Patents by Inventor Thomas Wunderer

Thomas Wunderer 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).

  • Patent number: 8964796
    Abstract: A semiconductor light emitting device includes a light guiding structure, a light emitting layer disposed within the light guiding structure, and a structure for discharging excess electric charge within the device. The device may be excited by an electron beam, as opposed to an optical beam, to create electron-hole pairs. The light emitting layer is configured for light generation without requiring a p-n junction, and is therefore not embedded within nor part of a p-n junction. Doping with p-type species is obviated, reducing device loss and permitting operation at a short wavelengths, such as below 300 nm. Various structures, such as a top-side cladding layer, are disclosed for discharging beam-induced charge. A single device may be operated with multiple electron beam pumps, either to enable a relatively thick active layer or to drive multiple separate active layers. Cooperatively curved end facets accommodate for possible off-axis resonance within the active region(s).
    Type: Grant
    Filed: June 18, 2013
    Date of Patent: February 24, 2015
    Assignee: Palo Alto Research Center Incorporated
    Inventors: Thomas Wunderer, John E. Northrup, Mark R. Teepe, Zhihong Yang, Christopher L. Chua, Noble M. Johnson
  • Publication number: 20140369367
    Abstract: A semiconductor light emitting device includes a light guiding structure, a light emitting layer disposed within the light guiding structure, and a structure for discharging excess electric charge within the device. The device may be excited by an electron beam, as opposed to an optical beam, to create electron-hole pairs. The light emitting layer is configured for light generation without requiring a p-n junction, and is therefore not embedded within nor part of a p-n junction. Doping with p-type species is obviated, reducing device loss and permitting operation at a short wavelengths, such as below 300 nm. Various structures, such as a top-side cladding layer, are disclosed for discharging beam-induced charge. A single device may be operated with multiple electron beam pumps, either to enable a relatively thick active layer or to drive multiple separate active layers. Cooperatively curved end facets accommodate for possible off-axis resonance within the active region(s).
    Type: Application
    Filed: June 18, 2013
    Publication date: December 18, 2014
    Applicant: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: Thomas Wunderer, John E. Northrup, Mark R. Teepe, Zhihong Yang, Christopher L. Chua, Noble M. Johnson
  • Patent number: 8908161
    Abstract: Approaches for substantially removing bulk aluminum nitride (AlN) from one or more layers epitaxially grown on the bulk AlN are discussed. The bulk AlN is exposed to an etchant during an etching process. During the etching process, the thickness of the bulk AlN can be measured and used to control etching.
    Type: Grant
    Filed: August 25, 2011
    Date of Patent: December 9, 2014
    Assignee: Palo Alto Research Center Incorporated
    Inventors: Brent S. Krusor, Christopher L. Chua, Thomas Wunderer, Noble M. Johnson, Bowen Cheng
  • Patent number: 8822314
    Abstract: An epitaxial growth method includes plasma treating a surface of a bulk crystalline Aluminum Nitride (AlN) substrate and subsequently heating the substrate in an ammonia-rich ambient to a temperature of above 1000° C. for at least 5 minutes without epitaxial growth. After heating the surface, a III-nitride layer is epitaxially grown on the surface.
    Type: Grant
    Filed: June 14, 2012
    Date of Patent: September 2, 2014
    Assignee: Palo Alto Research Center Incorporated
    Inventors: Christopher L. Chua, Mark R. Teepe, Thomas Wunderer, Zhihong Yang, Noble M. Johnson, Clifford Knollenberg
  • Publication number: 20140231745
    Abstract: A light emitting device includes a p-side heterostructure having a short period superlattice (SPSL) formed of alternating layers of AlxhighGa1-xhighN doped with a p-type dopant and AlxlowGa1-xlowN doped with the p-type dopant, where xlow?xhigh?0.9. Each layer of the SPSL has a thickness of less than or equal to about six bi-layers of AlGaN.
    Type: Application
    Filed: September 14, 2012
    Publication date: August 21, 2014
    Applicant: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: John E. Northrup, Bowen Cheng, Christopher L. Chua, Thomas Wunderer, Noble M. Johnson, Zhihong Yang
  • Publication number: 20140072009
    Abstract: A vertical external cavity surface emitting laser (VECSEL) structure includes a heterostructure and first and second reflectors. The heterostructure comprises an active region having one or more quantum well structures configured to emit radiation at a wavelength, ?lase, in response to pumping by an electron beam. One or more layers of the heterostructure may be doped. The active region is disposed between the first reflector and the second reflector and is spaced apart from the first reflector by an external cavity. An electron beam source is configured to generate the electron beam directed toward the active region. At least one electrical contact is electrically coupled to the heterostructure and is configured to provide a current path between the heterostructure and ground.
    Type: Application
    Filed: June 14, 2012
    Publication date: March 13, 2014
    Applicant: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: Thomas Wunderer, Noble M. Johnson, John E. Northrup
  • Publication number: 20140011345
    Abstract: An epitaxial growth method includes plasma treating a surface of a bulk crystalline Aluminum Nitride (AlN) substrate and subsequently heating the substrate in an ammonia-rich ambient to a temperature of above 1000° C. for at least 5 minutes without epitaxial growth. After heating the surface, a III-nitride layer is epitaxially grown on the surface.
    Type: Application
    Filed: June 14, 2012
    Publication date: January 9, 2014
    Applicant: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: Christopher L. Chua, Mark R. Teepe, Thomas Wunderer, Zhihong Yang, Noble M. Johnson, Clifford Knollenberg
  • Publication number: 20130343420
    Abstract: Surface emitting laser structures that include a partially reflecting element disposed in the laser optical cavity are disclosed. A vertical external cavity surface emitting laser (VECSEL) structure includes a pump source configured to emit radiation at a pump wavelength, ?pump, an external out-coupling reflector, a distributed Bragg reflector (DBR,) and an active region arranged between the DBR and the out-coupling reflector. The active region is configured to emit radiation at a lasing wavelength, ?lase. The VECSEL structure also includes partially reflecting element (PRE) arranged between the gain element and the external out-coupling reflector. The PRE has reflectivity of between about 30% and about 70% for the radiation at the lasing wavelength and reflectivity of between about 30% and about 70% for the radiation at the pump wavelength.
    Type: Application
    Filed: March 22, 2012
    Publication date: December 26, 2013
    Applicant: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: John E. Northrup, Thomas Wunderer, Noble M. Johnson
  • Publication number: 20130250986
    Abstract: Optically pumped laser structures incorporate reflectors that have high reflectivity and are bandwidth limited to a relatively narrow band around the central laser radiation wavelength. In some cases, the reflectors may be ¾-wavelength distributed Bragg reflectors (DBRs).
    Type: Application
    Filed: March 22, 2012
    Publication date: September 26, 2013
    Applicant: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: Thomas Wunderer, John E. Northrup, Mark R. Teepe, Noble M. Johnson
  • Patent number: 8536030
    Abstract: A method of manufacturing a semipolar semiconductor crystal comprising a group-III-nitride (III-N), the method comprising: providing a substrate comprising sapphire (Al2O3) having a first surface that intersects c-planes of the sapphire; forming a plurality of trenches in the first surface, each trench having a wall whose surface is substantially parallel to a c-plane of the substrate; epitaxially growing a group-III-nitride (III-N) material in the trenches on the c-plane surfaces of their walls until the material overgrows the trenches to form a second planar surface, substantially parallel to a (20-2l) crystallographic plane of the group-III-nitride, wherein l is an integer.
    Type: Grant
    Filed: March 18, 2011
    Date of Patent: September 17, 2013
    Assignee: Freiberger Compund Materials GmbH
    Inventors: Thomas Wunderer, Stephan Schwaiger, Ilona Argut, Rudolph Rosch, Frank Lipski, Ferdinand Scholz
  • Publication number: 20130082237
    Abstract: Light emitting devices having an enhanced degree of polarization, PD, and methods for fabricating such devices are described. A light emitting device may include a light emitting region that is configured to emit light having a central wavelength, ?, and a degree of polarization, PD, where PD>0.006??b for 200 nm???400 nm, wherein b?1.5.
    Type: Application
    Filed: December 16, 2011
    Publication date: April 4, 2013
    Applicant: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: John E. Northrup, Christopher L. Chua, Michael Kneissl, Thomas Wunderer, Noble M. Johnson
  • Publication number: 20130049005
    Abstract: One or more layers are epitaxially grown on a bulk crystalline AlN substrate. The epitaxial layers include a surface which is the initial surface of epitaxial growth of the epitaxial layers. The AlN substrate is substantially removed over a majority of the initial surface of epitaxial growth.
    Type: Application
    Filed: August 25, 2011
    Publication date: February 28, 2013
    Applicant: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: Christopher L. Chua, Brent S. Krusor, Thomas Wunderer, Noble M. Johnson
  • Publication number: 20130050686
    Abstract: A device includes one or more reflector components. Each reflector component comprises layer pairs of epitaxially grown reflective layers and layers of a non-epitaxial material, such as air. Vias extend through at least some of the layers of the reflector components. The device may include a light emitting layer.
    Type: Application
    Filed: August 25, 2011
    Publication date: February 28, 2013
    Applicant: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: Thomas Wunderer, Christopher L. Chua, Brent S. Krusor, Noble M. Johnson
  • Publication number: 20130052758
    Abstract: Approaches for substantially removing bulk aluminum nitride (AlN) from one or more layers epitaxially grown on the bulk AlN are discussed. The bulk AlN is exposed to an etchant during an etching process. During the etching process, the thickness of the bulk AlN can be measured and used to control etching.
    Type: Application
    Filed: August 25, 2011
    Publication date: February 28, 2013
    Applicant: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: Brent S. Krusor, Christopher L. Chua, Thomas Wunderer, Noble M. Johnson, Bowen Cheng
  • Publication number: 20110227198
    Abstract: A method of manufacturing a semipolar semiconductor crystal comprising a group-III-nitride (III-N), the method comprising: providing a substrate comprising sapphire (Al2O3) having a first surface that intersects c-planes of the sapphire; forming a plurality of trenches in the first surface, each trench having a wall whose surface is substantially parallel to a c-plane of the substrate; epitaxially growing a group-III-nitride (III-N) material in the trenches on the c-plane surfaces of their walls until the material overgrows the trenches to form a second planar surface, substantially parallel to a (20-2l) crystallographic plane of the group-III-nitride, wherein l is an integer.
    Type: Application
    Filed: March 18, 2011
    Publication date: September 22, 2011
    Applicant: FREIBERGER COMPOUND MATERIALS GMBH
    Inventors: Thomas WUNDERER, Stephan SCHWAIGER, Ilona ARGUT, Rudolph ROSCH, Frank LIPSKI, Ferdinand SCHOLZ
  • Patent number: 7727332
    Abstract: In a process for forming a mask material on a III-N layer, wherein III denotes an element of the group III of the Periodic Table of Elements, selected from Al, Ga and In, a III-N layer having a surface is provided which comprises more than one facet. Mask material is selectively deposited only on one or multiple, but not on all facets. The deposition of mask material may be particularly carried out during epitaxial growth of a III-N layer under growth conditions, by which (i) growth of at least a further III-N layer selectively on a first type or a first group of facet(s) and (ii) a deposition of mask material selectively on a second type or a second group of facet(s) proceed simultaneously. By the process according to the invention, it is possible to produce free-standing thick III-N layers. Further, semiconductor devices or components having special structures and layers can be produced.
    Type: Grant
    Filed: December 21, 2006
    Date of Patent: June 1, 2010
    Assignee: Freiberger Compound Materials GmbH
    Inventors: Frank Habel, Ferdinand Scholz, Barbara Neubert, Peter Brückner, Thomas Wunderer
  • Publication number: 20070163490
    Abstract: In a process for forming a mask material on a III-N layer, wherein III denotes an element of the group III of the Periodic Table of Elements, selected from Al, Ga and In, a III-N layer having a surface is provided which comprises more than one facet. Mask material is selectively deposited only on one or multiple, but not on all facets. The deposition of mask material may be particularly carried out during epitaxial growth of a III-N layer under growth conditions, by which (i) growth of at least a further III-N layer selectively on a first type or a first group of facet(s) and (ii) a deposition of mask material selectively on a second type or a second group of facet(s) proceed simultaneously. By the process according to the invention, it is possible to produce free-standing thick III-N layers. Further, semiconductor devices or components having special structures and layers can be produced.
    Type: Application
    Filed: December 21, 2006
    Publication date: July 19, 2007
    Inventors: Frank Habel, Ferdinand Scholz, Barbara Neubert, Peter Bruckner, Thomas Wunderer