Patents by Inventor Robert D. Armitage

Robert D. Armitage 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).

  • Hafnium nitride buffer layers for growth of GaN on silicon
    Patent number: 6929867
    Abstract: Gallium nitride is grown by plasma-assisted molecular-beam epitaxy on (111) and (001) silicon substrates using hafnium nitride buffer layers. Wurtzite GaN epitaxial layers are obtained on both the (111) and (001) HfN/Si surfaces, with crack-free thickness up to 1.2 m. However, growth on the (001) surface results in nearly stress-free films, suggesting that much thicker crack-free layers could be obtained.
    Type: Grant
    Filed: May 16, 2003
    Date of Patent: August 16, 2005
    Assignee: The Regents of the University of California
    Inventors: Robert D. Armitage, Eicke R. Weber
  • Hafnium nitride buffer layers for growth of GaN on silicon
    Publication number: 20040077165
    Abstract: Gallium nitride is grown by plasma-assisted molecular-beam epitaxy on (111) and (001) silicon substrates using hafnium nitride buffer layers. Wurtzite GaN epitaxial layers are obtained on both the (111) and (001) HfN/Si surfaces, with crack-free thickness up to 1.2 m. However, growth on the (001) surface results in nearly stress-free films, suggesting that much thicker crack-free layers could be obtained.
    Type: Application
    Filed: May 16, 2003
    Publication date: April 22, 2004
    Inventors: Robert D. Armitage, Eicke R. Weber