Patents by Inventor Tobias Wikstroem

Tobias Wikstroem 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: 20250015172
    Abstract: According to an embodiment, the semiconductor device (100) comprises a semiconductor body (1) with a first side (10) and a second side (20) opposite to the first side. The semiconductor device further comprises a first thyristor structure (I) and a second thyristor structure (II). The second thyristor structure is arranged laterally beside the first thyristor structure. Each of the first and the second thyristor structure comprises a first base region (11a, 11b) at the first side and agate electrode (1a, 1b) on the first side adjoining the assigned first base region. The first base regions of the two thyristor structures are regions of the semiconductor body and are of the same conductivity type. The gate electrodes of the thyristor structures are individually and independently electrically contactable.
    Type: Application
    Filed: November 23, 2022
    Publication date: January 9, 2025
    Inventors: Tobias WIKSTROEM, Quang Tien TRAN, Hans-Günter ECKEL, Umamaheswara VEMULAPATI
  • Patent number: 12148818
    Abstract: A power semiconductor device includes a semiconductor wafer, a thyristor structure, and a bipolar junction transistor. The thyristor structure includes a first emitter layer of a first conductivity type adjacent the first main side, a first base layer of a second conductivity type, a second base layer of the first conductivity type, a second emitter layer of the second conductivity type, a gate electrode, a first main electrode, and a second main electrode arranged. The bipolar junction transistor includes a base electrode electrically separated from the gate electrode, a third main electrode arranged on the first main side and a fourth main electrode arranged on the second main side. The first main electrode is electrically connected to the third main electrode and the second main electrode is electrically connected to the fourth main electrode.
    Type: Grant
    Filed: March 9, 2021
    Date of Patent: November 19, 2024
    Assignee: Hitachi Energy Ltd
    Inventor: Tobias Wikstroem
  • Patent number: 12094791
    Abstract: A power semiconductor device includes a semiconductor wafer having a junction and a junction termination laterally surrounding the junction. A protection layer covers the lateral side of the semiconductor wafer and covers the second main side at least in an area of the junction termination. A first metal disk is arranged on the first main side to cover the first main side of the semiconductor wafer. An interface between the first metal disk and the semiconductor wafer is a free floating interface. A metal layer sandwiched between the first metal disk and the semiconductor wafer.
    Type: Grant
    Filed: October 10, 2019
    Date of Patent: September 17, 2024
    Assignee: Hitachi Energy Ltd
    Inventors: Jagoda Dobrzynska, Jan Vobecky, David Guillon, Tobias Wikstroem
  • Patent number: 11967638
    Abstract: A power diode comprises a plurality of diode cells (10). Each diode cell (10) comprises a first conductivity type first anode layer (40), a first conductivity type second anode layer (45) having a lower doping concentration than the first anode layer (40) and being separated from an anode electrode layer (20) by the first anode layer (40), a second conductivity type drift layer (50) forming a pn-junction with the second anode layer (45), a second conductivity type cathode layer (60) being in direct contact with the cathode electrode layer (60), and a cathode-side segmentation layer (67) being in direct contact with the cathode electrode layer (30). A material of the cathode-side segmentation layer (67) is a first conductivity type semiconductor, wherein an integrated doping content of the cathode-side, which is integrated along a direction perpendicular to the second main side (102), is below 2·1013 cm?2, or a material of the cathode-side segmentation layer (67) is an insulating material.
    Type: Grant
    Filed: April 1, 2020
    Date of Patent: April 23, 2024
    Assignee: Hitachi Energy Ltd
    Inventors: Tobias Wikstroem, Umamaheswara Vemulapati, Thomas Stiasny
  • Patent number: 11824091
    Abstract: An integrated gate-commutated thyristor (IGCT) includes a semiconductor wafer having a first main side and a second main side opposite to the first main side and a plurality of first type thyristor cells and second type thyristor cells. The cathode electrode of the first type thyristor cells forms an ohmic contact with the cathode region and the cathode electrode of the second type thyristor cells is insulated from the cathode region. A predefined percentage of second type thyristor cells of the overall amount of first type thyristor cells and second type thyristor cells in a segment ring is greater than 0% and less than or equal to 75%.
    Type: Grant
    Filed: February 22, 2021
    Date of Patent: November 21, 2023
    Assignee: Hitachi Energy Switzerland AG
    Inventors: Tobias Wikstroem, Umamaheswara Vemulapati
  • Publication number: 20230136897
    Abstract: A turn-off power semiconductor device includes first and second thyristor cells, a common gate contact and a plurality of stripe-shaped electrically conductive first gate runners. Each first gate runner has a first end portion, a second end portion opposite to the first end portion and a first connecting portion connecting the first end portion and the second end portion. The first end portion is directly connected to the common gate contact. The first gate electrode layer portions of all first thyristor cells are implemented as a first gate electrode layer. The second gate electrode layer portions of all second thyristor cells are implemented as a second gate electrode layer. The first gate electrode layer is directly connected to the common gate contact. At least the first connecting portion of each first gate runner is separated from the first gate electrode layer.
    Type: Application
    Filed: March 31, 2021
    Publication date: May 4, 2023
    Inventors: Tobias Wikstroem, Thomas Stiasny, Paul Commin
  • Publication number: 20230118951
    Abstract: A power semiconductor device includes a semiconductor wafer, a thyristor structure, and a bipolar junction transistor. The thyristor structure includes a first emitter layer of a first conductivity type adjacent the first main side, a first base layer of a second conductivity type, a second base layer of the first conductivity type, a second emitter layer of the second conductivity type, a gate electrode, a first main electrode, and a second main electrode arranged. The bipolar junction transistor includes a base electrode electrically separated from the gate electrode, a third main electrode arranged on the first main side and a fourth main electrode arranged on the second main side. The first main electrode is electrically connected to the third main electrode and the second main electrode is electrically connected to the fourth main electrode.
    Type: Application
    Filed: March 9, 2021
    Publication date: April 20, 2023
    Inventor: Tobias Wikstroem
  • Publication number: 20230111333
    Abstract: An integrated gate-commutated thyristor (IGCT) includes a semiconductor wafer having a first main side and a second main side opposite to the first main side and a plurality of first type thyristor cells and second type thyristor cells. The cathode electrode of the first type thyristor cells forms an ohmic contact with the cathode region and the cathode electrode of the second type thyristor cells is insulated from the cathode region. A predefined percentage of second type thyristor cells of the overall amount of first type thyristor cells and second type thyristor cells in a segment ring is greater than 0% and less than or equal to 75%.
    Type: Application
    Filed: February 22, 2021
    Publication date: April 13, 2023
    Inventors: Tobias Wikstroem, Umamaheswara Vemulapati
  • Publication number: 20230046742
    Abstract: A reverse conducting power semiconductor device includes a plurality of thyristor cells and a freewheeling diode are integrated in a semiconductor wafer. The freewheeling diode includes a diode anode layer, a diode anode electrode, a diode cathode layer, and a diode cathode electrode. The diode cathode layer includes diode cathode layer segments, each of which is stripe-shaped and arranged within a corresponding stripe-shaped first diode anode layer segment such that a longitudinal main axis of each diode cathode layer segment extends along the longitudinal main axis of the corresponding one of the first diode anode layer segments.
    Type: Application
    Filed: February 3, 2021
    Publication date: February 16, 2023
    Inventors: Tobias Wikstroem, Umamaheswara Vemulapati
  • Publication number: 20220181473
    Abstract: A power diode comprises a plurality of diode cells (10). Each diode cell (10) comprises a first conductivity type first anode layer (40), a first conductivity type second anode layer (45) having a lower doping concentration than the first anode layer (40) and being separated from an anode electrode layer (20) by the first anode layer (40), a second conductivity type drift layer (50) forming a pn-junction with the second anode layer (45), a second conductivity type cathode layer (60) being in direct contact with the cathode electrode layer (60), and a cathode-side segmentation layer (67) being in direct contact with the cathode electrode layer (30). A material of the cathode-side segmentation layer (67) is a first conductivity type semiconductor, wherein an integrated doping content of the cathode-side, which is integrated along a direction perpendicular to the second main side (102), is below 2·1013 cm?2, or a material of the cathode-side segmentation layer (67) is an insulating material.
    Type: Application
    Filed: April 1, 2020
    Publication date: June 9, 2022
    Inventors: Tobias Wikstroem, Umamaheswara Vemulapati, Thomas Stiasny
  • Publication number: 20210384091
    Abstract: A power semiconductor device includes a semiconductor wafer having a junction and a junction termination laterally surrounding the junction. A protection layer covers the lateral side of the semiconductor wafer and covers the second main side at least in an area of the junction termination. A first metal disk is arranged on the first main side to cover the first main side of the semiconductor wafer. An interface between the first metal disk and the semiconductor wafer is a free floating interface. A metal layer sandwiched between the first metal disk and the semiconductor wafer.
    Type: Application
    Filed: October 10, 2019
    Publication date: December 9, 2021
    Inventors: Jagoda Dobrzynska, Jan Vobecky, David Guillon, Tobias Wikstroem
  • Patent number: 10892245
    Abstract: The invention relates to a semi-fabricated switching device comprising a semiconductor element and a housing comprising a spring system with a ring-shaped washer laterally surrounding the semiconductor element for clamping the semiconductor element between two pole pieces. The washer is deflectable between the pole pieces by a first deflection element, which contacts the washer in a first contact area on a first side, and by a second deflection element, which contacts the washer in a second contact area on a second side. The first contact area is displaced to the second contact area. The first and second deflection element can deflect the washer such that in clamped condition an electrical contact is achievable between the pole pieces and the semiconductor element.
    Type: Grant
    Filed: July 17, 2019
    Date of Patent: January 12, 2021
    Assignee: ABB Power Grids Switzerland AG
    Inventor: Tobias Wikstroem
  • Publication number: 20190363065
    Abstract: The invention relates to a semi-fabricated switching device comprising a semiconductor element and a housing comprising a spring system with a ring-shaped washer laterally surrounding the semiconductor element for clamping the semiconductor element between two pole pieces. The washer is deflectable between the pole pieces by a first deflection element, which contacts the washer in a first contact area on a first side, and by a second deflection element, which contacts the washer in a second contact area on a second side. The first contact area is displaced to the second contact area. The first and second deflection element can deflect the washer such that in clamped condition an electrical contact is achievable between the pole pieces and the semiconductor element.
    Type: Application
    Filed: July 17, 2019
    Publication date: November 28, 2019
    Inventor: Tobias Wikstroem
  • Patent number: 8519433
    Abstract: The present disclosure provides a semiconductor switching device including a substrate having deposited thereon a cathode, an anode and a gate of the semiconductor switching device, and a connection means for electrically connecting the cathode in the gate of the semiconductor switching device to an external circuit unit. The connection includes a cathode-gate connection unit having a coaxial structure including a gate conductor and a cathode conductor for electrically connecting the cathode and the gate of the semiconductor switching device to the external circuit unit.
    Type: Grant
    Filed: June 10, 2010
    Date of Patent: August 27, 2013
    Assignee: ABB Research Ltd
    Inventors: Didier Cottet, Thomas Stiasny, Tobias Wikstroem
  • Publication number: 20100301384
    Abstract: A diode for fast switching applications includes a base layer of a first conductivity type with a first main side and a second main side opposite the first main side, an anode layer of a second conductivity type, which is arranged on the second main side, a plurality of first zones of the first conductivity type with a higher doping concentration than the base layer, and a plurality of second zones of the second conductivity type. The first and second zones are arranged alternately on the first main side. A cathode electrode is arranged on top of the first and second zones on the side of the zones which lies opposite the base layer, and a anode electrode is arranged on top of the anode layer on the side of the anode layer which lies opposite the base layer. The base layer includes a first sublayer, which is formed by the second main sided part of the base layer, and a second sublayer, which is formed by the first main sided part of the base layer.
    Type: Application
    Filed: June 21, 2010
    Publication date: December 2, 2010
    Applicant: ABB TECHNOLOGY AG
    Inventors: Iulian NISTOR, Arnost Kopta, Tobias Wikstroem
  • Publication number: 20100270584
    Abstract: The present disclosure provides a semiconductor switching device including a substrate having deposited thereon a cathode, an anode and a gate of the semiconductor switching device, and a connection means for electrically connecting the cathode in the gate of the semiconductor switching device to an external circuit unit. The connection includes a cathode-gate connection unit having a coaxial structure including a gate conductor and a cathode conductor for electrically connecting the cathode and the gate of the semiconductor switching device to the external circuit unit.
    Type: Application
    Filed: June 10, 2010
    Publication date: October 28, 2010
    Applicant: ABB RESEARCH LTD
    Inventors: Didier Cottet, Thomas Stiasny, Tobias Wikstroem