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).

  • Publication number: 20200251611
    Abstract: 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: Application
    Filed: April 24, 2020
    Publication date: August 6, 2020
    Inventors: Noritaka NIWA, Tetsuhiko INAZU, Haruhito SAKAI
  • Publication number: 20200235265
    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: Application
    Filed: April 2, 2020
    Publication date: July 23, 2020
    Inventors: Noritaka NIWA, Tetsuhiko INAZU
  • Patent number: 10720547
    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; removing 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; and forming an n-side electrode on the partial region of the n-type clad layer exposed. The removing includes first dry-etching performed by using both a reactive gas and an inert gas and second dry-etching performed after the first dry-etching by using a reactive gas.
    Type: Grant
    Filed: May 24, 2019
    Date of Patent: July 21, 2020
    Assignee: NIKKISO CO., LTD.
    Inventors: Haruhito Sakai, Noritaka Niwa, Tetsuhiko Inazu
  • Publication number: 20200220046
    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: Application
    Filed: January 7, 2020
    Publication date: July 9, 2020
    Inventors: Tetsuhiko INAZU, Noritaka NIWA
  • Patent number: 10665751
    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 light-extracting surface in which a rugged structure is provided, the light-emitting structure being provided on a principal surface opposite to the light-extracting surface of the light-extracting layer; forming a mask over the rugged structure in a partial region of the light-extracting surface; forming a planar surface by removing the rugged structure that is exposed without having the 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: August 24, 2018
    Date of Patent: May 26, 2020
    Assignee: Nikkiso Co., Ltd.
    Inventors: Noritaka Niwa, Tetsuhiko Inazu
  • Publication number: 20200144449
    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: Application
    Filed: December 26, 2019
    Publication date: May 7, 2020
    Inventors: Noritaka NIWA, Tetsuhiko INAZU, Yasumasa SUZAKI, Akifumi NAWATA, Satoru TANAKA
  • Publication number: 20200144450
    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 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: Application
    Filed: December 26, 2019
    Publication date: May 7, 2020
    Inventors: Noritaka NIWA, Tetsuhiko INAZU, Yasumasa SUZAKI, Akifumi NAWATA, Satoru TANAKA
  • Publication number: 20200066941
    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: Application
    Filed: October 30, 2019
    Publication date: February 27, 2020
    Inventors: Noritaka NIWA, Tetsuhiko INAZU
  • Publication number: 20190280149
    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; removing 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; and forming an n-side electrode on the partial region of the n-type clad layer exposed. The removing includes first dry-etching performed by using both a reactive gas and an inert gas and second dry-etching performed after the first dry-etching by using a reactive gas.
    Type: Application
    Filed: May 24, 2019
    Publication date: September 12, 2019
    Inventors: Haruhito SAKAI, Noritaka NIWA, Tetsuhiko INAZU
  • Publication number: 20190280150
    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: Application
    Filed: May 24, 2019
    Publication date: September 12, 2019
    Inventors: Kazushige IGARASHI, Noritaka NIWA, Tetsuhiko INAZU
  • Publication number: 20190229238
    Abstract: 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: Application
    Filed: March 29, 2019
    Publication date: July 25, 2019
    Inventors: Noritaka NIWA, Tetsuhiko INAZU, Yasumasa SUZAKI, Akifumi NAWATA, Satoru TANAKA
  • Publication number: 20190067519
    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 light-extracting surface in which a rugged structure is provided, the light-emitting structure being provided on a principal surface opposite to the light-extracting surface of the light-extracting layer; forming a mask over the rugged structure in a partial region of the light-extracting surface; forming a planar surface by removing the rugged structure that is exposed without having the 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: Application
    Filed: August 24, 2018
    Publication date: February 28, 2019
    Inventors: Noritaka NIWA, Tetsuhiko INAZU
  • Publication number: 20190067520
    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: Application
    Filed: October 29, 2018
    Publication date: February 28, 2019
    Inventors: Haruhito SAKAI, Noritaka NIWA, Tetsuhiko INAZU, Cyril PERNOT
  • Patent number: 9281439
    Abstract: A nitride semiconductor element 1 includes a base structure part 5, and an element structure part 11 formed on the base structure part 5 and having at least an n-type AlGaN based semiconductor layer 6, and p-type AlGaN based semiconductor layers 8, 9, 10, and further includes an n-electrode contact part 13a formed on the n-type AlGaN based semiconductor layer 6, an n-electrode pad part 13b formed on the n-electrode contact part 13a, and a p-electrode 12 formed on the p-type AlGaN based semiconductor layers 8, 9, 10, in which an AlN mole fraction in the n-type AlGaN based semiconductor layer 6 is 20% or more, the n-electrode contact part 13a includes one or more metal layers, and the p-electrode 12 and the n-electrode pad part 13b have a common laminated structure of two or more layers having an Au layer as an uppermost layer, and an Au diffusion preventing layer composed of conductive metal oxide and formed under the uppermost layer to prevent Au diffusion.
    Type: Grant
    Filed: September 30, 2011
    Date of Patent: March 8, 2016
    Assignee: Soko Kagaku Co., Ltd.
    Inventors: Noritaka Niwa, Tetsuhiko Inazu
  • Publication number: 20150048304
    Abstract: A nitride semiconductor element 1 includes a base structure part 5, and an element structure part 11 formed on the base structure part 5 and having at least an n-type AlGaN based semiconductor layer 6, and p-type AlGaN based semiconductor layers 8, 9, 10, and further includes an n-electrode contact part 13a formed on the n-type AlGaN based semiconductor layer 6, an n-electrode pad part 13b formed on the n-electrode contact part 13a, and a p-electrode 12 formed on the p-type AlGaN based semiconductor layers 8, 9, 10, in which an AlN mole fraction in the n-type AlGaN based semiconductor layer 6 is 20% or more, the n-electrode contact part 13a includes one or more metal layers, and the p-electrode 12 and the n-electrode pad part 13b have a common laminated structure of two or more layers having an Au layer as an uppermost layer, and an Au diffusion preventing layer composed of conductive metal oxide and formed under the uppermost layer to prevent Au diffusion.
    Type: Application
    Filed: September 30, 2011
    Publication date: February 19, 2015
    Applicant: SOKO KAGAKU CO., LTD.
    Inventors: Noritaka Niwa, Tetsuhiko Inazu