Patents by Inventor Michael D. Craven

Michael D. Craven 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).

  • Growth of reduced dislocation density non-polar gallium nitride by hydride vapor phase epitaxy
    Patent number: 7220658
    Abstract: Lateral epitaxial overgrowth (LEO) of non-polar a-plane gallium nitride (GaN) films by hydride vapor phase epitaxy (HVPE) results in significantly reduced defect density.
    Type: Grant
    Filed: July 15, 2003
    Date of Patent: May 22, 2007
    Assignee: The Regents of the University of California
    Inventors: Benjamin A Haskell, Michael D. Craven, Paul T. Fini, Steven P. DenBaars, James S. Speck, Shuji Nakamura
  • Non-polar (Al,B,In,Ga)N quantum well and heterostructure materials and devices
    Patent number: 7091514
    Abstract: A method for forming non-polar (Al,B,In,Ga)N quantum well and heterostructure materials and devices. Non-polar (11{overscore (2)}0) a-plane GaN layers are grown on an r-plane (1{overscore (1)}02) sapphire substrate using MOCVD. These non-polar (11{overscore (2)}0) a-plane GaN layers comprise templates for producing non-polar (Al,B,In,Ga)N quantum well and heterostructure materials and devices.
    Type: Grant
    Filed: April 15, 2003
    Date of Patent: August 15, 2006
    Assignee: The Regents of the University of California
    Inventors: Michael D. Craven, Stacia Keller, Steven P. Denbaars, Tal Margalith, James Stephen Speck, Shuji Nakamura, Umesh K. Mishra
  • Dislocation reduction in non-polar gallium nitride thin films
    Patent number: 6900070
    Abstract: Lateral epitaxial overgrowth of non-polar (11{overscore (2)}0) a-plane GaN seed layers reduces threading dislocations in the GaN films. First, a thin patterned dielectric mask is applied to the seed layer. Second, a selective epitaxial regrowth is performed to achieve a lateral overgrowth based on the patterned mask. Upon regrowth, the GaN films initially grow vertically through openings in the dielectric mask before laterally overgrowing the mask in directions perpendicular to the vertical growth direction. Threading dislocations are reduced in the overgrown regions by (1) the mask blocking the propagation of dislocations vertically into the growing film and (2) the bending of dislocations through the transition from vertical to lateral growth.
    Type: Grant
    Filed: April 15, 2003
    Date of Patent: May 31, 2005
    Assignee: The Regents of the University of California
    Inventors: Michael D. Craven, Steven P. Denbaars, James Stephen Speck
  • Dislocation reduction in non-polar gallium nitride thin films
    Publication number: 20030230235
    Abstract: Lateral epitaxial overgrowth of non-polar (11{overscore (2)}0) a-plane GaN seed layers reduces threading dislocations in the GaN films. First, a thin patterned dielectric mask is applied to the seed layer. Second, a selective epitaxial regrowth is performed to achieve a lateral overgrowth based on the patterned mask. Upon regrowth, the GaN films initially grow vertically through openings in the dielectric mask before laterally overgrowing the mask in directions perpendicular to the vertical growth direction. Threading dislocations are reduced in the overgrown regions by (1) the mask blocking the propagation of dislocations vertically into the growing film and (2) the bending of dislocations through the transition from vertical to lateral growth.
    Type: Application
    Filed: April 15, 2003
    Publication date: December 18, 2003
    Inventors: Michael D. Craven, Steven P. Denbaars, James Stephen Speck
  • Non-polar a-plane gallium nitride thin films grown by metalorganic chemical vapor deposition
    Publication number: 20030198837
    Abstract: Non-polar (11{overscore (2)}0) a-plane gallium nitride (GaN) films with planar surfaces are grown on (1{overscore (1)}02) r-plane sapphire substrates by employing a low temperature nucleation layer as a buffer layer prior to a high temperature growth of the non-polar (11{overscore (2)}0) a-plane GaN thin films.
    Type: Application
    Filed: April 15, 2003
    Publication date: October 23, 2003
    Inventors: Michael D. Craven, James Stephen Speck