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: 20100148195
    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: Application
    Filed: February 22, 2010
    Publication date: June 17, 2010
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: John F. Kaeding, Dong-Seon Lee, Michael Iza, Troy J. Baker, Hiroshi Sato, Benjamin A. Haskell, James S. Speck, Steven P. DenBaars, Shuji Nakamura
  • Publication number: 20100142576
    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: June 1, 2009
    Publication date: June 10, 2010
    Applicant: The Regents of the University of California
    Inventors: Daniel A. Cohen, Steven P. DenBaars, Shuji Nakamura
  • Publication number: 20100133663
    Abstract: A method for growing planar, semi-polar nitride film on a miscut spinel substrate, in which a large area of the planar, semi-polar nitride film is parallel to the substrate's surface.
    Type: Application
    Filed: February 1, 2010
    Publication date: June 3, 2010
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Troy J. Baker, Benjamin A. Haskell, Paul T. Fini, Steven P. DenBaars, James S. Speck, Shuji Nakamua
  • Patent number: 7723745
    Abstract: A structure using integrated optical elements is comprised of a substrate, a buffer layer grown on the substrate, one or more patterned layers formed on the buffer layer and one or more active layers formed on or between the patterned layers, for instance by Lateral Epitaxial Overgrowth (LEO), and including one or more light emitting species. The patterned layer comprises a mask (made of insulating, semiconducting or metallic material) and material filling holes in the mask. The patterned layer, due to a large index difference with the active layer and/or variations of a refractive index between the mask and materials filling holes in the mask, acts as an optical confinement layer, a mirror, a diffraction grating, a wavelength selective element, a beam shaping element or a beam directing element.
    Type: Grant
    Filed: February 13, 2008
    Date of Patent: May 25, 2010
    Assignee: The Regents of the University of California
    Inventors: Claude C. A. Weisbuch, Aurelien J. F. David, James S. Speck, Steven P. DenBaars
  • Patent number: 7723746
    Abstract: A polarized light emitting diode (LED) includes a marker indicating a polarization direction. A package for the LED also includes a marker indicating the polarization direction. The markers on the LED and package are used for mutual alignment, wherein the LED is attached in a favorable orientation with respect to a package, so that the polarization direction of emitted light from the package is apparent. The marker is placed on the LED before die separation and the marker is placed on the package before alignment. The marker on the LED comprises a photolithographic pattern, an asymmetric die shape, a notch on the die, or a scratch on the die, while the marker on the package comprises an electrode shape or pattern, an asymmetric package shape, a notch on the package, or a scratch on the package. Finally, the LED or package may be installed in an external circuit or system that also indicates the polarization direction.
    Type: Grant
    Filed: November 17, 2008
    Date of Patent: May 25, 2010
    Assignees: The Regents of the University of California, Japan Science and Technology Agency
    Inventors: Hisashi Masui, Shuji Nakamura, Steven P. DenBaars
  • Patent number: 7723216
    Abstract: A method for growing reduced defect density planar gallium nitride (GaN) films is disclosed. The method includes the steps of (a) growing at least one silicon nitride (SiNx) nanomask layer over a GaN template, and (b) growing a thickness of a GaN film on top of the SiNx nanomask layer.
    Type: Grant
    Filed: May 9, 2007
    Date of Patent: May 25, 2010
    Assignee: The Regents of the University of California
    Inventors: Arpan Chakraborty, Kwang-Choong Kim, James S. Speck, Steven P. DenBaars, Umesh K. Mishra
  • Patent number: 7719020
    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: June 16, 2006
    Date of Patent: May 18, 2010
    Assignees: The Regents of the University of California, Japan Science and Technology Agency
    Inventors: Akihiko Murai, Christina Ye Chen, Daniel B. Thompson, Lee S. McCarthy, Steven P. DenBaars, Shuji Nakamura, Umesh K. Mishra
  • Publication number: 20100111808
    Abstract: The present invention provides a method for growing group III-nitride crystals wherein the group III-nitride crystal growth occurs on an etched seed crystal. The etched seed is fabricated prior to growth using a temperature profile which produces a high solubility of the group III-nitride material in a seed crystals zone as compared to a source materials zone. The measured X-ray diffraction of the obtained crystals have significantly narrower Full Width at Half Maximum values as compared to crystals grown without etch back of the seed crystal surfaces prior to growth.
    Type: Application
    Filed: November 4, 2009
    Publication date: May 6, 2010
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Siddha Pimputkar, Derrick S. Kamber, Makoto Saito, Steven P. DenBaars, James S. Speck, Shuji Nakamura
  • Publication number: 20100108985
    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: Application
    Filed: November 2, 2009
    Publication date: May 6, 2010
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Roy B. Chung, Zhen Chen, James S. Speck, Steven P. DenBaars, Shuji Nakamura
  • Publication number: 20100109018
    Abstract: A method for fabricating a single crystal, high quality, semi-insulating (SI) gallium nitride (GaN) layer using an AlxGa1-xN blocking layer. A buffer layer is grown on a substrate, the AlxGa1-xN blocking layer is grown on the buffer layer, and a single crystal, high quality, SI-GaN layer is grown on the AlxGa1-xN blocking layer. The AlxGa1-xN blocking layer acts as a diffusion blocking layer that prevents the diffusion of donors from the substrate from reaching the SI-GaN layer. The resulting SI-GaN layer reduces parasitic current flow and parasitic capacitive effects in electronic devices.
    Type: Application
    Filed: November 2, 2009
    Publication date: May 6, 2010
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Zhen Chen, Umesh K. Mishra, Steven P. DenBaars, Shuji Nakamura
  • Patent number: 7709284
    Abstract: A method for growing an improved quality device by depositing a low temperature (LT) magnesium (Mg) doped nitride semiconductor thin film. The low temperature Mg doped nitride semiconductor thin film may have a thickness greater than 50 nm. A multi quantum well (MQW) active layer may be grown at a growth temperature and the LT Mg doped nitride semiconductor thin film may deposited on the MQW active layer at a substrate temperature no greater than 150° C. above the growth temperature.
    Type: Grant
    Filed: August 16, 2007
    Date of Patent: May 4, 2010
    Assignee: The Regents of the University of California
    Inventors: Michael Iza, Hitoshi Sato, Steven P. DenBaars, Shuji Nakamura
  • Patent number: 7704331
    Abstract: A method for growing planar, semi-polar nitride film on a miscut spinel substrate, in which a large area of the planar, semi-polar nitride film is parallel to the substrate's surface. The planar films and substrates are: (1) {10 11} gallium nitride (GaN) grown on a {100} spinel substrate miscut in specific directions, (2) {10 13} gallium nitride (GaN) grown on a {110} spinel substrate, (3) {11 22} gallium nitride (GaN) grown on a {1 100} sapphire substrate, and (4) {10 13} gallium nitride (GaN) grown on a {1 100} sapphire substrate.
    Type: Grant
    Filed: January 9, 2007
    Date of Patent: April 27, 2010
    Assignees: The Regents of the University of California, Japan Science and Technology Agency
    Inventors: Troy J. Baker, Benjamin A. Haskell, Paul T. Fini, Steven P. DenBaars, James S. Speck, Shuji Nakamura
  • Patent number: 7691658
    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: January 19, 2007
    Date of Patent: April 6, 2010
    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
  • Patent number: 7687293
    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: January 19, 2007
    Date of Patent: March 30, 2010
    Assignee: The Regents of the University of California
    Inventors: Hiroshi Sato, John F. Kaeding, Michael Iza, Troy J. Baker, Benjamin A. Haskell, Steven P. DenBaars, Shuji Nakamura
  • Patent number: 7687813
    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: November 15, 2007
    Date of Patent: March 30, 2010
    Assignee: The Regents of the University of California
    Inventors: Shuji Nakamura, Steven P. DenBaars
  • Publication number: 20100075107
    Abstract: A technique for growing high quality bulk hexagonal single crystals using a solvo-thermal method, and a technique for achieving the high quality and high growth rate at the same time. The crystal quality strongly depends on the growth planes, wherein a nonpolar or semipolar seed surface such as {10-10}, {10-11}, {10-1-1}, {10-12}, {10-1-2}, {11-20}, {11-22}, {11-2-2} gives a higher crystal quality as compared to a c-plane seed surface such as (0001) and (000-1). Also, the growth rate strongly depends on the growth planes, wherein a semipolar seed surface such as {10-12}, {10-1-2}, {11-22}, {11-2-2} gives a higher growth rate. High crystal quality and high growth rate are achievable at the same time by choosing the suitable growth plane.
    Type: Application
    Filed: May 28, 2009
    Publication date: March 25, 2010
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Makoto Saito, Steven P. DenBaars, James S. Speck, Shuji Nakamura
  • Publication number: 20100052008
    Abstract: An off-axis cut of a nonpolar III-nitride wafer towards a polar (?c) orientation results in higher polarization ratios for light emission than wafers without such off-axis cuts. A 5° angle for an off-axis cut has been confirmed to provide the highest polarization ratio (0.9) than any other examined angles for off-axis cuts between 0 and 27°.
    Type: Application
    Filed: February 2, 2009
    Publication date: March 4, 2010
    Applicant: The Regents of the University of California
    Inventors: Hisashi Masui, Hisashi Yamada, Kenji Iso, Asako Hirai, Makoto Saito, James S. Speck, Shuji Nakamura, Steven P. DenBaars
  • Publication number: 20100032695
    Abstract: A lighting apparatus for emitting polarized white light, which includes at least a first light source for emitting primary light comprised of one or more first wavelengths and having a first polarization direction; and at least a second light source for emitting secondary light in the first polarization direction, comprised of one or more secondary wavelengths, wherein the first light and the secondary light are combined to produce a polarized white light. The lighting apparatus may further comprise a polarizer for controlling the primary light's intensity, wherein a rotation of the polarizer varies an alignment of its polarization axis with respect to the first polarization direction, which varies transmission of the primary light through the polarizer, which controls a color co-ordinate or hue of the white light.
    Type: Application
    Filed: August 5, 2009
    Publication date: February 11, 2010
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Natalie N. Fellows-DeMille, Hisashi Masui, Steven P. DenBaars, Shuji Nakamura
  • Publication number: 20090315055
    Abstract: A method for photoelectrochemical (PEC) etching of a p-type gallium nitride (GaN) layer of a heterostructure, comprising using an internal bias in a semiconductor structure to prevent electrons from reaching a surface of the p-type layer, and to promote holes reaching the surface of the p-type layer, wherein the semiconductor structure includes the p-type layer, an active layer for absorbing PEC illumination, and an n-type layer.
    Type: Application
    Filed: May 12, 2009
    Publication date: December 24, 2009
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Adele Tamboli, Evelyn Lynn Hu, Steven P. DenBaars, Shuji Nakamura
  • Publication number: 20090310640
    Abstract: A III-nitride optoelectronic device comprising a light emitting diode (LED) or laser diode with a peak emission wavelength longer than 500 nm. The III-nitride device has a dislocation density, originating from interfaces between an indium containing well layer and barrier layers, less than 9×109 cm?2. The III-nitride device is grown with an interruption time, between growth of the well layer and barrier layers, of more than 1 minute.
    Type: Application
    Filed: April 6, 2009
    Publication date: December 17, 2009
    Applicant: The Regents of the University of California
    Inventors: Hitoshi Sato, Roy B. Chung, Feng Wu, James S. Speck, Steven P. DenBaars, Shuji Nakamura