Patents Assigned to Crystal IS Inc.
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Patent number: 8080833Abstract: In various embodiments, a semiconductor device includes an aluminum nitride single-crystal substrate, a pseudomorphic strained layer disposed thereover that comprises at least one of AlN, GaN, InN, or an alloy thereof, and, disposed over the strained layer, a semiconductor layer that is lattice-mismatched to the substrate and substantially relaxed.Type: GrantFiled: April 21, 2010Date of Patent: December 20, 2011Assignee: Crystal IS, Inc.Inventors: James R. Grandusky, Leo J. Schowalter, Shawn R. Gibb, Joseph A. Smart, Shiwen Liu
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Patent number: 8012257Abstract: Fabrication of doped and undoped stoichiometric polycrystalline AlN ceramics with high purity is accomplished by, for example, reacting Al pellets with nitrogen gas. Such polycrystalline AlN ceramics may be utilized in the fabrication of high purity AlN single crystals, which may be annealed to enhance a conductivity thereof.Type: GrantFiled: March 30, 2007Date of Patent: September 6, 2011Assignee: Crystal IS, Inc.Inventors: Kenneth E. Morgan, Leo J. Schowalter, Glen A. Slack
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Patent number: 7994417Abstract: A solar PV panel has an array of primary mirrors that collects and reflects solar radiation toward an array of dichroic secondary elements. The dichroic secondary elements reflect near-visible solar radiation to an array of near-visible radiation sensitive solar cells and simultaneously transmit infrared radiation to an array of infrared sensitive solar cells. The array of near-visible radiation sensitive cells and the array of infrared sensitive cells are wired in series. The optical properties of the dichoic secondary element, near-visible radiation sensitive cell, and IR sensitive cell are chosen for simultaneous maximum power production from the panel.Type: GrantFiled: February 23, 2007Date of Patent: August 9, 2011Assignee: JX Crystals Inc.Inventor: Lewis M. Fraas
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Publication number: 20110011332Abstract: A method and apparatus for producing bulk single crystals of AlN having low dislocation densities of about 10,000 cm?2 or less includes a crystal growth enclosure with Al and N2 source material therein, capable of forming bulk crystals. The apparatus maintains the N2 partial pressure at greater than stoichiometric pressure relative to the Al within the crystal growth enclosure, while maintaining the total vapor pressure in the crystal growth enclosure at super-atmospheric pressure. At least one nucleation site is provided in the crystal growth enclosure, and provision is made for cooling the nucleation site relative to other locations in the crystal growth enclosure. The Al and N2 vapor is then deposited to grow single crystalline low dislocation density AlN at the nucleation site. High efficiency ultraviolet light emitting diodes and ultraviolet laser diodes are fabricated on low defect density AlN substrates, which are cut from the low dislocation density AlN crystals.Type: ApplicationFiled: July 22, 2010Publication date: January 20, 2011Applicant: Crystal IS, Inc.Inventors: Leo J. Schowalter, Glen A. Slack, J. Carlos Rojo
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Patent number: 7872192Abstract: A planar concentrator solar power module has a planar base, an aligned array of linear photovoltaic cell circuits on the base and an array of linear Fresnel lenses or linear mirrors for directing focused solar radiation on the aligned array of linear photovoltaic cell circuits. The cell circuits are mounted on a back panel which may be a metal back plate. The cell circuit area is less than a total area of the module. Each linear lens or linear mirror has a length greater than a length of the adjacent cell circuit. The cell circuit may have cells mounted in shingle fashion to form a shingled-cell circuit. In an alternative module, linear extrusions on the circuit element have faces for mounting the linear mirrors for deflecting sun rays impinging on each mirror onto the shingled-cells. The linear extrusions are side-wall and inner extrusions with triangular cross-sections. The circuit backplate is encapsulated by lamination for weather protection.Type: GrantFiled: June 11, 2008Date of Patent: January 18, 2011Assignee: JX Crystals Inc.Inventors: Lewis M. Fraas, Jany X. Fraas, Han Xiang Huang, James E. Avery
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Patent number: 7776153Abstract: A method and apparatus for producing bulk single crystals of AlN having low dislocation densities of about 10,000 cm?2 or less includes a crystal growth enclosure with Al and N2 source material therein, capable of forming bulk crystals. The apparatus maintains the N2 partial pressure at greater than stoichiometric pressure relative to the Al within the crystal growth enclosure, while maintaining the total vapor pressure in the crystal growth enclosure at super-atmospheric pressure. At least one nucleation site is provided in the crystal growth enclosure, and provision is made for cooling the nucleation site relative to other locations in the crystal growth enclosure. The Al and N2 vapor is then deposited to grow single crystalline low dislocation density AlN at the nucleation site. High efficiency ultraviolet light emitting diodes and ultraviolet laser diodes are fabricated on low defect density AlN substrates, which are cut from the low dislocation density AlN crystals.Type: GrantFiled: November 3, 2005Date of Patent: August 17, 2010Assignee: Crystal IS, Inc.Inventors: Leo J. Schowalter, Glen A. Slack, J. Carlos Rojo
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Publication number: 20100187541Abstract: 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: ApplicationFiled: December 18, 2009Publication date: July 29, 2010Applicant: Crystal IS, Inc.Inventors: Glen A. Slack, Leo J. Schowalter
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Publication number: 20100135349Abstract: Semiconductor structures and devices based thereon include an aluminum nitride single-crystal substrate and at least one layer epitaxially grown thereover. The epitaxial layer may comprise at least one of AlN, GaN, InN, or any binary or tertiary alloy combination thereof, and have an average dislocation density within the semiconductor heterostructure is less than about 106 cm?2.Type: ApplicationFiled: November 12, 2009Publication date: June 3, 2010Applicant: Crystal IS, Inc.Inventors: Leo J. Schowalter, Joseph A. Smart, Shiwen Liu, Kenneth E. Morgan, Robert T. Bondokov, Timothy J. Bettles, Glen A. Slack
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Patent number: 7641735Abstract: 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: GrantFiled: December 4, 2006Date of Patent: January 5, 2010Assignee: Crystal IS, Inc.Inventors: Glen A. Slack, Leo J. Schowalter
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Patent number: 7638346Abstract: Semiconductor structures and devices based thereon include an aluminum nitride single-crystal substrate and at least one layer epitaxially grown thereover. The epitaxial layer may comprise at least one of AlN, GaN, InN, or any binary or tertiary alloy combination thereof, and have an average dislocation density within the semiconductor heterostructure is less than about 106 cm?2.Type: GrantFiled: August 14, 2006Date of Patent: December 29, 2009Assignee: Crystal IS, Inc.Inventors: Leo J. Schowalter, Joseph A. Smart, Shiwen Liu, Kenneth E. Morgan, Robert T. Bondokov, Timothy J. Bettles, Glen A. Slack
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Publication number: 20090283028Abstract: Semiconductor structures and devices based thereon include an aluminum nitride single-crystal substrate and at least one layer epitaxially grown thereover. The epitaxial layer may comprise at least one of AlN, GaN, InN, or any binary or tertiary alloy combination thereof, and have an average dislocation density within the semiconductor heterostructure is less than about 106 cm?2.Type: ApplicationFiled: August 14, 2006Publication date: November 19, 2009Applicant: Crystal IS, Inc.Inventors: Leo J. Schowalter, Joseph A. Smart, Shiwen Liu, Kenneth E. Morgan, Robert T. Bondokov, Timothy J. Bettles, Glen A. Slack
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Publication number: 20090050050Abstract: Single-crystal materials are fabricated from a melt at temperatures below their melting points.Type: ApplicationFiled: May 23, 2008Publication date: February 26, 2009Applicant: Crystal IS, Inc.Inventors: Glen A. Slack, Sandra B. Schujman
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Publication number: 20080182092Abstract: Bulk single crystal of aluminum nitride (AlN) having an a real 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: ApplicationFiled: January 17, 2008Publication date: July 31, 2008Applicant: Crystal IS, Inc.Inventors: Robert T. Bondokov, Kenneth E. Morgan, Leo J. Schowalter, Glen A. Slack
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Patent number: 7388146Abstract: A planar concentrator solar power module has a planar base, an aligned array of linear photovoltaic cell circuits on the base and an array of linear Fresnel lenses or linear mirrors for directing focused solar radiation on the aligned array of linear photovoltaic cell circuits. The cell circuits are mounted on a back panel which may be a metal back plate. The cell circuit area is less than a total area of the module. Each linear lens or linear mirror has a length greater than a length of the adjacent cell circuit. The cell circuit may have cells mounted in shingle fashion to form a shingled-cell circuit. In an alternative module, linear extrusions on the circuit element have faces for mounting the linear mirrors for deflecting sun rays impinging on each mirror onto the shingled-cells. The linear extrusions are side-wall and inner extrusions with triangular cross-sections. The circuit backplate is encapsulated by lamination for weather protection.Type: GrantFiled: August 2, 2002Date of Patent: June 17, 2008Assignee: JX Crystals Inc.Inventors: Lewis M. Fraas, Jany X. Fraas, Han Xiang Huang, James E. Avery
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Publication number: 20080134957Abstract: A crucible for growing III-nitride (e.g., aluminum nitride) single crystals is provided. The crucible includes an elongated wall structure defining an interior crystal growth cavity. Embodiments include a plurality of grains and a wall thickness of at least about 1.5 times the average grain size. In particular embodiments, the crucible includes first and second layers of grains the first layer including grains forming an inside surface thereof and the second layer being superposed with the first layer. The crucible may be fabricated from tungsten-rhenium (W—Re) alloys; rhenium (Re); tantalum monocarbide (TaC); tantalum nitride (Ta2N); hafnium nitride (HfN); a mixture of tungsten and tantalum (W—Ta); tungsten (W); and combinations thereof.Type: ApplicationFiled: March 23, 2007Publication date: June 12, 2008Applicant: Crystal IS, Inc.Inventors: Leo J. Schowalter, Glen A. Slack
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Patent number: 7385749Abstract: An acousto-optic modulator includes a (100), (010) or (001) single crystal silicon acousto-optic interaction medium, and at least one transducer for emitting an acoustic wave attached to the single crystal. The transducer has a first electrode layer disposed on one side and a second electrode layer disposed on its other side. The transducer is aligned to the single crystal so that the direction of acoustic propagation in the silicon crystal is substantially along the (100), (010) or (001) direction. A q-switched laser includes a modulator according to the invention.Type: GrantFiled: September 26, 2006Date of Patent: June 10, 2008Assignee: Cleveland Crystals, Inc.Inventors: Christopher N. Pannell, Thomas Stenger, Jonathan David Ward, Melvin E. Pedinoff, Ramesh K. Shori
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Patent number: 7323414Abstract: According to one aspect of the invention, an improved process for preparing a surface of substrate is provided wherein the surface of the substrate is prepared for a chemical mechanical polishing (CMP) process, the CMP process is performed on the surface of the substrate, and the surface of the substrate is finished to clear the substrate surface of any active ingredients from the CMP process. Also, an improved substrate produced by the method is provided. According to one aspect of the invention, particular polishing materials and procedures may be used that allow for increased quality of AlN substrate surfaces.Type: GrantFiled: February 28, 2006Date of Patent: January 29, 2008Assignees: Crystal IS, Inc., Rensselaer Polytechnic InstituteInventors: Leo J. Schowalter, Javier Martinez Lopez, Juan Carlos Rojo, Kenneth Morgan
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Publication number: 20080006200Abstract: A method and apparatus for producing bulk single crystals of AlN having low dislocation densities of about 10,000 cm?2 or less includes a crystal growth enclosure with Al and N2 source material therein, capable of forming bulk crystals. The apparatus maintains the N2 partial pressure at greater than stoichiometric pressure relative to the Al within the crystal growth enclosure, while maintaining the total vapor pressure in the crystal growth enclosure at super-atmospheric pressure. At least one nucleation site is provided in the crystal growth enclosure, and provision is made for cooling the nucleation site relative to other locations in the crystal growth enclosure. The Al and N2 vapor is then deposited to grow single crystalline low dislocation density AlN at the nucleation site. High efficiency ultraviolet light emitting diodes and ultraviolet laser diodes are fabricated on low defect density AlN substrates, which are cut from the low dislocation density AlN crystals.Type: ApplicationFiled: November 3, 2005Publication date: January 10, 2008Applicant: Crystal IS, Inc.Inventors: Leo Schowalter, Glen Slack, J. Rojo
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Publication number: 20070289946Abstract: According to one aspect of the invention, an improved process for preparing a surface of substrate is provided wherein the surface of the substrate is prepared for a chemical mechanical polishing (CMP) process, the CMP process is performed on the surface of the substrate, and the surface of the substrate is finished to clear the substrate surface of any active ingredients from the CMP process. Also, an improved substrate produced by the method is provided. According to one aspect of the invention, particular polishing materials and procedures may be used that allow for increased quality of AlN substrate surfaces.Type: ApplicationFiled: February 28, 2006Publication date: December 20, 2007Applicants: Rensselaer Polytechnic Institute, Crystal IS Inc.Inventors: Leo Schowalter, Javier Lopez, Juan Rojo, Kenneth Morgan
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Publication number: 20070243653Abstract: Fabrication of doped and undoped stoichiometric polycrystalline AlN ceramics with high purity is accomplished by, for example, reacting Al pellets with nitrogen gas. Such polycrystalline AlN ceramics may be utilized in the fabrication of high purity AlN single crystals, which may be annealed to enhance a conductivity thereof.Type: ApplicationFiled: March 30, 2007Publication date: October 18, 2007Applicant: Crystal IS, Inc.Inventors: Kenneth Morgan, Leo Schowalter, Glen Slack