Patents by Inventor Alexander A. Suvorov

Alexander A. Suvorov 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: 20110101377
    Abstract: A method is disclosed for forming a high electron mobility transistor. The method includes the steps of implanting a Group III nitride layer at a defined position with ions that when implanted produce an improved ohmic contact between the layer and contact metals, with the implantation being carried out at a temperature higher than room temperature and hot enough to reduce the amount of damage done to the Group III nitride layer, but below a temperature at which surface problems causing leakage at the gate or epitaxial layer dissociation would occur. An ohmic contact selected from the group consisting of titanium, aluminum, nickel and alloys thereof is added to the implanted defined position on the Group III nitride layer.
    Type: Application
    Filed: January 3, 2011
    Publication date: May 5, 2011
    Applicant: CREE, INC.
    Inventors: Alexander Suvorov, Scott T. Sheppard
  • Patent number: 7880172
    Abstract: A unit cell of a metal-semiconductor field-effect transistor (MESFET) includes a semi-insulating substrate having a surface, an implanted n-type channel region in the substrate, and implanted source and drain regions extending from the surface of the substrate into the implanted channel region. A gate contact is between the source and the drain regions, and an implanted p-type region is beneath the source region. The implanted p-type region has an end that extends towards the drain region, is spaced apart vertically from the implanted channel layer, and is electrically coupled to the source region. Methods of forming transistors including implanted channels and implanted p-type regions beneath the source region are also disclosed.
    Type: Grant
    Filed: January 31, 2007
    Date of Patent: February 1, 2011
    Assignee: Cree, Inc.
    Inventors: Jason P. Henning, Allan Ward, Alexander Suvorov
  • Patent number: 7875537
    Abstract: A method is disclosed for forming a high electron mobility transistor. The method includes the steps of implanting a Group III nitride layer at a defined position with ions that when implanted produce an improved ohmic contact between the layer and contact metals, with the implantation being carried out at a temperature higher than room temperature and hot enough to reduce the amount of damage done to the Group III nitride layer, but below a temperature at which surface problems causing leakage at the gate or epitaxial layer dissociation would occur. An ohmic contact selected from the group consisting of titanium, aluminum, nickel and alloys thereof is added to the implanted defined position on the Group III nitride layer.
    Type: Grant
    Filed: August 29, 2007
    Date of Patent: January 25, 2011
    Assignee: Cree, Inc.
    Inventors: Alexander Suvorov, Scott T. Sheppard
  • Patent number: 7675068
    Abstract: A silicon carbide structure is disclosed that is suitable for use as a substrate in the manufacture of electronic devices such as light emitting diodes. The structure includes a silicon carbide wafer having a first and second surface and having a predetermined conductivity type and an initial carrier concentration; a region of implanted dopant atoms extending from the first surface into the silicon carbide wafer to a predetermined depth, with the region having a higher carrier concentration than the initial carrier concentration in the remainder of the wafer; and an epitaxial layer on the first surface of the silicon carbide wafer.
    Type: Grant
    Filed: October 5, 2005
    Date of Patent: March 9, 2010
    Assignee: Cree, Inc.
    Inventors: Davis Andrew McClure, Alexander Suvorov, John Adam Edmond, David Beardsley Slater, Jr.
  • Publication number: 20090309124
    Abstract: A semiconductor light emitting diode includes a semiconductor substrate, an epitaxial layer of n-type Group III nitride on the substrate, a p-type epitaxial layer of Group III nitride on the n-type epitaxial layer and forming a p-n junction with the n-type layer, and a resistive gallium nitride region on the n-type epitaxial layer and adjacent the p-type epitaxial layer for electrically isolating portions of the p-n junction. A metal contact layer is formed on the p-type epitaxial layer. In method embodiments disclosed, the resistive gallium nitride border is formed by forming an implant mask on the p-type epitaxial region and implanting ions into portions of the p-type epitaxial region to render portions of the p-type epitaxial region semi-insulating. A photoresist mask or a sufficiently thick metal layer may be used as the implant mask.
    Type: Application
    Filed: July 22, 2009
    Publication date: December 17, 2009
    Applicant: CREE, INC.
    Inventors: Yifeng Wu, Gerald H. Negley, David B. Slater, JR., Valeri F. Tsvetkov, Alexander Suvorov
  • Patent number: 7592634
    Abstract: A semiconductor light emitting diode includes a semiconductor substrate, an epitaxial layer of n-type Group III nitride on the substrate, a p-type epitaxial layer of Group III nitride on the n-type epitaxial layer and forming a p-n junction with the n-type layer, and a resistive gallium nitride region on the n-type epitaxial layer and adjacent the p-type epitaxial layer for electrically isolating portions of the p-n junction. A metal contact layer is formed on the p-type epitaxial layer. In method embodiments disclosed, the resistive gallium nitride border is formed by forming an implant mask on the p-type epitaxial region and implanting ions into portions of the p-type epitaxial region to render portions of the p-type epitaxial region semi-insulating. A photoresist mask or a sufficiently thick metal layer may be used as the implant mask.
    Type: Grant
    Filed: June 16, 2005
    Date of Patent: September 22, 2009
    Assignee: Cree, Inc.
    Inventors: Yifeng Wu, Gerald H. Negley, David B. Slater, Jr., Valeri F. Tsvetkov, Alexander Suvorov
  • Publication number: 20090197357
    Abstract: A semiconductor device fabrication apparatus includes a load lock chamber, a loading assembly in the load lock chamber, and an ion implantation target chamber that is hermetically connected to the load lock chamber. The load lock chamber is configured to store a plurality of wafer plates. Each wafer plate respectively includes at least one semiconductor wafer thereon. The ion implantation target chamber is configured to implant an ion species into a semiconductor wafer on a currently loaded wafer plate. The loading assembly is also configured to load a next one of the plurality of wafer plates from the load lock chamber into the ion implantation target chamber. The loading assembly may be configured to load the next wafer plate from the load lock chamber into the ion implantation target chamber while substantially maintaining a current temperature within the ion implantation target chamber and/or without depressurizing the ion implantation target chamber. Related methods and devices are also discussed.
    Type: Application
    Filed: April 13, 2009
    Publication date: August 6, 2009
    Inventor: Alexander Suvorov
  • Patent number: 7547897
    Abstract: A semiconductor device fabrication apparatus includes a load lock chamber, a loading assembly in the load lock chamber, and an ion implantation target chamber that is hermetically connected to the load lock chamber. The load lock chamber is configured to store a plurality of wafer plates. Each wafer plate respectively includes at least one semiconductor wafer thereon. The ion implantation target chamber is configured to implant an ion species into a semiconductor wafer on a currently loaded wafer plate. The loading assembly is also configured to load a next one of the plurality of wafer plates from the load lock chamber into the ion implantation target chamber. The loading assembly may be configured to load the next wafer plate from the load lock chamber into the ion implantation target chamber while substantially maintaining a current temperature within the ion implantation target chamber and/or without depressurizing the ion implantation target chamber. Related methods and devices are also discussed.
    Type: Grant
    Filed: May 26, 2006
    Date of Patent: June 16, 2009
    Assignee: Cree, Inc.
    Inventor: Alexander Suvorov
  • Publication number: 20090104726
    Abstract: A semiconductor light emitting diode includes a semiconductor substrate, an epitaxial layer of n-type Group III nitride on the substrate, a p-type epitaxial layer of Group III nitride on the n-type epitaxial layer and forming a p-n junction with the n-type layer, and a resistive gallium nitride region on the n-type epitaxial layer and adjacent the p-type epitaxial layer for electrically isolating portions of the p-n junction. A metal contact layer is formed on the p-type epitaxial layer. Some embodiments include a semiconductor substrate, an epitaxial layer of n-type Group III nitride on the substrate, a p-type epitaxial layer of Group III nitride on the n-type epitaxial layer and forming a p-n junction with the n-type layer, wherein portions of the epitaxial region are patterned into a mesa and wherein the sidewalls of the mesa comprise a resistive Group III nitride region for electrically isolating portions of the p-n junction.
    Type: Application
    Filed: December 4, 2008
    Publication date: April 23, 2009
    Applicant: Cree, Inc.
    Inventors: David Beardsley Slater, JR., John Adam Edmond, Alexander Suvorov, Iain Hamilton
  • Publication number: 20090057718
    Abstract: A method is disclosed for forming a high electron mobility transistor. The method includes the steps of implanting a Group III nitride layer at a defined position with ions that when implanted produce an improved ohmic contact between the layer and contact metals, with the implantation being carried out at a temperature higher than room temperature and hot enough to reduce the amount of damage done to the Group III nitride layer, but below a temperature at which surface problems causing leakage at the gate or epitaxial layer dissociation would occur. An ohmic contact selected from the group consisting of titanium, aluminum, nickel and alloys thereof is added to the implanted defined position on the Group III nitride layer.
    Type: Application
    Filed: August 29, 2007
    Publication date: March 5, 2009
    Inventors: Alexander Suvorov, Scott T. Sheppard
  • Publication number: 20080179637
    Abstract: A unit cell of a metal-semiconductor field-effect transistor (MESFET) includes a semi-insulating substrate having a surface, an implanted n-type channel region in the substrate, and implanted source and drain regions extending from the surface of the substrate into the implanted channel region. A gate contact is between the source and the drain regions, and an implanted p-type region is beneath the source region. The implanted p-type region has an end that extends towards the drain region, is spaced apart vertically from the implanted channel layer, and is electrically coupled to the source region. Methods of forming transistors including implanted channels and implanted p-type regions beneath the source region are also disclosed.
    Type: Application
    Filed: January 31, 2007
    Publication date: July 31, 2008
    Inventors: Jason P. Henning, Allan Ward, Alexander Suvorov
  • Publication number: 20080067432
    Abstract: A semiconductor device fabrication apparatus includes a load lock chamber, a loading assembly in the load lock chamber, and an ion implantation target chamber that is hermetically connected to the load lock chamber. The load lock chamber is configured to store a plurality of wafer plates. Each wafer plate respectively includes at least one semiconductor wafer thereon. The ion implantation target chamber is configured to implant an ion species into a semiconductor wafer on a currently loaded wafer plate. The loading assembly is also configured to load a next one of the plurality of wafer plates from the load lock chamber into the ion implantation target chamber. The loading assembly may be configured to load the next wafer plate from the load lock chamber into the ion implantation target chamber while substantially maintaining a current temperature within the ion implantation target chamber and/or without depressurizing the ion implantation target chamber. Related methods and devices are also discussed.
    Type: Application
    Filed: May 26, 2006
    Publication date: March 20, 2008
    Inventor: Alexander Suvorov
  • Patent number: 7338822
    Abstract: A semiconductor light emitting diode includes a semiconductor substrate, an epitaxial layer of n-type Group III nitride on the substrate, a p-type epitaxial layer of Group III nitride on the n-type epitaxial layer and forming a p-n junction with the n-type layer, and a resistive gallium nitride region on the n-type epitaxial layer and adjacent the p-type epitaxial layer for electrically isolating portions of the p-n junction. A metal contact layer is formed on the p-type epitaxial layer. In method embodiments disclosed, the resistive gallium nitride border is formed by forming an implant mask on the p-type epitaxial region and implanting ions into portions of the p-type epitaxial region to render portions of the p-type epitaxial region semi-insulating. A photoresist mask or a sufficiently thick metal layer may be used as the implant mask.
    Type: Grant
    Filed: May 6, 2004
    Date of Patent: March 4, 2008
    Assignee: Cree, Inc.
    Inventors: Yifeng Wu, Gerald H. Negley, David B. Slater, Jr., Valeri F. Tsvetkov, Alexander Suvorov
  • Publication number: 20070292999
    Abstract: A MESFET includes a silicon carbide layer, spaced apart source and drain regions in the silicon carbide layer, a channel region positioned within the silicon carbide layer between the source and drain regions and doped with implanted dopants, and a gate contact on the silicon carbide layer. Methods of forming a MESFET include providing a layer of silicon carbide, forming spaced apart source and drain regions in the silicon carbide layer, implanting impurity atoms to form a channel region between the source and drain regions, annealing the implanted impurity atoms, and forming a gate contact on the silicon carbide layer.
    Type: Application
    Filed: April 16, 2007
    Publication date: December 20, 2007
    Inventors: Jason Henning, Allan Ward, Alexander Suvorov
  • Publication number: 20070269966
    Abstract: A method of fabricating a semiconductor device includes selecting an element for implanting into a substrate. The element has at least a first isotope and a second isotope. At least one implant contaminant is identified as having a particle weight that is substantially identical to an atomic weight of the first isotope of the element. As such, ions of the second isotope of the element are selectively implanted into a region of the substrate. The second isotope has an atomic weight that is different from the particle weight of the at least one implant contaminant. For example, the selected element may be silicon (Si), the implant contaminant may be nitrogen (N2), the first isotope having the substantially identical atomic weight may be silicon-28, and the second isotope having the different atomic weight may be silicon-29. Related methods, apparatus, and devices are also discussed.
    Type: Application
    Filed: May 16, 2006
    Publication date: November 22, 2007
    Inventor: Alexander Suvorov
  • Patent number: 7294859
    Abstract: A method is disclosed for treating a silicon carbide substrate for improved epitaxial deposition thereon and for use as a precursor in the manufacture of devices such as light emitting diodes. The method includes the steps of implanting dopant atoms of a first conductivity type into the first surface of a conductive silicon carbide wafer having the same conductivity type as the implanting ions at one or more predetermined dopant concentrations and implant energies to form a dopant profile, annealing the implanted wafer, and growing an epitaxial layer on the implanted first surface of the wafer.
    Type: Grant
    Filed: February 14, 2005
    Date of Patent: November 13, 2007
    Assignee: Cree, Inc.
    Inventors: Davis Andrew McClure, Alexander Suvorov, John Adam Edmond, David Beardsley Slater, Jr.
  • Patent number: 7138291
    Abstract: A method is disclosed for treating a silicon carbide substrate for improved epitaxial deposition thereon and for use as a precursor in the manufacture of devices such as light emitting diodes. The method includes the steps of implanting dopant atoms of a first conductivity type into the first surface of a conductive silicon carbide wafer having the same conductivity type as the implanting ions at one or more predetermined dopant concentrations and implant energies to form a dopant profile, annealing the implanted wafer, and growing an epitaxial layer on the implanted first surface of the wafer.
    Type: Grant
    Filed: January 30, 2003
    Date of Patent: November 21, 2006
    Assignee: Cree, Inc.
    Inventors: Davis Andrew McClure, Alexander Suvorov, John Adam Edmond, David Beardsley Slater, Jr.
  • Publication number: 20060226482
    Abstract: A method is disclosed for fabricating a silicon nitride regions in silicon carbide. The method includes the steps of implanting a sufficient dose and energy of nitrogen ions into a silicon carbide substrate maintained at a temperature above about 350° C. to produce an as-implanted layer of a silicon nitride composition in the silicon carbide, and annealing the as-implanted layer to form a silicon nitride composition. In some embodiments, the formed region of silicon nitride provides an insulating layer. In some embodiments, the silicon nitride region is buried under a surface layer of silicon carbide. Methods of separating silicon carbide by implantation and lift-off are additionally disclosed.
    Type: Application
    Filed: March 30, 2005
    Publication date: October 12, 2006
    Inventor: Alexander Suvorov
  • Publication number: 20060108595
    Abstract: A semiconductor light emitting diode includes a semiconductor substrate, an epitaxial layer of n-type Group III nitride on the substrate, a p-type epitaxial layer of Group III nitride on the n-type epitaxial layer and forming a p-n junction with the n-type layer, and a resistive gallium nitride region on the n-type epitaxial layer and adjacent the p-type epitaxial layer for electrically isolating portions of the p-n junction. A metal contact layer is formed on the p-type epitaxial layer. In method embodiments disclosed, the resistive gallium nitride border is formed by forming an implant mask on the p-type epitaxial region and implanting ions into portions of the p-type epitaxial region to render portions of the p-type epitaxial region semi-insulating. A photoresist mask or a sufficiently thick metal layer may be used as the implant mask.
    Type: Application
    Filed: May 6, 2004
    Publication date: May 25, 2006
    Inventors: Yifeng Wu, Gerald Negley, David Slater, Valeri Tsvetkov, Alexander Suvorov
  • Publication number: 20060033111
    Abstract: A silicon carbide structure is disclosed that is suitable for use as a substrate in the manufacture of electronic devices such as light emitting diodes. The structure includes a silicon carbide wafer having a first and second surface and having a predetermined conductivity type and an initial carrier concentration; a region of implanted dopant atoms extending from the first surface into the silicon carbide wafer to a predetermined depth, with the region having a higher carrier concentration than the initial carrier concentration in the remainder of the wafer; and an epitaxial layer on the first surface of the silicon carbide wafer.
    Type: Application
    Filed: October 5, 2005
    Publication date: February 16, 2006
    Inventors: Davis McClure, Alexander Suvorov, John Edmond, David Slater