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).

  • Publication number: 20210104504
    Abstract: A flip chip III-Nitride LED which utilizes a dielectric coating backed by a metallic reflector (e.g., aluminum or silver). High reflectivity and low resistance contacts for optoelectronic devices. Low ESD rating optoelectronic devices. A VCSEL comprising a tunnel junction for current and optical confinement.
    Type: Application
    Filed: August 17, 2017
    Publication date: April 8, 2021
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Benjamin P. Yonkee, Erin C. Young, Charles Forman, John T. Leonard, SeungGeun Lee, Dan Cohen, Robert M. Farrell, Michael Iza, Burhan Saifaddin, Abdullah Almogbel, Humberto Foronda, James S. Speck, Steven P. DenBaars, Shuji Nakamura
  • Publication number: 20200335663
    Abstract: A III-nitride optoelectronic device includes at least one n-type layer, an active region grown on or above the n-type layer, at least one p-type layer grown on or above the active region, and a tunnel junction grown on or above the p-type layer. A conductive oxide may be wafer bonded on or above the tunnel junction, wherein the conductive oxide comprises a transparent conductor and may contain light extraction features on its non-bonded face. The tunnel junction also enables monolithic incorporation of electrically-injected and optically-pumped III-nitride layers, wherein the optically-pumped III-nitride layers comprise high-indium-content III-nitride layers formed as quantum wells (QWs) that are grown on or above the tunnel junction. The optically-pumped high-indium-content III-nitride layers emit light at a longer wavelength than the electrically-injected III-nitride layers.
    Type: Application
    Filed: February 6, 2017
    Publication date: October 22, 2020
    Applicant: The Regents of the University of California
    Inventors: Asad J. Mughal, Stacy J. Kowsz, Robert M. Farrell, Benjamin P. Yonkee, Erin C. Young, Christopher D. Pynn, Tal Margalith, James S. Speck, Shuji Nakamura, Steven P. DenBaars
  • Publication number: 20200243334
    Abstract: A method for protecting a semiconductor film comprised of one or more layers during processing. The method includes placing a surface of the semiconductor film in direct contact with a surface of a protective covering, such as a separate substrate piece, that forms an airtight or hermetic seal with the surface of the semiconductor film, so as to reduce material degradation and evaporation in the semiconductor film. The method includes processing the semiconductor film under some conditions, such as a thermal annealing and/or controlled ambient, which might cause the semiconductor film's evaporation or degradation without the protective covering.
    Type: Application
    Filed: January 24, 2020
    Publication date: July 30, 2020
    Applicant: The Regents of the University of California
    Inventors: Christian J. Zollner, Michael Iza, James S. Speck, Shuji Nakamura, Steven P. DenBaars
  • Publication number: 20200244036
    Abstract: A Vertical Cavity Surface Emitting Laser (VCSEL) including a light emitting III-nitride active region including quantum wells (QWs), wherein each of the quantum wells have a thickness of more than 8 nm, a cavity length of at least 7 ?, or at least 20 ?, where lambda is a peak wavelength of the light emitted from the active region, layers with reduced surface roughness, a tunnel junction intracavity contact. The VCSEL is flip chip bonded using In-Au bonding. This is the first report of a VCSEL capable of continuous wave operation.
    Type: Application
    Filed: October 2, 2018
    Publication date: July 30, 2020
    Applicant: The Regents of the University of California
    Inventors: Charles Forman, SeungGeun Lee, Erin C. Young, Jared Kearns, Steven P. DenBaars, James S. Speck, Shuji Nakamura
  • Patent number: 10685835
    Abstract: A III-nitride tunnel junction with a modified p-n interface, wherein the modified p-n interface includes a delta-doped layer to reduce tunneling resistance. The delta-doped layer may be doped using donor atoms comprised of Oxygen (O), Germanium (Ge) or Silicon (Si); acceptor atoms comprised of Magnesium (Mg) or Zinc (Zn); or impurities comprised of Iron (Fe) or Carbon (C).
    Type: Grant
    Filed: November 1, 2016
    Date of Patent: June 16, 2020
    Assignees: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA, KING ABDULAZIZ CITY FOR SCIENCE AND TECHNOLOGY (KACST)
    Inventors: Benjamin P. Yonkee, Erin C. Young, John T. Leonard, Tal Margalith, James S. Speck, Steven P. DenBaars, Shuji Nakamura
  • Patent number: 10658557
    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: September 12, 2019
    Date of Patent: May 19, 2020
    Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Shuji Nakamura, Steven P. DenBaars, Hirokuni Asamizu
  • Patent number: 10644213
    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: September 11, 2019
    Date of Patent: May 5, 2020
    Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Shuji Nakamura, Steven P. DenBaars, Hirokuni Asamizu
  • Patent number: 10593854
    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: September 13, 2019
    Date of Patent: March 17, 2020
    Assignee: The Regents of the University of California
    Inventors: Shuji Nakamura, Steven P. DenBaars, Hirokuni Asamizu
  • Patent number: 10495268
    Abstract: A white light emitting device includes an edge-emitting laser diode, such as a III-nitride laser diode, emitting light in a first wavelength range that is converted to light at a longer wavelength by a single crystal, ceramic or polycrystalline phosphor, such as a Ce:YAG single crystal phosphor, wherein the phosphor absorbs only some of the light emitted from the laser diode, such that a combination of remaining light emitted from the laser diode with the light at the longer wavelength emitted from the phosphor results in emission of high-intensity white light from the device. Reflectors on either side of the edge-emitting III-nitride laser diode reflect the light from both ends of the edge-emitting laser diode towards the phosphor. One or more sides of the phosphor may roughened, or a scattering layer may be added, to promote uniform color mixing of the emissions.
    Type: Grant
    Filed: November 2, 2015
    Date of Patent: December 3, 2019
    Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Michael Cantore, Shuji Nakamura, Steven P. DenBaars
  • Patent number: 10454010
    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: May 24, 2019
    Date of Patent: October 22, 2019
    Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Shuji Nakamura, Steven P. DenBaars, Hirokuni Asamizu
  • Publication number: 20190273194
    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: Application
    Filed: January 3, 2019
    Publication date: September 5, 2019
    Applicant: The Regents of the University of California
    Inventors: Shuji Nakamura, Steven P. DenBaars, Hirokuni Asamizu
  • Publication number: 20190264100
    Abstract: A method for fabricating a composite useful in a white light emitting device, includes mixing a phosphor and a filler to form a mixture; sintering the mixture (e.g., using spark plasma sintering) to form a composite; and annealing the composite to reduce oxygen vacancies and improve optical properties of the composite. Also disclosed is a white light emitting device including a laser diode or light emitting diode optically pumping the phosphor in the composite to produce white light. The composite fabricated using the method (and having. e.g., at most 50% phosphor by weight) can (1) reduce an operating temperature of the phosphor by 55 degrees, (2) increase an external quantum efficiency (e.g., by at least 15%) of the white light emitting device, and (3) result in color points and quality of the white light that is equal to or improved, as compared to without the filler.
    Type: Application
    Filed: July 31, 2017
    Publication date: August 29, 2019
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clayton J. Cozzan, Steven P. DenBaars, Ram Seshadri
  • Publication number: 20190245112
    Abstract: A method for fabricating an (Al,Ga,In,B)N or III-nitride semiconductor device, including performing a growth of III-nitride or (Al,Ga,In,B)N material including a p-n junction with an active region and using metal-organic chemical vapor deposition (MOCVD) or chemical vapor deposition; and performing a subsequent regrowth of n-type (Al,Ga,In,B)N or III-nitride material using MOCVD or chemical vapor deposition while utilizing a pulsed delta n-type doping scheme to realize an abrupt, smoother surface of the n-type material and a higher carrier concentration in the n-type material. In another example, the method comprises forming a mesa having a top surface; and activating magnesium in the p-type GaN of the (Al,Ga,In,B)N material through openings in the top surface that expose the p-type GaN's surface. The openings are formed before or after the subsequent regrowth of the tunnel junction.
    Type: Application
    Filed: February 7, 2019
    Publication date: August 8, 2019
    Inventors: Abdullah Ibrahim Alhassan, James S. Speck, Steven P. DenBaars
  • Publication number: 20190207043
    Abstract: A physical vapor deposition (e.g., sputter deposition) method for III-nitride tunnel junction devices uses metal-organic chemical vapor deposition (MOCVD) to grow one or more light-emitting or light-absorbing structures and electron cyclotron resonance (ECR) sputtering to grow one or more tunnel junctions. In another method, the surface of the p-type layer is treated before deposition of the tunnel junction on the p-type layer. In yet another method, the whole device (including tunnel junction) is grown using MOCVD and the p-type layers of the III-nitride material are reactivated by lateral diffusion of hydrogen through mesa sidewalls in the III-nitride material, with one or more lateral dimensions of the mesa that are less than or equal to about 200 ?m. A flip chip display device is also disclosed.
    Type: Application
    Filed: August 17, 2017
    Publication date: July 4, 2019
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Benjamin P. Yonkee, Asad J. Mughal, David Hwang, Erin C. Young, James S. Speck, Steven P. DenBaars, Shuji Nakamura
  • Publication number: 20190165213
    Abstract: A III-Nitride LED which utilizes n-type III-Nitride layers for current spreading on both sides of the device. A multilayer dielectric coating is used underneath the wire bond pads, both LED contacts are deposited in one step, and the p-side wire bond pad is moved off of the mesa. The LED has a wall plug efficiency or External Quantum Efficiency (EQE) over 70%, a fractional EQE droop of less than 7% at 20 A/cm2 drive current and less than 15% at 35 A/cm2 drive current. The LEDs can be patterned into an LED array and each LED can have an edge dimension of between 5 and 50 ?m. The LED emission wavelength can be below 400 nm and aluminum can be added to the n-type III-Nitride layers such that the bandgap of the n-type III-nitride layers is larger than the LED emission photon energy.
    Type: Application
    Filed: August 17, 2017
    Publication date: May 30, 2019
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Benjamin P. Yonkee, Erin C. Young, James S. Speck, Steven P. DenBaars, Shuji Nakamura
  • Patent number: 10297721
    Abstract: A method for fabricating a Zinc Oxide (ZnO) conductive film on a semiconductor material, including depositing a doped ZnO seed layer on a diode, wherein the ZnO seed layer forms an electrical contact to the diode; and depositing a ZnO layer on the ZnO seed layer, wherein the ZnO seed layer and the ZnO layer each have a thickness, a crystal quality, and a doping level such that (1) the diode comprising III-nitride material is turned on with a turn on voltage of 2.75 volts or less applied across the ZnO layers and the diode, and (2) a contact resistance, of a structure comprising the ZnO layers and the diode, is lower as compared to a contact resistance of a structure comprising the ZnO layer directly on the diode without the ZnO seed layer.
    Type: Grant
    Filed: February 28, 2018
    Date of Patent: May 21, 2019
    Assignee: The Regents of the University of California
    Inventors: Asad J. Mughal, Sang Ho Oh, Steven P. DenBaars
  • Publication number: 20190074404
    Abstract: A hybrid growth method for III-nitride tunnel junction devices uses metal-organic chemical vapor deposition (MOCVD) to grow one or more light-emitting or light-absorbing structures and ammonia-assisted or plasma-assisted molecular beam epitaxy (MBE) to grow one or more tunnel junctions. Unlike p-type gallium nitride (p-GaN) grown by MOCVD, p-GaN grown by MBE is conductive as grown, which allows for its use in a tunnel junction. Moreover, the doping limits of MBE materials are higher than MOCVD materials. The tunnel junctions can be used to incorporate multiple active regions into a single device. In addition, n-type GaN (n-GaN) can be used as a current spreading layer on both sides of the device, eliminating the need for a transparent conductive oxide (TCO) layer or a silver (Au) mirror.
    Type: Application
    Filed: July 11, 2016
    Publication date: March 7, 2019
    Applicant: The Regents of the University of California
    Inventors: Erin C. Young, Benjamin P. Yonkee, John T. Leonard, Tal Margalith, James S. Speck, Steven P. DenBaars, Shuji Nakamura
  • Patent number: 10217916
    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: August 15, 2014
    Date of Patent: February 26, 2019
    Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Shuji Nakamura, Steven P. DenBaars, Hirokuni Asamizu
  • Patent number: 10205300
    Abstract: Laser dazzler devices and methods of using laser dazzler devices are disclosed. More specifically, embodiments of the present invention provide laser dazzling devices power by one or more green laser diodes characterized by a wavelength of about 500 nm to 540 nm. In various embodiments, laser dazzling devices according to the present invention include non-polar and/or semi-polar green laser diodes. In a specific embodiment, a laser dazzling device includes a plurality of green laser diodes.
    Type: Grant
    Filed: December 30, 2015
    Date of Patent: February 12, 2019
    Inventors: James W. Raring, Paul Rudy, Vinod Khosla, Pierre Lamond, Steven P. Denbaars, Shuji Nakamura, Richard T. Ogawa
  • Publication number: 20180374699
    Abstract: A III-nitride tunnel junction with a modified p-n interface, wherein the modified p-n interface includes a delta-doped layer to reduce tunneling resistance. The delta-doped layer may be doped using donor atoms comprised of Oxygen (O), Germanium (Ge) or Silicon (Si); acceptor atoms comprised of Magnesium (Mg) or Zinc (Zn); or impurities comprised of Iron (Fe) or Carbon (C).
    Type: Application
    Filed: November 1, 2016
    Publication date: December 27, 2018
    Applicant: The Regents of the University of California
    Inventors: Benjamin P. Yonkee, Erin C. Young, John T. Leonard, Tal Margalith, James S. Speck, Steven P. DenBaars, Shuji Nakamura