Patents by Inventor J. Carlos Rojo

J. Carlos Rojo 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).

  • Method and apparatus for producing large, single-crystals of aluminum nitride
    Patent number: 8545629
    Abstract: Bulk single crystals of AlN having a diameter greater than about 25 mm and dislocation densities of about 10,000 cm?2 or less and high-quality AlN substrates having surfaces of any desired crystallographic orientation fabricated from these bulk crystals.
    Type: Grant
    Filed: May 9, 2006
    Date of Patent: October 1, 2013
    Assignee: Crystal IS, Inc.
    Inventors: Leo J. Schowalter, Glen A. Slack, J. Carlos Rojo, Robert T. Bondokov, Kenneth E. Morgan, Joseph A. Smart
  • Method and apparatus for producing large, single-crystals of aluminum nitride
    Patent number: 8123859
    Abstract: A method and apparatus for producing bulk single crystals of AlN having low dislocation densities of about 10,000 cm?2 or less includes a crystal growth enclosure with Al and N2 source material therein, capable of forming bulk crystals. The apparatus maintains the N2 partial pressure at greater than stoichiometric pressure relative to the Al within the crystal growth enclosure, while maintaining the total vapor pressure in the crystal growth enclosure at super-atmospheric pressure. At least one nucleation site is provided in the crystal growth enclosure, and provision is made for cooling the nucleation site relative to other locations in the crystal growth enclosure. The Al and N2 vapor is then deposited to grow single crystalline low dislocation density AlN at the nucleation site. High efficiency ultraviolet light emitting diodes and ultraviolet laser diodes are fabricated on low defect density AlN substrates, which are cut from the low dislocation density AlN crystals.
    Type: Grant
    Filed: July 22, 2010
    Date of Patent: February 28, 2012
    Assignee: Crystal IS, Inc.
    Inventors: Leo J. Schowalter, Glen A. Slack, J. Carlos Rojo
  • METHOD AND APPARATUS FOR PRODUCING LARGE, SINGLE-CRYSTALS OF ALUMINUM NITRIDE
    Publication number: 20110011332
    Abstract: A method and apparatus for producing bulk single crystals of AlN having low dislocation densities of about 10,000 cm?2 or less includes a crystal growth enclosure with Al and N2 source material therein, capable of forming bulk crystals. The apparatus maintains the N2 partial pressure at greater than stoichiometric pressure relative to the Al within the crystal growth enclosure, while maintaining the total vapor pressure in the crystal growth enclosure at super-atmospheric pressure. At least one nucleation site is provided in the crystal growth enclosure, and provision is made for cooling the nucleation site relative to other locations in the crystal growth enclosure. The Al and N2 vapor is then deposited to grow single crystalline low dislocation density AlN at the nucleation site. High efficiency ultraviolet light emitting diodes and ultraviolet laser diodes are fabricated on low defect density AlN substrates, which are cut from the low dislocation density AlN crystals.
    Type: Application
    Filed: July 22, 2010
    Publication date: January 20, 2011
    Applicant: Crystal IS, Inc.
    Inventors: Leo J. Schowalter, Glen A. Slack, J. Carlos Rojo
  • Method and apparatus for producing large, single-crystals of aluminum nitride
    Patent number: 7776153
    Abstract: A method and apparatus for producing bulk single crystals of AlN having low dislocation densities of about 10,000 cm?2 or less includes a crystal growth enclosure with Al and N2 source material therein, capable of forming bulk crystals. The apparatus maintains the N2 partial pressure at greater than stoichiometric pressure relative to the Al within the crystal growth enclosure, while maintaining the total vapor pressure in the crystal growth enclosure at super-atmospheric pressure. At least one nucleation site is provided in the crystal growth enclosure, and provision is made for cooling the nucleation site relative to other locations in the crystal growth enclosure. The Al and N2 vapor is then deposited to grow single crystalline low dislocation density AlN at the nucleation site. High efficiency ultraviolet light emitting diodes and ultraviolet laser diodes are fabricated on low defect density AlN substrates, which are cut from the low dislocation density AlN crystals.
    Type: Grant
    Filed: November 3, 2005
    Date of Patent: August 17, 2010
    Assignee: Crystal IS, Inc.
    Inventors: Leo J. Schowalter, Glen A. Slack, J. Carlos Rojo
  • Method and apparatus for producing large, single-crystals of aluminum nitride
    Patent number: 6770135
    Abstract: A method and apparatus for producing bulk single crystals of AlN includes a crystal growth enclosure with Al and N2 source material therein, capable of forming bulk crystals. The apparatus maintains the N2 partial pressure at greater than stoichiometric pressure relative to the Al within the crystal growth enclosure, while maintaining the total vapor pressure in the crystal growth enclosure at super-atmospheric pressure. At least one nucleation site is provided in the crystal growth enclosure, and provision is made for cooling the nucleation site relative to other locations in crystal growth enclosure. The Al and N2 vapor is then deposited to grow single crystalline AlN at the nucleation site.
    Type: Grant
    Filed: December 20, 2002
    Date of Patent: August 3, 2004
    Assignee: Crystal IS, Inc.
    Inventors: Leo J. Schowalter, Glen A. Slack, J. Carlos Rojo
  • Method and apparatus for producing large, single-crystals of aluminum nitride
    Publication number: 20030168003
    Abstract: A method and apparatus for producing bulk single crystals of AlN includes a crystal growth enclosure with Al and N2 source material therein, capable of forming bulk crystals. The apparatus maintains the N2 partial pressure at greater than stoichiometric pressure relative to the Al within the crystal growth enclosure, while maintaining the total vapor pressure in the crystal growth enclosure at super-atmospheric pressure. At least one nucleation site is provided in the crystal growth enclosure, and provision is made for cooling the nucleation site relative to other locations in crystal growth enclosure. The Al and N2 vapor is then deposited to grow single crystalline AlN at the nucleation site.
    Type: Application
    Filed: December 20, 2002
    Publication date: September 11, 2003
    Inventors: Leo J. Schowalter, Glen A. Slack, J. Carlos Rojo