Patents by Inventor Bernhard Birkmann

Bernhard Birkmann 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: 8728233
    Abstract: The present invention relates to a method for the production of crystal layers or bulk crystals of group III nitride or of mixtures of different group III nitrides by means of precipitation, at a first temperature T1 in a first temperature range, from a group-III containing fused metal on a group-III-nitride crystal seed placed in the fused metal or on a foreign substrate placed in the fused metal, with the admixture of nitrogen in the fused metal at a pressure P. With the method a solvent additive is added to the fused metal which increases the conversion rate of group III metal to group III nitride in the fused metal. The fused metal runs through at least one temperature cycle with a first and a second process phase in which cycle the fused metal cools after the first process phase from the first temperature to a second temperature T2 below the first temperature range and at the end of the second process phase is heated from the second temperature back to a temperature within the first temperature range.
    Type: Grant
    Filed: October 4, 2005
    Date of Patent: May 20, 2014
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der Angewandten Forschung E.V.
    Inventors: Jochen Friedrich, Georg Müller, Rainer Apelt, Elke Meissner, Bernhard Birkmann, Stephan Hussy
  • Patent number: 7883645
    Abstract: The present invention relates to a method for increasing the conversion of group III metal to group III nitride in a fused metal containing group III elements, with the introduction of nitrogen into the fused metal containing group III, at temperatures?1100° C. and at pressures of below 1×108 Pa, wherein a solvent adjunct is added to the fused metal containing group III elements, which is at least one element of the following elements C, Si, Ge, Fe, and/or at least one element of the rare earths, or an alloy or a compound of these elements, in particular their nitrides.
    Type: Grant
    Filed: October 4, 2005
    Date of Patent: February 8, 2011
    Assignee: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
    Inventors: Jochen Friedrich, Georg Muller, Elke Meissner, Bernhard Birkmann, Stephan Hussy
  • Publication number: 20080290327
    Abstract: The present invention relates to a method for increasing the conversion of group III metal to group III nitride in a fused metal containing group III elements, with the introduction of nitrogen into the fused metal containing group III, at temperatures?1100° C. and at pressures of below 1×108 Pa, wherein a solvent adjunct is added to the fused metal containing group III elements, which is at least one element of the following elements C, Si, Ge, Fe, and/or at least one element of the rare earths, or an alloy or a compound of these elements, in particular their nitrides.
    Type: Application
    Filed: October 4, 2005
    Publication date: November 27, 2008
    Inventors: Jochen Friedrich, Georg Muller, Elke Meissner, Bernhard Birkmann, Stephan Hussy
  • Publication number: 20080118648
    Abstract: The present invention relates to a method for the production of crystal layers or bulk crystals of group III nitride or of mixtures of different group III nitrides by means of precipitation, at a first temperature T1 in a first temperature range, from a group-III containing fused metal on a group-III-nitride crystal seed placed in the fused metal or on a foreign substrate placed in the fused metal, with the admixture of nitrogen in the fused metal at a pressure P. With the method a solvent additive is added to the fused metal which increases the conversion rate of group III metal to group III nitride in the fused metal. The fused metal runs through at least one temperature cycle with a first and a second process phase in which cycle the fused metal cools after the first process phase from the first temperature to a second temperature T2 below the first temperature range and at the end of the second process phase is heated from the second temperature back to a temperature within the first temperature range.
    Type: Application
    Filed: October 4, 2005
    Publication date: May 22, 2008
    Inventors: Jochen Friedrich, Georg Muller, Rainer Apelt, Elke Meissner, Bernhard Birkmann, Stephan Hussy