Patents by Inventor Noritaka Niwa
Noritaka Niwa 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: 11961942Abstract: The semiconductor light-emitting element includes an n-type semiconductor layer; an active layer on the n-type semiconductor layer; a p-type semiconductor layer on the active layer; a p-side contact electrode in contact with the p-type semiconductor layer; a p-side current diffusion layer on the p-side contact electrode; an n-side contact electrode in contact with the n-type semiconductor layer; and an n-side current diffusion layer that includes a first current diffusion layer on the n-side contact electrode, and a second current diffusion layer on the first current diffusion layer, and including a TiN layer. A height difference between upper surfaces of the p-side contact electrode and the first current diffusion layer is 100 nm or smaller; and a height difference between upper surfaces of the p-side current diffusion layer and the second current diffusion layer is 100 nm or smaller.Type: GrantFiled: March 22, 2023Date of Patent: April 16, 2024Assignee: NIKKISO CO., LTD.Inventors: Noritaka Niwa, Tetsuhiko Inazu
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Publication number: 20230420603Abstract: A method of manufacturing a semiconductor light-emitting element includes: forming an active layer of an AlGaN-based semiconductor material on an n-type semiconductor layer of an n-type AlGaN-based semiconductor material; forming a p-type semiconductor layer on the active layer; removing a portion of the p-type semiconductor layer and the active layer by dry etching to expose an upper surface of the n-type semiconductor layer; treating the upper surface of the n-type semiconductor layer with a plasma in an atmosphere including an N2 gas and an NH3 gas; and forming a n-side contact electrode on the upper surface of the n-type semiconductor layer treated with the plasma.Type: ApplicationFiled: June 23, 2023Publication date: December 28, 2023Inventors: Noritaka NIWA, Tetsuhiko INAZU
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Publication number: 20230352631Abstract: A semiconductor light-emitting element includes: a first protective layer made of SiO2 and a second protective layer made of SiNx. The first protective layer covers the n-type semiconductor layer, the active layer, the p-type semiconductor layer, the p-side contact electrode, the n-side contact electrode, the p-side current diffusion layer, and the n-side current diffusion layer in portions different from portions of the first p-side pad opening and the first n-side pad opening. The second protective layer covers the first protective layer in a portion different from portions of the second p-side pad opening and the second n-side pad opening, covers an inner circumferential surface of the first protective layer that defines the first p-side pad opening, and covers an inner circumferential surface of the first protective layer that defines the first n-side pad opening.Type: ApplicationFiled: April 28, 2023Publication date: November 2, 2023Inventors: Noritaka NIWA, Tetsuhiko INAZU
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Patent number: 11777060Abstract: A semiconductor light-emitting element includes: an n-type semiconductor layer made of an n-type AlGaN-based semiconductor material; an active layer made of an AlGaN-based semiconductor material provided on the n-type semiconductor layer; a p-type semiconductor layer provided on the active layer; a p-side contact electrode made of Rh and in contact with the p-type semiconductor layer; a p-side electrode covering layer made of TiN that covers the p-side contact electrode; a dielectric protective layer that covers the n-type semiconductor layer, the active layer, the p-type semiconductor layer, and the p-side electrode covering layer; and a p-side pad electrode in contact with the p-side electrode covering layer in a p-side opening that extends through the dielectric protective layer on the p-side contact electrode.Type: GrantFiled: June 8, 2022Date of Patent: October 3, 2023Assignee: NIKKISO CO., LTD.Inventors: Noritaka Niwa, Tetsuhiko Inazu
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Patent number: 11769860Abstract: The semiconductor light-emitting element has an n-type semiconductor layer; an active layer provided on a first upper surface of the n-type semiconductor layer; a p-type semiconductor layer provided on the active layer; a p-side contact electrode provided in contact with the upper surface of the p-type semiconductor layer; a p-side current diffusion layer provided on the p-side contact electrode in a region narrower than a formation region of the p-side contact electrode; a p-side pad electrode provided on the p-side current diffusion layer; an n-side contact electrode provided in contact with a second upper surface of the n-type semiconductor layer; an n-side current diffusion layer provided on the n-side contact electrode over a region wider than a formation region of the n-side contact electrode, and including a TiN layer; and an n-side pad electrode provided on the n-side current diffusion layer.Type: GrantFiled: April 29, 2021Date of Patent: September 26, 2023Assignee: NIKKISO CO., LTD.Inventors: Noritaka Niwa, Tetsuhiko Inazu
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Publication number: 20230238486Abstract: The semiconductor light-emitting element includes an n-type semiconductor layer; an active layer on the n-type semiconductor layer; a p-type semiconductor layer on the active layer; a p-side contact electrode in contact with the p-type semiconductor layer; a p-side current diffusion layer on the p-side contact electrode; an n-side contact electrode in contact with the n-type semiconductor layer; and an n-side current diffusion layer that includes a first current diffusion layer on the n-side contact electrode, and a second current diffusion layer on the first current diffusion layer, and including a TiN layer. A height difference between upper surfaces of the p-side contact electrode and the first current diffusion layer is 100 nm or smaller; and a height difference between upper surfaces of the p-side current diffusion layer and the second current diffusion layer is 100 nm or smaller.Type: ApplicationFiled: March 22, 2023Publication date: July 27, 2023Inventors: Noritaka NIWA, Tetsuhiko INAZU
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Publication number: 20230231077Abstract: A semiconductor light-emitting element includes: an n-type semiconductor layer made of an n-type AlGaN-based semiconductor material; an active layer provided on a first upper surface of the n-type semiconductor layer and made of an AlGaN-based semiconductor material; a p-type semiconductor layer provided on the active layer; an n-side contact electrode that includes a Ti layer in contact with a second upper surface of the n-type semiconductor layer, an Al layer provided on the Ti layer, and a nitride layer that covers the Al layer. The nitride layer includes a first portion made of TiN and a second portion containing TiAlN.Type: ApplicationFiled: January 18, 2023Publication date: July 20, 2023Inventors: Noritaka NIWA, Tetsuhiko INAZU
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Patent number: 11705538Abstract: A semiconductor light emitting element includes: an n-type semiconductor layer made of an n-type aluminum gallium nitride (AlGaN)-based semiconductor material provided on a substrate; an active layer made of an AlGaN-based semiconductor material provided on the n-type semiconductor layer; a p-type semiconductor layer provided on the active layer; and a covering layer made of a dielectric material that covers the n-type semiconductor layer, the active layer, and the p-type semiconductor layer. Each of the active layer and the p-type semiconductor layer has a sloped surface that is sloped at a first angle with respect to the substrate and is covered by the covering layer. The n-type semiconductor layer has a sloped surface that is sloped at a second angle larger than the first angle with respect to the substrate and is covered by the covering layer.Type: GrantFiled: November 23, 2021Date of Patent: July 18, 2023Assignee: NIKKISO CO., LTD.Inventors: Noritaka Niwa, Tetsuhiko Inazu
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Publication number: 20230223499Abstract: A semiconductor light-emitting element includes: an n-type semiconductor layer; an active layer; a p-side contact electrode made of Rh; a p-side electrode covering layer made of Ti or TiN that covers the p-side contact electrode; a first protective layer made of SiO2 or SiON that covers an upper surface and a side surface of the p-side electrode covering layer in a portion different from that of a first p-side pad opening; a second protective layer made of Al2O3 that covers the first protective layer, a side surface of a p-side semiconductor layer, and a side surface of the active layer in a portion different from that of a second p-side pad opening; and a p-side pad electrode that is in contact with the p-side electrode covering layer in the first p-side pad opening and the second p-side pad opening.Type: ApplicationFiled: March 7, 2023Publication date: July 13, 2023Inventors: Noritaka NIWA, Tetsuhiko INAZU
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Publication number: 20230155081Abstract: A semiconductor light-emitting element has an n-type semiconductor layer arranged on a base layer, and is made of an n-type AlGaN-based semiconductor material; an active layer arranged on the n-type semiconductor layer, and is made of an AlGaN-based semiconductor material; a p-type semiconductor layer arranged on the active layer; a p-side contact electrode that contacts the top face of the p-type semiconductor layer; a dielectric protective layer that covers the p-side contact electrode, contacts the top face of the p-type semiconductor layer, and is made of SiO2; and a dielectric cover layer that contacts the individual side faces of the active layer and the p-type semiconductor layer, contacts the top face of the p-type semiconductor layer, covers the dielectric protective layer, and is made of Al2O3.Type: ApplicationFiled: November 7, 2022Publication date: May 18, 2023Inventors: Noritaka NIWA, Tetsuhiko INAZU
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Patent number: 11652191Abstract: The semiconductor light-emitting element includes an n-type semiconductor layer; an active layer on the n-type semiconductor layer; a p-type semiconductor layer on the active layer; a p-side contact electrode in contact with the p-type semiconductor layer; a p-side current diffusion layer on the p-side contact electrode; an n-side contact electrode in contact with the n-type semiconductor layer; and an n-side current diffusion layer that includes a first current diffusion layer on the n-side contact electrode, and a second current diffusion layer on the first current diffusion layer, and including a TiN layer. A height difference between upper surfaces of the p-side contact electrode and the first current diffusion layer is 100 nm or smaller; and a height difference between upper surfaces of the p-side current diffusion layer and the second current diffusion layer is 100 nm or smaller.Type: GrantFiled: April 29, 2021Date of Patent: May 16, 2023Assignee: NIKKISO CO., LTD.Inventors: Noritaka Niwa, Tetsuhiko Inazu
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Patent number: 11626540Abstract: A semiconductor light-emitting element includes: an n-type semiconductor layer; an active layer; a p-side contact electrode made of Rh; a p-side electrode covering layer made of Ti or TiN that covers the p-side contact electrode; a first protective layer made of SiO2 or SiON that covers an upper surface and a side surface of the p-side electrode covering layer in a portion different from that of a first p-side pad opening; a second protective layer made of Al2O3 that covers the first protective layer, a side surface of a p-side semiconductor layer, and a side surface of the active layer in a portion different from that of a second p-side pad opening; and a p-side pad electrode that is in contact with the p-side electrode covering layer in the first p-side pad opening and the second p-side pad opening.Type: GrantFiled: September 4, 2020Date of Patent: April 11, 2023Assignee: NIKKISO CO., LTD.Inventors: Noritaka Niwa, Tetsuhiko Inazu
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Patent number: 11575068Abstract: A method of manufacturing a semiconductor light emitting element includes: forming an active layer made of an aluminum gallium nitride (AlGaN)-based semiconductor material on an n-type clad layer made of an n-type AlGaN-based semiconductor material; removing a portion of each of the active layer and the n-type clad layer by dry etching to expose a portion of the n-type clad layer; forming a first metal layer including titanium (Ti) on an exposed surface of the n-type clad layer; forming a second metal layer including aluminum (Al) on the first metal layer; and forming an n-side electrode by annealing the first metal layer and the second metal layer at a temperature not lower than 560° C. and not higher than 650° C. A film density of the second metal layer before the annealing is lower than 2.7 g/cm3.Type: GrantFiled: April 24, 2020Date of Patent: February 7, 2023Assignee: NIKKISO CO., LTD.Inventors: Noritaka Niwa, Tetsuhiko Inazu, Haruhito Sakai
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Publication number: 20230035901Abstract: A semiconductor light-emitting element includes: an n-type semiconductor layer made of an n-type AlGaN-based semiconductor material; an active layer provided on the n-type semiconductor layer and made of an AlGaN-based semiconductor material; a p-type semiconductor layer provided on the active layer; a p-side contact electrode that includes a Rh layer in contact with an upper surface of the p-type semiconductor layer; and a p-side current diffusion layer that is in contact with an upper surface and a side surface of the p-side contact electrode and includes a TiN layer, a Ti layer, a Rh layer, and a TiN layer stacked successively. A film density of the Rh layer included in the p-side contact electrode is larger than a film density of the Rh layer included in the p-side current diffusion layer.Type: ApplicationFiled: July 28, 2022Publication date: February 2, 2023Inventors: Noritaka NIWA, Tetsuhiko INAZU, Haruhisa AIDA
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Publication number: 20230034297Abstract: A semiconductor light-emitting element includes: an n-type semiconductor layer made of an n-type AlGaN-based semiconductor material; an active layer provided on the n-type semiconductor layer and made of an AlGaN-based semiconductor material; a p-type semiconductor layer provided on the active layer; a p-side contact electrode that includes a Rh layer in contact with an upper surface of the p-type semiconductor layer; and a p-side current diffusion layer that is in contact with an upper surface and a side surface of the p-side contact electrode and includes a TiN layer, a Ti layer, a Rh layer, and a TiN layer stacked successively. An Ar concentration in the Rh layer included in the p-side contact electrode is smaller than an Ar concentration in the Rh layer included in the p-side current diffusion layer.Type: ApplicationFiled: July 28, 2022Publication date: February 2, 2023Inventors: Natsuki KOJIMA, Tetsuhiko INAZU, Noritaka NIWA
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Publication number: 20230029549Abstract: A semiconductor light-emitting element includes: an n-type semiconductor layer made of an n-type AlGaN-based semiconductor material; an active layer provided on the n-type semiconductor layer and made of an AlGaN-based semiconductor material; a p-type semiconductor layer provided on the active layer; a p-side contact electrode that includes a Rh layer in contact with an upper surface of the p-type semiconductor layer; a p-side electrode covering layer that is in contact with an upper surface and a side surface of the p-side contact electrode and includes a Ti layer, a Rh layer, and a TiN layer stacked successively; a dielectric covering layer that has a connection opening provided on the p-side electrode covering layer and covers the p-side electrode covering layer in a portion different from the connection opening; and a p-side current diffusion layer that connects to the p-side electrode covering layer in the connection opening.Type: ApplicationFiled: July 28, 2022Publication date: February 2, 2023Inventors: Noritaka NIWA, Tetsuhiko INAZU, Haruhisa AIDA
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Patent number: 11489091Abstract: A semiconductor light emitting device includes a light extraction layer having a light extraction surface. The light extraction layer includes: a plurality of cone-shaped parts formed in an array on the light extraction surface, and a plurality of granular parts formed both on a side part of the cone-shaped part and in a space between adjacent cone-shaped parts. A method of manufacturing the semiconductor light emitting device includes: forming a mask having an array pattern on the light extraction layer; and etching the mask and the light extraction layer from above the mask. The etching includes first dry-etching performed until an entirety of the mask is removed and second dry-etching performed to further dry-etch the light extraction layer after the mask is removed.Type: GrantFiled: March 29, 2019Date of Patent: November 1, 2022Assignees: NIKKISO CO., LTD., SCIVAX CORPORATIONInventors: Noritaka Niwa, Tetsuhiko Inazu, Yasumasa Suzaki, Akifumi Nawata, Satoru Tanaka
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Publication number: 20220320375Abstract: A semiconductor light-emitting element includes: an n-type semiconductor layer made of an n-type AlGaN-based semiconductor material; an active layer made of an AlGaN-based semiconductor material provided on the n-type semiconductor layer; a p-type semiconductor layer provided on the active layer; a p-side contact electrode made of Rh and in contact with the p-type semiconductor layer; a p-side electrode covering layer made of TiN that covers the p-side contact electrode; a dielectric protective layer that covers the n-type semiconductor layer, the active layer, the p-type semiconductor layer, and the p-side electrode covering layer; and a p-side pad electrode in contact with the p-side electrode covering layer in a p-side opening that extends through the dielectric protective layer on the p-side contact electrode.Type: ApplicationFiled: June 8, 2022Publication date: October 6, 2022Inventors: Noritaka NIWA, Tetsuhiko INAZU
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Patent number: 11430914Abstract: A semiconductor light emitting device includes a light extraction layer having a light extraction surface. Multiple cone-shaped parts formed in an array are provided on the light extraction surface of the semiconductor light emitting device. A proportion of an area occupied by the multiple cone-shaped parts per a unit area of the light extraction surface is not less than 65% and not more than 95% in a plan view of the light extraction surface, and an aspect ratio h/p defined as a proportion of a height h of the cone-shaped part relative to a distance p between apexes of adjacent cone-shaped parts is not less than 0.3 and not more than 1.0.Type: GrantFiled: December 26, 2019Date of Patent: August 30, 2022Assignee: NIKKISO CO., LTD.Inventors: Noritaka Niwa, Tetsuhiko Inazu, Yasumasa Suzaki, Akifumi Nawata, Satoru Tanaka
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Patent number: 11404606Abstract: A semiconductor light-emitting element is configured to emit ultraviolet light having a wavelength of 320 nm or shorter. Denoting a total area of a principal surface of a substrate as S0, an area on a p-type semiconductor layer in which a p-side contact electrode is formed as S1, an area on an n-type semiconductor layer in which an n-side contact electrode is formed as S2, a reflectivity of the p-side contact electrode for ultraviolet having a wavelength of 280 nm incident from a side of the p-type semiconductor layer as R1, and a reflectivity of the n-side contact electrode for ultraviolet light having a wavelength of 280 nm incident from a side of the n-type semiconductor layer as R2, (S1/S0)×R1+(S2/S0)×R2?0.5, S1>S2, and R1?R2.Type: GrantFiled: June 8, 2020Date of Patent: August 2, 2022Assignee: NIKKISO CO., LTD.Inventors: Tetsuhiko Inazu, Noritaka Niwa