Patents by Inventor Yukie Nishikawa

Yukie Nishikawa 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: 20160049484
    Abstract: A semiconductor device includes a second conductivity-type second semiconductor layer selectively provided on a first conductivity-type first semiconductor layer, a first conductivity-type third semiconductor layer provided on the second semiconductor layer, and at least one control electrode that is spaced from the second semiconductor layer and the third semiconductor layer by an insulating film. In addition, the semiconductor device further includes a second conductivity-type fourth semiconductor layer provided on a side of the control electrode opposite to a side thereof where the second semiconductor layer is located, and a semiconductor region that is provided between the first semiconductor layer and the fourth semiconductor layer, the first semiconductor layer making contact in the insulating film at the bottom of the control electrode, and containing at least one type of electrically inactive element in at least any one of the first semiconductor layer and the fourth semiconductor layer.
    Type: Application
    Filed: March 1, 2015
    Publication date: February 18, 2016
    Inventors: Yukie NISHIKAWA, Yasuhiko AKAIKE
  • Patent number: 9224916
    Abstract: According to an embodiment, a semiconductor light emitting device includes a first semiconductor layer, a second semiconductor layer, a dielectric film and an electrode. The first semiconductor layer is capable of emitting light. The second semiconductor layer has a first major surface in contact with the first semiconductor layer and a second major surface opposite to the first major surface, the second major surface including a first region having convex structures and a second region not having the convex structures. The dielectric film is provided at least at a tip portion of the convex structures, and the electrode is provided above the second region.
    Type: Grant
    Filed: September 13, 2012
    Date of Patent: December 29, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hironori Yamasaki, Yukie Nishikawa
  • Publication number: 20150262813
    Abstract: According to one embodiment, a semiconductor device includes a first electrode on a surface of a semiconductor layer and a plurality of second electrodes on the first electrode. Each second electrode has a shape in a plane that is parallel to the surface of the semiconductor layer having dimensions of 50 micrometers or less. A resin layer is between the plurality of second electrodes, and has a modulus that is lower than a modulus of the second electrodes.
    Type: Application
    Filed: August 29, 2014
    Publication date: September 17, 2015
    Inventors: Motoya KISHIDA, Yukie NISHIKAWA, Nobuhiro TAKAHASHI, Yasuhiko AKAIKE
  • Patent number: 9041143
    Abstract: The semiconductor device includes a first semiconductor layer of the first conductive type, a second semiconductor layer having the cubic crystalline structure formed on the first semiconductor layer, an electrode formed on the second semiconductor layer, and a reactive region formed between the second semiconductor layer and the electrode. The second semiconductor layer includes an upper surface that is tilted from the (100) plane. The reactive region includes at least one element constituting the second semiconductor layer, at least one element constituting the electrode, and forming a protuberance extending toward the second semiconductor layer.
    Type: Grant
    Filed: September 3, 2013
    Date of Patent: May 26, 2015
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yukie Nishikawa, Nobuhiro Takahashi, Hironobu Shibata
  • Publication number: 20150069614
    Abstract: A semiconductor device includes a first metal layer disposed on a first surface of a semiconductor layer, or a portion thereof. The first metal layer is made of a first metal. At least a portion of the first metal layer is crystallized. A second metal layer is disposed on a second surface of the semiconductor layer. The second surface is opposite the first surface. The second metal layer is also made of the first metal and has at least a portion that is crystallized. In some embodiments, the first metal may be nickel. In some embodiments, the semiconductor device may be a power semiconductor device, such as an insulated gate bipolar transistor and a fast recovery diode.
    Type: Application
    Filed: February 28, 2014
    Publication date: March 12, 2015
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yukie NISHIKAWA, Hironobu SHIBATA, Nobuhiro TAKAHASHI
  • Patent number: 8969157
    Abstract: According to one embodiment, in a method of a semiconductor device, a trench is formed in the direction of a lower surface from an upper surface of a semiconductor layer. A first insulating film is formed to cover an inner surface of the trench. An electrode material is formed to fill the trench and cover the upper surface of the semiconductor layer. The electrode material is selectively removed except a portion of the electrode material to fill the trench and a portion of the electrode material to cover an opening of the trench. The first insulating film to cover an upper portion of the trench is removed. The portions of the electrode material to fill the trench and cover the opening of the trench are etched back to form a first electrode at a lower portion of the trench.
    Type: Grant
    Filed: September 10, 2013
    Date of Patent: March 3, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Nobuhiro Takahashi, Yukie Nishikawa, Yasuhiko Akaike
  • Publication number: 20140284755
    Abstract: The semiconductor device includes a first semiconductor layer of the first conductive type, a second semiconductor layer having the cubic crystalline structure formed on the first semiconductor layer, an electrode formed on the second semiconductor layer, and a reactive region formed between the second semiconductor layer and the electrode. The second semiconductor layer includes an upper surface that is tilted from the (100) plane. The reactive region includes at least one element constituting the second semiconductor layer, at least one element constituting the electrode, and forming a protuberance extending toward the second semiconductor layer.
    Type: Application
    Filed: September 3, 2013
    Publication date: September 25, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yukie NISHIKAWA, Nobuhiro TAKAHASHI, Hironobu SHIBATA
  • Publication number: 20140287574
    Abstract: According to one embodiment, in a method of a semiconductor device, a trench is formed in the direction of a lower surface from an upper surface of a semiconductor layer. A first insulating film is formed to cover an inner surface of the trench. An electrode material is formed to fill the trench and cover the upper surface of the semiconductor layer. The electrode material is selectively removed except a portion of the electrode material to fill the trench and a portion of the electrode material to cover an opening of the trench. The first insulating film to cover an upper portion of the trench is removed. The portions of the electrode material to fill the trench and cover the opening of the trench are etched back to form a first electrode at a lower portion of the trench.
    Type: Application
    Filed: September 10, 2013
    Publication date: September 25, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Nobuhiro Takahashi, Yukie Nishikawa, Yasuhiko Akaike
  • Patent number: 8772809
    Abstract: According to one embodiment, a semiconductor light emitting device includes a light emitting layer, a first electrode, a first conductivity type layer, a second conductivity type layer, and a second electrode. The first electrode includes a reflection metal layer. The first conductivity type layer is provided between the light emitting layer and the first electrode. The second conductivity type layer has a first surface on the light emitting layer side and a second surface on an opposite side of the first surface. The second electrode is provided on the second surface of the second conductivity type layer. A plurarity of interfaces, provided between the first conductivity type layer and the reflection metal layer, has at least first concave-convex structures. A region of the second surface of the second conductivity type layer, where the second electrode is not provided, has second concave-convex structures.
    Type: Grant
    Filed: August 30, 2012
    Date of Patent: July 8, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Katsuyoshi Furuki, Hironori Yamasaki, Yukie Nishikawa
  • Patent number: 8674384
    Abstract: According to one embodiment, a light emitting element includes a light emitting layer, a cladding layer, a current spreading layer, a second layer, and an electrode. The light emitting layer is capable of emitting emission light. The current spreading layer includes a surface processed layer and a first layer. The surface processed layer has a surface including convex portions and bottom portions provided adjacent to the convex portions. The first layer is provided between the surface processed layer and the cladding layer. The second layer is provided between the surface processed layer and the cladding layer and includes a region having an impurity concentration higher than an impurity concentration of the current spreading layer. The electrode is provided in a region of the surface of the surface processed layer where the convex portions and the bottom portions are not provided.
    Type: Grant
    Filed: March 15, 2011
    Date of Patent: March 18, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takashi Kataoka, Yukie Nishikawa, Hironori Yamasaki
  • Patent number: 8618551
    Abstract: According to one embodiment, a semiconductor light emitting device includes a substrate, a first electrode, a first conductivity type layer, a light emitting layer, a second conductivity type layer and a second electrode. The first conductivity type layer includes a first contact layer, a window layer having a lower impurity concentration than the first contact layer and a first cladding layer. The second conductivity type layer includes a second cladding layer, a current spreading layer and a second contact layer. The second electrode includes a narrow-line region on the second contact layer and a pad region electrically connected to the narrow-line region. Band gap energies of the first contact and window layers are larger than that of the light emitting layer. The first contact layer is provided selectively between the window layer and the first electrode and without overlapping the second contact layer as viewed from above.
    Type: Grant
    Filed: August 29, 2011
    Date of Patent: December 31, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yukie Nishikawa, Hironori Yamasaki, Katsuyoshi Furuki, Takashi Kataoka
  • Patent number: 8530913
    Abstract: According to one embodiment, a light emitting device includes a light emitting layer, a first electrode, a first and second layers, and a cladding layer. The first layer has a first impurity concentration of a first conductivity type, and allows a carrier to be diffused in the light emitting layer. The second layer has a second impurity concentration of the first conductivity type higher than the first impurity concentration, and includes a first and second surfaces. The first surface is with the first layer. The second surface has a formation region and a non-formation region of the first electrode. The non-formation region includes convex structures with an average pitch not more than a wavelength of the emission light. The cladding layer is provided between the first layer and the light emitting layer and has an impurity concentration of the first conductivity type.
    Type: Grant
    Filed: February 2, 2011
    Date of Patent: September 10, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yukie Nishikawa, Takashi Kataoka, Hironori Yamasaki, Hisashi Mori, Kazunari Yabe
  • Publication number: 20130221367
    Abstract: According to one embodiment, a semiconductor light emitting device includes a light emitting layer, a first electrode, a first conductivity type layer, a second conductivity type layer, and a second electrode. The first electrode includes a reflection metal layer. The first conductivity type layer is provided between the light emitting layer and the first electrode. The second conductivity type layer has a first surface on the light emitting layer side and a second surface on an opposite side of the first surface. The second electrode is provided on the second surface of the second conductivity type layer. A plurarity of interfaces, provided between the first conductivity type layer and the reflection metal layer, has at least first concave-convex structures. A region of the second surface of the second conductivity type layer, where the second electrode is not provided, has second concave-convex structures.
    Type: Application
    Filed: August 30, 2012
    Publication date: August 29, 2013
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Katsuyoshi Furuki, Hironori Yamasaki, Yukie Nishikawa
  • Patent number: 8519411
    Abstract: A semiconductor light emitting device includes an active layer, an electrode formed above the active layer, a current spreading layer formed between the active layer and the electrode, having n-type conductivity, having a larger bandgap energy than the active layer, and spreading electrons injected from the electrode in the plane of the active layer, and a surface processed layer formed on the current spreading layer, having a larger bandgap energy than the active layer, and having an uneven surface region with a large number of concave-convex structures. The electrode is not formed on the uneven surface region. The conduction band edge energy from the Fermi level of the surface processed layer is higher than that of the current spreading layer.
    Type: Grant
    Filed: July 11, 2008
    Date of Patent: August 27, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yukie Nishikawa, Shinji Nunotani
  • Publication number: 20130126919
    Abstract: According to an embodiment, a semiconductor light emitting device includes a first semiconductor layer, a second semiconductor layer, a dielectric film and an electrode. The first semiconductor layer is capable of emitting light. The second semiconductor layer has a first major surface in contact with the first semiconductor layer and a second major surface opposite to the first major surface, the second major surface including a first region having convex structures and a second region not having the convex structures. The dielectric film is provided at least at a tip portion of the convex structures, and the electrode is provided above the second region.
    Type: Application
    Filed: September 13, 2012
    Publication date: May 23, 2013
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hironori Yamasaki, Yukie Nishikawa
  • Publication number: 20120273793
    Abstract: According to one embodiment, a semiconductor light emitting device includes a substrate, a first electrode, a first conductivity type layer, a light emitting layer, a second conductivity type layer and a second electrode. The first conductivity type layer includes a first contact layer, a window layer having a lower impurity concentration than the first contact layer and a first cladding layer. The second conductivity type layer includes a second cladding layer, a current spreading layer and a second contact layer. The second electrode includes a narrow-line region on the second contact layer and a pad region electrically connected to the narrow-line region. Band gap energies of the first contact and window layers are larger than that of the light emitting layer. The first contact layer is provided selectively between the window layer and the first electrode and without overlapping the second contact layer as viewed from above.
    Type: Application
    Filed: August 29, 2011
    Publication date: November 1, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yukie Nishikawa, Hironori Yamasaki, Katsuyoshi Furuki, Takashi Kataoka
  • Publication number: 20120146072
    Abstract: According to one embodiment, a semiconductor light emitting element includes a light emitting layer, a current spreading layer of a first conductivity type, and a pad electrode. The light emitting layer is capable of emitting light. The current spreading layer has a first surface and a second surface. The light emitting layer is disposed on a side of the first surface. A light extraction surface having convex structures of triangle cross-sectional shape and a flat surface which is a crystal growth plane are included in the second surface. The pad electrode is provided on the flat surface. One base angle of the convex structure is 90 degrees or more.
    Type: Application
    Filed: March 22, 2011
    Publication date: June 14, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hironori Yamasaki, Katsuyoshi Furuki, Yukie Nishikawa
  • Publication number: 20120104431
    Abstract: According to one embodiment, a light emitting element includes a light emitting layer, a cladding layer, a current spreading layer, a second layer, and an electrode. The light emitting layer is capable of emitting emission light. The current spreading layer includes a surface processed layer and a first layer. The surface processed layer has a surface including convex portions and bottom portions provided adjacent to the convex portions. The first layer is provided between the surface processed layer and the cladding layer. The second layer is provided between the surface processed layer and the cladding layer and includes a region having an impurity concentration higher than an impurity concentration of the current spreading layer. The electrode is provided in a region of the surface of the surface processed layer where the convex portions and the bottom portions are not provided.
    Type: Application
    Filed: March 15, 2011
    Publication date: May 3, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Takashi Kataoka, Yukie Nishikawa, Hironori Yamasaki
  • Publication number: 20120025233
    Abstract: According to one embodiment, a light emitting device includes a light emitting layer, a first electrode, a first and second layers, and a cladding layer. The first layer has a first impurity concentration of a first conductivity type, and allows a carrier to be diffused in the light emitting layer. The second layer has a second impurity concentration of the first conductivity type higher than the first impurity concentration, and includes a first and second surfaces. The first surface is with the first layer. The second surface has a formation region and a non-formation region of the first electrode. The non-formation region includes convex structures with an average pitch not more than a wavelength of the emission light. The cladding layer is provided between the first layer and the light emitting layer and has an impurity concentration of the first conductivity type.
    Type: Application
    Filed: February 2, 2011
    Publication date: February 2, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yukie Nishikawa, Takashi Kataoka, Hironori Yamasaki, Hisashi Mori, Kazunari Yabe
  • Patent number: RE44215
    Abstract: The present invention is intended to provide a semiconductor optoelectric device with high luminescent efficiency and a method of manufacturing the same. The semiconductor optoelectric device 18 according to the present invention is constructed by depositing compound-semiconductor layers 13 and 14 on a monocrystalline substrate 11 of a hexagonal close-packed structure. The shape of the monocrystalline substrate 11 is a parallelogram. Individual sides of the parallelogram are parallel to a <11-20> orientation. As the monocrystalline substrate, sapphire, zinc oxide or silicon carbide may be used. As the compound-semiconductor layers, an n-type GaN layer 13 and p-type GaN layer 14 may be used.
    Type: Grant
    Filed: October 11, 2011
    Date of Patent: May 14, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masahiro Yamamoto, Hidetoshi Fujimoto, Yoshihiro Kokubun, Masayuki Ishikawa, Shinji Saito, Yukie Nishikawa, John Rennie