Patents by Inventor Shuhei Higashihara
Shuhei Higashihara 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).
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Publication number: 20240142852Abstract: A waveguide device includes: a photonic crystal layer having holes periodically formed in an electro-optical crystal substrate; a line-defect optical waveguide formed in the photonic crystal layer; a first electrode arranged above the electro-optical crystal substrate, the first electrode being transparent to light; and a second electrode arranged below the electro-optical crystal substrate. Each of an optical scanning device and an optical modulation device includes the above-mentioned waveguide device.Type: ApplicationFiled: January 12, 2024Publication date: May 2, 2024Inventors: Kentaro TANI, Jungo KONDO, Keiichiro ASAI, Shuhei HIGASHIHARA, Naoki FUJITA
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Publication number: 20200411718Abstract: A method of producing a functional device has an etched gallium nitride layer and a functional layer having a nitride of a group 13 element. The method includes providing a body comprising a surface gallium nitride layer, performing a dry etching treatment of a surface of the surface gallium nitride layer to provide the etched gallium nitride layer using a plasma etching system comprising an inductively coupled plasma generating system, introducing an etchant during the dry etching treatment, the etchant consisting essentially of a fluorine-based gas, and forming the functional layer on a surface of the etched gallium nitride layer.Type: ApplicationFiled: September 16, 2020Publication date: December 31, 2020Applicant: NGK INSULATORS, LTD.Inventors: Shuhei Higashihara, Makoto Iwai, Katsuhiro Imai
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Patent number: 10859747Abstract: A phosphor element comprises: a support substrate; an optical waveguide for propagating an excitation light through the waveguide, the optical waveguide comprising a phosphor generating a fluorescence, and the optical waveguide comprising an emission side end surface emitting the excitation light and the fluorescence, an opposing end surface opposing the emission side end surface, a bottom surface, a top surface opposing the bottom surface and a pair of side surfaces; a bottom surface side clad layer covering the bottom surface of the optical waveguide; a top surface side clad layer covering the top surface of the optical waveguide; side surface side clad layers covering the side surfaces of the optical waveguide, respectively; a top surface side reflection film covering the top surface side clad layer; side surface side reflection films covering the side surface side clad layers, respectively; and a bottom surface side reflection film provided between the support substrate and the bottom surface side clad laType: GrantFiled: June 13, 2019Date of Patent: December 8, 2020Assignee: NGK Insulators, Ltd.Inventors: Jungo Kondo, Naotake Okada, Shoichiro Yamaguchi, Keiichiro Asai, Shuhei Higashihara, Yuichi Iwata, Tetsuya Ejiri, Akira Hamajima
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Publication number: 20190309936Abstract: An optical component includes a first substrate including a phosphor substrate and a second substrate including a translucent substrate and supporting the first substrate. A bonding layer is provided between the first substrate and the second substrate, and the bonding layer includes at least one kind of element contained on a surface of the first substrate facing the second substrate and at least one kind of element contained on a surface of the second substrate facing the first substrate. The bonding layer contains 2% by weight or more and 45% by weight or less of at least one kind of metal element which is not included in any of the first substrate and the second substrate.Type: ApplicationFiled: June 11, 2019Publication date: October 10, 2019Inventors: Jungo KONDO, Naotake OKADA, Keiichiro ASAI, Shuhei HIGASHIHARA, Shoichiro YAMAGUCHI
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Publication number: 20190310408Abstract: A phosphor element comprises: a support substrate; an optical waveguide for propagating an excitation light through the waveguide, the optical waveguide comprising a phosphor generating a fluorescence, and the optical waveguide comprising an emission side end surface emitting the excitation light and the fluorescence, an opposing end surface opposing the emission side end surface, a bottom surface, a top surface opposing the bottom surface and a pair of side surfaces; a bottom surface side clad layer covering the bottom surface of the optical waveguide; a top surface side clad layer covering the top surface of the optical waveguide; side surface side clad layers covering the side surfaces of the optical waveguide, respectively; a top surface side reflection film covering the top surface side clad layer; side surface side reflection films covering the side surface side clad layers, respectively; and a bottom surface side reflection film provided between the support substrate and the bottom surface side clad laType: ApplicationFiled: June 13, 2019Publication date: October 10, 2019Applicant: NGK INSULATORS, LTD.Inventors: Jungo KONDO, Naotake OKADA, Shoichiro YAMAGUCHI, Keiichiro ASAI, Shuhei HIGASHIHARA, Yuichi Iwata, Tetsuya Ejiri, Akira Hamajima
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Patent number: 10190233Abstract: A group 13 element source, a flux comprising at least one of an alkali metal and an alkaline earth metal, and an additive being liquid at an ambient temperature are placed in a crystal growing vessel. The crystal growing vessel is heated and pressurized under a nitrogen atom-containing gas atmosphere to form a melt containing the group 13 element source, the flux and the additive. Evaporation of the additive is prevented until the flux is melted. The crystal of the nitride of the group 13 element is then grown in the melt.Type: GrantFiled: June 22, 2017Date of Patent: January 29, 2019Assignee: NGK INSULATORS, LTD.Inventors: Suguru Noguchi, Shuhei Higashihara, Takayuki Hirao, Tetsuya Uchikawa
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Patent number: 10156022Abstract: It is produced a crystal of a nitride of a group 13 element in a melt including the group 13 element and a flux including at least an alkali metal under atmosphere comprising a nitrogen-containing gas. An amount of carbon is made 0.005 to 0.018 atomic percent, provided that 100 atomic percent is assigned to a total amount of said flux, said group 13 element and carbon in said melt.Type: GrantFiled: February 18, 2016Date of Patent: December 18, 2018Assignee: NGK INSULATORS, LTD.Inventors: Takayuki Hirao, Shuhei Higashihara, Katsuhiro Imai
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Patent number: 10041186Abstract: It is used a crucible containing a flux and a source material, a reaction vessel containing the crucible, an intermediate vessel containing the reaction vessel, and a pressure vessel containing the intermediate vessel and used to fill a gas comprising at least a nitrogen atom. When the flux and the source material are melted by heating to grow the nitride crystal, a vapor of an organic compound is provided in a space outside of the reaction vessel and inside of the intermediate vessel.Type: GrantFiled: August 17, 2016Date of Patent: August 7, 2018Assignee: NGK INSULATORS, LTD.Inventors: Katsuhiro Imai, Makoto Iwai, Masahiro Sakai, Takanao Shimodaira, Shuhei Higashihara, Takayuki Hirao
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Publication number: 20170283983Abstract: A group 13 element source, a flux comprising at least one of an alkali metal and an alkaline earth metal, and an additive being liquid at an ambient temperature are placed in a crystal growing vessel. The crystal growing vessel is heated and pressurized under a nitrogen atom-containing gas atmosphere to form a melt containing the group 13 element source, the flux and the additive. Evaporation of the additive is prevented until the flux is melted. The crystal of the nitride of the group 13 element is then grown in the melt.Type: ApplicationFiled: June 22, 2017Publication date: October 5, 2017Applicant: NGK INSULATORS, LTD.Inventors: Suguru Noguchi, Shuhei Higashihara, Takayuki Hirao, Tetsuya Uchikawa
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Publication number: 20160355945Abstract: It is used a crucible containing a flux and a source material, a reaction vessel containing the crucible, an intermediate vessel containing the reaction vessel, and a pressure vessel containing the intermediate vessel and used to fill a gas comprising at least a nitrogen atom. When the flux and the source material are melted by heating to grow the nitride crystal, a vapor of an organic compound is provided in a space outside of the reaction vessel and inside of the intermediate vessel.Type: ApplicationFiled: August 17, 2016Publication date: December 8, 2016Applicant: NGK INSULATORS, LTD.Inventors: Katsuhiro Imai, Makoto Iwai, Masahiro Sakai, Takanao Shimodaira, Shuhei Higashihara, Takayuki Hirao
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Publication number: 20160300980Abstract: In a substrate having a gallium nitride layer, surface damage after surface treatment of the gallium nitride layer is reduced and quality of a functional device formed thereon is improved. A substrate 4 having at least a gallium nitride layer 4 is provided. A plasma etching system equipped with an inductively coupled plasma generating system is used and a fluorine-based gas is introduced at a standardized direct current bias potential of ?10V/cm2 or higher to subject a surface 3a of the gallium nitride layer to dry etching treatment.Type: ApplicationFiled: June 23, 2016Publication date: October 13, 2016Applicant: NGK INSULATORS, LTD.Inventors: Shuhei Higashihara, Makoto Iwai, Katsuhiro Imai
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Publication number: 20160168749Abstract: It is produced a crystal of a nitride of a group 13 element in a melt including the group 13 element and a flux including at least an alkali metal under atmosphere comprising a nitrogen-containing gas. An amount of carbon is made 0.005 to 0.018 atomic percent, provided that 100 atomic percent is assigned to a total amount of said flux, said group 13 element and carbon in said melt.Type: ApplicationFiled: February 18, 2016Publication date: June 16, 2016Applicant: NGK INSULATORS, LTD.Inventors: Takayuki Hirao, Shuhei Higashihara, Katsuhiro Imai
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Publication number: 20150303066Abstract: In a substrate having a gallium nitride layer, surface damage after surface treatment of the gallium nitride layer is reduced and quality of a functional device formed thereon is improved. A substrate 4 having at least a gallium nitride layer 4 is provided. A plasma etching system equipped with an inductively coupled plasma generating system is used and a fluorine-based gas is introduced at a standardized direct current bias potential of ?10V/cm2 or higher to subject a surface 3a of the gallium nitride layer to dry etching treatment.Type: ApplicationFiled: June 30, 2015Publication date: October 22, 2015Applicant: NGK INSULATORS, LTD.Inventors: Shuhei Higashihara, Makoto Iwai, Katsuhiro Imai
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Patent number: 8795431Abstract: A gallium nitride layer is produced using a seed crystal substrate by flux method. The seed crystal substrate 8A includes a supporting body 1, a plurality of seed crystal layers 4A each comprising gallium nitride single crystal and separated from one another, a low temperature buffer layer 2 provided between the seed crystal layers 4A and the supporting body and made of a nitride of a group III metal element, and an exposed layer 3 exposed to spaces between the adjacent seed crystal layers 4A and made of aluminum nitride single crystal or aluminum gallium nitride single crystal. The gallium nitride layer is grown on the seed crystal layers by flux method.Type: GrantFiled: September 20, 2013Date of Patent: August 5, 2014Assignee: NGK Insulators, Ltd.Inventors: Katsuhiro Imai, Makota Iwai, Takanao Shimodaira, Masahiro Sakai, Shuhei Higashihara, Takayuki Hirao
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Publication number: 20140026809Abstract: A seed crystal substrate 10 includes a supporting body 1, and a seed crystal film 3A formed on the supporting body 1 and composed of a single crystal of a nitride of a Group 13 metal element. The seed crystal film 3A includes main body parts 3a and thin parts 3b having a thickness smaller than that of the main body parts 3a. The main body parts 3a and thin part 3b are exposed to a surface of the seed crystal substrate 10. A nitride 15 of a Group 13 metal element is grown on the seed crystal film 3A by flux method.Type: ApplicationFiled: September 17, 2013Publication date: January 30, 2014Applicant: NGK INSULATORS, LTD.Inventors: Makoto Iwai, Takanao Shimodaira, Shuhei Higashihara, Takayuki Hirao, Masahiro Sakai, Katsuhiro Imai
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Publication number: 20140014028Abstract: A gallium nitride layer is produced using a seed crystal substrate by flux method. The seed crystal substrate 8A includes a supporting body 1, a plurality of seed crystal layers 4A each comprising gallium nitride single crystal and separated from one another, a low temperature buffer layer 2 provided between the seed crystal layers 4A and the supporting body and made of a nitride of a group III metal element, and an exposed layer 3 exposed to spaces between the adjacent seed crystal layers 4A and made of aluminum nitride single crystal or aluminum gallium nitride single crystal. The gallium nitride layer is grown on the seed crystal layers by flux method.Type: ApplicationFiled: September 20, 2013Publication date: January 16, 2014Applicant: NGK INSULATORS, LTD.Inventors: Katsuhiro Imai, Makoto Iwai, Takanao Shimodaira, Masahiro Sakai, Shuhei Higashihara, Takayuki Hirao
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Patent number: 8568532Abstract: Materials of a nitride single crystal of a metal belonging to III group and a flux are contained in a crucible, which is contained in a reaction container, the reaction container is contained in an outer container, the outer container is contained in a pressure container, and nitrogen-containing atmosphere is supplied into the outer container and melt is generated in the crucible to grow a nitride single crystal of a metal belonging to III group. The reaction container includes a main body containing the crucible and a lid. The main body includes a side wall having a fitting face and a groove opening at the fitting face and a bottom wall. The lid has an upper plate part including a contact face for the fitting face of the main body and a flange part extending from the upper plate part and surrounding an outer side of said side wall.Type: GrantFiled: December 9, 2011Date of Patent: October 29, 2013Assignees: NGK Insulators, Ltd.Inventors: Makoto Iwai, Shuhei Higashihara, Yusuke Mori, Yasuo Kitaoka, Naoya Miyoshi
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Patent number: 8501141Abstract: An object of the present invention is to effectively add Ge in the production of GaN through the Na flux method. In a crucible, a seed crystal substrate is placed such that one end of the substrate remains on the support base, whereby the seed crystal substrate remains tilted with respect to the bottom surface of the crucible, and gallium solid and germanium solid are placed in the space between the seed crystal substrate and the bottom surface of the crucible. Then, sodium solid is placed on the seed crystal substrate. Through employment of this arrangement, when a GaN crystal is grown on the seed crystal substrate through the Na flux method, germanium is dissolved in molten gallium before formation of a sodium-germanium alloy. Thus, the GaN crystal can be effectively doped with Ge.Type: GrantFiled: March 26, 2010Date of Patent: August 6, 2013Assignees: Toyoda Gosei Co., Ltd., NGK Insulators, Ltd., Osaka UniversityInventors: Takayuki Sato, Seiji Nagai, Makoto Iwai, Shuhei Higashihara, Yusuke Mori, Yasuo Kitaoka
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Publication number: 20120137961Abstract: Materials of a nitride single crystal of a metal belonging to III group and a flux are contained in a crucible, which is contained in a reaction container, the reaction container is contained in an outer container, the outer container is contained in a pressure container, and nitrogen-containing atmosphere is supplied into the outer container and melt is generated in the crucible to grow a nitride single crystal of a metal belonging to III group. The reaction container includes a main body containing the crucible and a lid. The main body includes a side wall having a fitting face and a groove opening at the fitting face and a bottom wall. The lid has an upper plate part including a contact face for the fitting face of the main body and a flange part extending from the upper plate part and surrounding an outer side of said side wall.Type: ApplicationFiled: December 9, 2011Publication date: June 7, 2012Inventors: Makoto Iwai, Shuhei Higashihara, Yusuke Mori, Yasuo Kitaoka, Naoya Miyoshi
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Publication number: 20110259261Abstract: It is provided a method of growing a single crystal by flux process from a melt containing sodium, in that a flux is contained in a reaction vessel made of yttrium-aluminum garnet. Compared with the case that an alumina or yttria vessel is used, it can be successfully obtained a single crystal whose incorporation amounts of oxygen and silicon can be considerably reduced, residual carrier density can be lowered, and electron mobility and specific resistance can be improved.Type: ApplicationFiled: July 6, 2011Publication date: October 27, 2011Applicants: NGK Insulators, Ltd., Osaka University, Toyoda Gosei Co., Ltd.Inventors: Makoto IWAI, Shuhei Higashihara, Yasuo Kitaoka, Yusuke Mori, Takayuki Sato, Seiji Nagai