Patents Assigned to Norstel AB
  • Patent number: 8803160
    Abstract: A semiconductor device including a drift zone of a first conductivity type serving as a substrate layer having a front side and a back side. A first contact electrode is arranged at the front side of the drift zone. A control region is arranged at the front side and controls an injection of carriers of at least the first conductivity type into the drift zone. A second contact electrode is arranged at the backside of the drift zone. The drift zone is arranged to carry a carrier flow between the first and the second contact electrode. The drift zone includes a silicon carbide wafer with a net carrier concentration less than 1015 cm?3 and a carrier lifetime of at least 50 ns.
    Type: Grant
    Filed: December 29, 2011
    Date of Patent: August 12, 2014
    Assignees: Siced Electronics Development GmbH & Co. KG, Norstel AB
    Inventors: Alexandre Ellison, Björn Magnusson, Asko Vehanen, Dietrich Stephani, Heinz Mitlehner, Peter Friedrichs
  • Patent number: 8492772
    Abstract: A wafer including a SiC substrate having a surface that is inclined relative to a (0001) basal plane at an angle higher than 0.1 degree but less than 1 degree, a SiC homoepitaxial device layer, and a SiC homoepitaxial boundary layer having a thickness up to 1 ?m arranged between the substrate and the device layer. The boundary layer has been grown on the substrate under an atmosphere of lower supersaturation than when forming the device layer and at a C/Si ratio above 1.
    Type: Grant
    Filed: March 12, 2009
    Date of Patent: July 23, 2013
    Assignee: Norstel AB
    Inventors: Alexandre Ellison, Christer Hallin, Björn Magnusson, Peder Bergman
  • Publication number: 20120091471
    Abstract: A semiconductor device including a drift zone of a first conductivity type serving as a substrate layer having a front side and a back side. A first contact electrode is arranged at the front side of the drift zone. A control region is arranged at the front side and controls an injection of carriers of at least the first conductivity type into the drift zone. A second contact electrode is arranged at the backside of the drift zone. The drift zone is arranged to carry a carrier flow between the first and the second contact electrode. The drift zone includes a silicon carbide wafer with a net carrier concentration less than 1015 cm?3 and a carrier lifetime of at least 50 ns.
    Type: Application
    Filed: December 29, 2011
    Publication date: April 19, 2012
    Applicants: SICED ELECTRONICS DEVELOPMENT GMBH, NORSTEL AB
    Inventors: Alexandre ELLISON, Björn Magnusson, Asko Vehanen, Dietrich Stephani, Heinz Mitlehner, Peter Friedrichs
  • Patent number: 8097524
    Abstract: A method for manufacturing a silicon carbide single crystal. A silicon carbide single crystal is grown. The crystal has a boron concentration less than 5×1014 cm?3, and a concentration of transition metals impurities less than 5×1014 cm?3. Intrinsic defects in the crystal are minimised. The intrinsic defects include silicon vacancies or carbon vacancies. The crystal is annealed for a desired time at a temperature above 700° C. in an atmosphere containing any of the gases hydrogen or a mixture of hydrogen and an inert gas, such that the density of intrinsic defects and any associated defects is decreased to a concentration low enough to confer to the crystal a desired carrier life time of at least 50 ns at room temperature.
    Type: Grant
    Filed: January 13, 2009
    Date of Patent: January 17, 2012
    Assignees: Norstel AB, Siced Electronics Development GmbH & Co. KG
    Inventors: Alexandre Ellison, Björn Magnusson, Asko Vehanen, Dietrich Stephani, Heinz Mitlehner, Peter Friedrichs
  • Publication number: 20090230406
    Abstract: A wafer including a SiC substrate having a surface that is inclined relative to a (0001) basal plane at an angle higher than 0.1 degree but less than 1 degree, a SiC homoepitaxial device layer, and a SiC homoepitaxial boundary layer having a thickness up to 1 ?m arranged between the substrate and the device layer. The boundary layer has been grown on the substrate under an atmosphere of lower supersaturation than when forming the device layer and at a C/Si ratio above 1.
    Type: Application
    Filed: March 12, 2009
    Publication date: September 17, 2009
    Applicant: NORSTEL AB
    Inventors: Alexandre Ellison, Christer Hallin, Bjorn Magnusson, Peder Bergman
  • Patent number: 7531433
    Abstract: A method for producing, on an SiC substrate, SiC homoepitaxial layers of the same polytype as the substrate. The layers are grown on a surface of the SiC substrate, wherein the surface is inclined relative to the (0001) basal plane at an angle higher than 0.1 degree but less than 1 degree. An homoepitaxial growth is started by forming a boundary layer with a thickness up to 1 ?m.
    Type: Grant
    Filed: July 14, 2005
    Date of Patent: May 12, 2009
    Assignee: Norstel AB
    Inventors: Alexandre Ellison, Christer Hallin, Björn Magnusson, Peder Bergman
  • Publication number: 20090114924
    Abstract: A method for manufacturing a silicon carbide single crystal. A silicon carbide single crystal is grown. The crystal has a boron concentration less than 5×1014 cm?3, and a concentration of transition metals impurities less than 5×1014 cm?3. Intrinsic defects in the crystal are minimised. The intrinsic defects include silicon vacancies or carbon vacancies. The crystal is annealed for a desired time at a temperature above 700° C. in an atmosphere containing any of the gases hydrogen or a mixture of hydrogen and an inert gas, such that the density of intrinsic defects and any associated defects is decreased to a concentration low enough to confer to the crystal a desired carrier life time of at least 50 ns at room temperature.
    Type: Application
    Filed: January 13, 2009
    Publication date: May 7, 2009
    Applicants: NORSTEL AB, SICED ELECTRONICS DEVELOPMENT GMBH
    Inventors: Alexandre Ellison, Björn Magnusson, Asko Vehanen, Dietrich Stephani, Heinz Mitlehner, Peter Friedrichs
  • Patent number: 7482068
    Abstract: A uniform silicon carbide single crystal with either an n-type or a p-type conductivity. The crystal has a net carrier concentration less than 1015 cm?3 and a carrier lifetime of at least 50 ns at room temperature.
    Type: Grant
    Filed: August 22, 2003
    Date of Patent: January 27, 2009
    Assignees: Norstel AB, SiCED Electronics Development GmbH & Co. KG
    Inventors: Alexandre Ellison, Björn Magnusson, Asko Vehanen, Dietrich Stephani, Heinz Mitlehner, Peter Friedrichs
  • Publication number: 20080149020
    Abstract: A method and a device to grow from the vapor phase, a single crystal of either SiC, a group III-nitride, or alloys thereof, at a growth rate and for a period of time sufficient to produce a crystal of preferably several centimeters length. The diameter of the growing crystal may be controlled. To prevent the formation of undesirable polycrystalline deposits on surfaces in the downstream vicinity of the single crystal growth area, the local supersaturation of at least one component of the material grown is lowered by introducing a separate gas flow comprising at least one halogen element or a combination of said halogen and hydrogen species.
    Type: Application
    Filed: February 29, 2008
    Publication date: June 26, 2008
    Applicant: NORSTEL AB
    Inventors: Erik Janzen, Peter Raback, Alexandre Ellison
  • Patent number: 7361222
    Abstract: A method and a device to grow from the vapor phase, a single crystal of either SiC, a group III-nitride, or alloys thereof, at a growth rate and for a period of time sufficient to produce a crystal of preferably several centimeters length. The diameter of the growing crystal may be controlled. To prevent the formation of undesirable polycrystalline deposits on surfaces in the downstream vicinity of the single crystal growth area, the local supersaturation of at least one component of the material grown is lowered by introducing a separate gas flow comprising at least one halogen element or a combination of said halogen and hydrogen species.
    Type: Grant
    Filed: April 23, 2004
    Date of Patent: April 22, 2008
    Assignee: Norstel AB
    Inventors: Erik Janzén, Peter Råback, Alexandre Ellison
  • Patent number: 7018597
    Abstract: The purpose of the invention is to provide a high resistivity silicon carbide substrate with electrical properties and structural quality suitable for subsequent device manufacturing, such as for example high frequency devices, so that the devices can exhibit stable and linear characteristics and to provide a high resistivity silicon carbide substrate having a low density of structural defects and a substantially controlled uniform radial distribution of its resistivity.
    Type: Grant
    Filed: October 28, 2002
    Date of Patent: March 28, 2006
    Assignee: Norstel AB
    Inventors: Alexandre Ellison, Nguyen Tien Son, Björn Magnusson, Erik Janzén
  • Publication number: 20060011128
    Abstract: A method for producing, on an SiC substrate, SiC homoepitaxial layers of the same polytype as the substrate. The layers are grown on a surface of the SiC substrate, wherein the surface is inclined relative to the (0001) basal plane at an angle higher than 0.1 degree but less than 1 degree. An homoepitaxial growth is started by forming a boundary layer with a thickness up to 1 ?m.
    Type: Application
    Filed: July 14, 2005
    Publication date: January 19, 2006
    Applicant: NORSTEL AB
    Inventors: Alexandre Ellison, Christer Hallin, Bjorn Magnusson, Peder Bergman