Patents by Inventor Leo J. Schowalter

Leo J. Schowalter 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).

  • LARGE, UV-TRANSPARENT ALUMINUM NITRIDE SINGLE CRYSTALS
    Publication number: 20190153618
    Abstract: In various embodiments, single-crystal aluminum nitride boules and substrates having high transparency to ultraviolet light and low defect density are formed. The single-crystal aluminum nitride may function as a platform for the fabrication of light-emitting devices such as light-emitting diodes and lasers.
    Type: Application
    Filed: November 9, 2018
    Publication date: May 23, 2019
    Inventors: Robert T. BONDOKOV, Jianfeng CHEN, Keisuke YAMAOKA, Shichao WANG, Shailaja P. RAO, Takashi SUZUKI, Leo J. SCHOWALTER
  • THERMAL CONTROL FOR FORMATION AND PROCESSING OF ALUMINUM NITRIDE
    Publication number: 20190145020
    Abstract: In various embodiments, controlled heating and/or cooling conditions are utilized during the fabrication of aluminum nitride single crystals and aluminum nitride bulk polycrystalline ceramics. Thermal treatments may also be utilized to control properties of aluminum nitride crystals after fabrication.
    Type: Application
    Filed: November 9, 2018
    Publication date: May 16, 2019
    Inventors: Robert T. BONDOKOV, Jianfeng CHEN, Keisuke YAMAOKA, Shichao WANG, Shailaja P. RAO, Takashi SUZUKI, Leo J. SCHOWALTER
  • ELECTROCHEMICAL REMOVAL OF ALUMINUM NITRIDE SUBSTRATES FOR ELECTRONIC AND OPTOELECTRONIC DEVICES
    Publication number: 20190115501
    Abstract: In various embodiments, an electrochemical process is utilized to remove at least a portion of a substrate from multiple singulated or unsingulated electronic-device or optoelectronic-device dies. The dies may be attached to a submount for the removal process, and the dies may be immersed in or non-immersively contact an electrolyte during the removal process.
    Type: Application
    Filed: October 16, 2018
    Publication date: April 18, 2019
    Inventors: Ken KITAMURA, Jianfeng CHEN, Leo J. SCHOWALTER
  • DEFECT REDUCTION IN SEEDED ALUMINUM NITRIDE CRYSTAL GROWTH
    Publication number: 20190106808
    Abstract: Bulk single crystal of aluminum nitride (AlN) having an areal planar defect density ?100 cm=2, Methods for growing single crystal aluminum nitride include melting an aluminum foil to uniformly wet a foundation with a layer of aluminum, the foundation forming a portion of an AlN seed holder, for an AlN seed to be used for the AlN growth. The holder may consist essentially of a substantially impervious backing plate.
    Type: Application
    Filed: October 15, 2018
    Publication date: April 11, 2019
    Inventors: Robert T. Bondokov, Kenneth E. Morgan, Leo J. Schowalter, Glen A. Slack
  • Ultraviolet light-emitting devices incorporating two-dimensional hole gases
    Patent number: 10211369
    Abstract: In various embodiments, light-emitting devices incorporate graded layers with compositional offsets at one or both end points of the graded layer to promote formation of two-dimensional carrier gases and polarization doping, thereby enhancing device performance.
    Type: Grant
    Filed: May 11, 2017
    Date of Patent: February 19, 2019
    Assignee: CRYSTAL IS, INC.
    Inventors: Craig Moe, James R. Grandusky, Shawn R. Gibb, Leo J. Schowalter, Kosuke Sato, Tomohiro Morishita
  • Ultraviolet light-emitting devices incorporating graded layers and compositional offsets
    Patent number: 10211368
    Abstract: In various embodiments, light-emitting devices incorporate graded layers with compositional offsets at one or both end points of the graded layer to promote formation of two-dimensional carrier gases and polarization doping, thereby enhancing device performance.
    Type: Grant
    Filed: May 5, 2017
    Date of Patent: February 19, 2019
    Assignee: CRYSTAL IS, INC.
    Inventors: Craig Moe, James R. Grandusky, Shawn R. Gibb, Leo J. Schowalter, Kosuke Sato, Tomohiro Morishita
  • DOPED ALUMINUM NITRIDE CRYSTALS AND METHODS OF MAKING THEM
    Publication number: 20190035898
    Abstract: Fabrication of doped AlN crystals and/or AlGaN epitaxial layers with high conductivity and mobility is accomplished by, for example, forming mixed crystals including a plurality of impurity species and electrically activating at least a portion of the crystal.
    Type: Application
    Filed: August 6, 2018
    Publication date: January 31, 2019
    Inventors: Glen A. SLACK, Leo J. SCHOWALTER
  • PHOTON EXTRACTION FROM NITRIDE ULTRAVIOLET LIGHT-EMITTING DEVICES
    Publication number: 20190035992
    Abstract: In various embodiments, a rigid lens is attached to a light-emitting semiconductor die via a layer of encapsulant having a thickness insufficient to prevent propagation of thermal expansion mismatch-induced strain between the rigid lens and the semiconductor die.
    Type: Application
    Filed: August 9, 2018
    Publication date: January 31, 2019
    Inventors: Leo J. SCHOWALTER, Jianfeng CHEN, James R. GRANDUSKY
  • TWO-STAGE SEEDED GROWTH OF LARGE ALUMINUM NITRIDE SINGLE CRYSTALS
    Publication number: 20180363164
    Abstract: In various embodiments, growth of large, high-quality single crystals of aluminum nitride is enabled via a two-stage process utilizing two different crystalline seeds.
    Type: Application
    Filed: June 14, 2018
    Publication date: December 20, 2018
    Inventors: Leo J. SCHOWALTER, Robert T. BONDOKOV, James R. GRANDUSKY, SR.
  • ALUMINUM NITRIDE SUBSTRATE REMOVAL FOR ULTRAVIOLET LIGHT-EMITTING DEVICES
    Publication number: 20180331253
    Abstract: In various embodiments, extraction efficiency of light-emitting devices fabricated on aluminum nitride substrates is enhanced via removal of at least a portion of the substrate.
    Type: Application
    Filed: May 11, 2018
    Publication date: November 15, 2018
    Inventors: James R. GRANDUSKY, Leo J. SCHOWALTER, Craig MOE
  • Defect reduction in seeded aluminum nitride crystal growth
    Patent number: 10125432
    Abstract: Bulk single crystal of aluminum nitride (AlN) having an areal planar defect density?100 cm?2. Methods for growing single crystal aluminum nitride include melting an aluminum foil to uniformly wet a foundation with a layer of aluminum, the foundation forming a portion of an AlN seed holder, for an AlN seed to be used for the AlN growth. The holder may consist essentially of a substantially impervious backing plate.
    Type: Grant
    Filed: March 20, 2017
    Date of Patent: November 13, 2018
    Assignee: CRYSTAL IS , INC.
    Inventors: Robert T. Bondokov, Kenneth E. Morgan, Leo J. Schowalter, Glen A. Slack
  • System for growth of large aluminum nitride single crystals with thermal-gradient control
    Patent number: 10106913
    Abstract: In various embodiments, non-zero thermal gradients are formed within a growth chamber both substantially parallel and substantially perpendicular to the growth direction during formation of semiconductor crystals, where the ratio of the two thermal gradients (parallel to perpendicular) is less than 10, by, e.g., arrangement of thermal shields outside of the growth chamber.
    Type: Grant
    Filed: January 20, 2017
    Date of Patent: October 23, 2018
    Assignee: CRYSTAL IS, INC.
    Inventors: Robert T. Bondokov, Shailaja P. Rao, Shawn Robert Gibb, Leo J. Schowalter
  • Photon extraction from nitride ultraviolet light-emitting devices
    Patent number: 10074784
    Abstract: In various embodiments, a rigid lens is attached to a light-emitting semiconductor die via a layer of encapsulant having a thickness insufficient to prevent propagation of thermal expansion mismatch-induced strain between the rigid lens and the semiconductor die.
    Type: Grant
    Filed: January 14, 2015
    Date of Patent: September 11, 2018
    Assignee: CRYSTAL IS, INC.
    Inventors: Leo J. Schowalter, Jianfeng Chen, James R. Grandusky
  • Doped aluminum nitride crystals and methods of making them
    Patent number: 10068973
    Abstract: Fabrication of doped AlN crystals and/or AlGaN epitaxial layers with high conductivity and mobility is accomplished by, for example, forming mixed crystals including a plurality of impurity species and electrically activating at least a portion of the crystal.
    Type: Grant
    Filed: November 10, 2016
    Date of Patent: September 4, 2018
    Assignee: CRYSTAL IS, INC.
    Inventors: Glen A. Slack, Leo J. Schowalter
  • PHOTON EXTRACTION FROM ULTRAVIOLET LIGHT-EMITTING DEVICES
    Publication number: 20180190883
    Abstract: In various embodiments, a layer of organic encapsulant is provided over a surface of an ultraviolet (UV) light-emitting semiconductor die, and at least a portion of the encapsulant is exposed to UV light to convert at least some of said portion of the encapsulant into non-stoichiometric silica material. The non-stoichiometric silica material includes silicon, oxygen, and carbon, and a carbon content of the non-stoichiometric silica material is greater than 1 ppm and less than 40 atomic percent.
    Type: Application
    Filed: February 16, 2018
    Publication date: July 5, 2018
    Inventors: Ken Kitamura, Masato Toita, Hironori Ishii, Yuting Wang, Leo J. Schowalter, Jianfeng Chen, James R. Grandusky
  • Photon extraction from ultraviolet light-emitting devices
    Patent number: 9935247
    Abstract: In various embodiments, a layer of organic encapsulant is provided over a surface of an ultraviolet (UV) light-emitting semiconductor die, and at least a portion of the encapsulant is exposed to UV light to convert at least some of said portion of the encapsulant into non-stoichiometric silica material. The non-stoichiometric silica material includes silicon, oxygen, and carbon, and a carbon content of the non-stoichiometric silica material is greater than 1 ppm and less than 40 atomic percent.
    Type: Grant
    Filed: July 23, 2015
    Date of Patent: April 3, 2018
    Assignee: CRYSTAL IS, INC.
    Inventors: Ken Kitamura, Masato Toita, Hironori Ishii, Yuting Wang, Leo J. Schowalter, Jianfeng Chen, James R. Grandusky
  • DEFECT REDUCTION IN SEEDED ALUMINUM NITRIDE CRYSTAL GROWTH
    Publication number: 20170350036
    Abstract: Bulk single crystal of aluminum nitride (AlN) having an areal planar defect density?100 cm?2. Methods for growing single crystal aluminum nitride include melting an aluminum foil to uniformly wet a foundation with a layer of aluminum, the foundation forming a portion of an AlN seed holder, for an AlN seed to be used for the AlN growth. The holder may consist essentially of a substantially impervious backing plate.
    Type: Application
    Filed: August 24, 2017
    Publication date: December 7, 2017
    Inventors: Robert T. Bondokov, Leo J. Schowalter, Kenneth Morgan, Glen A. Slack, Shailaja P. Rao, Shawn Robert Gibb
  • Ultraviolet light-emitting devices incorporating graded layers and compositional offsets
    Patent number: 9806227
    Abstract: In various embodiments, light-emitting devices incorporate graded layers with compositional offsets at one or both end points of the graded layer to promote formation of two-dimensional carrier gases and polarization doping, thereby enhancing device performance.
    Type: Grant
    Filed: September 16, 2016
    Date of Patent: October 31, 2017
    Assignee: CRYSTAL IS, INC.
    Inventors: Craig Moe, James R. Grandusky, Shawn R. Gibb, Leo J. Schowalter, Kosuke Sato, Tomohiro Morishita
  • ULTRAVIOLET LIGHT-EMITTING DEVICES INCORPORATING GRADED LAYERS AND COMPOSITIONAL OFFSETS
    Publication number: 20170309781
    Abstract: In various embodiments, light-emitting devices incorporate graded layers with compositional offsets at one or both end points of the graded layer to promote formation of two-dimensional carrier gases and polarization doping, thereby enhancing device performance.
    Type: Application
    Filed: May 5, 2017
    Publication date: October 26, 2017
    Inventors: Craig MOE, James R. GRANDUSKY, Shawn R. GIBB, Leo J. SCHOWALTER, Kosuke SATO, Tomohiro MORISHITA
  • ULTRAVIOLET LIGHT-EMITTING DEVICES INCORPORATING TWO-DIMENSIONAL HOLE GASES
    Publication number: 20170309782
    Abstract: In various embodiments, light-emitting devices incorporate graded layers with compositional offsets at one or both end points of the graded layer to promote formation of two-dimensional carrier gases and polarization doping, thereby enhancing device performance.
    Type: Application
    Filed: May 11, 2017
    Publication date: October 26, 2017
    Inventors: Craig MOE, James R. GRANDUSKY, Shawn R. GIBB, Leo J. SCHOWALTER, Kosuke SATO, Tomohiro MORISHITA