Patents by Inventor Robert E. Stahlbush

Robert E. Stahlbush 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).

  • Patent number: 11171055
    Abstract: A method of cleaving includes providing a substrate. Optionally, the substrate includes ?-gallium oxide, hexagonal zinc sulfide, or magnesium selenide. The substrate includes at least one natural cleave plane and a crystallinity. The substrate is cleaved along a first natural cleave plane of the at least one natural cleave plane. The cleaving the substrate along the first natural cleave plane includes the following. A micro-crack is generated in the substrate while maintaining the crystallinity adjacent to the micro-crack by generating a plurality of phonons in the substrate, the micro-crack comprising a micro-crack direction along the first natural cleave plane. The micro-crack is propagated along the first natural cleave plane while maintaining the crystallinity adjacent to the micro-crack. Optionally, generating a micro-crack in the substrate by generating a plurality of phonons in the substrate includes generating the plurality of phonons by electron-hole recombination.
    Type: Grant
    Filed: January 30, 2020
    Date of Patent: November 9, 2021
    Assignee: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Nadeemullah A. Mahadik, Robert E. Stahlbush, Marko J. Tadjer, Karl D. Hobart, Francis J. Kub
  • Publication number: 20200251389
    Abstract: A method of cleaving includes providing a substrate. Optionally, the substrate includes ?-gallium oxide, hexagonal zinc sulfide, or magnesium selenide. The substrate includes at least one natural cleave plane and a crystallinity. The substrate is cleaved along a first natural cleave plane of the at least one natural cleave plane. The cleaving the substrate along the first natural cleave plane includes the following. A micro-crack is generated in the substrate while maintaining the crystallinity adjacent to the micro-crack by generating a plurality of phonons in the substrate, the micro-crack comprising a micro-crack direction along the first natural cleave plane. The micro-crack is propagated along the first natural cleave plane while maintaining the crystallinity adjacent to the micro-crack. Optionally, generating a micro-crack in the substrate by generating a plurality of phonons in the substrate includes generating the plurality of phonons by electron-hole recombination.
    Type: Application
    Filed: January 30, 2020
    Publication date: August 6, 2020
    Inventors: NADEEMULLAH A. MAHADIK, Robert E. Stahlbush, Marko J. Tadjer, Karl D. Hobart, Francis J. Kub
  • Patent number: 10403509
    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: Grant
    Filed: April 6, 2015
    Date of Patent: September 3, 2019
    Assignee: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Marko J. Tadjer, Boris N. Feigelson, Nadeemullah A. Mahadik, Robert E. Stahlbush, Eugene A. Imhoff, Jordan Greenlee
  • Patent number: 10256090
    Abstract: A method of: providing an off-axis silicon carbide substrate, and etching the surface of the substrate with a dry gas, hydrogen, or an inert gas.
    Type: Grant
    Filed: March 11, 2014
    Date of Patent: April 9, 2019
    Assignee: The United States of America, as represented by the Secretary of the Navy
    Inventors: Rachael L. Myers-Ward, David Kurt Gaskill, Charles R. Eddy, Jr., Robert E. Stahlbush, Nadeemmullah A. Mahadik, Virginia D. Wheeler
  • Patent number: 10256094
    Abstract: A method of: providing an off-axis 4H—SiC substrate, and etching the surface of the substrate with hydrogen or an inert gas.
    Type: Grant
    Filed: March 11, 2014
    Date of Patent: April 9, 2019
    Assignee: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Rachael L. Myers-Ward, David Kurt Gaskill, Charles R. Eddy, Jr., Robert E. Stahlbush, Nadeemmullah A. Mahadik, Virginia D. Wheeler
  • Patent number: 10020366
    Abstract: A method and device including adding a protective layer on the surface of a substrate, annealing the substrate at a temperature approximately greater or equal to 1850° C., removing the protective layer from the surface of the substrate after the annealing, and growing a first epilayer on the substrate after the removing of the protective layer, wherein the first epilayer is grown without attempting to prevent the basal plane dislocations to propagate in the first epilayer when growing the first epilayer, and wherein the first epilayer is free of the basal plane dislocations.
    Type: Grant
    Filed: September 22, 2016
    Date of Patent: July 10, 2018
    Assignee: The United States of America, as represented by the Secretary of the Navy
    Inventors: Nadeemullah A. Mahadik, Robert E. Stahlbush, Eugene A. Imhoff, Marko J. Tadjer
  • Publication number: 20170092724
    Abstract: A method and device including adding a protective layer on the surface of a substrate, annealing the substrate at a temperature approximately greater or equal to 1850° C., removing the protective layer from the surface of the substrate after the annealing, and growing a first epilayer on the substrate after the removing of the protective layer, wherein the first epilayer is grown without attempting to prevent the basal plane dislocations to propagate in the first epilayer when growing the first epilayer, and wherein the first epilayer is free of the basal plane dislocations.
    Type: Application
    Filed: September 22, 2016
    Publication date: March 30, 2017
    Inventors: Nadeemullah A. Mahadik, Robert E. Stahlbush, Eugene A. Imhoff, Marko J. Tadjer
  • Patent number: 9464366
    Abstract: A method for reducing/eliminating basal plane dislocations from SiC epilayers is disclosed. An article having: an off-axis SiC substrate having an off-axis angle of no more than 6°; and a SiC epitaxial layer grown on the substrate. The epitaxial layer has no more than 2 basal plane dislocations per cm2 at the surface of the epitaxial layer. A method of growing an epitaxial SiC layer on an off-axis SiC substrate by: flowing a silicon source gas, a carbon source gas, and a carrier gas into a growth chamber under growth conditions to epitaxially grow SiC on the substrate in the growth chamber. The substrate has an off-axis angle of no more than 6°. The growth conditions include: a growth temperature of 1530-1650° C.; a pressure of 50-125 mbar; a C/H gas flow ratio of 9.38×10?5-1.5×10?3; a C/Si ratio of 0.5-3; a carbon source gas flow rate during ramp to growth temperature from 0 to 15 sccm; and an electron or hole concentration of 1013-1019/cm3.
    Type: Grant
    Filed: August 20, 2010
    Date of Patent: October 11, 2016
    Assignee: The United States of America, as represented by the Secretary of the Navy
    Inventors: Rachael L Myers-Ward, David Kurt Gaskill, Brenda L VanMil, Robert E Stahlbush, Charles R. Eddy, Jr.
  • Publication number: 20160056065
    Abstract: A method and apparatus wherein a photoluminescence in a semiconductor wafer is excited using an ultraviolet light source. A plurality of partial raw images of the photoluminescence is generated. The plurality of partial raw images includes at least one equipment-generated artifact The at least one equipment-generated artifact is removed from the cluster of partial raw images using the equipment-generated artifact image to generate a cluster of partial processed images. A plurality of clusters of partial processed images is generated. The plurality of clusters of partial processed images are aligned and combined to generate a wafer image tree of the at least one equipment-generated artifact.
    Type: Application
    Filed: August 14, 2015
    Publication date: February 25, 2016
    Inventor: Robert E. Stahlbush
  • 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: 20140193965
    Abstract: A method of: providing an off-axis 4H—SiC substrate, and etching the surface of the substrate with hydrogen or an inert gas.
    Type: Application
    Filed: March 11, 2014
    Publication date: July 10, 2014
    Applicant: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Rachael L. Myers-Ward, David Kurt Gaskill, Charles R. Eddy, JR., Robert E. Stahlbush, Nadeemmullah A. Mahadik, Virginia D. Wheeler
  • Publication number: 20140190399
    Abstract: A method of: providing an off-axis silicon carbide substrate, and etching the surface of the substrate with a dry gas, hydrogen, or an inert gas.
    Type: Application
    Filed: March 11, 2014
    Publication date: July 10, 2014
    Applicant: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Rachael L. Myers-Ward, David Kurt Gaskill, Charles R. Eddy, JR., Robert E. Stahlbush, Nadeemmullah A. Mahadik, Virginia D. Wheeler
  • Patent number: 8652255
    Abstract: A method of: flowing a silicon source gas, a carbon source gas, and a carrier gas into a growth chamber under growth conditions to epitaxial grow silicon carbide on a wafer in the growth chamber; stopping or reducing the flow of the silicon source gas to interrupt the silicon carbide growth and maintaining the flow of the carrier gas while maintaining an elevated temperature in the growth chamber for a period of time; and resuming the flow of the silicon source gas to reinitiate silicon carbide growth. The wafer remains in the growth chamber throughout the method.
    Type: Grant
    Filed: October 9, 2008
    Date of Patent: February 18, 2014
    Assignee: The United States of America, as represented by the Secretary of the Navy
    Inventors: Robert E Stahlbush, Brenda L VanMil, Kok-Keong Lew, Rachael L Myers-Ward, David Kurt Gaskill, Charles R. Eddy, Jr.
  • Patent number: 7915143
    Abstract: A method of reversing Shockley stacking fault expansion includes providing a bipolar or a unipolar SiC device exhibiting forward voltage drift caused by Shockley stacking fault nucleation and expansion. The SiC device is heated to a temperature above 150° C. A current is passed via forward bias operation through the SiC device sufficient to induce at least a partial recovery of the forward bias drift.
    Type: Grant
    Filed: April 30, 2009
    Date of Patent: March 29, 2011
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Joshua D. Caldwell, Robert E Stahlbush, Karl D Hobart, Marko J Tadjer, Orest J Glembocki
  • Publication number: 20110045281
    Abstract: A method for reducing/eliminating basal plane dislocations from SiC epilayers is disclosed. An article having: an off-axis SiC substrate having an off-axis angle of no more than 6°; and a SiC epitaxial layer grown on the substrate. The epitaxial layer has no more than 2 basal plane dislocations per cm2 at the surface of the epitaxial layer. A method of growing an epitaxial SiC layer on an off-axis SiC substrate by: flowing a silicon source gas, a carbon source gas, and a carrier gas into a growth chamber under growth conditions to epitaxially grow SiC on the substrate in the growth chamber. The substrate has an off-axis angle of no more than 6°. The growth conditions include: a growth temperature of 1530-1650° C.; a pressure of 50-125 mbar; a C/H gas flow ratio of 9.38×10?5-1.5×10?3; a C/Si ratio of 0.5-3; a carbon source gas flow rate during ramp to growth temperature from 0 to 15 sccm; and an electron or hole concentration of 1013-1019/cm3.
    Type: Application
    Filed: August 20, 2010
    Publication date: February 24, 2011
    Applicant: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Rachael L. Myers-Ward, David Kurt Gaskill, Brenda L. VanMil, Robert E. Stahlbush, Charles R. Eddy, JR.
  • Publication number: 20090273390
    Abstract: A method of reversing Shockley stacking fault expansion includes providing a bipolar or a unipolar SiC device exhibiting forward voltage drift caused by Shockley stacking fault nucleation and expansion. The SiC device is heated to a temperature above 150° C. A current is passed via forward bias operation through the SiC device sufficient to induce at least a partial recovery of the forward bias drift.
    Type: Application
    Filed: April 30, 2009
    Publication date: November 5, 2009
    Inventors: JOSHUA D. CALDWELL, Robert E. Stahlbush, Karl D. Hobart, Marko J. Tadjer, Orest J. Glembocki
  • Publication number: 20090114148
    Abstract: A method of: flowing a silicon source gas, a carbon source gas, and a carrier gas into a growth chamber under growth conditions to epitaxial grow silicon carbide on a wafer in the growth chamber; stopping or reducing the flow of the silicon source gas to interrupt the silicon carbide growth and maintaining the flow of the carrier gas while maintaining an elevated temperature in the growth chamber for a period of time; and resuming the flow of the silicon source gas to reinitiate silicon carbide growth. The wafer remains in the growth chamber throughout the method.
    Type: Application
    Filed: October 9, 2008
    Publication date: May 7, 2009
    Applicant: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Robert E. Stahlbush, Brenda L. VanMil, Kok-Keong Lew, Rachael L. Myers-Ward, David Kurt Gaskill, Charles R. Eddy, JR.
  • Patent number: 4396769
    Abstract: Crystalline, non-dusting bis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate is made by heating the sebacate ester to a temperature above its melting point and then slowly cooling the melt with agitation to form the product in a crystalline, non-dusting form. This ester, also known as TINUVIN 770, is a valuable commercial light stabilizer for a myriad of substrates.
    Type: Grant
    Filed: February 11, 1982
    Date of Patent: August 2, 1983
    Assignee: Ciba-Geigy Corporation
    Inventors: Anibal L. Ferreira, Robert E. Stahlbush