Patents by Inventor Yukio Narukawa
Yukio Narukawa 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: 9054271Abstract: A light emitting element having a recess-protrusion structure on a substrate is provided. A semiconductor light emitting element 100 has a light emitting structure of a semiconductor 20 on a first main surface of a substrate 10. The first main surface of the substrate 10 has substrate protrusion portion 11, the bottom surface 14 of each protrusion is wider than the top surface 13 thereof in a cross-section, or the top surface 13 is included in the bottom surface 14 in a top view of the substrate. The bottom surface 14 has an approximately polygonal shape, and the top surface 13 has an approximately circular or polygonal shape with more sides than that of the bottom surface 14.Type: GrantFiled: January 10, 2014Date of Patent: June 9, 2015Assignee: NICHIA CORPORATIONInventors: Shunsuke Minato, Junya Narita, Yohei Wakai, Yukio Narukawa, Motokazu Yamada
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Publication number: 20140124805Abstract: A light emitting element having a recess-protrusion structure on a substrate is provided. A semiconductor light emitting element 100 has a light emitting structure of a semiconductor 20 on a first main surface of a substrate 10. The first main surface of the substrate 10 has substrate protrusion portion 11, the bottom surface 14 of each protrusion is wider than the top surface 13 thereof in a cross-section, or the top surface 13 is included in the bottom surface 14 in a top view of the substrate. The bottom surface 14 has an approximately polygonal shape, and the top surface 13 has an approximately circular or polygonal shape with more sides than that of the bottom surface 14.Type: ApplicationFiled: January 10, 2014Publication date: May 8, 2014Applicant: NICHIA CORPORATIONInventors: Shunsuke MINATO, Junya NARITA, Yohei WAKAI, Yukio NARUKAWA, Motokazu YAMADA
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Patent number: 8686457Abstract: A light emitting element having a recess-protrusion structure on a substrate is provided. A semiconductor light emitting element 100 has a light emitting structure of a semiconductor 20 on a first main surface of a substrate 10. The first main surface of the substrate 10 has substrate protrusion portion 11, the bottom surface 14 of each protrusion is wider than the top surface 13 thereof in a cross-section, or the top surface 13 is included in the bottom surface 14 in a top view of the substrate. The bottom surface 14 has an approximately polygonal shape, and the top surface 13 has an approximately circular or polygonal shape with more sides than that of the bottom surface 14.Type: GrantFiled: February 5, 2013Date of Patent: April 1, 2014Assignee: Nichia CorporationInventors: Shunsuke Minato, Junya Narita, Yohei Wakai, Yukio Narukawa, Motokazu Yamada
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Patent number: 8394652Abstract: A light emitting element having a recess-protrusion structure on a substrate is provided. A semiconductor light emitting element 100 has a light emitting structure of a semiconductor 20 on a first main surface of a substrate 10. The first main surface of the substrate 10 has substrate protrusion portion 11, the bottom surface 14 of each protrusion is wider than the top surface 13 thereof in a cross-section, or the top surface 13 is included in the bottom surface 14 in a top view of the substrate. The bottom surface 14 has an approximately polygonal shape, and the top surface 13 has an approximately circular or polygonal shape with more sides than that of the bottom surface 14.Type: GrantFiled: June 15, 2010Date of Patent: March 12, 2013Assignee: Nichia CorporationInventors: Shunsuke Minato, Junya Narita, Yohei Wakai, Yukio Narukawa, Motokazu Yamada
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Patent number: 8076694Abstract: It is an object of the present invention to provide a nitride semiconductor element, which uses Si as a substrate, and whose voltage in the forward direction (Vf) is lower than in the prior art. In the nitride semiconductor element which has a nitride semiconductor layer over an Si substrate, at least a portion of the Si substrate and the nitride semiconductor layer are included in an current pass region, and the electrical conductivity type of the current pass region on the Si substrate is p-type. Furthermore, in the nitride semiconductor element which has a nitride semiconductor layer over an Si substrate, at least a portion of the Si substrate and the nitride semiconductor layer are included in an current pass region, and the majority carriers of the current pass region of the Si substrate are holes.Type: GrantFiled: April 28, 2006Date of Patent: December 13, 2011Assignee: Nichia CorporationInventors: Yukio Narukawa, Tomotsugu Mitani, Masatsugu Ichikawa, Akira Kitano, Takao Misaki
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Publication number: 20100255621Abstract: A light emitting element having a recess-protrusion structure on a substrate is provided. A semiconductor light emitting element 100 has a light emitting structure of a semiconductor 20 on a first main surface of a substrate 10. The first main surface of the substrate 10 has substrate protrusion portion 11, the bottom surface 14 of each protrusion is wider than the top surface 13 thereof in a cross-section, or the top surface 13 is included in the bottom surface 14 in a top view of the substrate. The bottom surface 14 has an approximately polygonal shape, and the top surface 13 has an approximately circular or polygonal shape with more sides than that of the bottom surface 14.Type: ApplicationFiled: June 15, 2010Publication date: October 7, 2010Inventors: Shunsuke MINATO, Junya Narita, Yohei Wakai, Yukio Narukawa, Motokazu Yamada
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Patent number: 7781790Abstract: A semiconductor light emitting element having a semiconductor light emitting structure on a first main surface of a substrate, wherein the first main surface of the substrate has a substrate protrusion portion thereon, wherein a bottom surface of a protrusion is wider than a top surface thereof in a cross section of the substrate and the top surface is included in the bottom surface in a top view of the substrate, the bottom surface has an approximately polygonal shape which has a convex portion on each constituent side of the bottom surface, and the top surface has an approximately circular shape.Type: GrantFiled: December 20, 2007Date of Patent: August 24, 2010Assignee: Nichia CorporationInventors: Shunsuke Minato, Junya Narita, Yohei Wakai, Yukio Narukawa, Motokazu Yamada
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Publication number: 20080303042Abstract: A light emitting element having a recess-protrusion structure on a substrate is provided. A semiconductor light emitting element 100 has a light emitting structure of a semiconductor 20 on a first main surface of a substrate 10. The first main surface of the substrate 10 has substrate protrusion portion 11, the bottom surface 14 of each protrusion is wider than the top surface 13 thereof in a cross-section, or the top surface 13 is included in the bottom surface 14 in a top view of the substrate. The bottom surface 14 has an approximately polygonal shape, and the top surface 13 has an approximately circular or polygonal shape with more sides than that of the bottom surface 14.Type: ApplicationFiled: December 20, 2007Publication date: December 11, 2008Applicant: NICHIA CORPORATIONInventors: Shunsuke Minato, Junya Narita, Yohei Wakai, Yukio Narukawa, Motokazu Yamada
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Patent number: 7348600Abstract: The invention provides a nitride semiconductor light-emitting device comprising gallium nitride semiconductor layers formed on a heterogeneous substrate, wherein light emissions having different light emission wavelengths or different colors are given out of the same active layer. Recesses 106 are formed by etching in the first electrically conductive (n) type semiconductor layer 102 formed on a substrate with a buffer layer interposed between them. Each recess is exposed in plane orientations different from that of the major C plane. For instance, the plane orientation of the A plane is exposed. An active layer is grown and joined on the plane of this plane orientation, on the bottom of the recess and the C-plane upper surface of a non-recess portion. The second electrically conductive (p) type semiconductor layer is formed on the inner surface of the recess.Type: GrantFiled: October 20, 2003Date of Patent: March 25, 2008Assignees: Nichia Corporation, California Institute of TechnologyInventors: Yukio Narukawa, Isamu Niki, Axel Scherer, Koichi Okamoto, Yoichi Kawakami, Mitsuru Funato, Shigeo Fujita
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Patent number: 7345297Abstract: A semiconductor device includes an active layer, an n-side contact layer, and a p-side contact layer. The nitride semiconductor device includes at least a first n-side layer, a second n-side layer, a third n-side layer and a fourth n-side layer formed in this order from the n-side contact layer between the n-side contact layer and the active layer, while at least the second n-side layer and the fourth n-side layer each contain an n-type impurity, and the concentration of the n-type impurity in at least the second n-side layer and the fourth n-side layer is higher than the concentration of the n-type impurity in the first n-side layer and the third n-side layer.Type: GrantFiled: February 8, 2005Date of Patent: March 18, 2008Assignee: Nichia CorporationInventors: Masahito Yamazoe, Masayuki Eguchi, Hiroki Narimatsu, Kazunori Sasakura, Yukio Narukawa
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Publication number: 20060243988Abstract: It is an object of the present invention to provide a nitride semiconductor element, which uses Si as a substrate, and whose voltage in the forward direction (Vf) is lower than in the prior art. In the nitride semiconductor element which has a nitride semiconductor layer over an Si substrate, at least a portion of the Si substrate and the nitride semiconductor layer are included in an current pass region, and the electrical conductivity type of the current pass region on the Si substrate is p-type. Furthermore, in the nitride semiconductor element which has a nitride semiconductor layer over an Si substrate, at least a portion of the Si substrate and the nitride semiconductor layer are included in an current pass region, and the majority carriers of the current pass region of the Si substrate are holes.Type: ApplicationFiled: April 28, 2006Publication date: November 2, 2006Inventors: Yukio Narukawa, Tomotsugu Mitani, Masatsugu Ichikawa, Akira Kitano, Takao Misaki
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Publication number: 20050205881Abstract: In light emitting devices of the prior art, there has been such cases that the device characteristics are insufficient, such as uneven forward voltage (Vf) within a wafer and variability of Vf with the lapse of driving time. The present invention is directed to a nitride semiconductor device comprising an active layer provided between an n-type contact layer that has an n electrode and a p-type contact layer that has a p electrode. The nitride semiconductor device comprises at least a first n-side layer, a second n-side layer, a third n-side layer and a fourth n-side layer formed in this order from the n-type contact layer between the n-type contact layer and the active layer, while at least the second n-side layer and the fourth n-side layer each have n-type impurity, and the concentration of the n-type impurity in at least the second n-side layer and the fourth n-side layer is higher than the concentration of the n-type impurity in the first n-side layer and the third n-side layer.Type: ApplicationFiled: February 8, 2005Publication date: September 22, 2005Applicant: NICHIA CORPORATIONInventors: Masahito Yamazoe, Masayuki Eguchi, Hiroki Narimatsu, Kazunori Sasakura, Yukio Narukawa
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Publication number: 20050082544Abstract: The invention provides a nitride semiconductor light-emitting device comprising gallium nitride semiconductor layers formed on a heterogeneous substrate, wherein light emissions having different light emission wavelengths or different colors are given out of the same active layer. Recesses 106 are formed by etching in the first electrically conductive (n) type semiconductor layer 102 formed on a substrate with a buffer layer interposed between them. Each recess is exposed in plane orientations different from that of the major C plane. For instance, the plane orientation of the A plane is exposed. An active layer is grown and joined on the plane of this plane orientation, on the bottom of the recess and the C-plane upper surface of a non-recess portion. The second electrically conductive (p) type semiconductor layer is formed on the inner surface of the recess.Type: ApplicationFiled: October 20, 2003Publication date: April 21, 2005Inventors: Yukio Narukawa, Isamu Niki, Axel Scherer, Koichi Okamoto, Yoichi Kawakami, Mitsuru Funato, Shigeo Fujita
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Patent number: 6876009Abstract: The luminous efficiency of a nitride semiconductor device comprising a gallium nitride-based semiconductor layer formed on a dissimilar substrate is improved. An n-type layer formed on the substrate with a buffer layer interposed between them comprises a portion of recess-and-projection shape in section as viewed in the longitudinal direction. Active layers are formed on at least two side faces of the projection with the recess located between them. A p-type layer is formed within the recess. An insulating layer is formed on the top face of the projection, and on the bottom face of the recess. The n-type layer is provided with an n-electrode while the p-type layer is provided with a p-electrode contact layer. As viewed from the p-type layer formed within the recess in the gallium nitride-based semiconductor layer, the active layer and the n-type layer are located in an opposite relation to each other.Type: GrantFiled: December 9, 2002Date of Patent: April 5, 2005Assignee: Nichia CorporationInventors: Yukio Narukawa, Isamu Niki, Axel Scherer, Koichi Okamoto, Yoichi Kawakami, Mitsuru Funato, Shigeo Fujita
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Publication number: 20040108513Abstract: The luminous efficiency of a nitride semiconductor device comprising a gallium nitride-based semiconductor layer formed on a dissimilar substrate is improved. An n-type layer formed on the substrate with a buffer layer interposed between them comprises a portion of recess-and-projection shape in section as viewed in the longitudinal direction. Active layers are formed on at least two side faces of the projection with the recess located between them. A p-type layer is formed within the recess. An insulating layer is formed on the top face of the projection, and on the bottom face of the recess. The n-type layer is provided with an n-electrode while the p-type layer is provided with a p-electrode contact layer. As viewed from the p-type layer formed within the recess in the gallium nitride-based semiconductor layer, the active layer and the n-type layer are located in an opposite relation to each other.Type: ApplicationFiled: December 9, 2002Publication date: June 10, 2004Inventors: Yukio Narukawa, Isamu Niki, Axel Scherer, Koichi Okamoto, Yoichi Kawakami, Mitsuru Funato, Shigeo Fujita