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).

  • Photoelectrochemical etching of P-type semiconductor heterostructures
    Patent number: 8053264
    Abstract: A method for photoelectrochemical (PEC) etching of a p-type semiconductor layer simply and efficiently, by providing a driving force for holes to move towards a surface of a p-type cap layer to be etched, wherein the p-type cap layer is on a heterostructure and the heterostructure provides the driving force from an internal bias generated internally in the heterostructure; generating electron-hole pairs in a separate area of the heterostructure than the surface to be etched; and using an etchant solution to etch the surface of the p-type layer.
    Type: Grant
    Filed: May 12, 2009
    Date of Patent: November 8, 2011
    Assignee: The Regents of the University of California
    Inventors: Adele Tamboli, Evelyn Lynn Hu, Mathew C. Schmidt, Shuji Nakamura, Steven P. DenBaars
  • HIGH BRIGHTNESS LIGHT EMITTING DIODE COVERED BY ZINC OXIDE LAYERS ON MULTIPLE SURFACES GROWN IN LOW TEMPERATURE AQUEOUS SOLUTION
    Publication number: 20110266551
    Abstract: A high brightness III-Nitride based Light Emitting Diode (LED), comprising multiple surfaces covered by Zinc Oxide (ZnO) layers, wherein the ZnO layers are grown in a low temperature aqueous solution and each have a (0001) c-orientation and a top surface that is a (0001) plane.
    Type: Application
    Filed: November 3, 2010
    Publication date: November 3, 2011
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Daniel B. Thompson, Jacob J. Richardson, Ingrid Koslow, Jun Seok Ha, Frederick F. Lange, Steven P. DenBaars, Shuji Nakamura, Maryann E. Lange
  • 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
  • Enhancement of optical polarization of nitride light-emitting diodes by increased indium incorporation
    Patent number: 8044417
    Abstract: An increase in the Indium (In) content in light-emitting layers of light-emitting diode (LED) structures prepared on nonpolar III-nitride substrates result in higher polarization ratios for light emission than LED structures containing lesser In content. Polarization ratios should be higher than 0.7 at wavelengths longer than 470 nm.
    Type: Grant
    Filed: February 2, 2009
    Date of Patent: October 25, 2011
    Assignee: The Regents of the University of California
    Inventors: Hisashi Masui, Hisashi Yamada, Kenji Iso, James S. Speck, Shuji Nakamura, Steven P. DenBaars
  • III-V NITRIDE-BASED THERMOELECTRIC DEVICE
    Publication number: 20110253187
    Abstract: A method to suppress thermal conductivities of nitride films by using stacking faults and/or nano-scale In-composition fluctuation(s). Therefore, the present invention reduces thermal conductivity of nitride while keeping electrical conductivity high. In addition, In composition fluctuations can enhance the Seebeck coefficient through thermionic emission. The present invention further discloses a nitride based (e.g. GaN) thermoelectric lateral device with a short length.
    Type: Application
    Filed: April 18, 2011
    Publication date: October 20, 2011
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Hiroaki Ohta, Alexander Sztein, Steven P. DenBaars, Shuji Nakamura
  • Multi element, multi color solid state LED/laser
    Patent number: 8035117
    Abstract: A light emitting diode (LED) grown on a substrate doped with one or more rare earth or transition elements. The dopant ions absorb some or all of the light from the LED's active layer, pumping the dopant ion electrons to a higher energy state. The electrons are naturally drawn to their equilibrium state and they emit light at a wavelength that depends on the type of dopant ion. The invention is particularly applicable to nitride based LEDs emitting UV light and grown on a sapphire substrate doped with chromium. The chromium ions absorb the UV light, exciting the electrons on ions to a higher energy state. When they return to their equilibrium state they emit red light and some of the red light will emit from the LED's surface. The LED can also have active layers that emit green, blue and UV light, such that the LED emits green, blue, red and UV light which combines to create white light.
    Type: Grant
    Filed: July 10, 2006
    Date of Patent: October 11, 2011
    Assignee: Cree, Inc.
    Inventors: Steven P. DenBaars, Eric J. Tarsa, Michael Mack, Bernd Keller, Brian Thibeault
  • ALUMINUM GALLIUM NITRIDE BARRIERS AND SEPARATE CONFINEMENT HETEROSTRUCTURE (SCH) LAYERS FOR SEMIPOLAR PLANE III-NITRIDE SEMICONDUCTOR-BASED LIGHT EMITTING DIODES AND LASER DIODES
    Publication number: 20110243172
    Abstract: A semipolar plane III-nitride semiconductor-based laser diode or light emitting diode, comprising a semipolar Indium containing multiple quantum wells for emitting light, having Aluminum containing quantum well barriers, wherein the Indium containing multiple quantum well and Aluminum containing barriers are grown in a semipolar orientation on a semipolar plane.
    Type: Application
    Filed: April 5, 2011
    Publication date: October 6, 2011
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: You-Da Lin, Hiroaki Ohta, Shuji Nakamura, Steven P. DenBaars, James S. Speck
  • PLANAR NONPOLAR GROUP III-NITRIDE FILMS GROWN ON MISCUT SUBSTRATES
    Publication number: 20110237054
    Abstract: A nonpolar III-nitride film grown on a miscut angle of a substrate. The miscut angle towards the <000-1> direction is 0.75° or greater miscut and less than 27° miscut towards the <000-1> direction. Surface undulations are suppressed and may comprise faceted pyramids. A device fabricated using the film is also disclosed. A nonpolar III-nitride film having a smooth surface morphology fabricated using a method comprising selecting a miscut angle of a substrate upon which the nonpolar III-nitride films are grown in order to suppress surface undulations of the nonpolar III-nitride films. A nonpolar III-nitride-based device grown on a film having a smooth surface morphology grown on a miscut angle of a substrate which the nonpolar III-nitride films are grown. The miscut angle may also be selected to achieve long wavelength light emission from the nonpolar film.
    Type: Application
    Filed: June 3, 2011
    Publication date: September 29, 2011
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Kenji Iso, Hisashi Yamada, Makoto Saito, Asako Hirai, Steven P. DenBaars, James S. Speck, Shuji Nakamura
  • Standing transparent mirrorless light emitting diode
    Patent number: 8022423
    Abstract: An (Al, Ga, In)N light emitting diode (LED) in which multi-directional light can be extracted from one or more surfaces of the LED before entering a shaped optical element and subsequently being extracted to air. In particular, the (Al, Ga, In)N and transparent contact layers (such as ITO or ZnO) are embedded in or combined with a shaped optical element comprising an epoxy, glass, silicon or other material molded into an inverted cone shape, wherein most of the light entering the inverted cone shape lies within a critical angle and is extracted. In addition, the present invention stands the LED on end, i.e., rotates the position of the LED within the shaped optical element by approximately 90° as compared to a conventional LED, in order to extract light more effectively from the LED.
    Type: Grant
    Filed: March 3, 2010
    Date of Patent: September 20, 2011
    Assignee: The Regents of the University of California
    Inventors: Shuji Nakamura, Steven P. DenBaars
  • 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
  • NON-POLAR (Al,B,In,Ga)N QUANTUM WELL AND HETEROSTRUCTURE MATERIALS AND DEVICES
    Publication number: 20110204329
    Abstract: A method for forming non-polar (Al,B,In,Ga)N quantum well and heterostructure materials and devices. Non-polar (11 20) a-plane GaN layers are grown on an r-plane (1 102) sapphire substrate using MOCVD. These non-polar (11 20) a-plane GaN layers comprise templates for producing non-polar (Al,B,In,Ga)N quantum well and heterostructure materials and devices.
    Type: Application
    Filed: May 3, 2011
    Publication date: August 25, 2011
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Michael D. Craven, Stacia Keller, Steven P. DenBaars, Tal Margalith, James Stephen Speck, Shuji Nakamura, Umesh K. Mishra
  • GROWTH OF PLANAR REDUCED DISLOCATION DENSITY M-PLANE GALLIUM NITRIDE BY HYDRIDE VAPOR PHASE EPITAXY
    Publication number: 20110193094
    Abstract: A method of growing highly planar, fully transparent and specular m-plane gallium nitride (GaN) films. The method provides for a significant reduction in structural defect densities via a lateral overgrowth technique. High quality, uniform, thick m-plane GaN films are produced for use as substrates for polarization-free device growth.
    Type: Application
    Filed: April 14, 2011
    Publication date: August 11, 2011
    Applicants: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA, JAPAN SCIENCE AND TECHNOLOGY AGENCY
    Inventors: Benjamin A. Haskell, Melvin B. McLaurin, Steven P. DenBaars, James Stephen Speck, Shuji Nakamura
  • High light extraction efficiency light emitting diode (LED)
    Patent number: 7994527
    Abstract: An (Al, Ga, In)N and ZnO direct wafer bonded light emitting diode (LED) combined with a shaped plastic optical element, in which the directional light from the ZnO cone, or from any high refractive index material in contact with the LED surface, entering the shaped plastic optical element is extracted to air.
    Type: Grant
    Filed: November 6, 2006
    Date of Patent: August 9, 2011
    Assignee: The Regents of the University of California
    Inventors: Steven P. DenBaars, Shuji Nakamura, Hisashi Masui, Natalie Nichole Fellows, Akihiko Murai
  • Non-polar (Al,B,In,Ga)N quantum well and heterostructure materials and devices
    Patent number: 7982208
    Abstract: A method for forming non-polar (Al,B,In,Ga)N quantum well and heterostructure materials and devices. Non-polar (11 20) a-plane GaN layers are grown on an r-plane (1 102) sapphire substrate using MOCVD. These non-polar (11 20) a-plane GaN layers comprise templates for producing non-polar (Al, B, In, Ga)N quantum well and heterostructure materials and devices.
    Type: Grant
    Filed: June 21, 2006
    Date of Patent: July 19, 2011
    Assignee: The Regents of the University of California
    Inventors: Michael D. Craven, Stacia Keller, Steven P. Denbaars, Tal Margalith, James Stephen Speck, Shuji Nakamura, Umesh K. Mishra
  • TECHNIQUES FOR ACHIEVING LOW RESISTANCE CONTACTS TO NONPOLAR AND SEMIPOLAR P-TYPE (Al,Ga,In)N
    Publication number: 20110169138
    Abstract: A method of fabricating a p-type contact on a nonpolar or semipolar (Al,Ga,In)N device, includes the steps of growing a p-type layer on an (Al,Ga,In)N device, wherein the (Al,Ga,In)N device is a nonpolar or semipolar (Al,Ga,In)N device, and the p-type layer is a nonpolar or semipolar (Al,Ga,In)N layer; and cooling the p-type layer down, in the presence of Bis(Cyclopentadienyl)Magnesium (Cp2Mg), to form a magnesium-nitride (MgxNy) layer on the p-type layer. A metal deposition is performed to fabricate a p-type contact on the p-type layer of the (Al,Ga,In)N device, after the cooling step, wherein the p-type contact has a contact resistivity lower than a p-type contact of a polar (Al,Ga,In)N device with substantially similar composition. A hydrogen chloride (HCl) pre-treatment of the p-type layer may be performed, after the cooling step and before the metal deposition step.
    Type: Application
    Filed: October 21, 2010
    Publication date: July 14, 2011
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: You-Da Lin, Arpan Chakraborty, Shuji Nakamura, Steven P. DenBaars
  • 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
  • High light extraction efficiency light emitting diode (LED) with emitters within structured materials
    Patent number: 7977694
    Abstract: Light Emitting Diodes (LEDs) where the emission region, usually a (Al,In,Ga)N layer, is structured for efficient light extraction, are disclosed. The structuring is designed for light extraction from thin films, such as a photonic crystal acting as a diffraction grating. In addition, the structuring controls the in-plane emission and allows new modes into which light will be emitted. Various electrode designs are proposed, including ZnO structures which are known to lead to both excellent electrical properties, such as good carrier injection, and high transparency. Alternatively, the (Al,In,Ga)N layer can be replaced by structures with other materials compositions, in order to achieve efficient light extraction.
    Type: Grant
    Filed: November 15, 2007
    Date of Patent: July 12, 2011
    Assignee: The Regents of the University of California
    Inventors: Aurelien J. F. David, Claude C. A. Weisbuch, Steven P. DenBaars, Stacia Keller
  • Defect reduction of non-polar and semi-polar III-nitrides with sidewall lateral epitaxial overgrowth (SLEO)
    Patent number: 7955983
    Abstract: A method of reducing threading dislocation densities in non-polar such as a-{11-20} plane and m-{1-100} plane or semi-polar such as {10-1n} plane III-Nitrides by employing lateral epitaxial overgrowth from sidewalls of etched template material through a patterned mask. The method includes depositing a patterned mask on a template material such as a non-polar or semi polar GaN template, etching the template material down to various depths through openings in the mask, and growing non-polar or semi-polar III-Nitride by coalescing laterally from the tops of the sidewalls before the vertically growing material from the trench bottoms reaches the tops of the sidewalls. The coalesced features grow through the openings of the mask, and grow laterally over the dielectric mask until a fully coalesced continuous film is achieved.
    Type: Grant
    Filed: March 3, 2008
    Date of Patent: June 7, 2011
    Assignees: The Regents of the University of California, Japan Science and Technology Agency
    Inventors: Bilge M. Imer, James S. Speck, Steven P. DenBaars
  • Growth of planar reduced dislocation density M-plane gallium nitride by hydride vapor phase epitaxy
    Patent number: 7956360
    Abstract: A method of growing highly planar, fully transparent and specular m-plane gallium nitride (GaN) films. The method provides for a significant reduction in structural defect densities via a lateral overgrowth technique. High quality, uniform, thick m-plane GaN films are produced for use as substrates for polarization-free device growth.
    Type: Grant
    Filed: April 6, 2007
    Date of Patent: June 7, 2011
    Assignees: The Regents of the University of California, Japan Science and Technology Agency
    Inventors: Benjamin A. Haskell, Melvin B. McLaurin, Steven P. DenBaars, James Stephen Speck, Shuji Nakamura
  • High efficiency light emitting diode (LED)
    Patent number: 7956371
    Abstract: An (Al, Ga, In)N light emitting diode (LED), wherein light extraction from chip and/or phosphor conversion layer is optimized. By novel shaping of LED and package optics, a high efficiency light emitting diode is achieved.
    Type: Grant
    Filed: December 8, 2006
    Date of Patent: June 7, 2011
    Assignee: The Regents of the University of California
    Inventors: Steven P. DenBaars, Shuji Nakamura, James S. Speck