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).

  • Patent number: 11387386
    Abstract: A semiconductor light emitting element includes: an n-type semiconductor layer; an active layer provided in a first region on the n-type semiconductor layer; a p-type semiconductor layer provided on the active layer; a first covering layer that is provided to cover a second region on the n-type semiconductor layer different from the first region, a side of the active layer, and the p-type semiconductor layer and that is made of aluminum oxide (Al2O3); an n-side contact electrode that extends through the first covering layer and is in contact with the n-type semiconductor layer; a p-side contact electrode that extends through the first covering layer and is in contact with the p-type semiconductor layer; and a second covering layer provided to cover the first covering layer, the n-side contact electrode, and the p-side contact electrode.
    Type: Grant
    Filed: January 7, 2020
    Date of Patent: July 12, 2022
    Assignee: NIKKISO CO., LTD.
    Inventors: Tetsuhiko Inazu, Noritaka Niwa
  • Patent number: 11387385
    Abstract: 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: Grant
    Filed: August 18, 2020
    Date of Patent: July 12, 2022
    Assignee: NIKKISO CO., LTD.
    Inventors: Noritaka Niwa, Tetsuhiko Inazu
  • Publication number: 20220216375
    Abstract: A semiconductor light-emitting element includes a p-side pad opening provided on a p-side contact electrode and an n-side pad opening provided on an n-side contact electrode, covers side surfaces of an n-type semiconductor layer, an active layer, and a p-type semiconductor layer, covers the p-side contact electrode in a portion different from the p-side pad opening, and covers the n-side contact electrode in a portion different from the n-side pad opening. The protective layer includes a first dielectric layer made of SiO2, a second dielectric layer made of an oxide material different from a material of the first dielectric layer and covering the first dielectric layer, and a third dielectric layer made of SiO2 and covering the second dielectric layer. A carbon concentration of the first dielectric layer is smaller than a carbon concentration of the third dielectric layer.
    Type: Application
    Filed: October 20, 2021
    Publication date: July 7, 2022
    Inventors: Noritaka NIWA, Tetsuhiko INAZU
  • Patent number: 11355670
    Abstract: A deep ultraviolet light emitting device includes: a light extraction surface; an n-type semiconductor layer provided on the light extraction surface; an active layer having a band gap of 3.4 eV or larger; and a p-type semiconductor layer provided on the active layer. Deep ultraviolet light emitted by the active layer is output outside from the light extraction surface. A side surface of the active layer is inclined with respect to an interface between the n-type semiconductor layer and the active layer, and an angle of inclination of the side surface is not less than 15° and not more than 50°.
    Type: Grant
    Filed: October 29, 2018
    Date of Patent: June 7, 2022
    Assignee: NIKKISO CO., LTD.
    Inventors: Haruhito Sakai, Noritaka Niwa, Tetsuhiko Inazu, Cyril Pernot
  • Patent number: 11322656
    Abstract: A semiconductor light emitting element includes: an n-type clad layer of an n-type aluminum gallium nitride (AlGaN)-based semiconductor material; an active layer of an AlGaN-based semiconductor material provided on a first top surface of the n-type clad layer; and an n-side electrode provided on a second top surface of the n-type clad layer adjacent to the first top surface. The n-side electrode includes a first metal layer on the second top surface containing titanium (Ti) and a second metal layer on the first metal layer containing aluminum (Al). A root-mean-square roughness (Rq) of a top surface of the second metal layer is 5 nm or less.
    Type: Grant
    Filed: May 4, 2020
    Date of Patent: May 3, 2022
    Assignee: NIKKISO CO., LTD.
    Inventors: Haruhito Sakai, Noritaka Niwa, Tetsuhiko Inazu
  • Publication number: 20220085242
    Abstract: 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: Application
    Filed: November 23, 2021
    Publication date: March 17, 2022
    Inventors: Noritaka NIWA, Tetsuhiko INAZU
  • Publication number: 20220045243
    Abstract: 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; and a p-side contact electrode that includes an Rh layer in contact with an upper surface of the p-type semiconductor layer and having a thickness of 10 nm or smaller and an Al layer in contact with an upper surface of the Rh layer and having a thickness of 20 nm or larger.
    Type: Application
    Filed: July 16, 2021
    Publication date: February 10, 2022
    Inventors: Tetsuhiko INAZU, Noritaka NIWA
  • Patent number: 11227976
    Abstract: 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: Grant
    Filed: April 13, 2020
    Date of Patent: January 18, 2022
    Assignee: NIKKISO CO., LTD.
    Inventors: Noritaka Niwa, Tetsuhiko Inazu
  • Publication number: 20220013690
    Abstract: A device includes: an active layer provided in a first comb tooth region on an n-type semiconductor layer; a p-type semiconductor layer provided on the active layer; an n-side contact electrode provided in a second comb tooth region on the n-type semiconductor layer; a p-side contact electrode provided in a third comb tooth region on the p-type semiconductor layer; a protective layer having a p-side pad opening provided in a fourth comb tooth region on the p-side contact electrode, having an n-side pad opening provided in a fifth comb tooth region on the n-side contact electrode, and made of a dielectric material; a p-side pad electrode connected to the p-side contact electrode in the p-side pad opening; and an n-side pad electrode connected to the n-side contact electrode in the n-side pad opening.
    Type: Application
    Filed: June 22, 2021
    Publication date: January 13, 2022
    Inventors: Tetsuhiko INAZU, Noritaka NIWA
  • Patent number: 11222995
    Abstract: 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. The cone-shaped part has a first portion having a first angle of inclination of a side surface and a second portion having a second angle of inclination of a side surface smaller than the first angle. The second portion is closer to an apex of the cone-shaped part than the first portion and has a larger height than the first portion.
    Type: Grant
    Filed: December 26, 2019
    Date of Patent: January 11, 2022
    Assignees: NIKKISO CO., LTD., SCIVAX CORPORATION.
    Inventors: Noritaka Niwa, Tetsuhiko Inazu, Yasumasa Suzaki, Akifumi Nawata, Satoru Tanaka
  • Patent number: 11217728
    Abstract: A semiconductor light emitting element includes: an n-type semiconductor layer provided on a substrate; an active layer provided in a first region of the n-type semiconductor layer and made of an AlGaN-based semiconductor material; a p-type semiconductor layer provided on the active layer; a first protective layer provided on the p-type semiconductor layer and made of silicon oxide (SiO2) or silicon oxynitride (SiON); a second protective layer provided to cover a top of the first protective layer, a second region on the n-type semiconductor layer different from the first region, and a lateral surface of the active layer and made of aluminum oxide (Al2O3), aluminum oxynitride (AlON), or aluminum nitride (AlN); a p-side electrode provided contiguously on the p-type semiconductor layer; and an n-side electrode provided contiguously on the n-type semiconductor layer.
    Type: Grant
    Filed: October 30, 2019
    Date of Patent: January 4, 2022
    Assignee: NIKKISO CO., LTD.
    Inventors: Noritaka Niwa, Tetsuhiko Inazu
  • Publication number: 20210359162
    Abstract: 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: Application
    Filed: April 29, 2021
    Publication date: November 18, 2021
    Inventors: Noritaka NIWA, Tetsuhiko INAZU
  • Publication number: 20210359161
    Abstract: 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: Application
    Filed: April 29, 2021
    Publication date: November 18, 2021
    Inventors: Noritaka NIWA, Tetsuhiko INAZU
  • Patent number: 11164996
    Abstract: A method of manufacturing a semiconductor light-emitting device includes: preparing a layer stack including a light-extracting layer and a light-emitting structure, the light-extracting layer having a first principal surface and a second principal surface opposite to the first principal surface, the light-emitting structure being provided on the first principal surface of the light-extracting layer; forming a pattern mask over a partial region of the second principal surface; dry-etching the second principal surface to form a rugged structure in a region where the pattern mask is formed and to form a recess portion having a planar surface in a region that is exposed without having the pattern mask formed thereover; and singulating the layer stack by irradiating the planar surface with a laser and cutting at least the light-extracting layer at a position of the planar surface.
    Type: Grant
    Filed: April 2, 2020
    Date of Patent: November 2, 2021
    Assignee: NIKKISO CO., LTD.
    Inventors: Noritaka Niwa, Tetsuhiko Inazu
  • Publication number: 20210135058
    Abstract: 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: Application
    Filed: September 4, 2020
    Publication date: May 6, 2021
    Inventors: Noritaka NIWA, Tetsuhiko INAZU
  • Publication number: 20210057609
    Abstract: 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: Application
    Filed: August 18, 2020
    Publication date: February 25, 2021
    Inventors: Noritaka Niwa, Tetsuhiko Inazu
  • Publication number: 20200395506
    Abstract: 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: Application
    Filed: June 8, 2020
    Publication date: December 17, 2020
    Inventors: Tetsuhiko INAZU, Noritaka NIWA
  • Patent number: 10854773
    Abstract: A method of manufacturing a semiconductor light emitting device includes: forming an active layer of an aluminum gallium nitride (AlGaN)-based semiconductor material on an n-type clad layer of an n-type AlGaN-based semiconductor material; forming a p-type semiconductor layer on the active layer; dry-etching portions of the p-type semiconductor layer, the active layer, and the n-type clad layer so as to expose a partial region of the n-type clad layer; causing nitrogen atoms (N) to react with the partial region of the n-type clad layer exposed; and forming an n-side electrode on the partial region of the n-type clad layer that the nitrogen atoms are caused to react with.
    Type: Grant
    Filed: May 24, 2019
    Date of Patent: December 1, 2020
    Assignee: Nikkiso Co., Ltd.
    Inventors: Kazushige Igarashi, Noritaka Niwa, Tetsuhiko Inazu
  • Publication number: 20200335664
    Abstract: 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: Application
    Filed: April 13, 2020
    Publication date: October 22, 2020
    Inventors: Noritaka NIWA, Tetsuhiko INAZU
  • Publication number: 20200266320
    Abstract: A semiconductor light emitting element includes: an n-type clad layer of an n-type aluminum gallium nitride (AlGaN)-based semiconductor material; an active layer of an AlGaN-based semiconductor material provided on a first top surface of the n-type clad layer; and an n-side electrode provided on a second top surface of the n-type clad layer adjacent to the first top surface. The n-side electrode includes a first metal layer on the second top surface containing titanium (Ti) and a second metal layer on the first metal layer containing aluminum (Al). A root-mean-square roughness (Rq) of a top surface of the second metal layer is 5 nm or less.
    Type: Application
    Filed: May 4, 2020
    Publication date: August 20, 2020
    Inventors: Haruhito SAKAI, Noritaka NIWA, Tetsuhiko INAZU