly doped semiconductor regions of a first polarity formed over the first III-nitride semiconductor region, the first plurality of highly doped semiconductor regions being formed between the first terminal and the second terminal; a first gate region operatively connected to the first plurality of highly doped semiconductor regions; and a second heterojunction transistor formed on th
    Type: Application
    Filed: May 7, 2019
    Publication date: November 12, 2020
    Inventors: Florin Udrea, Loizos Efthymiou, Giorgia Longobardi, Martin Arnold
  • Publication number: 20200357906
    Abstract: We disclose herein a depletion mode III-nitride semiconductor based heterojunction device, comprising: a substrate; a III-nitride semiconductor region formed over the substrate, wherein the III-nitride semiconductor region comprises a heterojunction comprising at least one two-dimensional carrier gas of second conductivity type; a first terminal operatively connected to the III-nitride semiconductor region; a second terminal laterally spaced from the first terminal in a first dimension and operatively connected to the III-nitride semiconductor region; at least two highly doped semiconductor regions of a first conductivity type formed over the III-nitride semiconductor region, the at least two highly doped semiconductor regions being formed between the first terminal and the second terminal; and a gate terminal formed over the at least two highly doped semiconductor regions; wherein the at least two highly doped semiconductor regions are spaced from each other in a second dimension.
    Type: Application
    Filed: May 7, 2019
    Publication date: November 12, 2020
    Inventors: Florin Udrea, Loizos Efthymiou, Giorgia Longobardi, Martin Arnold
  • Patent number: 10818786
    Abstract: We disclose a III-nitride semiconductor based heterojunction power device, comprising: a first heterojunction transistor formed on a substrate, the first heterojunction transistor comprising: a first III-nitride semiconductor region formed over the substrate, wherein the first III-nitride semiconductor region comprises a first heterojunction comprising at least one two dimensional carrier gas of second conductivity type; a first terminal operatively connected to the first III-nitride semiconductor region; a second terminal laterally spaced from the first terminal and operatively connected to the first III-nitride semiconductor region; a first gate terminal formed over the first III-nitride semiconductor region between the first terminal and the second terminal.
    Type: Grant
    Filed: May 7, 2019
    Date of Patent: October 27, 2020
    Assignee: CAMBRIDGE GAN DEVICES LIMITED
    Inventors: Florin Udrea, Loizos Efthymiou, Giorgia Longobardi, Martin Arnold
  • Publication number: 20200335493
    Abstract: The disclosure relates to a III-nitride power semiconductor based heterojunction device including a low voltage terminal, a high voltage terminal, a control terminal and an active heterojunction transistor formed on a substrate, and further including the following monolithically integrated components: voltage clamp circuit configured to limit a maximum potential that can be applied to the internal gate terminal, an on-state circuit configured to control the internal gate terminal of the active heterojunction transistor during an on-state operation, a turn-off circuit configured to control the internal gate terminal of the active heterojunction transistor during a turn-off operation and during an off-state.
    Type: Application
    Filed: July 2, 2020
    Publication date: October 22, 2020
    Inventors: Martin ARNOLD, Loizos EFTHYMIOU, David Bruce VAIL, John William FINDLAY, Giorgia LONGOBARDI, Florin UDREA
  • Publication number: 20200287536
    Abstract: A device includes a heterojunction device, a unipolar power transistor operatively connected in series with said hetero junction device; an external control terminal for driving said unipolar power transistor and said heterojunction device; and an interface unit having a plurality of interface terminals. A first interface terminal is operatively connected to an active gate region of the heterojunction device and a second interface terminal is operatively connected to said external control terminal. The heterojunction device includes a threshold voltage less than a threshold voltage of the unipolar power transistor, wherein the threshold voltage of the heterojunction device is less than a blocking voltage of the unipolar power transistor.
    Type: Application
    Filed: May 20, 2020
    Publication date: September 10, 2020
    Inventors: Florin UDREA, Loizos EFTHYMIOU, Giorgia LONGOBARDI, Martin ARNOLD
  • Publication number: 20200168599
    Abstract: The disclosure relates to power semiconductor devices in GaN technology. The disclosure proposes an integrated auxiliary gate terminal (15) and a pulldown network to achieve a normally-off (E-Mode) GaN transistor with threshold voltage higher than 2V, low gate leakage current and enhanced switching performance. The high threshold voltage GaN transistor has a high-voltage active GaN device (205) and a low-voltage auxiliary GaN device (210) wherein the high-voltage GaN device has the gate connected to the source of the integrated auxiliary low-voltage GaN transistor and the drain being the external high-voltage drain terminal and the source being the external source terminal, while the low-voltage auxiliary GaN transistor has the gate (first auxiliary electrode) connected to the drain (second auxiliary electrode) functioning as an external gate terminal.
    Type: Application
    Filed: July 13, 2018
    Publication date: May 28, 2020
    Inventors: Florin Udrea, Loizos Efthymiou, Giorgia Longobardi
  • Patent number: 10483356
    Abstract: A power semiconductor device and method for making same are disclosed. The device includes a source bonding pad and a drain bonding pad, a drain metallization structure including a drain field plate connected to the drain bonding pad, and a source metallization structure comprising a source field plate connected to the source bonding pad. At least a portion of at least one of the bonding pads is situated directly over an active area. A dimension of at least one of the field plates varies depending upon the structure adjacent to the field plate.
    Type: Grant
    Filed: February 27, 2018
    Date of Patent: November 19, 2019
    Assignee: SILICONIX INCORPORATED
    Inventors: Max Shih-kuan Chen, Hao-Che Chien, Loizos Efthymiou, Florin Udrea, Giorgia Longobardi, Gianluca Camuso
  • Publication number: 20190267456
    Abstract: A power semiconductor device and method for making same are disclosed. The device includes a source bonding pad and a drain bonding pad, a drain metallization structure including a drain field plate connected to the drain bonding pad, and a source metallization structure comprising a source field plate connected to the source bonding pad. At least a portion of at least one of the bonding pads is situated directly over an active area. A dimension of at least one of the field plates varies depending upon the structure adjacent to the field plate.
    Type: Application
    Filed: February 27, 2018
    Publication date: August 29, 2019
    Applicant: SILICONIX INCORPORATED
    Inventors: Max Shih-kuan Chen, Hao-Che Chien, Loizos Efthymiou, Florin Udrea, Giorgia Longobardi, Gianluca Camuso
  • Publication number: 20190267482
    Abstract: The disclosure relates to power semiconductor devices in GaN technology. The disclosure proposes an integrated auxiliary (double) gate terminal and a pulldown network to achieve a normally-off (E-Mode) GaN transistor with threshold voltage higher than 2V, low gate leakage current and enhanced switching performance. The high threshold voltage GaN transistor has a high-voltage active GaN device and a low-voltage auxiliary GaN device wherein the high-voltage GaN device has the gate connected to the source of the integrated auxiliary low-voltage GaN transistor and the drain being the external high-voltage drain terminal and the source being the external source terminal, while the low-voltage auxiliary GaN transistor has the gate (first auxiliary electrode) connected to the drain (second auxiliary electrode) functioning as an external gate terminal.
    Type: Application
    Filed: May 7, 2019
    Publication date: August 29, 2019
    Inventors: Florin Udrea, Loizos Efthymiou, Giorgia Longobardi, Martin Arnold