Patents by Inventor Ronald H. Birkhahn

Ronald H. Birkhahn 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: 9741841
    Abstract: According to one exemplary embodiment, a group III-V semiconductor device includes at least one transition layer situated over a substrate. The group III-V semiconductor device further includes a first strain-relieving interlayer situated over the at least one transition layer and a second strain-relieving interlayer situated over the first strain-relieving interlayer. The group III-V semiconductor device further includes a first group III-V semiconductor body situated over the second strain-relieving interlayer. The first and second strain-relieving interlayers comprise different semiconductor materials so as to reduce a strain in the first group III-V semiconductor body. The second strain-relieving interlayer can be substantially thinner than the first strain-relieving interlayer.
    Type: Grant
    Filed: April 13, 2016
    Date of Patent: August 22, 2017
    Assignee: Infineon Technologies Americas Corp.
    Inventors: Scott Nelson, Ronald H. Birkhahn, Brett Hughes
  • Publication number: 20160233327
    Abstract: According to one exemplary embodiment, a group III-V semiconductor device includes at least one transition layer situated over a substrate. The group III-V semiconductor device further includes a first strain-relieving interlayer situated over the at least one transition layer and a second strain-relieving interlayer situated over the first strain-relieving interlayer. The group III-V semiconductor device further includes a first group III-V semiconductor body situated over the second strain-relieving interlayer. The first and second strain-relieving interlayers comprise different semiconductor materials so as to reduce a strain in the first group III-V semiconductor body. The second strain-relieving interlayer can be substantially thinner than the first strain-relieving interlayer.
    Type: Application
    Filed: April 13, 2016
    Publication date: August 11, 2016
    Inventors: Scott Nelson, Ronald H. Birkhahn, Brett Hughes
  • Patent number: 8269253
    Abstract: According to one embodiment, a high electron mobility transistor (HEMT) comprises an insulator layer comprising a first group III-V intrinsic layer doped with a rare earth additive. The HEMT also comprises a second group III-V intrinsic layer formed over the insulator layer, and a group III-V semiconductor layer formed over the second group III-V intrinsic layer. In one embodiment, a method for fabricating a HEMT comprises forming a first group III-V intrinsic layer and doping the first group III-V intrinsic layer with a rare earth additive to produce an insulator layer. The method also comprises forming a second group III-V intrinsic layer over the insulator layer, and further forming a group III-V semiconductor layer over the second group III-V intrinsic layer. A two-dimensional electron gas (2DEG) is formed at a heterojunction interface of the group III-V semiconductor layer and the second group III-V intrinsic layer.
    Type: Grant
    Filed: June 8, 2009
    Date of Patent: September 18, 2012
    Assignee: International Rectifier Corporation
    Inventor: Ronald H. Birkhahn
  • Publication number: 20120153351
    Abstract: According to one embodiment, a group III-V semiconductor device comprises a compositionally graded body disposed over a substrate and below a buffer layer supporting an active area of the group III-V semiconductor device. The compositionally graded body includes a first region applying compressive stress to the substrate. The compositionally graded body further includes a stress modulating region over the first region, where the stress modulating region applies tensile stress to the substrate. In one embodiment, a method for fabricating a group III-V semiconductor device comprises providing a substrate for the group III-V semiconductor device and forming a first region of a compositionally graded body over the substrate to apply compressive stress to the substrate. The method further comprises forming a stress modulating region of the compositionally graded body over the first region, where the stress modulating region applies tensile stress to the substrate.
    Type: Application
    Filed: December 21, 2010
    Publication date: June 21, 2012
    Applicant: INTERNATIONAL RECTIFIER CORPORATION
    Inventors: Anilkumar Chandolu, Ronald H. Birkhahn, Troy Larsen, Brett Hughes, Steve Hoff, Scott Nelson, Robert Brown, Leanne Sass
  • Publication number: 20100308375
    Abstract: According to one embodiment, a high electron mobility transistor (HEMT) comprises an insulator layer comprising a first group III-V intrinsic layer doped with a rare earth additive. The HEMT also comprises a second group III-V intrinsic layer formed over the insulator layer, and a group III-V semiconductor layer formed over the second group III-V intrinsic layer. In one embodiment, a method for fabricating a HEMT comprises forming a first group III-V intrinsic layer and doping the first group III-V intrinsic layer with a rare earth additive to produce an insulator layer. The method also comprises forming a second group III-V intrinsic layer over the insulator layer, and further forming a group III-V semiconductor layer over the second group III-V intrinsic layer. A two-dimensional electron gas (2DEG) is formed at a heterojunction interface of the group III-V semiconductor layer and the second group III-V intrinsic layer.
    Type: Application
    Filed: June 8, 2009
    Publication date: December 9, 2010
    Applicant: INTERNATIONAL RECTIFIER CORPORATION
    Inventor: Ronald H. Birkhahn
  • Patent number: 6406930
    Abstract: A visible light emitting device includes a wide band gap semiconductor layer doped with one or more elements which emit light at various wavelengths based upon atomic transitions. The semiconductor preferably is GaN, InN, AIN, BN or alloys thereof doped with a lanthanide element such as Er, Pr or Tm. The light emission can be enhanced by annealing the WBGS.
    Type: Grant
    Filed: April 30, 2001
    Date of Patent: June 18, 2002
    Assignee: University of Cincinnati
    Inventors: Ronald H. Birkhahn, Liang-Chiun Chao, Michael J. Garter, James D. Scofield, Andrew J. Steckl
  • Publication number: 20010015469
    Abstract: A visible light emitting device includes a wide band gap semiconductor layer doped with one or more elements which emit light at various wavelengths based upon atomic transitions. The semiconductor preferably is GaN, InN, AIN, BN or alloys thereof doped with a lanthanide element such as Er, Pr or Tm. The light emission can be enhanced by annealing the WBGS.
    Type: Application
    Filed: April 30, 2001
    Publication date: August 23, 2001
    Applicant: University of Cincinnati
    Inventors: Ronald H. Birkhahn, Liang-Chiun Chao, Michael J. Garter, James D. Scofield, Andrew J. Steckl
  • Patent number: 6255669
    Abstract: A visible light emitting device includes a wide band gap semiconductor layer doped with one or more elements which emit light at various wavelengths based upon atomic transitions. The semiconductor preferably is GaN, InN, AIN, BN or alloys thereof doped with a lanthanide element such as Er, Pr or Tm. The light emission can be enhanced by annealing the WBGS.
    Type: Grant
    Filed: April 23, 1999
    Date of Patent: July 3, 2001
    Assignee: The University of Cincinnati
    Inventors: Ronald H. Birkhahn, Liang-Chiun Chao, Michael J. Garter, James D. Scofield, Andrew J. Steckl
  • Patent number: 5693850
    Abstract: A process for the production of water soluble glycerol esters useful as parenteral nutrients is disclosed. The process comprises the reaction of glycerol or a protected glycerol and an acetoacetate ester or acetoacetate precursor, yielding an acetoacetyl glycerol which is thereafter reduced, providing a glycerol ester of 3-hydroxybutyric acid.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: December 2, 1997
    Assignee: Eastman Chemical Company
    Inventors: Ronald H. Birkhahn, Robert J. Clemens, Charles A. McCombs
  • Patent number: 5519161
    Abstract: Novel compositions that are useful as nutrients are disclosed. These compounds are preferably water soluble parenteral nutrients and are glycerol esters of .beta.-acyloxybutyrates of the formula ##STR1## wherein each R is the same or different and is hydrogen, or --COCH.sub.2 CHOR'CH.sub.3), provided that at least one R is not hydrogen and wherein R' is a linear acid ester of even carbon number from 2 to 20 carbons. These compositions are useful as a substitute for glucose in feeding.
    Type: Grant
    Filed: May 3, 1995
    Date of Patent: May 21, 1996
    Inventors: Ronald H. Birkhahn, Robert J. Clemens, Charles A. McCombs, John C. Hubbs
  • Patent number: 5420335
    Abstract: Novel parenteral nutrient compositions are disclosed. These compositions are sterile aqueous solutions containing an effective amount of at least one glycerol bisacetoacetate of the formula: ##STR1## wherein one R group is hydrogen, and two R groups are --COCH.sub.2 COCH.sub.3). These compositions are useful as a substitute for glucose in intravenous feeding.
    Type: Grant
    Filed: September 30, 1993
    Date of Patent: May 30, 1995
    Inventors: Ronald H. Birkhahn, Robert J. Clemens, John C. Hubbs