Patents by Inventor Lars Knoll

Lars Knoll 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: 20230327014
    Abstract: A power semiconductor device comprises a drift layer of a first conductivity type, a source layer of the first conductivity type on the drift layer, with an insulated trench gate electrode which extends through the source layer into the drift layer, and an implant layer of a second conductivity type different than the first conductivity type with a homogeneous doping region having a doping variation of at most 8%. The homogeneous doping region is arranged between the source layer and the drift layer and has a homogeneous doping region thickness of at least 150 nm. A method is provided for producing a power semiconductor device with an insulated trench gate electrode.
    Type: Application
    Filed: October 8, 2021
    Publication date: October 12, 2023
    Inventors: Marco BELLINI, Lars KNOLL
  • Publication number: 20230187525
    Abstract: An insulated gate structure includes a wide bandgap material layer having a channel region of a first conductivity type. A gate insulating layer is arranged directly on the channel region and has a first nitride layer that is arranged directly on the channel region. The gate insulating layer has a concentration of carbon atoms that is less than 1018 atoms/cm?3 at a distance of 3 nm from an interface between the wide bandgap material layer and the first nitride layer. An electrically conductive gate electrode layer overlies the gate insulating layer so that the gate electrode layer is separated from the wide bandgap material layer by the gate insulating layer.
    Type: Application
    Filed: February 25, 2021
    Publication date: June 15, 2023
    Inventors: Lars Knoll, Stephan Wirths, Andrei Mihaila
  • Publication number: 20220320290
    Abstract: A silicon carbide (SiC) planar transistor device includes a SiC semiconductor substrate of a first charge type, a SiC epitaxial layer of the first charge type formed at a top surface of the SiC semiconductor substrate, a source structure of the first charge type formed at a top surface of the SiC epitaxial layer, a drain structure of the first charge type formed at a bottom surface of the SiC semiconductor substrate, a gate structure comprising a gate runner and a gate dielectric that covers at least part of the source structure and the gate runner, and a channel region of a second charge type located in vertical direction below the gate structure and adjacent to the source structure. The channel can be formed by performing a plurality of implantation steps so that the channel region comprises a first region and a second region.
    Type: Application
    Filed: July 31, 2020
    Publication date: October 6, 2022
    Applicant: Hitachi Energy Switzerland AG
    Inventors: Marco Bellini, Lars Knoll
  • Publication number: 20220302309
    Abstract: A SiC transistor device includes a SiC semiconductor substrate, a SiC epitaxial layer formed on the top surface of the SiC semiconductor substrate, a source structure formed in the top surface of the SiC epitaxial layer, a source contact structure electrically coupled to the top surface of the source structure, and a gate structure that includes a gate dielectric, a metal gate, and a gate insulation. A first backside metal contact is formed on the bottom surface of the SiC semiconductor substrate, a stress inducing layer is formed on the first backside metal contact, and a second backside metal contact is formed on the stress inducing layer.
    Type: Application
    Filed: August 7, 2020
    Publication date: September 22, 2022
    Inventors: Stephan Wirths, Lars Knoll
  • Publication number: 20220278205
    Abstract: A silicon carbide transistor device includes a silicon carbide semiconductor and a silicon carbide epitaxial layer formed at a top surface of the substrate. A source structure is formed in a top surface of the silicon carbide epitaxial layer and includes a p-well region, an n-type source region and a p-type contact region. A source contact structure is formed over and electrically connected to a top surface of the source structure. A planar gate structure includes a gate dielectric and a gate runner adjacent a p-type channel region. The gate dielectric covers the channel region, at least part of the source structure and at least part of the source contact structure. The gate runner is electrically insulated from the channel region and the source structure and the source contact structure by the gate dielectric and overlaps the channel region.
    Type: Application
    Filed: July 31, 2020
    Publication date: September 1, 2022
    Inventors: Marco Bellini, Lars Knoll, Stephan Wirths
  • Patent number: 11302811
    Abstract: A silicon carbide power device, e.g., a vertical power MOSFET or an IGBT, includes a silicon carbide wafer. A first stressor and a second stressor are arranged in the silicon carbide wafer at a first main side. A first channel region, a first portion of a drift layer and a second channel region are laterally arranged between the first stressor and the second stressor in a second lateral direction parallel to the first main side and perpendicular to the first lateral direction. A stress can be introduced by the first stressor and the second stressor in the first channel region and in the second channel region.
    Type: Grant
    Filed: December 16, 2019
    Date of Patent: April 12, 2022
    Assignee: Hitachi Energy Switzerland AG
    Inventors: Marco Bellini, Lars Knoll, Lukas Kranz
  • Publication number: 20220045213
    Abstract: A silicon carbide power device, e.g., a vertical power MOSFET or an IGBT, includes a silicon carbide wafer. A first stressor and a second stressor are arranged in the silicon carbide wafer at a first main side. A first channel region, a first portion of a drift layer and a second channel region are laterally arranged between the first stressor and the second stressor in a second lateral direction parallel to the first main side and perpendicular to the first lateral direction. A stress can be introduced by the first stressor and the second stressor in the first channel region and in the second channel region.
    Type: Application
    Filed: December 16, 2019
    Publication date: February 10, 2022
    Inventors: Marco Bellini, Lars Knoll, Lukas Kranz
  • Publication number: 20220028976
    Abstract: Disclosed is a vertical silicon carbide power MOSFET with a 4H-SiC substrate of n+-type as drain and a 4H-Si C epilayer of n?-type, epitaxially grown on the 4H-SiC substrate acting as drift region and a source region of p++-type, a well region of p-type, a channel region of p-type and a contact region of n++-type implanted into the drift region and a metal gate insulated from the source and drift region by a gate-oxide. A high mobility layer with a vertical thickness in a range 0.1 nm to 50 nm exemplarily in the range of 0.5 nm to 10 nm is provided at the interface between the 4H-SiC epilayer and the gate-oxide.
    Type: Application
    Filed: October 22, 2019
    Publication date: January 27, 2022
    Inventors: Stephan Wirths, Andrei Mihaila, Lars Knoll
  • Patent number: 11031473
    Abstract: A power semiconductor device includes a semiconductor wafer having a first main side surface and a second main side surface. The semiconductor wafer includes a first semiconductor layer having a first conductivity type and a plurality of columnar or plate-shaped first semiconductor regions extending in the first semiconductor layer between the first main side surface and the second main side surface in a vertical direction perpendicular to the first main side surface and the second main side surface. The first semiconductor regions have a second conductivity type, which is different from the first conductivity type. Therein, the first semiconductor is a layer of hexagonal silicon carbide. The first semiconductor regions are regions of 3C polytype silicon carbide.
    Type: Grant
    Filed: September 3, 2019
    Date of Patent: June 8, 2021
    Assignee: ABB POWER GRIDS SWITZERLAND AG
    Inventors: Friedhelm Bauer, Lars Knoll, Marco Bellini, Renato Minamisawa, Umamaheswara Vemulapati
  • Publication number: 20210043735
    Abstract: An embodiment provides a power semiconductor device having a low on-state resistance while avoiding any short channel effects and having a low subthreshold slope. The embodiment provides a trench power semiconductor device, which comprises a compensation layer of a first conductivity type, wherein the compensation layer is extending on a gate insulation layer between a source layer of the first conductivity type and a substrate layer of the first conductivity type directly adjacent to a channel region of a second conductivity type.
    Type: Application
    Filed: October 23, 2020
    Publication date: February 11, 2021
    Inventors: Renato Minamisawa, Lars Knoll
  • Publication number: 20210020753
    Abstract: A power semiconductor device includes a wide-bandgap semiconductor layer having an active region and a termination region that laterally surrounds the active region. The wide-bandgap semiconductor layer has a first recess that is recessed from the first main side in the termination region and surrounds the active region and a second recess that is recessed from the first main side in the active region and is filled with an insulating material. A depth of the second recess is the same as a depth of the first recess. A field plate on the first main side of the wide-bandgap semiconductor layer exposes a first portion of the wide-bandgap semiconductor layer in the termination region.
    Type: Application
    Filed: March 5, 2019
    Publication date: January 21, 2021
    Inventors: Andrei Mihaila, Lars Knoll, Lukas Kranz
  • Patent number: 10553437
    Abstract: A method of manufacturing a semiconductor device is provided with: (a) providing a wide bandgap substrate product, (b) forming source regions by applying a first mask with a first and second mask layer and applying an n dopant, forming a well layer by removing such part of the first mask, which is arranged between the two source regions, and applying a p dopant, forming two channel regions by forming a third mask by performing an etching step, by which the first mask layer is farther removed at the openings than the second mask layer, and then removing the second mask layer, wherein the remaining first mask layer forms a third mask and applying a p dopant, wherein a well layer depth is at least as large as a channel layer depth, (c) after step (b) for forming a plug applying a fourth mask, which covers the source regions and the channel layers and applying a p fourth dopant to a greater depth than the well layer depth and with a higher doping concentration than the well layers.
    Type: Grant
    Filed: June 4, 2018
    Date of Patent: February 4, 2020
    Assignee: ABB Schweiz AG
    Inventors: Holger Bartolf, Munaf Rahimo, Lars Knoll, Andrei Mihaila, Renato Minamisawa
  • Publication number: 20200006496
    Abstract: A power semiconductor device includes a semiconductor wafer having a first main side surface and a second main side surface. The semiconductor wafer includes a first semiconductor layer having a first conductivity type and a plurality of columnar or plate-shaped first semiconductor regions extending in the first semiconductor layer between the first main side surface and the second main side surface in a vertical direction perpendicular to the first main side surface and the second main side surface. The first semiconductor regions have a second conductivity type, which is different from the first conductivity type. Therein, the first semiconductor is a layer of hexagonal silicon carbide. The first semiconductor regions are regions of 3C polytype silicon carbide.
    Type: Application
    Filed: September 3, 2019
    Publication date: January 2, 2020
    Inventors: Friedhelm Bauer, Lars Knoll, Marco Bellini, Renato Minamisawa, Umamaheswara Vemulapati
  • Patent number: 10516022
    Abstract: A wide bandgap semiconductor device is comprising an (n?) doped drift layer between a first main side and a second main side. On the first main side, n doped source regions are arranged which are laterally surrounded by p doped channel layers having a channel layer depth. P+ doped well layers having a well layer depth, which is at least as large as the channel layer depth is arranged at the bottom of the source regions. A p++ doped plug extends from a depth, which is at least as deep as the source layer depth and less deep than the well layer depth, to a plug depth, which is as least as deep as the well layer depth, and having a higher doping concentration than the well layers, is arranged between the source regions and well layers. On the first main side, an ohmic contact contacts as a first main electrode the source regions, the well layers and the plug.
    Type: Grant
    Filed: June 4, 2018
    Date of Patent: December 24, 2019
    Assignee: ABB Schweiz AG
    Inventors: Holger Bartolf, Munaf Rahimo, Lars Knoll, Andrei Mihaila, Renato Minamisawa
  • Publication number: 20190363166
    Abstract: The power semiconductor device according to the invention is a trench power field effect transistor, at all locations within a channel region a first local doping concentration is less than 1·1017 cm?3. In the base layer a second local doping concentration is at least 1·1017 cm?3 at all locations within the base layer. In the invention a channel length LCH, fulfils the following inequation: L CH > 4 ? ? ( ( ? CH ? t CH ? t GI ) ? GI ) , wherein ?CH is a permittivity of the channel region, ?GI is a permittivity of the gate insulation layer, tCH is a thickness of the channel region in a direction perpendicular to an interface between the gate insulation layer and the channel region, and tGI is a thickness of the gate insulation layer in a direction perpendicular to the interface between the gate insulation layer and the channel region.
    Type: Application
    Filed: December 31, 2018
    Publication date: November 28, 2019
    Inventors: Lars Knoll, Renato Minamisawa
  • Patent number: 10490658
    Abstract: A power semiconductor device includes a plurality of vertical field effect transistor cells arranged in a plurality of parallel rows, each row including vertical field effect transistor cells arranged along a first direction, wherein in each vertical field effect transistor cell a body region is surrounded by the gate layer from two lateral surfaces of the body region opposite to each other. In each row of vertical field effect transistor cells the body regions are separated from each other in the first direction by first gate regions of the gate layer, each first gate region penetrating through the body layer, so that in each row of vertical field effect transistor cells the first gate regions alternate with the body regions along the first direction. The first gate regions within each row of vertical field effect transistor cells are connected with each other by second gate regions extending across the body regions of the respective vertical field effect transistor cells in the first direction.
    Type: Grant
    Filed: August 2, 2018
    Date of Patent: November 26, 2019
    Assignee: ABB Schweiz AG
    Inventors: Lars Knoll, Renato Minamisawa
  • Patent number: 10361082
    Abstract: A method of manufacturing a semiconductor device is provided with: (a) providing a wide bandgap substrate product, (b) for forming two channel layers applying a first mask and applying a p first dopant, for forming two source regions forming a second mask by applying a further layer on the lateral sides of the first mask and applying an n second dopant, for forming two well layers forming a third mask by removing such part of the second mask between the source regions and applying a p third dopant, wherein a well layer depth is at least as large as a channel layer depth, (c) after step (b) for forming a plug applying a fourth mask, which covers the source regions and the channel layers and applying a p fourth dopant to a greater depth than the well layer depth and with a higher doping concentration than the well layers; wherein the well layers surround the plug in the lateral direction and separate it from the two source regions.
    Type: Grant
    Filed: June 4, 2018
    Date of Patent: July 23, 2019
    Assignee: ABB Schweiz AG
    Inventors: Holger Bartolf, Munaf Rahimo, Lars Knoll, Andrei Mihaila, Renato Minamisawa
  • Publication number: 20190035928
    Abstract: The present application provides a power semiconductor device having a low on-state resistance while avoiding any short channel effects and having a low subthreshold slope. To attain this object the invention provides a trench power semiconductor device, which includes a compensation layer of a first conductivity type, wherein the compensation layer is extending on a gate insulation layer between a source layer of the first conductivity type and a substrate layer of the first conductivity type directly adjacent to a channel region of a second conductivity type, and wherein: L ch > 4 ? ? ( ? CR ? t COMP ? t GI ? GI ) . In the above inequation Lch is a channel length, ?CR is a permittivity of the channel region, ?GI is a permittivity of the gate insulation layer, tCOMP is a thickness of the compensation layer and tGI is a thickness of the gate insulation layer.
    Type: Application
    Filed: October 2, 2018
    Publication date: January 31, 2019
    Inventors: Renato Minamisawa, Lars Knoll
  • Patent number: 10164126
    Abstract: A semiconductor power rectifier with increased surge current capability is described. A semiconductor layer includes a drift layer having a first conductivity type, at least one pilot region having a second conductivity type different from the first conductivity type, a plurality of stripe-shaped emitter regions having the second conductivity type, and a transition region having the second conductivity type, wherein the at least one pilot region has in any lateral direction parallel to the first main side a width of at least 200 ?m and is formed adjacent to the first main side to form a first p-n junction with the drift layer, each emitter region is formed adjacent to the first main side form a second p-n junction with the drift layer, and the transition region is formed adjacent to the first main side to form a third p-n junction with the drift layer.
    Type: Grant
    Filed: January 3, 2018
    Date of Patent: December 25, 2018
    Assignee: ABB Schweiz AG
    Inventors: Andrei Mihaila, Munaf Rahimo, Renato Minamisawa, Lars Knoll, Liutauras Storasta
  • Publication number: 20180350602
    Abstract: A method of manufacturing a semiconductor device is provided with: (a) providing a wide bandgap substrate product, (b) forming source regions by applying a first mask with a first and second mask layer and applying an n dopant, forming a well layer by removing such part of the first mask, which is arranged between the two source regions, and applying a p dopant, forming two channel regions by forming a third mask by performing an etching step, by which the first mask layer is farther removed at the openings than the second mask layer, and then removing the second mask layer, wherein the remaining first mask layer forms a third mask and applying a p dopant, wherein a well layer depth is at least as large as a channel layer depth, (c) after step (b) for forming a plug applying a fourth mask, which covers the source regions and the channel layers and applying a p fourth dopant to a greater depth than the well layer depth and with a higher doping concentration than the well layers.
    Type: Application
    Filed: June 4, 2018
    Publication date: December 6, 2018
    Inventors: Holger Bartolf, Munaf Rahimo, Lars Knoll, Andrei Mihaila, Renato Minamisawa