Patents Assigned to Hexatech, Inc.
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Patent number: 9840790Abstract: The invention provides highly transparent single crystalline AlN layers as device substrates for light emitting diodes in order to improve the output and operational degradation of light emitting devices. The highly transparent single crystalline AlN layers have a refractive index in the a-axis direction in the range of 2.250 to 2.400 and an absorption coefficient less than or equal to 15 cm-1 at a wavelength of 265 nm. The invention also provides a method for growing highly transparent single crystalline AlN layers, the method including the steps of maintaining the amount of Al contained in wall deposits formed in a flow channel of a reactor at a level lower than or equal to 30% of the total amount of aluminum fed into the reactor, and maintaining the wall temperature in the flow channel at less than or equal to 1200° C.Type: GrantFiled: August 23, 2012Date of Patent: December 12, 2017Assignees: Hexatech, Inc., National University Corporation Tokyo University of Agriculture and Technology, Tokuyama CorporationInventors: Akinori Koukitu, Yoshinao Kumagai, Toru Nagashima, Toru Kinoshita, Yuki Kubota, Rafael F. Dalmau, Jinqiao Xie, Baxter F. Moody, Raoul Schlesser, Zlatko Sitar
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Patent number: 9748409Abstract: The invention provides a power semiconductor device including an aluminum nitride single crystalline substrate, wherein the dislocation density of the substrate is less than about 105 cm?2 and the Full Width Half Maximum (FWHM) of the double axis rocking curve for the (002) and (102) crystallographic planes is less than about 200 arcsec; and a power semiconductor structure comprising at least one doped AlxGa1?xN layer overlying the aluminum nitride single crystalline substrate.Type: GrantFiled: March 13, 2014Date of Patent: August 29, 2017Assignee: HexaTech, Inc.Inventors: Baxter Moody, Seiji Mita, Jinqiao Xie
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Patent number: 9680062Abstract: The invention provides an optoelectronic device adapted to emit ultraviolet light, including an aluminum nitride single crystalline substrate, wherein the dislocation density of the substrate is less than about 105 cm?2 and the Full Width Half Maximum (FWHM) of the double axis rocking curve for the (002) and (102) crystallographic planes is less than about 200 arcsec; and an ultraviolet light-emitting diode structure overlying the aluminum nitride single crystalline substrate, the diode structure including a first electrode electrically connected to an n-type semiconductor layer and a second electrode electrically connected to a p-type semiconductor layer. In certain embodiments, the optoelectronic devices of the invention exhibit a reverse leakage current less than about 10?5 A/cm2 at ?10 V and/or an L80 of at least about 5000 hours at an injection current density of 28 A/cm2.Type: GrantFiled: February 26, 2016Date of Patent: June 13, 2017Assignee: HexaTech, Inc.Inventors: Jinqiao Xie, Baxter Moody, Seiji Mita
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Patent number: 9321647Abstract: Methods of preparing polycrystalline aluminum nitride materials that have high density, high purity, and favorable surface morphology are disclosed. The methods generally comprises pressing aluminum nitride powders to form a slug, sintering the slug to form a sintered, polycrystalline aluminum nitride boule, and optionally shaping the boule and/or polishing at least a portion of the boule to provide a finished substrate. The sintered, polycrystalline aluminum nitride materials beneficially are prepared without the use of any sintering aid or binder, and the formed materials exhibit excellent density, AlN purity, and surface morphology.Type: GrantFiled: February 6, 2015Date of Patent: April 26, 2016Assignee: HEXATECH, INC.Inventors: Baxter Moody, Rafael Dalmau, David Henshall, Raoul Schlesser
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Patent number: 9299883Abstract: The invention provides an optoelectronic device adapted to emit ultraviolet light, including an aluminum nitride single crystalline substrate, wherein the dislocation density of the substrate is less than about 105 cm?2 and the Full Width Half Maximum (FWHM) of the double axis rocking curve for the (002) and (102) crystallographic planes is less than about 200 arcsec; and an ultraviolet light-emitting diode structure overlying the aluminum nitride single crystalline substrate, the diode structure including a first electrode electrically connected to an n-type semiconductor layer and a second electrode electrically connected to a p-type semiconductor layer. In certain embodiments, the optoelectronic devices of the invention exhibit a reverse leakage current less than about 10?5 A/cm2 at ?10V and/or an L80 of at least about 5000 hours at an injection current density of 28 A/cm2.Type: GrantFiled: January 28, 2014Date of Patent: March 29, 2016Assignee: Hexatech, Inc.Inventors: Jinqiao Xie, Baxter Moody, Seiji Mita
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Patent number: 8974726Abstract: Methods of preparing polycrystalline aluminum nitride materials that have high density, high purity, and favorable surface morphology are disclosed. The methods generally comprises pressing aluminum nitride powders to form a slug, sintering the slug to form a sintered, polycrystalline aluminum nitride boule, and optionally shaping the boule and/or polishing at least a portion of the boule to provide a finished substrate. The sintered, polycrystalline aluminum nitride materials beneficially are prepared without the use of any sintering aid or binder, and the formed materials exhibit excellent density, AlN purity, and surface morphology.Type: GrantFiled: July 19, 2011Date of Patent: March 10, 2015Assignee: Hexatech, Inc.Inventors: Baxter Moody, Rafael Dalmau, David Henshall, Raoul Schlesser
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Publication number: 20140264714Abstract: The invention provides a power semiconductor device including an aluminum nitride single crystalline substrate, wherein the dislocation density of the substrate is less than about 105 cm?2 and the Full Width Half Maximum (FWHM) of the double axis rocking curve for the (002) and (102) crystallographic planes is less than about 200 arcsec; and a power semiconductor structure comprising at least one doped AlxGa1?xN layer overlying the aluminum nitride single crystalline substrate.Type: ApplicationFiled: March 13, 2014Publication date: September 18, 2014Applicant: HEXATECH, INC.Inventors: Baxter Moody, Seiji Mita, Jinqiao Xie
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Publication number: 20140209923Abstract: The invention provides an optoelectronic device adapted to emit ultraviolet light, including an aluminum nitride single crystalline substrate, wherein the dislocation density of the substrate is less than about 105 cm?2 and the Full Width Half Maximum (FWHM) of the double axis rocking curve for the (002) and (102) crystallographic planes is less than about 200 arcsec; and an ultraviolet light-emitting diode structure overlying the aluminum nitride single crystalline substrate, the diode structure including a first electrode electrically connected to an n-type semiconductor layer and a second electrode electrically connected to a p-type semiconductor layer. In certain embodiments, the optoelectronic devices of the invention exhibit a reverse leakage current less than about 10?5 A/cm2 at ?10V and/or an L80 of at least about 5000 hours at an injection current density of 28 A/cm2.Type: ApplicationFiled: January 28, 2014Publication date: July 31, 2014Applicant: Hexatech, Inc.Inventors: Jinqiao Xie, Baxter Moody, Seiji Mita
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Patent number: 8766274Abstract: Disclosed are methods and materials useful in the preparation of semiconductor devices. In particular embodiments, disclosed are methods for engineering polycrystalline aluminum nitride substrates that are thermally matched to further materials that can be combined therewith. For example, the polycrystalline aluminum nitride substrates can be engineered to have a coefficient of thermal expansion (CTE) that is closely matched to the CTE of a semiconductor material and/or to a material that can be used as a growth substrate for a semiconductor material. The invention also encompasses devices incorporating such thermally engineered substrates and semiconductor materials grown using such thermally engineered substrates. The thermally engineered substrates are advantageous for overcoming problems caused by damage arising from CTE mismatch between component layers in semiconductor preparation methods and materials.Type: GrantFiled: December 13, 2011Date of Patent: July 1, 2014Assignee: Hexatech, Inc.Inventors: Spalding Craft, Baxter Moody, Rafael Dalmau, Raoul Schlesser