Patents by Inventor Willy Hermansson

Willy Hermansson 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: 20030020133
    Abstract: A method for controlling the temperature dependence of a junction barrier Schottky diode of a semiconductor material having an energy gap between the valence band and the conduction band exceeding 2 eV provides for doing this when producing the diode by adjusting the on-state resistance of the grid portion of the diode during the production for obtaining a temperature dependence of the operation of the diode adapted to the intended use thereof.
    Type: Application
    Filed: July 25, 2001
    Publication date: January 30, 2003
    Inventors: Fanny Dahlqvist, Heinz Lendenmann, Willy Hermansson
  • Patent number: 6278314
    Abstract: An electric circuit comprises a plurality of high power switching services connected in series and adapted to be controlled to be all conducting or blocking substantially simultaneously act together as a single switch and each holding a part of a high voltage to be held by the switch in the blocking state of the switching devices. Each switching device has an avalanche diode of SiC connected in anti-parallel therewith and adapted to start to conduct current when reverse biased as of a predetermined voltage limit for preventing that the voltage across the respective switching device exceeds such limit.
    Type: Grant
    Filed: December 8, 1998
    Date of Patent: August 21, 2001
    Assignee: ABB Research Ltd.
    Inventors: Gunnar Asplund, Bo Danielsson, Willy Hermansson, Peter Lundberg, Christer Ovrén, Anders Åberg
  • Patent number: 6104043
    Abstract: A Schottky diode of SiC has a substrate layer, a drift layer and emitter layer regions formed in the drift layer. A metal layer makes an ohmic contact to the emitter layer regions and Schottky contact to the drift layer. A depletion of the drift layer region between two adjacent emitter layer regions is allowed in the blocking state of the diode making the two adjacent p-type emitter layer regions form a continuous depleted region therebetween in this state.
    Type: Grant
    Filed: February 20, 1997
    Date of Patent: August 15, 2000
    Assignee: ABB Research Ltd.
    Inventors: Willy Hermansson, Bo Bijlenga, Lennart Ramberg, Kurt Rottner, Lennart Zdansky, Christopher Ian Harris, Mietek Bakowski, Adolf Schoner, Nils Lundberg, Mikael Ostling, Fanny Dahlquist
  • Patent number: 5914499
    Abstract: The invention relates to a method in which proton or ion implantation is used for restructuring a silicon carbide region from being conductive to being resistive and wherein this implantation method is used for manufacturing a semiconductor device which comprises a p-n junction where both the p-conductive and the n-conductive layers are designed as doped layers of silicon carbide (SiC), whereby the implantation method is used for at least one of the steps passivation of a silicon carbide surface of the device with a semi-insulating layer, definition of the area of the p-n junction during manufacture, termination of the edges of the p-n junction by means of a semi-insulating layer, creation of a positive edge angle at the edge of the p-n junction, and insulation of different devices from one another during manufacture of a plurality of devices on one and the same wafer of silicon carbide, wherein the invention also relates to the implantation method proper.
    Type: Grant
    Filed: March 5, 1997
    Date of Patent: June 22, 1999
    Assignee: ABB Research Ltd.
    Inventors: Willy Hermansson, Lennart Ramberg, Dag Sigurd
  • Patent number: 5879462
    Abstract: The present invention is directed to a device for heat treatment of objects. It comprises a susceptor for receiving an object in the form of a substrate and a gas mixture fed to the substrate for epitaxial growth of a crystal on said substrate by Chemical Vapor Deposition. The susceptor includes an inner wall and an outer, circumferential wall enclosing the inner wall at a distance therefrom. The inner wall defines a chamber for receiving the object. An enclosed space is formed between the inner and outer wall, and is filled with a powder. The powder is made of SiC, a group III nitride or alloys thereof. Also, for heating the susceptor and thereby also the object, a Rf-field radiator is provided surrounding the susceptor.
    Type: Grant
    Filed: October 16, 1995
    Date of Patent: March 9, 1999
    Assignees: ABB Research Ltd., Okmetic Ltd.
    Inventors: Olle Kordina, Willy Hermansson, Marko Tuominen
  • Patent number: 5814546
    Abstract: A method for producing a bipolar semiconductor device having a first layer doped according to a first doping type, the first layer being adapted to have minority charge carriers injected thereinto from a second layer of the device of a doping type opposite to that of the first layer in a forward conducting state of the device, comprises the steps of a) epitaxially growing the first layer and b) providing at least one region of the first layer with the minority charge carriers having a lifetime lower than in other parts of the first layer, the lower lifetime region of the first layer being formed directly during the epitaxial growth of this region by changing composition of substances fed to the first layer for the growth thereof when the region is grown.
    Type: Grant
    Filed: November 1, 1996
    Date of Patent: September 29, 1998
    Assignee: ABB Research Ltd.
    Inventor: Willy Hermansson
  • Patent number: 5661644
    Abstract: A converter circuit has at least one switching device and a SiC diode arranged to be conducting when the device is turned off and reverse-biased when the device is turned on.
    Type: Grant
    Filed: August 4, 1995
    Date of Patent: August 26, 1997
    Assignee: ABB Research Ltd.
    Inventors: Karl Bergman, Bo Bijlenga, Willy Hermansson, Lennart Zdansky