Patents by Inventor Kazuyuki Iizuka
Kazuyuki Iizuka 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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Patent number: 8120051Abstract: A semiconductor light emitting element includes a group III-V compound semiconductor layer, a first main surface and a second main surface, a reflection metal film formed on the second main surface, a front surface electrode formed on the first main surface, and an ohmic contact joint part formed between the reflection metal film and the group III-V compound semiconductor layer except a region directly under the front surface electrode. The ohmic contact joint part is disposed in a side of an outer peripheral part of the semiconductor light emitting element, formed so as to surround the front surface electrode when the ohmic contact joint part is viewed from a side of the front surface electrode, and disposed so that distance from each location of outer edge parts of the front surface electrode to the ohmic contact joint part nearest to the each location becomes equal to each other.Type: GrantFiled: April 27, 2010Date of Patent: February 21, 2012Assignee: Hitachi Cable, Ltd.Inventors: Kazuyuki Iizuka, Masahiro Watanabe
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Patent number: 8071992Abstract: A semiconductor light-emitting device includes a support structure, and a light-emitting structure. The support structure includes a support substrate, and a support substrate side bonding layer disposed on one surface of the support substrate. The light-emitting structure includes a light-emitting structure side bonding layer bonded to the support substrate side bonding layer, a reflection region disposed on the support substrate side bonding layer opposite the support substrate, and a semiconductor multilayer structure including a light-emitting layer disposed on the reflection region opposite the light-emitting structure side bonding layer for emitting a light with a predetermined wavelength, and a light-extraction surface disposed on the light-emitting layer opposite the reflection region for reflecting diffusely the light.Type: GrantFiled: August 26, 2008Date of Patent: December 6, 2011Assignee: Hitachi Cable, Ltd.Inventors: Nobuaki Kitano, Masahiro Arai, Kazuyuki Iizuka
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Patent number: 7884381Abstract: A light emitting device includes a semiconductor multilayer structure having a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, and an active layer. A reflecting layer is provided at a side of one surface of the semiconductor multilayer structure and reflects a light emitted from the active layer. A supporting substrate of Si or Ge is provided at an opposite side of the reflecting layer with respect to the side of the semiconductor multilayer structure and supports the semiconductor multilayer structure via a metal bonding layer. A back surface electrode is provided at an opposite side of the supporting substrate with respect to a side of the metal bonding layer and includes Au alloyed with the support substrate. A hardness of the back surface electrode is higher than a hardness of the Au.Type: GrantFiled: July 29, 2009Date of Patent: February 8, 2011Assignee: Hitachi Cable, Ltd.Inventors: Masahiro Arai, Kazuyuki Iizuka
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Publication number: 20100301362Abstract: A semiconductor light emitting element includes a group III-V compound semiconductor layer, a first main surface and a second main surface, a reflection metal film formed on the second main surface, a front surface electrode formed on the first main surface, and an ohmic contact joint part formed between the reflection metal film and the group III-V compound semiconductor layer except a region directly under the front surface electrode. The ohmic contact joint part is disposed in a side of an outer peripheral part of the semiconductor light emitting element, formed so as to surround the front surface electrode when the ohmic contact joint part is viewed from a side of the front surface electrode, and disposed so that distance from each location of outer edge parts of the front surface electrode to the ohmic contact joint part nearest to the each location becomes equal to each other.Type: ApplicationFiled: April 27, 2010Publication date: December 2, 2010Applicant: HITACHI CABLE, LTD.Inventors: Kazuyuki Iizuka, Masahiro Watanabe
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Publication number: 20100207146Abstract: A light emitting element includes a semiconductor laminated structure including a first semiconductor layer of first conductivity type, a second semiconductor layer of second conductivity type different from the first conductivity type, and an active layer sandwiched between the first semiconductor layer and the second semiconductor layer, a surface electrode including a center electrode disposed on one surface of the semiconductor laminated structure and a thin wire electrode extending from a periphery of the center electrode, and a contact part disposed on a part of another surface of the semiconductor laminated structure extruding a part located directly below the surface electrode, in parallel along the thin wire electrode, and including a plurality of first regions forming the shortest current pathway between the thin wire electrode and a second region allowing the plural first regions to be connected.Type: ApplicationFiled: January 20, 2010Publication date: August 19, 2010Applicant: HITACHI CABLE, LTD.Inventors: Kazuyuki IIZUKA, Masahiro ARAI
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Patent number: 7692203Abstract: A plurality of semiconductor layers including an active layer 6 and a light extract layer 4, and a reflective metal film 11 are formed in a semiconductor light emitting device. The light extract layer 4 is formed of a plurality of layers 23, 24 having different composition ratios. An irregularity 22 is formed on the layers 23, 24 including an outermost layer to provide a main surface S as a rough-surface.Type: GrantFiled: October 19, 2007Date of Patent: April 6, 2010Assignee: Hitachi Cable, Ltd.Inventors: Taichiroo Konno, Kazuyuki Iizuka, Masahiro Arai
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Publication number: 20100078659Abstract: A light-emitting element includes a semiconductor laminated structure including a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type different from the first conductivity type and an active layer sandwiched by the first and second semiconductor layers, a first electrode on one surface side of the semiconductor laminated structure, a conductive reflective layer on an other surface side of the semiconductor laminated structure for reflecting light emitted from the active layer, a contact portion partially formed between the semiconductor laminated structure and the conductive reflective layer and being in ohmic contact with the semiconductor laminated structure, and a second electrode on a part of a surface of the conductive reflective layer on the semiconductor laminated structure without contacting the semiconductor laminated structure for feeding current to the contact portion.Type: ApplicationFiled: September 25, 2009Publication date: April 1, 2010Applicant: HITACHI CABLE, LTD.Inventors: Kazuyuki Iizuka, Masahiro Arai
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Publication number: 20100065869Abstract: A light emitting device includes a semiconductor multilayer structure having a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, and an active layer. A reflecting layer is provided at a side of one surface of the semiconductor multilayer structure and reflects a light emitted from the active layer. A supporting substrate of Si or Ge is provided at an opposite side of the reflecting layer with respect to the side of the semiconductor multilayer structure and supports the semiconductor multilayer structure via a metal bonding layer. A back surface electrode is provided at an opposite side of the supporting substrate with respect to a side of the metal bonding layer and includes Au alloyed with the support substrate. A hardness of the back surface electrode is higher than a hardness of the Au.Type: ApplicationFiled: July 29, 2009Publication date: March 18, 2010Applicant: HITACHI CABLE, LTD.Inventors: Masahiro Arai, Kazuyuki Iizuka
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Patent number: 7608859Abstract: A semiconductor light-emitting device with a transparent conductive film has: a light-emitting portion formed on a semiconductor substrate, the light-emitting portion having an n-type clad layer, an active layer and a p-type clad layer; an As-based contact layer formed on the light-emitting portion, the contact layer being doped with a p-type dopant of 1×1019/cm3 or more; a current spreading layer formed on the contact layer, the current spreading layer being formed of a transparent conductive film made of a metal oxide material; and a buffer layer formed between the contact layer and the p-type clad layer. The buffer layer has two or more buffer layer parts, and the adjacent buffer layer parts are different each other in material or composition.Type: GrantFiled: July 13, 2006Date of Patent: October 27, 2009Assignee: Hitachi Cable, Ltd.Inventors: Taichiroo Konno, Kazuyuki Iizuka, Masahiro Arai
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Publication number: 20090206354Abstract: A semiconductor light-emitting device includes a support structure, and a light-emitting structure. The support structure includes a support substrate, and a support substrate side bonding layer disposed on one surface of the support substrate. The light-emitting structure includes a light-emitting structure side bonding layer bonded to the support substrate side bonding layer, a reflection region disposed on the support substrate side bonding layer opposite the support substrate, and a semiconductor multilayer structure including a light-emitting layer disposed on the reflection region opposite the light-emitting structure side bonding layer for emitting a light with a predetermined wavelength, and a light-extraction surface disposed on the light-emitting layer opposite the reflection region for reflecting diffusely the light.Type: ApplicationFiled: August 26, 2008Publication date: August 20, 2009Applicant: Hitachi Cable, Ltd.Inventors: Nobuaki Kitano, Masahiro Arai, Kazuyuki Iizuka
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Patent number: 7569866Abstract: A semiconductor light-emitting device having: a light-emitting portion formed on a semiconductor substrate, the light-emitting portion having an n-type clad layer, an active layer and a p-type clad layer; an As-based contact layer formed on the light-emitting portion, the contact layer being doped with a p-type dopant of 1×1019/cm3 or more; a current spreading layer formed on the contact layer, the current spreading layer being formed of a transparent conductive film of a metal oxide material; and a buffer layer formed between the contact layer and the p-type clad layer or formed being inserted inside of the p-type clad layer. The buffer layer is of an undoped group III/V semiconductor, and the group III/V semiconductor is of a group V element having P (phosphorus) as a main component thereof.Type: GrantFiled: August 2, 2006Date of Patent: August 4, 2009Assignee: Hitachi Cable, Ltd.Inventors: Taichiroo Konno, Kazuyuki Iizuka, Masahiro Arai
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Patent number: 7535026Abstract: A semiconductor light-emitting device has a semiconductor substrate, an n-type cladding layer, an active layer, a p-type cladding layer, a p-type buffer layer, a p-type contact layer, and a current spreading layer. A part or all of the p-type buffer layer has a low Mg concentration buffer layer with a Mg concentration of 3.0×1017/cm3 or less and a film thickness of 50 nm or more.Type: GrantFiled: August 29, 2006Date of Patent: May 19, 2009Assignee: Hitachi Cable, Ltd.Inventors: Kazuyuki Iizuka, Taichiroo Konno, Masahiro Arai
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Patent number: 7449722Abstract: A semiconductor light emitting element has a first conductive-type cladding layer, an undoped active layer, a second conductive-type cladding layer, and a second conductive-type current spreading layer that are formed on a first conductive-type semiconductor substrate. The second conductive-type cladding layer has a first dopant suppressing layer formed at a portion in the second conductive-type cladding layer, the portion being not in contact with the active layer. The first dopant suppressing layer has a dopant concentration lower than a region in the vicinity of the first dopant suppressing layer.Type: GrantFiled: November 23, 2005Date of Patent: November 11, 2008Assignee: Hitachi Cable, Ltd.Inventors: Taichiroo Konno, Kazuyuki Iizuka, Masahiro Arai, Takashi Furuya
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Patent number: 7368759Abstract: A semiconductor light emitting device has a light-emitting portion formed on a semiconductor substrate, an As-based p-type contact layer formed thereon, a current spreading layer formed thereon of a metal oxide material, and a buffer layer formed between the p-type cladding layer and the p-type contact layer. The buffer layer has a group III/V semiconductor with a p-type conductivity and hydrogen or carbon included intentionally or unavoidably therein, and the buffer layer has a thickness equal to or greater than a diffusion length L of a dopant doped into the p-type contact layer.Type: GrantFiled: July 13, 2006Date of Patent: May 6, 2008Assignee: Hitachi Cable, Ltd.Inventors: Masahiro Arai, Taichiroo Konno, Kazuyuki Iizuka, Katsuya Akimoto
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Publication number: 20080093612Abstract: A plurality of semiconductor layers including an active layer 6 and a light extract layer 4, and a reflective metal film 11 are formed in a semiconductor light emitting device. The light extract layer 4 is formed of a plurality of layers 23, 24 having different composition ratios. An irregularity 22 is formed on the layers 23, 24 including an outermost layer to provide a main surface S as a rough-surface.Type: ApplicationFiled: October 19, 2007Publication date: April 24, 2008Applicant: HITACHI CABLE, LTD.Inventors: Taichiroo Konno, Kazuyuki Iizuka, Masahiro Arai
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Patent number: 7300643Abstract: With a method producing hydrogen by making iron or iron oxide contact water, water vapor, or a gas including water vapor, a hydrogen generating medium, which has a high hydrogen generation reaction rate and is resistant to a repetition of oxidation-reduction without degrading its activity, is provided by adding a different metal (such as Ti, Zr, V, Nb, Cr, Mo, Al, Ga, Mg, Sc, Ni, Cu, etc.) other than the iron to the iron or the iron oxide.Type: GrantFiled: April 1, 2002Date of Patent: November 27, 2007Assignees: Uchiya Thermostat Co., Ltd., Kiyoshi OtsukaInventors: Kiyoshi Otsuka, Sakae Takenaka, Kiyozumi Nakamura, Kazuyuki Iizuka
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Patent number: 7294200Abstract: A method for producing a nitride semiconductor crystal comprising steps (a), (b) and (c), which steps follow in sequence as follows: a step (a) for forming fine crystal particles made of a nitride semiconductor on a substrate; a step (b) for forming a nitride semiconductor island structure having a plurality of facets inclined relative to a surface of the substrate using the fine crystal particles as nuclei; and a step (c) for causing the nitride semiconductor island structure to grow in a direction parallel with a surface of the substrate to merge a plurality of the nitride semiconductor island structures with each other, thereby forming a nitride semiconductor crystal layer having a flat surface; the steps (a)-(c) being continuously conducted in the same growing apparatus.Type: GrantFiled: March 26, 2003Date of Patent: November 13, 2007Assignee: Hitachi Cable, Ltd.Inventors: Hajime Fujikura, Kazuyuki Iizuka
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Patent number: 7230281Abstract: A semiconductor light emitting device has: a semiconductor substrate; a semiconductor layer having an n-type cladding layer, an active layer, a p-type cladding layer and a p-type contact layer, wherein the p-type contact layer is made of an As-based material and located at the top of the semiconductor layer and doped with a p-type dopant at a concentration of 1×1019/cm3 or more; a current spreading layer formed on the semiconductor layer and made of a metal oxide material; and a diffusion prevention layer formed between the p-type contact layer and the p-type cladding layer. The diffusion prevention layer is made of a group III–V semiconductor that has phosphorus as a group V element and has a crystal lattice mismatch ratio of within ±0.3% to the semiconductor substrate.Type: GrantFiled: June 24, 2005Date of Patent: June 12, 2007Assignee: Hitachi Cable, Ltd.Inventors: Masahiro Arai, Taichiroo Konno, Kazuyuki Iizuka
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Publication number: 20070075328Abstract: A semiconductor light-emitting device has a semiconductor substrate, an n-type cladding layer, an active layer, a p-type cladding layer, a p-type buffer layer, a p-type contact layer, and a current spreading layer. A part or all of the p-type buffer layer has a low Mg concentration buffer layer with a Mg concentration of 3.0×1017/cm3 or less and a film thickness of 50 nm or more.Type: ApplicationFiled: August 29, 2006Publication date: April 5, 2007Inventors: Kazuyuki Iizuka, Taichiroo Konno, Masahiro Arai
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Publication number: 20070075319Abstract: A semiconductor light-emitting device with a transparent conductive film has: a light-emitting portion formed on a semiconductor substrate, the light-emitting portion having an n-type clad layer, an active layer and a p-type clad layer; an As-based contact layer formed on the light-emitting portion, the contact layer being doped with a p-type dopant of 1×1019/cm3 or more; a current spreading layer formed on the contact layer, the current spreading layer being formed of a transparent conductive film made of a metal oxide material; and a buffer layer formed between the contact layer and the p-type clad layer. The buffer layer has two or more buffer layer parts, and the adjacent buffer layer parts are different each other in material or composition.Type: ApplicationFiled: July 13, 2006Publication date: April 5, 2007Inventors: Taichiroo Konno, Kazuyuki Iizuka, Masahiro Arai