Patents Assigned to Norstel AB
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Patent number: 8803160Abstract: 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: GrantFiled: December 29, 2011Date of Patent: August 12, 2014Assignees: Siced Electronics Development GmbH & Co. KG, Norstel ABInventors: Alexandre Ellison, Björn Magnusson, Asko Vehanen, Dietrich Stephani, Heinz Mitlehner, Peter Friedrichs
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Patent number: 8492772Abstract: 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: GrantFiled: March 12, 2009Date of Patent: July 23, 2013Assignee: Norstel ABInventors: Alexandre Ellison, Christer Hallin, Björn Magnusson, Peder Bergman
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Publication number: 20120091471Abstract: 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: ApplicationFiled: December 29, 2011Publication date: April 19, 2012Applicants: SICED ELECTRONICS DEVELOPMENT GMBH, NORSTEL ABInventors: Alexandre ELLISON, Björn Magnusson, Asko Vehanen, Dietrich Stephani, Heinz Mitlehner, Peter Friedrichs
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Patent number: 8097524Abstract: 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: GrantFiled: January 13, 2009Date of Patent: January 17, 2012Assignees: Norstel AB, Siced Electronics Development GmbH & Co. KGInventors: Alexandre Ellison, Björn Magnusson, Asko Vehanen, Dietrich Stephani, Heinz Mitlehner, Peter Friedrichs
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Publication number: 20090230406Abstract: 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: ApplicationFiled: March 12, 2009Publication date: September 17, 2009Applicant: NORSTEL ABInventors: Alexandre Ellison, Christer Hallin, Bjorn Magnusson, Peder Bergman
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Patent number: 7531433Abstract: 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: GrantFiled: July 14, 2005Date of Patent: May 12, 2009Assignee: Norstel ABInventors: Alexandre Ellison, Christer Hallin, Björn Magnusson, Peder Bergman
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Publication number: 20090114924Abstract: 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: ApplicationFiled: January 13, 2009Publication date: May 7, 2009Applicants: NORSTEL AB, SICED ELECTRONICS DEVELOPMENT GMBHInventors: Alexandre Ellison, Björn Magnusson, Asko Vehanen, Dietrich Stephani, Heinz Mitlehner, Peter Friedrichs
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Patent number: 7482068Abstract: 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: GrantFiled: August 22, 2003Date of Patent: January 27, 2009Assignees: Norstel AB, SiCED Electronics Development GmbH & Co. KGInventors: Alexandre Ellison, Björn Magnusson, Asko Vehanen, Dietrich Stephani, Heinz Mitlehner, Peter Friedrichs
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Publication number: 20080149020Abstract: 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: ApplicationFiled: February 29, 2008Publication date: June 26, 2008Applicant: NORSTEL ABInventors: Erik Janzen, Peter Raback, Alexandre Ellison
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Patent number: 7361222Abstract: 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: GrantFiled: April 23, 2004Date of Patent: April 22, 2008Assignee: Norstel ABInventors: Erik Janzén, Peter Råback, Alexandre Ellison
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Patent number: 7018597Abstract: 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: GrantFiled: October 28, 2002Date of Patent: March 28, 2006Assignee: Norstel ABInventors: Alexandre Ellison, Nguyen Tien Son, Björn Magnusson, Erik Janzén
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Publication number: 20060011128Abstract: 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: ApplicationFiled: July 14, 2005Publication date: January 19, 2006Applicant: NORSTEL ABInventors: Alexandre Ellison, Christer Hallin, Bjorn Magnusson, Peder Bergman