Patents Assigned to Crystal IS Inc.
  • Systems and methods for fluid treatment with homogeneous distribution of ultraviolet light
    Patent number: 9745209
    Abstract: In various embodiments, a fluid is treated by flowing the fluid through a flow cell having (i) a fluid entry, (ii) a fluid exit, (iii) a treatment region disposed between the fluid entry and exit, and (iv) an interior surface reflective to ultraviolet (UV) light, and diffusively reflecting UV light emitted from one or more UV light sources to illuminate the treatment region substantially uniformly, thereby treating the fluid.
    Type: Grant
    Filed: March 24, 2016
    Date of Patent: August 29, 2017
    Assignee: CRYSTAL IS, INC.
    Inventors: Jianfeng Chen, Rajul V. Randive, Craig Moe
  • Ultraviolet light-emitting devices incorporating two-dimensional hole gases
    Patent number: 9680057
    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: June 13, 2017
    Assignee: CRYSTAL IS, INC.
    Inventors: Craig Moe, James R. Grandusky, Shawn R. Gibb, Leo J. Schowalter, Kosuke Sato, Tomohiro Morishita
  • Defect reduction in seeded aluminum nitride crystal growth
    Patent number: 9670591
    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: August 13, 2014
    Date of Patent: June 6, 2017
    Assignee: CRYSTAL IS, INC.
    Inventors: Robert T. Bondokov, Kenneth E. Morgan, Leo J. Schowalter, Glen A. Slack
  • Defect reduction in seeded aluminum nitride crystal growth
    Patent number: 9624601
    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: August 13, 2014
    Date of Patent: April 18, 2017
    Assignee: CRYSTAL IS, INC.
    Inventors: Robert T. Bondokov, Kenneth E. Morgan, Leo J. Schowalter, Glen A. Stack
  • Pseudomorphic electronic and optoelectronic devices having planar contacts
    Patent number: 9620676
    Abstract: In various embodiments, light-emitting devices incorporate smooth contact layers and polarization doping (i.e., underlying layers substantially free of dopant impurities) and exhibit high photon extraction efficiencies.
    Type: Grant
    Filed: February 18, 2016
    Date of Patent: April 11, 2017
    Assignee: CRYSTAL IS, INC.
    Inventors: James R. Grandusky, Leo J. Schowalter, Muhammad Jamil, Mark C. Mendrick, Shawn R. Gibb
  • Large aluminum nitride crystals with reduced defects and methods of making them
    Patent number: 9598791
    Abstract: Reducing the microvoid (MV) density in AlN ameliorates numerous problems related to cracking during crystal growth, etch pit generation during the polishing, reduction of the optical transparency in an AlN wafer, and, possibly, growth pit formation during epitaxial growth of AlN and/or AlGaN. This facilitates practical crystal production strategies and the formation of large, bulk AlN crystals with low defect densities—e.g., a dislocation density below 104 cm?2 and an inclusion density below 104 cm?3 and/or a MV density below 104 cm?3.
    Type: Grant
    Filed: March 25, 2016
    Date of Patent: March 21, 2017
    Assignee: CRYSTAL IS, INC.
    Inventors: Robert Bondokov, Kenneth E. Morgan, Glen A. Slack, Leo J. Schowalter
  • Growth of large aluminum nitride single crystals with thermal-gradient control
    Patent number: 9580833
    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: April 15, 2015
    Date of Patent: February 28, 2017
    Assignee: CRYSTAL IS, INC.
    Inventors: Robert T. Bondokov, Shailaja P. Rao, Shawn R. Gibb, Leo J. Schowalter
  • Ultraviolet light-emitting devices and methods
    Patent number: 9548431
    Abstract: In various embodiments, an illumination device features an ultraviolet (UV) light-emitting device at least partially surrounded by an encapsulant and having a rigid lens. Downward forces is applied while the encapsulant is at least partially cured to substantially prevent partial or full detachment of the rigid lens from the light-emitting device, and/or substantially suppress formation of bubbles between the light-emitting device and the rigid lens.
    Type: Grant
    Filed: February 16, 2016
    Date of Patent: January 17, 2017
    Assignee: CRYSTAL IS, INC.
    Inventors: Masato Toita, Jianfeng Chen, Yuxin Li, Yuting Wang, Hironori Ishii, Ken Kitamura
  • Doped aluminum nitride crystals and methods of making them
    Patent number: 9525032
    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: March 26, 2014
    Date of Patent: December 20, 2016
    Assignee: CRYSTAL IS, INC.
    Inventors: Glen A. Slack, Leo J. Schowalter
  • Method and apparatus for producing large, single-crystals of aluminum nitride
    Patent number: 9447521
    Abstract: Bulk single crystals of AlN having a diameter greater than about 25 mm and dislocation densities of about 10,000 cm?2 or less and high-quality AlN substrates having surfaces of any desired crystallographic orientation fabricated from these bulk crystals.
    Type: Grant
    Filed: October 22, 2014
    Date of Patent: September 20, 2016
    Assignee: Crystal IS, Inc.
    Inventors: Leo Schowalter, Glen A. Slack, Juan Carlos Rojo, Robert T. Bondokov, Kenneth E. Morgan, Joseph A. Smart
  • Aluminum nitride bulk crystals having high transparency to untraviolet light and methods of forming them
    Patent number: 9447519
    Abstract: In various embodiments, methods of forming single-crystal AlN include providing a substantially undoped polycrystalline AlN ceramic having an oxygen concentration less than approximately 100 ppm, forming a single-crystal bulk AlN crystal by a sublimation-recondensation process at a temperature greater than approximately 2000° C., and cooling the bulk AlN crystal to a first temperature between approximately 1500° C. and approximately 1800° C. at a first rate less than approximately 250° C./hour.
    Type: Grant
    Filed: April 16, 2015
    Date of Patent: September 20, 2016
    Assignee: Crystal IS, Inc.
    Inventors: Sandra B. Schujman, Shailaja P. Rao, Robert T. Bondokov, Kenneth E. Morgan, Glen A. Slack, Leo J. Schowalter
  • Thick pseudomorphic nitride epitaxial layers
    Patent number: 9437430
    Abstract: Semiconductor structures are fabricated to include strained epitaxial layers exceeding a predicted critical thickness thereof.
    Type: Grant
    Filed: January 25, 2008
    Date of Patent: September 6, 2016
    Assignee: Crystal IS, Inc.
    Inventors: Leo J. Schowalter, Joseph A. Smart, James R. Grandusky, Shiwen Liu
  • Systems and methods for fluid treatment with homogeneous distribution of ultraviolet light
    Patent number: 9321658
    Abstract: In various embodiments, a fluid is treated by flowing the fluid through a flow cell having (i) a fluid entry, (ii) a fluid exit, (iii) a treatment region disposed between the fluid entry and exit, and (iv) an interior surface reflective to ultraviolet (UV) light, and diffusively reflecting UV light emitted from one or more UV light sources to illuminate the treatment region substantially uniformly, thereby treating the fluid.
    Type: Grant
    Filed: August 29, 2014
    Date of Patent: April 26, 2016
    Assignee: CRYSTAL IS, INC.
    Inventors: Jianfeng Chen, Rajul V. Randive, Craig Moe
  • Pseudomorphic electronic and optoelectronic devices having planar contacts
    Patent number: 9299880
    Abstract: In various embodiments, light-emitting devices incorporate smooth contact layers and polarization doping (i.e., underlying layers substantially free of dopant impurities) and exhibit high photon extraction efficiencies.
    Type: Grant
    Filed: March 13, 2014
    Date of Patent: March 29, 2016
    Assignee: Crystal IS, Inc.
    Inventors: James R. Grandusky, Leo J. Schowalter, Muhammad Jamil, Mark C. Mendrick, Shawn R. Gibb
  • Ultraviolet light-emitting devices and methods
    Patent number: 9293670
    Abstract: In various embodiments, an illumination device features an ultraviolet (UV) light-emitting device at least partially surrounded by an encapsulant. A barrier layer is disposed between the light-emitting device and the encapsulant and is configured to substantially prevent UV light emitted by the light-emitting device from entering the encapsulant.
    Type: Grant
    Filed: April 6, 2015
    Date of Patent: March 22, 2016
    Assignee: Crystal IS, Inc.
    Inventors: Masato Toita, Jianfeng Chen, Yuxin Li, Yuting Wang, Hironori Ishii, Ken Kitamura
  • Aluminum nitride bulk crystals having high transparency to ultraviolet light and methods of forming them
    Patent number: 9034103
    Abstract: In various embodiments, methods of forming single-crystal AlN include providing a substantially undoped polycrystalline AlN ceramic having an oxygen concentration less than approximately 100 ppm, forming a single-crystal bulk AlN crystal by a sublimation-recondensation process at a temperature greater than approximately 2000° C., and cooling the bulk AlN crystal to a first temperature between approximately 1500° C. and approximately 1800° C. at a first rate less than approximately 250° C./hour.
    Type: Grant
    Filed: June 30, 2010
    Date of Patent: May 19, 2015
    Assignee: CRYSTAL IS, INC.
    Inventors: Sandra B. Schujman, Shailaja P. Rao, Robert T. Bondokov, Kenneth E. Morgan, Glen A. Slack, Leo J. Schowalter
  • Growth of large aluminum nitride single crystals with thermal-gradient control
    Patent number: 9028612
    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: June 30, 2011
    Date of Patent: May 12, 2015
    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: 8962359
    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: July 19, 2012
    Date of Patent: February 24, 2015
    Assignee: Crystal IS, Inc.
    Inventors: Leo J. Schowalter, Jianfeng Chen, James R. Grandusky
  • USB memory drive
    Patent number: D725122
    Type: Grant
    Filed: February 17, 2014
    Date of Patent: March 24, 2015
    Assignee: GW Crystal, Inc.
    Inventors: Scott Erickson, Peter Gao
  • USB memory drive
    Patent number: D747324
    Type: Grant
    Filed: November 3, 2014
    Date of Patent: January 12, 2016
    Assignee: GW Crystal, Inc.
    Inventors: Scott Erickson, Peter Gao