Patents by Inventor Anurag Tyagi

Anurag Tyagi 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).

  • HIGH LIGHT EXTRACTION EFFICIENCY NITRIDE BASED LIGHT EMITTING DIODE BY SURFACE ROUGHENING
    Publication number: 20140346542
    Abstract: A III-nitride light emitting diode (LED) and method of fabricating the same, wherein at least one surface of a semipolar or nonpolar plane of a III-nitride layer of the LED is textured, thereby forming a textured surface in order to increase light extraction. The texturing may be performed by plasma assisted chemical etching, photolithography followed by etching, or nano-imprinting followed by etching.
    Type: Application
    Filed: August 11, 2014
    Publication date: November 27, 2014
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Hong Zhong, Anurag Tyagi, Kenneth J. Vampola, James S. Speck, Steven P. DenBaars, Shuji Nakamura
  • Anisotropic strain control in semipolar nitride quantum wells by partially or fully relaxed aluminum indium gallium nitride layers with misfit dislocations
    Patent number: 8866126
    Abstract: An epitaxial structure for a III-Nitride based optical device, comprising an active layer with anisotropic strain on an underlying layer, where a lattice constant and strain in the underlying layer are partially or fully relaxed in at least one direction due to a presence of misfit dislocations, so that the anisotropic strain in the active layer is modulated by the underlying layer.
    Type: Grant
    Filed: May 29, 2013
    Date of Patent: October 21, 2014
    Assignee: The Regents of the University of California
    Inventors: Hiroaki Ohta, Feng Wu, Anurag Tyagi, Arpan Chakraborty, James S. Speck, Steven P. DenBaars, Shuji Nakamura, Erin C. Young
  • Limiting strain relaxation in III-nitride hetero-structures by substrate and epitaxial layer patterning
    Patent number: 8853669
    Abstract: A method of fabricating a substrate for a semipolar III-nitride device, comprising patterning and forming one or more mesas on a surface of a semipolar III-nitride substrate or epilayer, thereby forming a patterned surface of the semipolar III-nitride substrate or epilayer including each of the mesas with a dimension l along a direction of a threading dislocation glide, wherein the threading dislocation glide results from a III-nitride layer deposited heteroepitaxially and coherently on a non-patterned surface of the substrate or epilayer.
    Type: Grant
    Filed: October 26, 2011
    Date of Patent: October 7, 2014
    Assignee: The Regents of the University of California
    Inventors: James S. Speck, Anurag Tyagi, Steven P. Denbaars, Shuji Nakamura
  • High light extraction efficiency nitride based light emitting diode by surface roughening
    Patent number: 8835200
    Abstract: A III-nitride light emitting diode (LED) and method of fabricating the same, wherein at least one surface of a semipolar or nonpolar plane of a III-nitride layer of the LED is textured, thereby forming a textured surface in order to increase light extraction. The texturing may be performed by plasma assisted chemical etching, photolithography followed by etching, or nano-imprinting followed by etching.
    Type: Grant
    Filed: January 12, 2012
    Date of Patent: September 16, 2014
    Assignee: The Regents of the University of California
    Inventors: Hong Zhong, Anurag Tyagi, Kenneth J. Vampola, James S. Speck, Steven P. DenBaars, Shuji Nakamura
  • ANISOTROPIC STRAIN CONTROL IN SEMIPOLAR NITRIDE QUANTUM WELLS BY PARTIALLY OR FULLY RELAXED ALUMINUM INDIUM GALLIUM NITRIDE LAYERS WITH MISFIT DISLOCATIONS
    Publication number: 20130259080
    Abstract: An epitaxial structure for a III-Nitride based optical device, comprising an active layer with anisotropic strain on an underlying layer, where a lattice constant and strain in the underlying layer are partially or fully relaxed in at least one direction due to a presence of misfit dislocations, so that the anisotropic strain in the active layer is modulated by the underlying layer.
    Type: Application
    Filed: May 29, 2013
    Publication date: October 3, 2013
    Inventors: Hiroaki Ohta, Feng Wu, Anurag Tyagi, Arpan Chakraborty, James S. Speck, Steven P. DenBaars, Shuji Nakamura, Erin C. Young
  • Cleaved facet (Ga,Al,In)N edge-emitting laser diodes grown on semipolar bulk gallium nitride substrates
    Patent number: 8541869
    Abstract: A III-nitride edge-emitting laser diode is formed on a surface of a III-nitride substrate having a semipolar orientation, wherein the III-nitride substrate is cleaved by creating a cleavage line along a direction substantially perpendicular to a nonpolar orientation of the III-nitride substrate, and then applying force along the cleavage line to create one or more cleaved facets of the III-nitride substrate, wherein the cleaved facets have an m-plane or a-plane orientation.
    Type: Grant
    Filed: February 12, 2008
    Date of Patent: September 24, 2013
    Assignee: The Regents of the University of California
    Inventors: Shuji Nakamura, James S. Speck, Steven P. DenBaars, Anurag Tyagi
  • Anisotropic strain control in semipolar nitride quantum wells by partially or fully relaxed aluminum indium gallium nitride layers with misfit dislocations
    Patent number: 8481991
    Abstract: An epitaxial structure for a III-Nitride based optical device, comprising an active layer with anisotropic strain on an underlying layer, where a lattice constant and strain in the underlying layer are partially or fully relaxed in at least one direction due to a presence of misfit dislocations, so that the anisotropic strain in the active layer is modulated by the underlying layer.
    Type: Grant
    Filed: August 23, 2010
    Date of Patent: July 9, 2013
    Assignee: The Regents of the University of California
    Inventors: Hiroaki Ohta, Feng Wu, Anurag Tyagi, Arpan Chakraborty, James S. Speck, Steven P. DenBaars, Shuji Nakamura, Erin C. Young
  • Method and System for Epitaxy Processes on Miscut Bulk Substrates
    Publication number: 20130075770
    Abstract: A method for providing (Al,Ga,In)N thin films on Ga-face c-plane (Al,Ga,In)N substrates using c-plane surfaces with a miscut greater than at least 0.35 degrees toward the m-direction. Light emitting devices are formed on the smooth (Al,Ga,In)N thin films. Devices fabricated on the smooth surfaces exhibit improved performance.
    Type: Application
    Filed: March 27, 2012
    Publication date: March 28, 2013
    Applicant: SORAA, Inc.
    Inventors: Arpan Chakraborty, Michael Grundmann, Anurag Tyagi
  • Thin p-type gallium nitride and aluminum gallium nitride electron-blocking layer free gallium nitride-based light emitting diodes
    Patent number: 8227819
    Abstract: A light emitting diode (LED) having a p-type layer having a thickness of 100 nm or less, an n-type layer, and an active layer, positioned between the p-type layer and the n-type layer, for emitting light, wherein the LED does not include a separate electron blocking layer.
    Type: Grant
    Filed: September 30, 2011
    Date of Patent: July 24, 2012
    Assignee: The Regents of the University of California
    Inventors: Hong Zhong, Anurag Tyagi, James Stephen Speck, Steven P. Denbaars, Shuji Nakamura
  • HIGH LIGHT EXTRACTION EFFICIENCY NITRIDE BASED LIGHT EMITTING DIODE BY SURFACE ROUGHENING
    Publication number: 20120104412
    Abstract: A III-nitride light emitting diode (LED) and method of fabricating the same, wherein at least one surface of a semipolar or nonpolar plane of a III-nitride layer of the LED is textured, thereby forming a textured surface in order to increase light extraction. The texturing may be performed by plasma assisted chemical etching, photolithography followed by etching, or nano-imprinting followed by etching.
    Type: Application
    Filed: January 12, 2012
    Publication date: May 3, 2012
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Hong Zhong, Anurag Tyagi, Kenneth J. Vampola, James S. Speck, Steven P. DenBaars, Shuji Nakamura
  • LIMITING STRAIN RELAXATION IN III-NITRIDE HETERO-STRUCTURES BY SUBSTRATE AND EPITAXIAL LAYER PATTERNING
    Publication number: 20120097919
    Abstract: A method of fabricating a substrate for a semipolar III-nitride device, comprising patterning and forming one or more mesas on a surface of a semipolar III-nitride substrate or epilayer, thereby forming a patterned surface of the semipolar III-nitride substrate or epilayer including each of the mesas with a dimension/along a direction of a threading dislocation glide, wherein the threading dislocation glide results from a III-nitride layer deposited heteroepitaxially and coherently on a non-patterned surface of the substrate or epilayer.
    Type: Application
    Filed: October 26, 2011
    Publication date: April 26, 2012
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: James S. Speck, Anurag Tyagi, Steven P. DenBaars, Shuji Nakamura
  • VICINAL SEMIPOLAR III-NITRIDE SUBSTRATES TO COMPENSATE TILT OF RELAXED HETERO-EPITAXIAL LAYERS
    Publication number: 20120100650
    Abstract: A method for fabricating a semi-polar III-nitride substrate for semi-polar III-nitride device layers, comprising providing a vicinal surface of the III-nitride substrate, so that growth of relaxed heteroepitaxial III-nitride device layers on the vicinal surface compensates for epilayer tilt of the III-nitride device layers caused by one or more misfit dislocations at one or more heterointerfaces between the device layers.
    Type: Application
    Filed: October 26, 2011
    Publication date: April 26, 2012
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: James S. Speck, Anurag Tyagi, Alexey E. Romanov, Shuji Nakamura, Steven P. DenBaars
  • THIN P-TYPE GALLIUM NITRIDE AND ALUMINUM GALLIUM NITRIDE ELECTRON-BLOCKING LAYER FREE GALLIUM NITRIDE-BASED LIGHT EMITTING DIODES
    Publication number: 20120037884
    Abstract: A light emitting diode (LED) having a p-type layer having a thickness of 100 nm or less, an n-type layer, and an active layer, positioned between the p-type layer and the n-type layer, for emitting light, wherein the LED does not include a separate electron blocking layer.
    Type: Application
    Filed: September 30, 2011
    Publication date: February 16, 2012
    Applicant: The Regents of the University of California
    Inventors: HONG ZHONG, ANURAG TYAGI, JAMES S. SPECK, STEVEN P. DENBAARS, SHUJI NAKAMURA
  • High light extraction efficiency nitride based light emitting diode by surface roughening
    Patent number: 8114698
    Abstract: A III-nitride light emitting diode (LED) and method of fabricating the same, wherein at least one surface of a semipolar or nonpolar plane of a III-nitride layer of the LED is textured, thereby forming a textured surface in order to increase light extraction. The texturing may be performed by plasma assisted chemical etching, photolithography followed by etching, or nano-imprinting followed by etching.
    Type: Grant
    Filed: December 1, 2008
    Date of Patent: February 14, 2012
    Assignee: The Regents of the University of California
    Inventors: Hong Zhong, Anurag Tyagi, Kenneth J. Vampola, James S. Speck, Steven P. DenBaars, Shuji Nakamura
  • Thin P-type gallium nitride and aluminum gallium nitride electron-blocking layer free gallium nitride-based light emitting diodes
    Patent number: 8044383
    Abstract: A light emitting diode (LED) having a p-type layer having a thickness of 100 nm or less, an n-type layer, and an active layer, positioned between the p-type layer and the n-type layer, for emitting light, wherein the LED does not include a separate electron blocking layer.
    Type: Grant
    Filed: November 2, 2009
    Date of Patent: October 25, 2011
    Assignee: The Regents of the University of California
    Inventors: Hong Zhong, Anurag Tyagi, James S. Speck, Steven P. DenBaars, Shuji Nakamura
  • SEMI-POLAR III-NITRIDE OPTOELECTRONIC DEVICES ON M-PLANE SUBSTRATES WITH MISCUTS LESS THAN +/-15 DEGREES IN THE C-DIRECTION
    Publication number: 20110216795
    Abstract: An optoelectronic device grown on a miscut of GaN, wherein the miscut comprises a semi-polar GaN crystal plane (of the GaN) miscut x degrees from an m-plane of the GaN and in a c-direction of the GaN, where ?15<x<?1 and 1<x<15 degrees.
    Type: Application
    Filed: March 4, 2011
    Publication date: September 8, 2011
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Po Shan Hsu, Kathryn M. Kelchner, Robert M. Farrell, Daniel A. Haeger, Hiroaki Ohta, Anurag Tyagi, Shuji Nakamura, Steven P. DenBaars, S. James Speck
  • SEMIPOLAR III-NITRIDE LASER DIODES WITH ETCHED MIRRORS
    Publication number: 20110170569
    Abstract: A semipolar {20-21} III-nitride based laser diode employing a cavity with one or more etched facet mirrors. The etched facet mirrors provide an ability to arbitrarily control the orientation and dimensions of the cavity or stripe of the laser diode, thereby enabling control of electrical and optical properties of the laser diode.
    Type: Application
    Filed: October 20, 2010
    Publication date: July 14, 2011
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Anurag Tyagi, Robert M. Farrell, Chia-Yen Huang, Po Shan Hsu, Daniel A. Haeger, Kathryn M. Kelchner, Hiroaki Ohta, Shuji Nakamura, Steven P. DenBaars, James S. Speck
  • ANISOTROPIC STRAIN CONTROL IN SEMIPOLAR NITRIDE QUANTUM WELLS BY PARTIALLY OR FULLY RELAXED ALUMINUM INDIUM GALLIUM NITRIDE LAYERS WITH MISFIT DISLOCATIONS
    Publication number: 20110062415
    Abstract: An epitaxial structure for a III-Nitride based optical device, comprising an active layer with anisotropic strain on an underlying layer, where a lattice constant and strain in the underlying layer are partially or fully relaxed in at least one direction due to a presence of misfit dislocations, so that the anisotropic strain in the active layer is modulated by the underlying layer.
    Type: Application
    Filed: August 23, 2010
    Publication date: March 17, 2011
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Hiroaki Ohta, Feng Wu, Anurag Tyagi, Arpan Chakraborty, James S. Speck, Steven P. DenBaars, Shuji Nakamura, Erin C. Young
  • SEMIPOLAR NITRIDE-BASED DEVICES ON PARTIALLY OR FULLY RELAXED ALLOYS WITH MISFIT DISLOCATIONS AT THE HETEROINTERFACE
    Publication number: 20110064103
    Abstract: A dislocation-free high quality template with relaxed lattice constant, fabricated by spatially restricting misfit dislocation(s) around heterointerfaces. This can be used as a template layer for high In composition devices. Specifically, the present invention prepares high quality InGaN templates (In composition is around 5-10%), and can grow much higher In-composition InGaN quantum wells (QWs) (or multi quantum wells (MQWs)) on these templates than would otherwise be possible.
    Type: Application
    Filed: August 23, 2010
    Publication date: March 17, 2011
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Hiroaki Ohta, Feng Wu, Anurag Tyagi, Arpan Chakraborty, James S. Speck, Steven P. DenBaars, Shuji Nakamura, Erin C. Young
  • THIN P-TYPE GALLIUM NITRIDE AND ALUMINUM GALLIUM NITRIDE ELECTRON-BLOCKING LAYER FREE GALLIUM NITRIDE-BASED LIGHT EMITTING DIODES
    Publication number: 20110037085
    Abstract: A light emitting diode (LED) having a p-type layer having a thickness of 100 nm or less, an n-type layer, and an active layer, positioned between the p-type layer and the n-type layer, for emitting light, wherein the LED does not include a separate electron blocking layer.
    Type: Application
    Filed: November 2, 2009
    Publication date: February 17, 2011
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Hong Zhong, Anurag Tyagi, James S. Speck, Steven P. DenBaars, Shuji Nakamura