Patents by Inventor Yohei Wakai
Yohei Wakai 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: 10381516Abstract: A semiconductor light emitting device which includes at least one concave on a light extraction surface opposite to a surface on which a semiconductor stack comprising a light emitting layer between a n-type semiconductor layer and a p-type semiconductor layer is mounted. The concave has not less than two slopes each having a different slope angle in a direction that a diameter of the concave becomes narrower toward a bottom of the concave from an opening of the concave and a slope having a gentle slope angle is provided with irregularities and a slope having a steep slope angle is a flat surface.Type: GrantFiled: July 21, 2016Date of Patent: August 13, 2019Assignee: NICHIA CORPORATIONInventors: Yohei Wakai, Masahiko Onishi
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Patent number: 9559253Abstract: A method of manufacturing a nitride semiconductor element includes preparing a wafer having a nitride semiconductor layer which includes p-type dopants, forming an altered portion by condensing laser beam on the wafer, and after the forming an altered portion, forming a p-type nitride semiconductor layer by subjecting the wafer to annealing.Type: GrantFiled: October 29, 2014Date of Patent: January 31, 2017Assignee: NICHIA CORPORATIONInventors: Junya Narita, Yohei Wakai, Kazuto Okamoto, Mizuki Nishioka
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Patent number: 9525103Abstract: The sapphire substrate has a principal surface for growing a nitride semiconductor to form a nitride semiconductor light emitting device and comprising a plurality of projections of the principal surface, wherein an outer periphery of a bottom surface of each of the projections has at least one depression. This depression is in the horizontal direction. The plurality of projections are arranged so that a straight line passes through the inside of at least any one of projections when the straight line is drawn at any position in any direction in a plane including the bottom surfaces of the plurality of projections.Type: GrantFiled: June 9, 2015Date of Patent: December 20, 2016Assignee: NICHIA CORPORATIONInventors: Junya Narita, Takuya Okada, Yohei Wakai, Yoshiki Inoue, Naoya Sako, Katsuyoshi Kadan
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Publication number: 20160329465Abstract: A semiconductor light emitting device which includes at least one concave on a light extraction surface opposite to a surface on which a semiconductor stack comprising a light emitting layer between a n-type semiconductor layer and a p-type semiconductor layer is mounted. The concave has not less than two slopes each having a different slope angle in a direction that a diameter of the concave becomes narrower toward a bottom of the concave from an opening of the concave and a slope having a gentle slope angle is provided with irregularities and a slope having a steep slope angle is a flat surface.Type: ApplicationFiled: July 21, 2016Publication date: November 10, 2016Inventors: Yohei WAKAI, Masahiko ONISHI
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Patent number: 9490393Abstract: A semiconductor light emitting device which includes at least one concave on a light extraction surface opposite to a surface on which a semiconductor stack comprising a light emitting layer between a n-type semiconductor layer and a p-type semiconductor layer is mounted. The concave has not less than two slopes each having a different slope angle in a direction that a diameter of the concave becomes narrower toward a bottom of the concave from an opening of the concave and a slope having a gentle slope angle is provided with irregularities and a slope having a steep slope angle is a flat surface.Type: GrantFiled: September 17, 2009Date of Patent: November 8, 2016Assignee: NICHIA CORPORATIONInventors: Yohei Wakai, Masahiko Onishi
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Patent number: 9159868Abstract: A semiconductor light emitting device having high reliability and excellent light distribution characteristics can be provided with an n-electrode arranged on a light extraction surface on the side opposite to the surface whereupon a semiconductor stack is mounted on a substrate. A plurality of convexes are arranged on a first convex region and a second convex region on the light extraction surface. The second convex region adjoins the interface between the n-electrode and the semiconductor stack, between the first convex region and the n-electrode. The base end of the first convex arranged in the first convex region is positioned closer to a light emitting layer than the interface between the n-electrode and the semiconductor stack, and the base end of the second convex arranged in the second convex region is positioned closer to the interface between the n-electrode and the semiconductor stack than the base end of the first convex.Type: GrantFiled: August 27, 2014Date of Patent: October 13, 2015Assignee: NICHIA CORPORATIONInventors: Yohei Wakai, Hiroaki Matsumura, Kenji Oka
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Publication number: 20150270443Abstract: The sapphire substrate has a principal surface for growing a nitride semiconductor to form a nitride semiconductor light emitting device and comprising a plurality of projections of the principal surface, wherein an outer periphery of a bottom surface of each of the projections has at least one depression. This depression is in the horizontal direction. The plurality of projections are arranged so that a straight line passes through the inside of at least any one of projections when the straight line is drawn at any position in any direction in a plane including the bottom surfaces of the plurality of projections.Type: ApplicationFiled: June 9, 2015Publication date: September 24, 2015Applicant: NICHIA CORPORATIONInventors: Junya NARITA, Takuya OKADA, Yohei WAKAI, Yoshiki INOUE, Naoya SAKO, Katsuyoshi KADAN
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Patent number: 9070814Abstract: The sapphire substrate has a principal surface for growing a nitride semiconductor to form a nitride semiconductor light emitting device and comprising a plurality of projections of the principal surface, wherein an outer periphery of a bottom surface of each of the projections has at least one depression. This depression is in the horizontal direction. The plurality of projections are arranged so that a straight line passes through the inside of at least any one of projections when the straight line is drawn at any position in any direction in a plane including the bottom surfaces of the plurality of projections.Type: GrantFiled: June 25, 2014Date of Patent: June 30, 2015Assignee: NICHIA CORPORATIONInventors: Junya Narita, Takuya Okada, Yohei Wakai, Yoshiki Inoue, Naoya Sako, Katsuyoshi Kadan
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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: 20150118775Abstract: A method of manufacturing a nitride semiconductor element includes preparing a wafer having a nitride semiconductor layer which includes p-type dopants, forming an altered portion by condensing laser beam on the wafer, and after the forming an altered portion, forming a p-type nitride semiconductor layer by subjecting the wafer to annealing.Type: ApplicationFiled: October 29, 2014Publication date: April 30, 2015Applicant: NICHIA CORPORATIONInventors: Junya NARITA, Yohei WAKAI, Kazuto OKAMOTO, Mizuki NISHIOKA
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Patent number: 9012936Abstract: The sapphire substrate has a principal surface for growing a nitride semiconductor to form a nitride semiconductor light emitting device and comprising a plurality of projections of the principal surface, wherein an outer periphery of a bottom surface of each of the projections has at least one depression. This depression is in the horizontal direction. The plurality of projections are arranged so that a straight line passes through the inside of at least any one of projections when the straight line is drawn at any position in any direction in a plane including the bottom surfaces of the plurality of projections.Type: GrantFiled: August 5, 2011Date of Patent: April 21, 2015Assignee: Nichia CorporationInventors: Junya Narita, Takuya Okada, Yohei Wakai, Yoshiki Inoue, Naoya Sako, Katsuyoshi Kadan
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Publication number: 20140370630Abstract: A semiconductor light emitting device having high reliability and excellent light distribution characteristics can be provided with an n-electrode arranged on a light extraction surface on the side opposite to the surface whereupon a semiconductor stack is mounted on a substrate. A plurality of convexes are arranged on a first convex region and a second convex region on the light extraction surface. The second convex region adjoins the interface between the n-electrode and the semiconductor stack, between the first convex region and the n-electrode. The base end of the first convex arranged in the first convex region is positioned closer to a light emitting layer than the interface between the n-electrode and the semiconductor stack, and the base end of the second convex arranged in the second convex region is positioned closer to the interface between the n-electrode and the semiconductor stack than the base end of the first convex.Type: ApplicationFiled: August 27, 2014Publication date: December 18, 2014Inventors: Yohei WAKAI, Hiroaki MATSUMURA, Kenji OKA
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Patent number: 8883529Abstract: A semiconductor light emitting device having high reliability and excellent light distribution characteristics can be provided with an n-electrode arranged on a light extraction surface on the side opposite to the surface whereupon a semiconductor stack is mounted on a substrate. A plurality of convexes are arranged on a first convex region and a second convex region on the light extraction surface. The second convex region adjoins the interface between the n-electrode and the semiconductor stack, between the first convex region and the n-electrode. The base end of the first convex arranged in the first convex region is positioned closer to a light emitting layer than the interface between the n-electrode and the semiconductor stack, and the base end of the second convex arranged in the second convex region is positioned closer to the interface between the n-electrode and the semiconductor stack than the base end of the first convex.Type: GrantFiled: September 9, 2013Date of Patent: November 11, 2014Assignee: Nichia CorporationInventors: Yohei Wakai, Hiroaki Matsumura, Kenji Oka
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Publication number: 20140306265Abstract: The sapphire substrate has a principal surface for growing a nitride semiconductor to form a nitride semiconductor light emitting device and comprising a plurality of projections of the principal surface, wherein an outer periphery of a bottom surface of each of the projections has at least one depression. This depression is in the horizontal direction. The plurality of projections are arranged so that a straight line passes through the inside of at least any one of projections when the straight line is drawn at any position in any direction in a plane including the bottom surfaces of the plurality of projections.Type: ApplicationFiled: June 25, 2014Publication date: October 16, 2014Inventors: Junya NARITA, Takuya Okada, Yohei Wakai, Yoshiki Inoue, Naoya Sako, Katsuyoshi Kadan
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Patent number: 8847262Abstract: A sapphire substrate having a principal surface for growing a nitride semiconductor to form a nitride semiconductor light emitting device comprises a plurality of projections on the principal surface. Each of the projections has a bottom that has a substantially polygonal shape. Each side of the bottom of the projections has a depression in its center. Vertexes of the bottoms of the respective projections extend in a direction that is within a range of ±10 degrees of a direction that is rotated counter-clockwise by 30 degrees from a crystal axis “a” of the sapphire substrate.Type: GrantFiled: March 14, 2013Date of Patent: September 30, 2014Assignee: Nichia CorporationInventors: Junya Narita, Takuya Okada, Yohei Wakai, Yoshiki Inoue, Naoya Sako, Katsuyoshi Kadan
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Patent number: 8847263Abstract: A sapphire substrate having a principal surface for growing a nitride semiconductor to form a nitride semiconductor light emitting device comprises a plurality of projections on the principal surface. Each of the projections has a bottom that has a substantially polygonal shape. Each side of the bottom of the projections has a depression in its center. Vertexes of the bottoms of the respective projections extend in a direction that is within a range of ±10 degrees of a direction that is rotated clockwise by 30 degrees from a crystal axis “a” of the sapphire substrate.Type: GrantFiled: March 14, 2013Date of Patent: September 30, 2014Assignee: Nichia CorporationInventors: Junya Narita, Takuya Okada, Yohei Wakai, Yoshiki Inoue, Naoya Sako, Katsuyoshi Kadan
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Patent number: 8779463Abstract: A sapphire substrate having one principal surface on which a nitride semiconductor is grown, said one principal surface having a plurality of projections. Each of the projections has a generally pyramidal shape with a not truncated, more sharpened tip and with an inclined surface composed of a crystal growth-suppression surface that lessens or suppresses the growth of the nitride semiconductor and also which has an inclination change line at which an inclination angle discontinuously varies.Type: GrantFiled: June 24, 2011Date of Patent: July 15, 2014Assignee: Nichia CorporationInventors: Junya Narita, Yohei Wakai, Takayoshi Wakaki
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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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Publication number: 20140038328Abstract: A semiconductor light emitting device having high reliability and excellent light distribution characteristics can be provided with an n-electrode arranged on a light extraction surface on the side opposite to the surface whereupon a semiconductor stack is mounted on a substrate. A plurality of convexes are arranged on a first convex region and a second convex region on the light extraction surface. The second convex region adjoins the interface between the n-electrode and the semiconductor stack, between the first convex region and the n-electrode. The base end of the first convex arranged in the first convex region is positioned closer to a light emitting layer than the interface between the n-electrode and the semiconductor stack, and the base end of the second convex arranged in the second convex region is positioned closer to the interface between the n-electrode and the semiconductor stack than the base end of the first convex.Type: ApplicationFiled: September 9, 2013Publication date: February 6, 2014Applicant: Nichia CorporationInventors: Yohei WAKAI, Hiroaki MATSUMURA, Kenji OKA