Patents by Inventor Boris N. Feigelson

Boris N. Feigelson 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: 20160300684
    Abstract: A thermionic dispenser cathode having a refractory metal matrix with scandium and barium compounds in contact with the metal matrix and methods for forming the same. The invention utilizes atomic layer deposition (ALD) to form a nanoscale, uniform, conformal distribution of a scandium compound on tungsten surfaces and further utilizes in situ high pressure consolidation/impregnation to enhance impregnation of a BaO-CaO-Al2O3 based emissive mixture into the scandate-coated tungsten matrix or to sinter a tungsten/scandate/barium composite structure. The result is a tungsten-scandate thermionic cathode having improved emission.
    Type: Application
    Filed: April 8, 2016
    Publication date: October 13, 2016
    Applicant: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Boris N. Feigelson, James A. Wollmershauser, Kedar Manandhar
  • Publication number: 20160233108
    Abstract: A symmetric multicycle rapid thermal annealing (SMRTA) method for annealing a semiconductor material without the material decomposing. The SMRTA method includes a first long-time annealing at a first temperature at which the material is thermodynamically stable, followed by multicycle rapid thermal annealing (MRTA) at temperatures at which the material is not thermodynamically stable, followed in turn by a second long-time annealing at a second temperature at which the material is thermodynamically stable. The SMRTA method can be used to form p-type and n-type semiconductor regions in doped III-nitride semiconductors, SiC, and diamond.
    Type: Application
    Filed: February 4, 2016
    Publication date: August 11, 2016
    Applicant: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Boris N. Feigelson, Jordan Greenlee, Travis J. Anderson, Francis J. Kub
  • Publication number: 20150287613
    Abstract: A method for removing existing basal plane dislocations (BPDs) from silicon carbide epilayers by using a pulsed rapid thermal annealing process where the BPDs in the epilayers were eliminated while preserving the epitaxial surface. This high temperature, high pressure method uses silicon carbide epitaxial layers with a carbon cap to protect the surface. These capped epilayers are subjected to a plurality of rapid heating and cooling cycles.
    Type: Application
    Filed: April 6, 2015
    Publication date: October 8, 2015
    Inventors: Marko J. Tadjer, Boris N. Feigelson, Nadeemullah A. Mahadik, Robert E. Stahlbush, Eugene A. Imhoff, Jordan Greenlee
  • Patent number: 9129799
    Abstract: A method to remove basal plane dislocations in post growth silicon carbide epitaxial layers by capping post growth silicon carbide epilayers with a graphite cap and annealing the capped silicon carbon epilayers at a temperature of 1750° C. or greater with a nitrogen overpressure of 60-110 psi, wherein basal plane dislocations in the epilayers are removed while surface morphology is preserved. Also disclosed is the related silicon carbide substrate material made by this method.
    Type: Grant
    Filed: September 26, 2014
    Date of Patent: September 8, 2015
    Assignee: The United States of America, as represented by the Secretary of the Navy
    Inventors: Nadeemullah A. Mahadik, Robert E. Stahlbush, Marko J. Tadjer, Eugene A. Imhoff, Boris N. Feigelson
  • Publication number: 20150155166
    Abstract: A method to remove basal plane dislocations in post growth silicon carbide epitaxial layers by capping post growth silicon carbide epilayers with a graphite cap and annealing the capped silicon carbon epilayers at a temperature of 1750° C. or greater with a nitrogen overpressure of 60-110 psi, wherein basal plane dislocations in the epilayers are removed while surface morphology is preserved. Also disclosed is the related silicon carbide substrate material made by this method.
    Type: Application
    Filed: September 26, 2014
    Publication date: June 4, 2015
    Inventors: Nadeemullah A. Mahadik, Robert E. Stahlbush, Marko J. Tadjer, Eugene A. Imhoff, Boris N. Feigelson
  • Publication number: 20150147590
    Abstract: A new Enhanced High Pressure Sintering (EHPS) method for making three-dimensional fully dense nanostructures and nano-heterostructures formed from nanoparticle powders, and three-dimensional fully dense nanostructures and nano-heterostructures formed using that method. A nanoparticle powder is placed into a reaction chamber and is treated at an elevated temperature under a gas flow to produce a cleaned powder. The cleaned powder is formed into a low density green compact which is then sintered at a temperature below conventional sintering temperatures to produce a fully dense bulk material having a retained nanostructure or nano-heterostructure corresponding to the nanostructure of the constituent nanoparticles. All steps are performed without exposing the nanoparticle powder to the ambient.
    Type: Application
    Filed: November 14, 2014
    Publication date: May 28, 2015
    Applicant: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Boris N. Feigelson, James A. Wollmershauser
  • Patent number: 8999060
    Abstract: Millimeter-scale GaN single crystals in filamentary form, also known as GaN whiskers, grown from solution and a process for preparing the same at moderate temperatures and near atmospheric pressures are provided. GaN whiskers can be grown from a GaN source in a reaction vessel subjected to a temperature gradient at nitrogen pressure. The GaN source can be formed in situ as part of an exchange reaction or can be preexisting GaN material. The GaN source is dissolved in a solvent and precipitates out of the solution as millimeter-scale single crystal filaments as a result of the applied temperature gradient.
    Type: Grant
    Filed: March 12, 2013
    Date of Patent: April 7, 2015
    Assignee: The United States of America, as represented by the Secretary of the Navy
    Inventors: Boris N. Feigelson, Jennifer K. Hite, Francis J. Kub, Charles R. Eddy, Jr.
  • Patent number: 8679248
    Abstract: Millimeter-scale GaN single crystals in filamentary form, also known as GaN whiskers, grown from solution and a process for preparing the same at moderate temperatures and near atmospheric pressures are provided. GaN whiskers can be grown from a GaN source in a reaction vessel subjected to a temperature gradient at nitrogen pressure. The GaN source can be formed in situ as part of an exchange reaction or can be preexisting GaN material. The GaN source is dissolved in a solvent and precipitates out of the solution as millimeter-scale single crystal filaments as a result of the applied temperature gradient.
    Type: Grant
    Filed: November 23, 2010
    Date of Patent: March 25, 2014
    Assignee: The United States of America, as represented by the Secretary of the Navy
    Inventors: Boris N. Feigelson, Jennifer K. Hite, Francis J. Kub, Charles R. Eddy, Jr.
  • Patent number: 8518808
    Abstract: A GaN sample in a sealed enclosure is heated very fast to a high temperature above the point where GaN is thermodynamically stable and is then cooled down very fast to a temperature where it is thermodynamically stable. The time of the GaN exposure to a high temperature range above its thermodynamic stability is sufficiently short, in a range of few seconds, to prevent the GaN from decomposing. This heating and cooling cycle is repeated multiple times without removing the sample from the enclosure. As a result, by accumulating the exposure time in each cycle, the GaN sample can be exposed to a high temperature above its point of thermodynamic stability for a long time but the GaN sample integrity is maintained (i.e., the GaN doesn't decompose) due to the extremely short heating duration of each single cycle.
    Type: Grant
    Filed: September 16, 2011
    Date of Patent: August 27, 2013
    Assignee: The United States of America, as represented by the Secretary of the Navy
    Inventors: Boris N. Feigelson, Travis Anderson, Francis J. Kub
  • Publication number: 20130186326
    Abstract: Millimeter-scale GaN single crystals in filamentary form, also known as GaN whiskers, grown from solution and a process for preparing the same at moderate temperatures and near atmospheric pressures are provided. GaN whiskers can be grown from a GaN source in a reaction vessel subjected to a temperature gradient at nitrogen pressure. The GaN source can be formed in situ as part of an exchange reaction or can be preexisting GaN material. The GaN source is dissolved in a solvent and precipitates out of the solution as millimeter-scale single crystal filaments as a result of the applied temperature gradient.
    Type: Application
    Filed: March 12, 2013
    Publication date: July 25, 2013
    Applicant: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Boris N. Feigelson, Jennifer K. Hite, Francis J. Kub, Charles R. Eddy, JR.
  • Patent number: 8449672
    Abstract: This disclosure pertains to a process for making single crystal Group III nitride, particularly gallium nitride, at low pressure and temperature, in the region of the phase diagram of Group III nitride where Group III nitride is thermodynamically stable comprises a charge in the reaction vessel of (a) Group III nitride material as a source, (b) a barrier of solvent interposed between said source of Group III nitride and the deposition site, the solvent being prepared from the lithium nitride (Li3N) combined with barium fluoride (BaF2), or lithium nitride combined with barium fluoride and lithium fluoride (LiF) composition, heating the solvent to render it molten, dissolution of the source of GaN material in the molten solvent and following precipitation of GaN single crystals either self seeded or on the seed, maintaining conditions and then precipitating out.
    Type: Grant
    Filed: April 25, 2008
    Date of Patent: May 28, 2013
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Boris N. Feigelson, Richard L. Henry
  • Publication number: 20120068188
    Abstract: A GaN sample in a sealed enclosure is heated very fast to a high temperature above the point where GaN is thermodynamically stable and is then cooled down very fast to a temperature where it is thermodynamically stable. The time of the GaN exposure to a high temperature range above its thermodynamic stability is sufficiently short, in a range of few seconds, to prevent the GaN from decomposing. This heating and cooling cycle is repeated multiple times without removing the sample from the enclosure. As a result, by accumulating the exposure time in each cycle, the GaN sample can be exposed to a high temperature above its point of thermodynamic stability for a long time but the GaN sample integrity is maintained (i.e., the GaN doesn't decompose) due to the extremely short heating duration of each single cycle.
    Type: Application
    Filed: September 16, 2011
    Publication date: March 22, 2012
    Applicant: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Boris N. Feigelson, Travis Anderson, Francis J. Kub
  • Publication number: 20110123425
    Abstract: Millimeter-scale GaN single crystals in filamentary form, also known as GaN whiskers, grown from solution and a process for preparing the same at moderate temperatures and near atmospheric pressures are provided. GaN whiskers can be grown from a GaN source in a reaction vessel subjected to a temperature gradient at nitrogen pressure. The GaN source can be formed in situ as part of an exchange reaction or can be preexisting GaN material. The GaN source is dissolved in a solvent and precipitates out of the solution as millimeter-scale single crystal filaments as a result of the applied temperature gradient.
    Type: Application
    Filed: November 23, 2010
    Publication date: May 26, 2011
    Applicant: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Boris N. Feigelson, Jennifer K. Hite, Francis J. Kub, Charles R. Eddy, JR.
  • Publication number: 20080229549
    Abstract: This disclosure pertains to a process for making single crystal Group III nitride, particularly gallium nitride, at low pressure and temperature, in the region of the phase diagram of Group III nitride where Group III nitride is thermodynamically stable comprises a charge in the reaction vessel of (a) Group III nitride material as a source, (b) a barrier of solvent interposed between said source of Group III nitride and the deposition site, the solvent being prepared from the lithium nitride (Li3N) combined with barium fluoride (BaF2), or lithium nitride combined with barium fluoride and lithium fluoride (LiF) composition, heating the solvent to render it molten, dissolution of the source of GaN material in the molten solvent and following precipitation of GaN single crystals either self seeded or on the seed, maintaining conditions and then precipitating out.
    Type: Application
    Filed: April 25, 2008
    Publication date: September 25, 2008
    Inventors: Boris N. Feigelson, Richard L. Henry