Patents by Inventor Kunihiro Takatani
Kunihiro Takatani 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: 8368168Abstract: A III-V-group compound semiconductor device includes a substrate, a channel layer provided over the substrate, a barrier layer provided on the channel layer so as to form a hetero-interface, a plurality of electrodes provided on the barrier layer, an insulator layer provided to cover an entire upper surface of the barrier layer except for at least partial regions of the electrodes, and a hydrogen-absorbing layer stacked on the insulator layer or an integrated layer in which an hydrogen-absorbing layer is integrated with the insulator layer.Type: GrantFiled: February 1, 2010Date of Patent: February 5, 2013Assignee: Sharp Kabushiki KaishaInventor: Kunihiro Takatani
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Publication number: 20120220122Abstract: Provided are a nitride semiconductor device and a manufacturing method thereof. The nitride semiconductor device includes an insulating layer and a metal layer formed on a nitride semiconductor layer. The insulating layer makes contact with the nitride semiconductor layer. A separation preventing layer is formed between the insulating layer and the metal layer so as to make contact with each of these layers. The separation preventing layer has, as a main component, at least one kind of oxide of a metal selected from the group consisting of tungsten, molybdenum, chromium, titanium, nickel, hafnium, zinc, indium and yttrium.Type: ApplicationFiled: May 10, 2012Publication date: August 30, 2012Inventors: Daisuke HANAOKA, Masafumi KONDO, Susumu OHMI, Kunihiro TAKATANI, Yoshika KANEKO
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Patent number: 8203152Abstract: The nitride semiconductor device includes an insulating layer and a metal layer formed on a nitride semiconductor layer. The insulating layer makes contact with the nitride semiconductor layer. A separation preventing layer is formed between the insulating layer and the metal layer so as to make contact with each of these layers. The separation preventing layer includes, as a main component, at least one oxide of a metal selected from a group of metals consisting of tungsten, molybdenum, chromium, titanium, nickel, hafnium, zinc, indium and yttrium.Type: GrantFiled: October 27, 2005Date of Patent: June 19, 2012Assignee: Sharp Kabushiki KaishaInventors: Daisuke Hanaoka, Masafumi Kondo, Susumu Ohmi, Kunihiro Takatani, Yoshika Kaneko
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Patent number: 7842956Abstract: On a nitride semiconductor layered portion formed on a substrate, there are formed an insulating film and a p-side electrode in this order. Furthermore, an end portion electrode protection layer is formed above the p-side electrode, around a position where cleavage will take place.Type: GrantFiled: December 11, 2006Date of Patent: November 30, 2010Assignee: Sharp Kabushiki KaishaInventors: Susumu Ohmi, Kunihiro Takatani, Fumio Yamashita, Mototaka Taneya
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Patent number: 7804880Abstract: In one embodiment of the present invention, a long-life nitride semiconductor laser element is disclosed wherein voltage characteristics do not deteriorate even when the element is driven at high current density. Specifically disclosed is a nitride semiconductor laser element which includes a p-type nitride semiconductor and a p-side electrode formed on the p-type nitride semiconductor. In at least one embodiment, the p-side electrode has a first layer which is in direct contact with the p-type nitride semiconductor and a conductive second layer formed on the first layer, and the second layer contains a metal element selected from the group consisting of Ti, Zr, Hf, W, Mo and Nb, and an oxygen element.Type: GrantFiled: June 2, 2006Date of Patent: September 28, 2010Assignee: Sharp Kabushiki KaishaInventors: Shigetoshi Ito, Kunihiro Takatani, Susumu Omi
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Publication number: 20100193839Abstract: A III-V-group compound semiconductor device includes a substrate, a channel layer provided over the substrate, a barrier layer provided on the channel layer so as to form a hetero-interface, a plurality of electrodes provided on the barrier layer, an insulator layer provided to cover an entire upper surface of the barrier layer except for at least partial regions of the electrodes, and a hydrogen-absorbing layer stacked on the insulator layer or an integrated layer in which an hydrogen-absorbing layer is integrated with the insulator layer.Type: ApplicationFiled: February 1, 2010Publication date: August 5, 2010Inventor: Kunihiro Takatani
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Patent number: 7656916Abstract: A nitride semiconductor device includes a stem. A heat sink is provided on the stem. At least one nitride semiconductor light-emitting element is connected to the heat sink. A light-detecting element for detecting light from the semiconductor light-emitting element is provided on the stem. A cap for encapsulating therein the heat sink, the semiconductor light-emitting element, and the light-detecting element in a sealed manner is connected to the stem. The space in the cap has an encapsulated atmosphere. The encapsulated atmosphere contains a component for inhibiting diffusion of hydrogen atoms contained in the semiconductor light-emitting element. The present invention suppresses defect due to an increase in operation voltage to increase a ratio of good goods thereby improving the fabrication yield of the semiconductor light-emitting device.Type: GrantFiled: December 19, 2007Date of Patent: February 2, 2010Assignee: Sharp Kabushiki KaishaInventors: Kunihiro Takatani, Daisuke Hanaoka, Masaya Ishida
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Publication number: 20090095964Abstract: In one embodiment of the present invention, a long-life nitride semiconductor laser element is disclosed wherein voltage characteristics do not deteriorate even when the element is driven at high current density. Specifically disclosed is a nitride semiconductor laser element which includes a p-type nitride semiconductor and a p-side electrode formed on the p-type nitride semiconductor. In at least one embodiment, the p-side electrode has a first layer which is in direct contact with the p-type nitride semiconductor and a conductive second layer formed on the first layer, and the second layer contains a metal element selected from the group consisting of Ti, Zr, Hf, W, Mo and Nb, and an oxygen element.Type: ApplicationFiled: June 2, 2006Publication date: April 16, 2009Inventors: Shigetoshi Ito, Kunihiro Takatani, Susumu Omi
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Publication number: 20080151952Abstract: A nitride semiconductor device includes a stem. A heat sink is provided on the stem. At least one nitride semiconductor light-emitting element is connected to the heat sink. A light-detecting element for detecting light from the semiconductor light-emitting element is provided on the stem. A cap for encapsulating therein the heat sink, the semiconductor light-emitting element, and the light-detecting element in a sealed manner is connected to the stem. The space in the cap has an encapsulated atmosphere. The encapsulated atmosphere contains a component for inhibiting diffusion of hydrogen atoms contained in the semiconductor light-emitting element. The present invention suppresses defect due to an increase in operation voltage to increase a ratio of good goods thereby improving the fabrication yield of the semiconductor light-emitting device.Type: ApplicationFiled: December 19, 2007Publication date: June 26, 2008Inventors: Kunihiro Takatani, Daisuke Hanaoka, Masaya Ishida
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Publication number: 20070131960Abstract: On a nitride semiconductor layered portion formed on a substrate, there are formed an insulating film and a p-side electrode in this order. Furthermore, an end portion electrode protection layer is formed above the p-side electrode, around a position where cleavage will take place.Type: ApplicationFiled: December 11, 2006Publication date: June 14, 2007Inventors: Susumu Ohmi, Kunihiro Takatani, Fumio Yamashita, Mototaka Taneya
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Publication number: 20070029571Abstract: In a nitride semiconductor light-emitting device, a cap is pressure-bonded on the top surface of a stem under electric discharge to form a package. The package encloses a heatsink, a nitride semiconductor laser element, electrode pins, and wires, and has sealed inside it a gas containing oxygen as a sealed atmosphere. At least the inner surface of the cap is plated with Ni and Pd, which are metals that can occlude hydrogen.Type: ApplicationFiled: August 1, 2006Publication date: February 8, 2007Inventors: Daisuke Hanaoka, Masaya Ishida, Kunihiro Takatani, Shigetoshi Ito
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Patent number: 7042011Abstract: A compound semiconductor laser of a III group nitride semiconductor of the present invention includes a first cladding layer 104 of a first conduction type formed on a substrate 101, an active layer 106 formed on the first cladding layer, a second cladding layer 108 of a second conduction type formed on the active layer 106, and a buried layer 110 formed on the second cladding layer 108, the buried layer having an opening portion for constricting a current in a selected region of the active layer, wherein an upper portion of the second cladding layer 108 has a ridge portion, the ridge portion residing in the opening portion of the buried layer 110, and the buried layer 110 does not substantially absorb light output from the active layer 106, and the buried layer has a refractive index which is approximately identical with that of the second cladding layer 108.Type: GrantFiled: November 18, 2004Date of Patent: May 9, 2006Assignee: Sharp Kabushiki KaishaInventor: Kunihiro Takatani
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Publication number: 20060091501Abstract: Provided are a nitride semiconductor device and a manufacturing method thereof The nitride semiconductor device includes an insulating layer and a metal layer formed on a nitride semiconductor layer. The insulating layer makes contact with the nitride semiconductor layer. A separation preventing layer is formed between the insulating layer and the metal layer so as to make contact with each of these layers. The separation preventing layer has, as a main component, at least one kind of oxide of a metal selected from the group consisting of tungsten, molybdenum, chromium, titanium, nickel, hafnium, zinc, indium and yttrium.Type: ApplicationFiled: October 27, 2005Publication date: May 4, 2006Inventors: Daisuke Hanaoka, Masafumi Kondo, Susumu Ohmi, Kunihiro Takatani, Yoshika Kaneko
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Patent number: 7015058Abstract: A nitride semiconductor laser device using a group III nitride semiconductor also as a substrate offers excellent operation characteristics and a long laser oscillation life. In a layered structure of a group III nitride semiconductor formed on a GaN substrate, a laser optical waveguide region is formed elsewhere than right above a dislocation-concentrated region extending so as to vertically penetrate the substrate, and electrodes are formed on the top surface of the layered structure and on the bottom surface of the substrate elsewhere than right above or below the dislocation-concentrated region. In a portion of the top surface of the layered structure and in a portion of the bottom surface of the substrate right above and below the dislocation-concentrated region, dielectric layers may be formed to prevent the electrodes from making contact with those regions.Type: GrantFiled: August 13, 2004Date of Patent: March 21, 2006Assignees: Sharp Kabushiki Kaisha, Sumitomo Electric Industries, Ltd.Inventors: Kunihiro Takatani, Shigetoshi Ito, Takayuki Yuasa, Mototaka Taneya, Kensaku Motoki
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Publication number: 20050135447Abstract: A compound semiconductor laser of a III group nitride semiconductor of the present invention includes a first cladding layer 104 of a first conduction type formed on a substrate 101, an active layer 106 formed on the first cladding layer, a second cladding layer 108 of a second conduction type formed on the active layer 106, and a buried layer 110 formed on the second cladding layer 108, the buried layer having an opening portion for constricting a current in a selected region of the active layer, wherein an upper portion of the second cladding layer 108 has a ridge portion, the ridge portion residing in the opening portion of the buried layer 110, and the buried layer 110 does not substantially absorb light output from the active layer 106, and the buried layer has a refractive index which is approximately identical with that of the second cladding layer 108.Type: ApplicationFiled: November 18, 2004Publication date: June 23, 2005Applicant: SHARP KABUSHIKI KAISHAInventor: Kunihiro Takatani
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Patent number: 6894391Abstract: An electrode structure on a p-type III group nitride semiconductor layer includes first, second and third electrode layers successively stacked on the semiconductor layer. The first electrode layer includes at least one selected from a first metal group of Ti, Hf, Zr, V, Nb, Ta, Cr, W and Sc. The second electrode layer includes at least one selected from a second metal group of Ni, Pd and Co. The third electrode layer includes Au.Type: GrantFiled: April 25, 2000Date of Patent: May 17, 2005Assignee: Sharp Kabushiki KaishaInventor: Kunihiro Takatani
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Publication number: 20050048682Abstract: A nitride semiconductor laser device using a group III nitride semiconductor also as a substrate offers excellent operation characteristics and a long laser oscillation life. In a layered structure of a group III nitride semiconductor formed on a GaN substrate, a laser optical waveguide region is formed elsewhere than right above a dislocation-concentrated region extending so as to vertically penetrate the substrate, and electrodes are formed on the top surface of the layered structure and on the bottom surface of the substrate elsewhere than right above or below the dislocation-concentrated region. In a portion of the top surface of the layered structure and in a portion of the bottom surface of the substrate right above and below the dislocation-concentrated region, dielectric layers may be formed to prevent the electrodes from making contact with those regions.Type: ApplicationFiled: August 13, 2004Publication date: March 3, 2005Applicants: SHARP KABUSHIKI KAISHA, SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Kunihiro Takatani, Shigetoshi Ito, Takayuki Yuasa, Mototaka Taneya, Kensaku Motoki
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Patent number: 6855570Abstract: A compound semiconductor laser of a III group nitride semiconductor of the present invention includes a first cladding layer 104 of a first conduction type formed on a substrate 101, an active layer 106 formed on the first cladding layer, a second cladding layer 108 of a second conduction type formed on the active layer 106, and a buried layer 110 formed on the second cladding layer 108, the buried layer having an opening portion for constricting a current in a selected region of the active layer, wherein an upper portion of the second cladding layer 108 has a ridge portion, the ridge portion residing in the opening portion of the buried layer 110, and the buried layer 110 does not substantially absorb light output from the active layer 106, and the buried layer has a refractive index which is approximately identical with that of the second cladding layer 108.Type: GrantFiled: June 18, 2003Date of Patent: February 15, 2005Assignee: Sharp Kabushiki KaishaInventor: Kunihiro Takatani
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Patent number: 6812496Abstract: A nitride semiconductor laser device using a group III nitride semiconductor also as a substrate offers excellent operation characteristics and a long laser oscillation life. In a layered structure of a group III nitride semiconductor formed on a GaN substrate, a laser optical waveguide region is formed elsewhere than right above a dislocation-concentrated region extending so as to vertically penetrate the substrate, and electrodes are formed on the top surface of the layered structure and on the bottom surface of the substrate elsewhere than right above or below the dislocation-concentrated region. In a portion of the top surface of the layered structure and in a portion of the bottom surface of the substrate right above and below the dislocation-concentrated region, dielectric layers may be formed to prevent the electrodes from making contact with those regions.Type: GrantFiled: December 31, 2002Date of Patent: November 2, 2004Assignees: Sharp Kabushiki Kaisha, Sumitomo Electric Industries, Ltd.Inventors: Kunihiro Takatani, Shigetoshi Ito, Takayuki Yuasa, Mototaka Taneya, Kensaku Motoki
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Publication number: 20030206567Abstract: A compound semiconductor laser of a III group nitride semiconductor of the present invention includes a first cladding layer 104 of a first conduction type formed on a substrate 101, an active layer 106 formed on the first cladding layer, a second cladding layer 108 of a second conduction type formed on the active layer 106, and a buried layer 110 formed on the second cladding layer 108, the buried layer having an opening portion for constricting a current in a selected region of the active layer, wherein an upper portion of the second cladding layer 108 has a ridge portion, the ridge portion residing in the opening portion of the buried layer 110, and the buried layer 110 does not substantially absorb light output from the active layer 106, and the buried layer has a refractive index which is approximately identical with that of the second cladding layer 108.Type: ApplicationFiled: June 18, 2003Publication date: November 6, 2003Inventor: Kunihiro Takatani