Patents by Inventor Ramón R. Collazo

Ramón R. Collazo 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).

  • Publication number: 20170154963
    Abstract: The energy of formation of a point defect in a compound semiconductor is a function of the process conditions and the Fermi energy (the energy of the charge carriers). In wide bandgap semiconductors or insulators, the contribution of this energy to the formation energy of charged point defects is significant. For doping for n- or p-type conductivity, the larger the energy gap, the higher the concentration of compensating point defects that is at equilibrium with the system. This is a fundamental problem with wide bandgap materials that will be directly addressed with these capabilities. In this approach, minority carrier injection is used to modify the quasi-Fermi level to control the formation energy of the point defects. Increasing the formation energy of unwanted point defect through an external excitation that leads to excess minority carriers during the growth of the semiconductor device structure leads to a reduction in compensating point defects.
    Type: Application
    Filed: November 11, 2016
    Publication date: June 1, 2017
    Inventors: Ramon R. Collazo, Zlatko Sitar, James Tweedie
  • Patent number: 8822045
    Abstract: The present invention provides methods of protecting a surface of an aluminum nitride substrate. The substrate with the protected surface can be stored for a period of time and easily activated to be in a condition ready for thin film growth or other processing. In certain embodiments, the method of protecting the substrate surface comprises forming a passivating layer on at least a portion of the substrate surface by performing a wet etch, which can comprise the use of one or more organic compounds and one or more acids. The invention also provides aluminum nitride substrates having passivated surfaces.
    Type: Grant
    Filed: March 9, 2012
    Date of Patent: September 2, 2014
    Assignee: North Carolina State University
    Inventors: Ramon R. Collazo, Zlatko Sitar, Rafael Dalmau
  • Patent number: 8734965
    Abstract: The present invention provides methods of preparing Group III-nitride films of controlled polarity and substrates coated with such controlled polarity films. In particular, the invention provides substrate preparation steps that optimize the substrate surface for facilitating growth of a Group III-polar film, an N-polar film, or a selectively patterned film with both a Group III-polar portion and an N-polar portion in precise positioning. The methods of the invention are particularly suited for use in CVD methods.
    Type: Grant
    Filed: September 30, 2010
    Date of Patent: May 27, 2014
    Assignee: North Carolina State University
    Inventors: Raoul Schlesser, Ramón R. Collazo, Zlatko Sitar
  • Publication number: 20120168772
    Abstract: The present invention provides methods of protecting a surface of an aluminum nitride substrate. The substrate with the protected surface can be stored for a period of time and easily activated to be in a condition ready for thin film growth or other processing. In certain embodiments, the method of protecting the substrate surface comprises forming a passivating layer on at least a portion of the substrate surface by performing a wet etch, which can comprise the use of one or more organic compounds and one or more acids. The invention also provides aluminum nitride substrates having passivated surfaces.
    Type: Application
    Filed: March 9, 2012
    Publication date: July 5, 2012
    Inventors: Ramon R. Collazo, Zlatko Sitar, Rafael Dalmau
  • Patent number: 8148802
    Abstract: The present invention provides methods of protecting a surface of an aluminum nitride substrate. The substrate with the protected surface can be stored for a period of time and easily activated to be in a condition ready for thin film growth or other processing. In certain embodiments, the method of protecting the substrate surface comprises forming a passivating layer on at least a portion of the substrate surface by performing a wet etch, which can comprise the use of one or more organic compounds and one or more acids. The invention also provides aluminum nitride substrates having passivated surfaces.
    Type: Grant
    Filed: February 16, 2011
    Date of Patent: April 3, 2012
    Assignee: North Carolina State University
    Inventors: Ramon R. Collazo, Zlatko Sitar, Rafael Dalmau
  • Publication number: 20110140124
    Abstract: The present invention provides methods of protecting a surface of an aluminum nitride substrate. The substrate with the protected surface can be stored for a period of time and easily activated to be in a condition ready for thin film growth or other processing. In certain embodiments, the method of protecting the substrate surface comprises forming a passivating layer on at least a portion of the substrate surface by performing a wet etch, which can comprise the use of one or more organic compounds and one or more acids. The invention also provides aluminum nitride substrates having passivated surfaces.
    Type: Application
    Filed: February 16, 2011
    Publication date: June 16, 2011
    Inventors: Ramon R. Collazo, Zlatko Sitar, Rafael Dalmau
  • Patent number: 7915178
    Abstract: The present invention provides methods of protecting a surface of an aluminum nitride substrate. The substrate with the protected surface can be stored for a period of time and easily activated to be in a condition ready for thin film growth or other processing. In certain embodiments, the method of protecting the substrate surface comprises forming a passivating layer on at least a portion of the substrate surface by performing a wet etch, which can comprise the use of one or more organic compounds and one or more acids. The invention also provides aluminum nitride substrates having passivated surfaces.
    Type: Grant
    Filed: July 30, 2008
    Date of Patent: March 29, 2011
    Assignee: North Carolina State University
    Inventors: Ramon R. Collazo, Zlatko Sitar, Rafael Dalmau
  • Publication number: 20110020602
    Abstract: The present invention provides methods of preparing Group III-nitride films of controlled polarity and substrates coated with such controlled polarity films. In particular, the invention provides substrate preparation steps that optimize the substrate surface for facilitating growth of a Group III-polar film, an N-polar film, or a selectively patterned film with both a Group III-polar portion and an N-polar portion in precise positioning. The methods of the invention are particularly suited for use in CVD methods.
    Type: Application
    Filed: September 30, 2010
    Publication date: January 27, 2011
    Inventors: Raoul Schlesser, Ramón R. Collazo, Zlatko Sitar
  • Patent number: 7815970
    Abstract: The present invention provides methods of preparing Group III-nitride films of controlled polarity and substrates coated with such controlled polarity films. In particular, the invention provides substrate preparation steps that optimize the substrate surface for facilitating growth of a Group III-polar film, an N-polar film, or a selectively patterned film with both a Group III-polar portion and an N-polar portion in precise positioning. The methods of the invention are particularly suited for use in CVD methods.
    Type: Grant
    Filed: May 11, 2006
    Date of Patent: October 19, 2010
    Assignee: North Carolina State University
    Inventors: Raoul Schlesser, Ramón R. Collazo, Zlatko Sitar
  • Publication number: 20100025823
    Abstract: The present invention provides methods of protecting a surface of an aluminum nitride substrate. The substrate with the protected surface can be stored for a period of time and easily activated to be in a condition ready for thin film growth or other processing. In certain embodiments, the method of protecting the substrate surface comprises forming a passivating layer on at least a portion of the substrate surface by performing a wet etch, which can comprise the use of one or more organic compounds and one or more acids. The invention also provides aluminum nitride substrates having passivated surfaces.
    Type: Application
    Filed: July 30, 2008
    Publication date: February 4, 2010
    Inventors: Ramon R. Collazo, Zlatko Sitar, Rafael Dalmau