Patents by Inventor Steven P. Denbaars

Steven P. Denbaars 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).

  • (Al,Ga,In)N DIODE LASER FABRICATED AT REDUCED TEMPERATURE
    Publication number: 20130215921
    Abstract: A method of fabricating an (Al,Ga,In)N laser diode, comprising depositing one or more III-N layers upon a growth substrate at a first temperature, depositing an indium containing laser core at a second temperature upon layers deposited at a first temperature, and performing all subsequent fabrication steps under conditions that inhibit degradation of the laser core, wherein the conditions are a substantially lower temperature than the second temperature.
    Type: Application
    Filed: August 23, 2012
    Publication date: August 22, 2013
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Daniel A. Cohen, Steven P. DenBaars, Shuji Nakamura
  • Fabrication of nonpolar indium gallium nitride thin films, heterostructures and devices by metalorganic chemical vapor deposition
    Patent number: 8502246
    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: February 12, 2009
    Date of Patent: August 6, 2013
    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
  • 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 FOR ENHANCING GROWTH OF SEMIPOLAR (Al,In,Ga,B)N VIA METALORGANIC CHEMICAL VAPOR DEPOSITION
    Publication number: 20130168833
    Abstract: A method for enhancing growth of device-quality planar semipolar nitride semiconductor thin films via metalorganic chemical vapor deposition (MOCVD) by using an (Al,In,Ga)N nucleation layer containing at least some indium. Specifically, the method comprises loading a substrate into a reactor, heating the substrate under a flow of nitrogen and/or hydrogen and/or ammonia, depositing an InxGa1-xN nucleation layer on the heated substrate, depositing a semipolar nitride semiconductor thin film on the InxGa1-xN nucleation layer, and cooling the substrate under a nitrogen overpressure.
    Type: Application
    Filed: February 25, 2013
    Publication date: July 4, 2013
    Inventors: Hitoshi Sato, John F. Kaeding, Michael Iza, Benjamin A. Haskell, Troy J. Baker, Steven P. DenBaars, Shuji Nakamura
  • Growth of planar, non-polar, group-III nitride films
    Patent number: 8450192
    Abstract: Growth methods for planar, non-polar, Group-III nitride films are described. The resulting films are suitable for subsequent device regrowth by a variety of growth techniques.
    Type: Grant
    Filed: September 9, 2008
    Date of Patent: May 28, 2013
    Assignees: The Regents of the University of California, Japan Science and Technology Center
    Inventors: Benjamin A. Haskell, Paul T. Fini, Shigemasa Matsuda, Michael D. Craven, Steven P. DenBaars, James S. Speck, Shuji Nakamura
  • LED with a current confinement structure aligned with a contact
    Patent number: 8410499
    Abstract: An LED having a p-type layer of material with an associated p-contact, an n-type layer of material with an associated n-contact and an active region between the p-type layer and the n-type layer, includes a confinement structure that is formed within one of the p-type layer of material and the n-type layer of material. The confinement structure is generally aligned with the contact on the top and primary emission surface of the LED and substantially prevents the emission of light from the area of the active region that is coincident with the area of the confinement structure and the top-surface contact. The LED may include a roughened emitting-side surface to further enhance light extraction.
    Type: Grant
    Filed: March 25, 2008
    Date of Patent: April 2, 2013
    Assignee: Cree, Inc.
    Inventors: Steven P. Denbaars, Shuji Nakamura, Max Batres
  • LED with current confinement structure and surface roughening
    Patent number: 8410490
    Abstract: An LED having a p-type layer of material with an associated p-contact, an n-type layer of material with an associated n-contact and an active region between the p-type layer and the n-type layer, includes a confinement structure that is formed within one of the p-type layer of material and the n-type layer of material. The confinement structure is generally aligned with the contact on the top and primary emission surface of the LED and substantially prevents the emission of light from the area of the active region that is coincident with the area of the confinement structure and the top-surface contact. The LED may include a roughened emitting-side surface to further enhance light extraction.
    Type: Grant
    Filed: November 9, 2007
    Date of Patent: April 2, 2013
    Assignee: Cree, Inc.
    Inventors: Steven P. Denbaars, Shuji Nakamura, Max Batres
  • Method for enhancing growth of semipolar (Al,In,Ga,B)N via metalorganic chemical vapor deposition
    Patent number: 8405128
    Abstract: A method for enhancing growth of device-quality planar semipolar nitride semiconductor thin films via metalorganic chemical vapor deposition (MOCVD) by using an (Al, In, Ga)N nucleation layer containing at least some indium. Specifically, the method comprises loading a substrate into a reactor, heating the substrate under a flow of nitrogen and/or hydrogen and/or ammonia, depositing an InxGa1-xN nucleation layer on the heated substrate, depositing a semipolar nitride semiconductor thin film on the InxGa1-xN nucleation layer, and cooling the substrate under a nitrogen overpressure.
    Type: Grant
    Filed: March 3, 2010
    Date of Patent: March 26, 2013
    Assignee: The Regents of the University of California
    Inventors: Hitoshi Sato, John F. Kaeding, Michael Iza, Benjamin A. Haskell, Troy J. Baker, Steven P. DenBaars, Shuji Nakamura
  • Single or multi-color high efficiency light emitting diode (LED) by growth over a patterned substrate
    Patent number: 8390011
    Abstract: An opto-electronic device, and a method of fabricating same, wherein the device has a patterned layer that includes a patterned, pierced or perforated mask, and an active layer formed over the patterned layer, wherein a refractive index of the patterned layer and a pattern of holes in the patterned layer are configured for controlling confinement or extraction of light emissions of the active layer into radiative and guided modes.
    Type: Grant
    Filed: June 4, 2010
    Date of Patent: March 5, 2013
    Assignee: The Regents of the University of California
    Inventors: Claude C. A. Weisbuch, Aurelien J. F. David, James S. Speck, Steven P. DenBaars
  • Light emitting diodes with a p-type surface bonded to a transparent submount to increase light extraction efficiency
    Patent number: 8368109
    Abstract: An (Al,Ga,In)N-based light emitting diode (LED), comprising a p-type surface of the LED bonded with a transparent submount material to increase light extraction at the p-type surface, wherein the LED is a substrateless membrane.
    Type: Grant
    Filed: November 15, 2011
    Date of Patent: February 5, 2013
    Assignee: The Regents of the University of California
    Inventors: Kenji Iso, Hirokuni Asamizu, Makoto Saito, Hitoshi Sato, Steven P. DenBaars, Shuji Nakamura
  • Miscut semipolar optoelectronic device
    Patent number: 8368179
    Abstract: A method for improved growth of a semipolar (Al,In,Ga,B)N semiconductor thin film using an intentionally miscut substrate. Specifically, the method comprises intentionally miscutting a substrate, loading a substrate into a reactor, heating the substrate under a flow of nitrogen and/or hydrogen and/or ammonia, depositing an InxGa1-xN nucleation layer on the heated substrate, depositing a semipolar nitride semiconductor thin film on the InxGa1-xN nucleation layer, and cooling the substrate under a nitrogen overpressure.
    Type: Grant
    Filed: December 6, 2011
    Date of Patent: February 5, 2013
    Assignees: The Regents of the University of California, Japan Science and Technology Agency
    Inventors: John F. Kaeding, Dong-Seon Lee, Michael Iza, Troy J. Baker, Hitoshi Sato, Benjamin A. Haskell, James S. Speck, Steven P. DenBaars, Shuji Nakamura
  • Optoelectronic device based on non-polar and semi-polar aluminum indium nitride and aluminum indium gallium nitride alloys
    Patent number: 8357925
    Abstract: A high-power and high-efficiency light emitting device with emission wavelength (?peak) ranging from 280 nm to 360 nm is fabricated. The new device structure uses non-polar or semi-polar AlInN and AlInGaN alloys grown on a non-polar or semi-polar bulk GaN substrate.
    Type: Grant
    Filed: November 21, 2011
    Date of Patent: January 22, 2013
    Assignee: The Regents of the University of California
    Inventors: Roy B. Chung, Zhen Chen, James S. Speck, Steven P. DenBaars, Shuji Nakamura
  • Oxyfluoride phosphors and white light emitting diodes including the oxyfluoride phosphor for solid-state lighting applications
    Patent number: 8344611
    Abstract: A blue-green emitting Ce3+-activated oxyfluoride phosphor for use with a light emitting diode (LED) in solid state lighting applications. The blue-green emitting Ce3+-activated oxyfluoride phosphor is represented as: (Sr1-x-yAEy)3(Al1-zTz)O4F:Ce3+x wherein 0<x?0.3, 0?y?1, AE includes at least one element selected from alkaline earth metals on the periodic table, for example, Mg, Ca and Ba, 0?z?1, and T includes at least one atom selected from Al, B, Ga, and In. The blue-green emitting Ce3+-activated oxyfluoride phosphor may be combined with another phosphor to generate the white light. Specifically, the present invention provides for white light generation by combining the blue-green emitting Ce3+-activated oxyfluoride phosphor with either a near-ultraviolet (UV) LED and red emitting phosphor, or with a near-UV LED and a red-yellow phosphor.
    Type: Grant
    Filed: June 16, 2010
    Date of Patent: January 1, 2013
    Assignee: The Regents of the University of California
    Inventors: Won-Bin Im, Ram Seshadri, Steven P. DenBaars
  • Method for fabricating a direct wafer bonded optoelectronic device
    Patent number: 8334151
    Abstract: An (Al, Ga, In)N and ZnO direct wafer bonded light emitting diode (LED), wherein light passes through electrically conductive ZnO. Flat and clean surfaces are prepared for both the (Al, Ga, In)N and ZnO wafers. A wafer bonding process is then performed between the (Al, Ga, In)N and ZnO wafers, wherein the (Al, Ga, In)N and ZnO wafers are joined together and then wafer bonded in a nitrogen ambient under uniaxial pressure at a set temperature for a set duration. After the wafer bonding process, ZnO is shaped for increasing light extraction from inside of LED.
    Type: Grant
    Filed: April 1, 2010
    Date of Patent: December 18, 2012
    Assignee: The Regents of the University of California
    Inventors: Akihiko Murai, Christina Ye Chen, Daniel B. Thompson, Lee S. McCarthy, Steven P. DenBaars, Shuji Nakamura, Umesh K. Mishra
  • LOW DROOP LIGHT EMITTING DIODE STRUCTURE ON GALLIUM NITRIDE SEMIPOLAR SUBSTRATES
    Publication number: 20120313076
    Abstract: A light emitting diode structure of (Al,Ga,In)N thin films grown on a gallium nitride (GaN) semipolar substrate by metal organic chemical vapor deposition (MOCVD) that exhibits reduced droop. The device structure includes a quantum well (QW) active region of two or more periods, n-type superlattice layers (n-SLs) located below the QW active region, and p-type superlattice layers (p-SLs) above the QW active region. The present invention also encompasses a method of fabricating such a device.
    Type: Application
    Filed: June 11, 2012
    Publication date: December 13, 2012
    Applicant: The Regents of the University of California
    Inventors: Shuji Nakamura, Steven P. DenBaars, Shinichi Tanaka, Daniel F. Feezell, Yuji Zhao, Chih-Chien Pan
  • HIGH EMISSION POWER AND LOW EFFICIENCY DROOP SEMIPOLAR BLUE LIGHT EMITTING DIODES
    Publication number: 20120313077
    Abstract: High emission power and low efficiency droop semipolar blue light emitting diodes (LEDs).
    Type: Application
    Filed: June 11, 2012
    Publication date: December 13, 2012
    Applicant: The Regents of the University of California
    Inventors: Shuji Nakamura, Steven P. DenBaars, Daniel F. Feezell, Chih-Chien Pan, Yuji Zhao, Shinichi Tanaka
  • SUPPRESSION OF INCLINED DEFECT FORMATION AND INCREASE IN CRITICAL THICKNESS BY SILICON DOPING ON NON-C-PLANE (Al,Ga,In)N
    Publication number: 20120286241
    Abstract: A method for fabricating a III-nitride based semiconductor device, including (a) growing one or more buffer layers on or above a semi-polar or non-polar GaN substrate, wherein the buffer layers are semi-polar or non-polar III-nitride buffer layers; and (b) doping the buffer layers so that a number of crystal defects in III-nitride device layers formed on or above the doped buffer layers is not higher than a number of crystal defects in III-nitride device layers formed on or above one or more undoped buffer layers. The doping can reduce or prevent formation of misfit dislocation lines and additional threading dislocations. The thickness and/or composition of the buffer layers can be such that the buffer layers have a thickness near or greater than their critical thickness for relaxation. In addition, one or more (AlInGaN) or III-nitride device layers can be formed on or above the buffer layers.
    Type: Application
    Filed: May 14, 2012
    Publication date: November 15, 2012
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Matthew T. Hardy, Po Shan Hsu, Steven P. DenBaars, James S. SPECK, Shuji Nakamura
  • HIGH INDIUM UPTAKE AND HIGH POLARIZATION RATIO FOR GROUP-III NITRIDE OPTOELECTRONIC DEVICES FABRICATED ON A SEMIPOLAR (20-2-1) PLANE OF A GALLIUM NITRIDE SUBSTRATE
    Publication number: 20120273796
    Abstract: A Group-III nitride optoelectronic device fabricated on a semipolar (20-2-1) plane of a Gallium Nitride (GaN) substrate is characterized by a high Indium uptake and a high polarization ratio.
    Type: Application
    Filed: April 30, 2012
    Publication date: November 1, 2012
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Yuji Zhao, Shinichi Tanaka, Chia-Yen Huang, Daniel F. Feezell, James S. Speck, Steven P. DenBaars, Shuji Nakamura
  • Method for fabrication of semipolar (Al, In, Ga, B)N based light emitting diodes
    Patent number: 8299452
    Abstract: A yellow Light Emitting Diode (LED) with a peak emission wavelength in the range 560-580 nm is disclosed. The LED is grown on one or more III-nitride-based semipolar planes and an active layer of the LED is composed of indium (In) containing single or multi-quantum well structures. The LED quantum wells have a thickness in the range 2-7 nm. A multi-color LED or white LED comprised of at least one semipolar yellow LED is also disclosed.
    Type: Grant
    Filed: February 27, 2012
    Date of Patent: October 30, 2012
    Assignee: The Regents of the University of California
    Inventors: Hitoshi Sato, Hirohiko Hirasawa, Roy B. Chung, Steven P. DenBaars, James S. Speck, Shuji Nakamura
  • Transparent light emitting diodes
    Patent number: 8294166
    Abstract: A transparent light emitting diode (LED) includes a plurality of III-nitride layers, including an active region that emits light, wherein all of the layers except for the active region are transparent for an emission wavelength of the light, such that the light is extracted effectively through all of the layers and in multiple directions through the layers. Moreover, the surface of one or more of the III-nitride layers may be roughened, textured, patterned or shaped to enhance light extraction.
    Type: Grant
    Filed: December 11, 2007
    Date of Patent: October 23, 2012
    Assignee: The Regents of the University of California
    Inventors: Shuji Nakamura, Steven P. DenBaars, Hirokuni Asamizu