Patents by Inventor Umesh K. Mishra

Umesh K. Mishra 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: 20160163846
    Abstract: A method of fabricating a III-nitride semiconductor device, including growing an III-nitride semiconductor and an oxide sequentially to form an oxide/III-nitride interface, without exposure to air in between growth of the oxide and growth of the III-nitride semiconductor.
    Type: Application
    Filed: January 28, 2016
    Publication date: June 9, 2016
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Xiang Liu, Umesh K. Mishra, Stacia Keller, Jeonghee Kim, Matthew Laurent, Jing Lu, Ramya Yeluri, Silvia H. Chan
  • Publication number: 20160079738
    Abstract: A method for growth and fabrication of semipolar (Ga,Al,In,B)N thin films, heterostructures, and devices, comprising identifying desired material properties for a particular device application, selecting a semipolar growth orientation based on the desired material properties, selecting a suitable substrate for growth of the selected semipolar growth orientation, growing a planar semipolar (Ga,Al,In,B)N template or nucleation layer on the substrate, and growing the semipolar (Ga,Al,In,B)N thin films, heterostructures or devices on the planar semipolar (Ga,Al,In,B)N template or nucleation layer. The method results in a large area of the semipolar (Ga,Al,In,B)N thin films, heterostructures, and devices being parallel to the substrate surface.
    Type: Application
    Filed: November 30, 2015
    Publication date: March 17, 2016
    Applicants: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA, Japan Science and Technology Agency
    Inventors: Robert M. Farrell, Troy J. Baker, Arpan Chakraborty, Benjamin A. Haskell, P. Morgan Pattison, Rajat Sharma, Umesh K. Mishra, Steven P. DenBaars, James S. Speck, Shuji Nakamura
  • Patent number: 9281183
    Abstract: A method of fabricating a III-nitride semiconductor device, including growing an III-nitride semiconductor and an oxide sequentially to form an oxide/III-nitride interface, without exposure to air in between growth of the oxide and growth of the III-nitride semiconductor.
    Type: Grant
    Filed: January 15, 2015
    Date of Patent: March 8, 2016
    Assignee: The Regents of the University of California
    Inventors: Xiang Liu, Umesh K. Mishra, Stacia Keller, Jeonghee Kim, Matthew Laurent, Jing Lu, Ramya Yeluri, Silvia H. Chan
  • Patent number: 9263423
    Abstract: The present invention discloses a plurality of interdigitated pixels arranged in an array, having a very low series-resistance with improved current spreading and improved heat-sinking. Each pixel is a square with sides of dimension l. The series resistance is minimized by increasing the perimeter of an active region for the pixels. The series resistance is also minimized by shrinking the space between a mesa and n-contact for each pixel.
    Type: Grant
    Filed: June 3, 2015
    Date of Patent: February 16, 2016
    Assignee: The Regents of the University of California
    Inventors: Arpan Chakraborty, Likun Shen, Umesh K. Mishra
  • Patent number: 9231376
    Abstract: A method for growth and fabrication of semipolar (Ga,Al,In,B)N thin films, heterostructures, and devices, comprising identifying desired material properties for a particular device application, selecting a semipolar growth orientation based on the desired material properties, selecting a suitable substrate for growth of the selected semipolar growth orientation, growing a planar semipolar (Ga,Al,In,B)N template or nucleation layer on the substrate, and growing the semipolar (Ga,Al,In,B)N thin films, heterostructures or devices on the planar semipolar (Ga,Al,In,B)N template or nucleation layer. The method results in a large area of the semipolar (Ga,Al,In,B)N thin films, heterostructures, and devices being parallel to the substrate surface.
    Type: Grant
    Filed: March 28, 2014
    Date of Patent: January 5, 2016
    Assignees: The Regents of the University of California, Japan Science and Technology Agency
    Inventors: Robert M. Farrell, Jr., Troy J. Baker, Arpan Chakraborty, Benjamin A. Haskell, P. Morgan Pattison, Rajat Sharma, Umesh K. Mishra, Steven P. DenBaars, James S. Speck, Shuji Nakamura
  • Publication number: 20150294960
    Abstract: The present invention discloses a plurality of interdigitated pixels arranged in an array, having a very low series-resistance with improved current spreading and improved heat-sinking Each pixel is a square with sides of dimension l. The series resistance is minimized by increasing the perimeter of an active region for the pixels. The series resistance is also minimized by shrinking the space between a mesa and n-contact for each pixel.
    Type: Application
    Filed: June 3, 2015
    Publication date: October 15, 2015
    Applicant: The Regents of the University of California
    Inventors: Arpan Chakraborty, Likun Shen, Umesh K. Mishra
  • Patent number: 9129977
    Abstract: Methods of controlling stress in GaN films deposited on silicon and silicon carbide substrates and the films produced therefrom are disclosed. A typical method comprises providing a substrate and depositing a graded gallium nitride layer on the substrate having a varying composition of a substantially continuous grade from an initial composition to a final composition formed from a supply of at least one precursor in a growth chamber without any interruption in the supply. A typical semiconductor film comprises a substrate and a graded gallium nitride layer deposited on the substrate having a varying composition of a substantially continuous grade from an initial composition to a final composition formed from a supply of at least one precursor in a growth chamber without any interruption in the supply.
    Type: Grant
    Filed: November 29, 2011
    Date of Patent: September 8, 2015
    Assignee: The Regents of the University of California
    Inventors: Hugues Marchand, Brendan J. Moran, Umesh K. Mishra, James S. Speck
  • Publication number: 20150200286
    Abstract: A method of fabricating a III-nitride semiconductor device, including growing an III-nitride semiconductor and an oxide sequentially to form an oxide/III-nitride interface, without exposure to air in between growth of the oxide and growth of the III-nitride semiconductor.
    Type: Application
    Filed: January 15, 2015
    Publication date: July 16, 2015
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Xiang Liu, Umesh K. Mishra, Stacia Keller, Jeonghee Kim, Matthew Laurent, Jing Lu, Ramya Yeluri, Silvia H. Chan
  • Patent number: 9076711
    Abstract: The present invention discloses a plurality of interdigitated pixels arranged in an array, having a very low series-resistance with improved current spreading and improved heat-sinking. Each pixel is a square with sides of dimension l. The series resistance is minimized by increasing the perimeter of an active region for the pixels. The series resistance is also minimized by shrinking the space between a mesa and n-contact for each pixel.
    Type: Grant
    Filed: November 25, 2014
    Date of Patent: July 7, 2015
    Assignee: The Regents of the University of California
    Inventors: Arpan Chakraborty, Likun Shen, Umesh K. Mishra
  • Patent number: 9076927
    Abstract: A method of fabricating a heterostructure device, including (a) obtaining a first layer or substrate; (b) growing a second layer on the first layer or substrate; and (c) forming the second layer that is at least partially relaxed wherein (1) the first layer and the second layer have the same lattice structure but different lattice constants, (2) the first layer and the second layer form a heterojunction, and (3) the heterojunction forms an active area of a device or serves as a pseudo-substrate for the device.
    Type: Grant
    Filed: November 6, 2013
    Date of Patent: July 7, 2015
    Assignee: The Regents of the University of California
    Inventors: Stacia Keller, Carl J. Neufeld, Umesh K. Mishra, Steven P. DenBaars
  • Publication number: 20150137137
    Abstract: A current aperture vertical electron transistor (CAVET) with ammonia (NH3) based molecular beam epitaxy (MBE) grown p-type Gallium Nitride (p-GaN) as a current blocking layer (CBL). Specifically, the CAVET features an active buried Magnesium (Mg) doped GaN layer for current blocking purposes. This structure is very advantageous for high power switching applications and for any device that requires a buried active p-GaN layer for its functionality.
    Type: Application
    Filed: December 10, 2014
    Publication date: May 21, 2015
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Srabanti Chowdhury, Ramya Yeluri, Christophe Hurni, Umesh K. Mishra, Ilan Ben-Yaacov
  • Publication number: 20150076533
    Abstract: The present invention discloses a plurality of interdigitated pixels arranged in an array, having a very low series-resistance with improved current spreading and improved heat-sinking. Each pixel is a square with sides of dimension l. The series resistance is minimized by increasing the perimeter of an active region for the pixels. The series resistance is also minimized by shrinking the space between a mesa and n-contact for each pixel.
    Type: Application
    Filed: November 25, 2014
    Publication date: March 19, 2015
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Arpan Chakraborty, Likun Shen, Umesh K. Mishra
  • Patent number: 8937338
    Abstract: A current aperture vertical electron transistor (CAVET) with ammonia (NH3) based molecular beam epitaxy (MBE) grown p-type Gallium Nitride (p-GaN) as a current blocking layer (CBL). Specifically, the CAVET features an active buried Magnesium (Mg) doped GaN layer for current blocking purposes. This structure is very advantageous for high power switching applications and for any device that requires a buried active p-GaN layer for its functionality.
    Type: Grant
    Filed: June 20, 2012
    Date of Patent: January 20, 2015
    Assignee: The Regents of the University of California
    Inventors: Srabanti Chowdhury, Ramya Yeluri, Christophe Hurni, Umesh K. Mishra, Ilan Ben-Yaacov
  • Patent number: 8922110
    Abstract: The present invention discloses a plurality of interdigitated pixels arranged in an array, having a very low series-resistances with improved current spreading and improved heat-sinking. Each pixel is a square with sides of dimension l. The series resistance is minimized by increasing the perimeter of an active region for the pixels. The series resistance is also minimized by shrinking the space between a mesa and n-contact for each pixel.
    Type: Grant
    Filed: June 20, 2014
    Date of Patent: December 30, 2014
    Assignee: The Regents of the University of California
    Inventors: Arpan Chakraborty, Likun Shen, Umesh K. Mishra
  • Publication number: 20140367698
    Abstract: Methods of controlling stress in GaN films deposited on silicon and silicon carbide substrates and the films produced therefrom are disclosed. A typical method comprises providing a substrate and depositing a graded gallium nitride layer on the substrate having a varying composition of a substantially continuous grade from an initial composition to a final composition formed from a supply of at least one precursor in a growth chamber without any interruption in the supply. A typical semiconductor film comprises a substrate and a graded gallium nitride layer deposited on the substrate having a varying composition of a substantially continuous grade from an initial composition to a final composition formed from a supply of at least one precursor in a growth chamber without any interruption in the supply.
    Type: Application
    Filed: August 22, 2014
    Publication date: December 18, 2014
    Applicant: The Regents of the University of California
    Inventors: Hugues Marchand, Brendan J. Moran, Umesh K. Mishra, James S. Speck
  • Patent number: 8882935
    Abstract: A method for the fabrication of nonpolar indium gallium nitride (InGaN) films as well as nonpolar InGaN-containing device structures using metalorganic chemical vapor deposition (MOVCD). The method is used to fabricate nonpolar InGaN/GaN violet and near-ultraviolet light emitting diodes and laser diodes.
    Type: Grant
    Filed: June 4, 2013
    Date of Patent: November 11, 2014
    Assignees: The Regents of the University of California, The Japan Science and Technology Agency
    Inventors: Arpan Chakraborty, Benjamin A. Haskell, Stacia Keller, James S. Speck, Steven P. DenBaars, Shuji Nakamura, Umesh K. Mishra
  • Patent number: 8878249
    Abstract: A method for growing high mobility, high charge Nitrogen polar (N-polar) or Nitrogen face (In,Al,Ga)N/GaN High Electron Mobility Transistors (HEMTs). The method can provide a successful approach to increase the breakdown voltage and reduce the gate leakage of the N-polar HEMTs, which has great potential to improve the N-polar or N-face HEMTs' high frequency and high power performance.
    Type: Grant
    Filed: April 12, 2013
    Date of Patent: November 4, 2014
    Assignee: The Regents of the University of California
    Inventors: Jing Lu, Stacia Keller, Umesh K. Mishra
  • Publication number: 20140299900
    Abstract: The present invention discloses a plurality of interdigitated pixels arranged in an array, having a very low series-resistances with improved current spreading and improved heat-sinking Each pixel is a square with sides of dimension 1. The series resistance is minimized by increasing the perimeter of an active region for the pixels. The series resistance is also minimized by shrinking the space between a mesa and n-contact for each pixel.
    Type: Application
    Filed: June 20, 2014
    Publication date: October 9, 2014
    Applicant: The Regents of the University of California
    Inventors: Arpan Chakraborty, Likun Shen, Umesh K. Mishra
  • Patent number: 8796912
    Abstract: The present invention discloses a plurality of interdigitated pixels arranged in an array, having a very low series-resistances with improved current spreading and improved heat-sinking. Each pixel is a square with sides of dimension l. The series resistance is minimized by increasing the perimeter of an active region for the pixels. The series resistance is also minimized by shrinking the space between a mesa and n-contact for each pixel.
    Type: Grant
    Filed: September 19, 2012
    Date of Patent: August 5, 2014
    Assignee: The Regents of the University of California
    Inventors: Arpan Chakraborty, Likun Shen, Umesh K. Mishra
  • Publication number: 20140211820
    Abstract: A method for growth and fabrication of semipolar (Ga,Al,In,B)N thin films, heterostructures, and devices, comprising identifying desired material properties for a particular device application, selecting a semipolar growth orientation based on the desired material properties, selecting a suitable substrate for growth of the selected semipolar growth orientation, growing a planar semipolar (Ga,Al,In,B)N template or nucleation layer on the substrate, and growing the semipolar (Ga,Al,In,B)N thin films, heterostructures or devices on the planar semipolar (Ga,Al,In,B)N template or nucleation layer. The method results in a large area of the semipolar (Ga,Al,In,B)N thin films, heterostructures, and devices being parallel to the substrate surface.
    Type: Application
    Filed: March 28, 2014
    Publication date: July 31, 2014
    Applicants: Japan Science and Technology Agency, The Regents of the University of California
    Inventors: Robert M. Farrell, JR., Troy J. Baker, Arpan Chakraborty, Benjamin A. Haskell, P. Morgan Pattison, Rajat Sharma, Umesh K. Mishra, Steven P. DenBaars, James S. Speck, Shuji Nakamura