Patents by Inventor Kotaro Zaima

Kotaro Zaima 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: 8809833
    Abstract: Certain embodiments provide a method for manufacturing a semiconductor light emitting device, including: providing a first stack film on a first substrate, the first stack film being formed by stacking a p-type nitride semiconductor layer, an active layer having a multiquantum well structure of a nitride semiconductor, and an n-type nitride semiconductor layer in this order; forming an n-electrode on an upper face of the n-type nitride semiconductor layer; and forming a concave-convex region on the upper face of the n-type nitride semiconductor layer by performing wet etching on the upper face of the n-type nitride semiconductor layer with the use of an alkaline solution, except for a region in which the n-electrode is formed.
    Type: Grant
    Filed: October 18, 2013
    Date of Patent: August 19, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kotaro Zaima, Toru Gotoda, Toshiyuki Oka, Shinya Nunoue
  • Publication number: 20140225061
    Abstract: Certain embodiments provide a semiconductor light emitting device including: a first metal layer; a stack film including a p-type nitride semiconductor layer, an active layer, and an n-type nitride semiconductor layer; an n-electrode; a second metal layer; and a protection film protecting an outer circumferential region of the upper face of the n-type nitride semiconductor layer, side faces of the stack film, a region of an upper face of the second metal layer other than a region in contact with the p-type nitride semiconductor layer, and a region of an upper face of the first metal layer other than a region in contact with the second metal layer. Concavities and convexities are formed in a region of the upper face of the n-type nitride semiconductor layer, the region being outside the region in which the n-electrode is provided and being outside the regions covered with the protection film.
    Type: Application
    Filed: April 15, 2014
    Publication date: August 14, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kotaro ZAIMA, Toru GOTODA, Toshiyuki OKA, Shinya NUNOUE
  • Patent number: 8772800
    Abstract: According to one embodiment, a semiconductor light-emitting device includes: a first conductivity type first semiconductor layer containing a nitride semiconductor crystal and having a tensile stress in a (0001) surface; a second conductivity type second semiconductor layer containing a nitride semiconductor crystal and having a tensile stress in the (0001) surface; a light emitting layer provided between the first semiconductor layer and the second semiconductor layer, containing a nitride semiconductor crystal, and having an average lattice constant larger than the lattice constant of the first semiconductor layer; and a first stress application layer provided on a side opposite to the light emitting layer of the first semiconductor layer and applying a compressive stress to the first semiconductor layer.
    Type: Grant
    Filed: October 21, 2013
    Date of Patent: July 8, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naoharu Sugiyama, Taisuke Sato, Kotaro Zaima, Jumpei Tajima, Toshiki Hikosaka, Yoshiyuki Harada, Hisashi Yoshida, Shinya Nunoue
  • Patent number: 8766297
    Abstract: According to one embodiment, a semiconductor light emitting device includes a stacked structural body, first and second electrodes, a high resistance layer and a transparent conductive layer. The stacked structural body includes first and second semiconductor layers and a light emitting layer. The first semiconductor layer is disposed between the first electrode and the second semiconductor layer. The second semiconductor layer is disposed between the second electrode and the first semiconductor layer. The second electrode has reflectivity with respect to luminescent light. The high resistance layer is in contact with the second semiconductor layer between the second semiconductor layer and the second electrode and includes a portion overlapping with the first electrode. The transparent conductive layer is in contact with the second semiconductor layer between the second semiconductor layer and the second electrode.
    Type: Grant
    Filed: February 18, 2011
    Date of Patent: July 1, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshihide Ito, Toshiyuki Oka, Kotaro Zaima, Taisuke Sato, Shinya Nunoue
  • Patent number: 8766305
    Abstract: A semiconductor light emitting device has a light emitting element, a first electrode layer, a second electrode layer, a seed electrode layer and a plated layer. The light emitting element has a nitride-based III-V compound semiconductor on a substrate and a light extraction surface. The first electrode layer is provided on the light extraction surface. The second electrode layer is provided on a surface opposite to the light extraction surface. The seed electrode layer is configured to cover the entire surface of the second electrode layer. The plated layer is provided on the seed electrode layer. The light emitting element has a light emitting layer, first conductive type semiconductor layer, and second conductive type semiconductor layer, and has a forward tapered shape of a width which gradually narrows in order of the second conductive type semiconductor layer, the light emitting layer and the first conductive type semiconductor layer.
    Type: Grant
    Filed: November 30, 2012
    Date of Patent: July 1, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toru Gotoda, Toshiyuki Oka, Shinya Nunoue, Kotaro Zaima
  • Patent number: 8766311
    Abstract: According to one embodiment, a semiconductor light emitting device includes a p-type semiconductor layer, an n-type semiconductor layer, a light emitting layer, a p-side electrode and an n-side electrode. The p-type semiconductor layer includes a nitride semiconductor and has a first major surface. The n-type semiconductor layer includes a nitride semiconductor and has a second major surface. The light emitting layer is provided between the n-type semiconductor layer and the p-type semiconductor layer. The p-side electrode contacts a part of the p-type semiconductor layer on the first major surface. The n-side electrode contacts a part of the n-type semiconductor layer on the second major surface. The n-side electrode is provided outside and around the p-side electrode in a plan view along a direction from the p-type semiconductor layer to the n-type semiconductor layer.
    Type: Grant
    Filed: August 10, 2011
    Date of Patent: July 1, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Taisuke Sato, Shigeya Kimura, Kotaro Zaima, Koichi Tachibana, Shinya Nunoue
  • Publication number: 20140167094
    Abstract: According to one embodiment, a semiconductor light emitting device includes an electrode layer, a first semiconductor layer, a first elongated electrode, a second semiconductor layer, and a light emitting layer. The first semiconductor layer includes a crystal having a cleavage plane. The first semiconductor layer includes a first thin film portion and a thick film portion. The first thin film portion extends in a first direction perpendicular to a stacking direction from the electrode layer toward the first semiconductor layer. The first thin film portion has a first thickness. The thick film portion is arranged with the first thin film portion in a plane perpendicular to the stacking direction. An angle between the first direction and the cleavage plane is not less than 3 degrees and not more than 27 degrees. The first elongated electrode extends in the first direction in contact with the first thin film portion.
    Type: Application
    Filed: November 19, 2013
    Publication date: June 19, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Jumpei TAJIMA, Kotaro ZAIMA, Toshiki HIKOSAKA, Hiroshi ONO, Naoharu SUGIYAMA, Shinya NUNOUE
  • Patent number: 8735925
    Abstract: Certain embodiments provide a semiconductor light emitting device including: a first metal layer; a stack film including a p-type nitride semiconductor layer, an active layer, and an n-type nitride semiconductor layer; an n-electrode; a second metal layer; and a protection film protecting an outer circumferential region of the upper face of the n-type nitride semiconductor layer, side faces of the stack film, a region of an upper face of the second metal layer other than a region in contact with the p-type nitride semiconductor layer, and a region of an upper face of the first metal layer other than a region in contact with the second metal layer. Concavities and convexities are formed in a region of the upper face of the n-type nitride semiconductor layer, the region being outside the region in which the n-electrode is provided and being outside the regions covered with the protection film.
    Type: Grant
    Filed: April 18, 2012
    Date of Patent: May 27, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kotaro Zaima, Toru Gotoda, Toshiyuki Oka, Shinya Nunoue
  • Patent number: 8680548
    Abstract: A semiconductor light emitting device has a support substrate, a light emitting element, and underfill material. The light emitting element includes a nitride-based group III-V compound semiconductor layer contacted via a bump on the support substrate. The underfill material is disposed between the support substrate and the light emitting element, the underfill material comprising a rib portion disposed outside of an end face of the light emitting element to surround the end surface of the light emitting element.
    Type: Grant
    Filed: September 2, 2010
    Date of Patent: March 25, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toru Gotoda, Hajime Nago, Toshiyuki Oka, Kotaro Zaima, Shinya Nunoue
  • Publication number: 20140048769
    Abstract: Certain embodiments provide a method for manufacturing a semiconductor light emitting device, including: providing a first stack film on a first substrate, the first stack film being formed by stacking a p-type nitride semiconductor layer, an active layer having a multiquantum well structure of a nitride semiconductor, and an n-type nitride semiconductor layer in this order; forming an n-electrode on an upper face of the n-type nitride semiconductor layer; and forming a concave-convex region on the upper face of the n-type nitride semiconductor layer by performing wet etching on the upper face of the n-type nitride semiconductor layer with the use of an alkaline solution, except for a region in which the n-electrode is formed.
    Type: Application
    Filed: October 18, 2013
    Publication date: February 20, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kotaro ZAIMA, Toru GOTODA, Toshiyuki OKA, Shinya NUNOUE
  • Publication number: 20140048819
    Abstract: According to one embodiment, a semiconductor light-emitting device includes: a first conductivity type first semiconductor layer containing a nitride semiconductor crystal and having a tensile stress in a (0001) surface; a second conductivity type second semiconductor layer containing a nitride semiconductor crystal and having a tensile stress in the (0001) surface; a light emitting layer provided between the first semiconductor layer and the second semiconductor layer, containing a nitride semiconductor crystal, and having an average lattice constant larger than the lattice constant of the first semiconductor layer; and a first stress application layer provided on a side opposite to the light emitting layer of the first semiconductor layer and applying a compressive stress to the first semiconductor layer.
    Type: Application
    Filed: October 21, 2013
    Publication date: February 20, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Naoharu Sugiyama, Taisuke Sato, Kotaro Zaima, Jumpei Tajima, Toshiki Hikosaka, Yoshiyuki Harada, Hisashi Yoshida, Shinya Nunoue
  • Publication number: 20130328075
    Abstract: According to one embodiment, a semiconductor light emitting device includes first and second electrodes, first and second semiconductor layers and a light emitting layer. The first electrode includes a first region, a second region, and a third region provided between them. The first semiconductor layer includes a first portion on the first region and a second portion on the second region. The light emitting layer includes a third portion on the first portion and a fourth portion on the second portion. The second semiconductor layer includes a fifth portion on the third portion and a sixth portion on the fourth portion. The insulating layer is provided between the first and second portions on the third region and between the third and fourth portions. The second electrode includes a seventh portion provided on the insulating layer, eighth and ninth portions contacting side surfaces of the fifth and sixth portions.
    Type: Application
    Filed: December 26, 2012
    Publication date: December 12, 2013
    Inventors: Jumpei Tajima, Kotaro Zaima, Hiroshi Ono, Shinji Yamada, Shigeya Kimura, Naoharu Sugiyama, Shinya Nunoue
  • Publication number: 20130328055
    Abstract: According to one embodiment, a semiconductor light emitting device includes first and second electrodes, first, second and third semiconductor layers, and a light emitting layer. The first semiconductor layer of a first conductivity type is provided on the first electrode. The light emitting layer is provided on the first semiconductor layer. The second semiconductor layer of a second conductivity type is provided on the light emitting layer. The third semiconductor layer with low impurity concentration is provided on a part of the second semiconductor layer. The second electrode includes a pad section and a narrow wire section. The pad section is provided on the third semiconductor layer. The narrow wire section extends out from the pad section and includes an extending portion extending along a plane perpendicular to a stacking direction. The narrow wire section is in contact with the second semiconductor layer.
    Type: Application
    Filed: December 21, 2012
    Publication date: December 12, 2013
    Inventors: Jumpei TAJIMA, Kotaro Zaima, Shigeya Kimura, Hiroshi Ono, Shinji Yamada, Satoshi Mitsugi, Naoharu Sugiyama, Shinya Nunoue
  • Patent number: 8598605
    Abstract: According to one embodiment, a semiconductor light-emitting device includes: a first conductivity type first semiconductor layer containing a nitride semiconductor crystal and having a tensile stress in a (0001) surface; a second conductivity type second semiconductor layer containing a nitride semiconductor crystal and having a tensile stress in the (0001) surface; a light emitting layer provided between the first semiconductor layer and the second semiconductor layer, containing a nitride semiconductor crystal, and having an average lattice constant larger than the lattice constant of the first semiconductor layer; and a first stress application layer provided on a side opposite to the light emitting layer of the first semiconductor layer and applying a compressive stress to the first semiconductor layer.
    Type: Grant
    Filed: August 31, 2012
    Date of Patent: December 3, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naoharu Sugiyama, Taisuke Sato, Kotaro Zaima, Jumpei Tajima, Toshiki Hikosaka, Yoshiyuki Harada, Hisashi Yoshida, Shinya Nunoue
  • Publication number: 20130244360
    Abstract: According to one embodiment, a method is disclosed for manufacturing a semiconductor light emitting element. The method can include bonding a stacked main body of a structural body to a substrate main body. The structural body includes a growth substrate and the stacked main body provided on the growth substrate. The stacked main body includes a first nitride semiconductor film, a light emitting film provided on the first nitride semiconductor film, and a second nitride semiconductor film provided on the light emitting film. The method can include removing the growth substrate. The method can include forming a plurality of stacked bodies. The method can include forming an uneven portion in a surface of a first nitride semiconductor layer. The method can include forming a plurality of the semiconductor light emitting elements.
    Type: Application
    Filed: August 31, 2012
    Publication date: September 19, 2013
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Taisuke SATO, Kotaro Zaima, Jumpei Tajima, Naoharu Sugiyama, Shinya Nunoue
  • Publication number: 20130234106
    Abstract: According to one embodiment, a semiconductor light-emitting device includes: a first conductivity type first semiconductor layer containing a nitride semiconductor crystal and having a tensile stress in a (0001) surface; a second conductivity type second semiconductor layer containing a nitride semiconductor crystal and having a tensile stress in the (0001) surface; a light emitting layer provided between the first semiconductor layer and the second semiconductor layer, containing a nitride semiconductor crystal, and having an average lattice constant larger than the lattice constant of the first semiconductor layer; and a first stress application layer provided on a side opposite to the light emitting layer of the first semiconductor layer and applying a compressive stress to the first semiconductor layer.
    Type: Application
    Filed: August 31, 2012
    Publication date: September 12, 2013
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Naoharu Sugiyama, Taisuke Sato, Kotaro Zaima, Jumpei Tajima, Toshiki Hikosaka, Yoshiyuki Harada, Hisashi Yoshida, Shinya Nunoue
  • Patent number: 8470625
    Abstract: A method of fabricating semiconductor light emitting device forms a laminated film by laminating an n-type nitride semiconductor layer, an active layer and a p-type nitride semiconductor layer in order on a uneven main surface of a first substrate, forms a plurality of first electrodes, on an upper surface of the p-type nitride semiconductor layer, forms a first metal layer to cover surfaces of the plurality of first electrodes and the p-type nitride semiconductor layer, forms a second metal layer on an upper surface of the second substrate, joins the first and second metal layers by facing the first and second substrates, cuts the first substrate or forming a groove on the first substrate along a border of the light emitting element from a surface side opposite to the first metal layer on the first substrate, and irradiates a laser toward areas of the light emitting devices from a surface side opposite to the first metal layer on the first substrate to peel off the first substrate.
    Type: Grant
    Filed: March 1, 2011
    Date of Patent: June 25, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kotaro Zaima, Toru Gotoda, Toshiyuki Oka, Shinya Nunoue
  • Publication number: 20130153922
    Abstract: A semiconductor light emitting device has a light emitting element, a first electrode layer, a second electrode layer, a seed electrode layer and a plated layer. The light emitting element has a nitride-based III-V compound semiconductor on a substrate and a light extraction surface. The first electrode layer is provided on the light extraction surface. The second electrode layer is provided on a surface opposite to the light extraction surface. The seed electrode layer is configured to cover the entire surface of the second electrode layer. The plated layer is provided on the seed electrode layer. The light emitting element has a light emitting layer, first conductive type semiconductor layer, and second conductive type semiconductor layer, and has a forward tapered shape of a width which gradually narrows in order of the second conductive type semiconductor layer, the light emitting layer and the first conductive type semiconductor layer.
    Type: Application
    Filed: November 30, 2012
    Publication date: June 20, 2013
    Inventors: Toru Gotoda, Toshiyuki Oka, Shinya Nunoue, Kotaro Zaima
  • Publication number: 20130059408
    Abstract: Certain embodiments provide a method for manufacturing a semiconductor light emitting device, including: providing a first stack film on a first substrate, the first stack film being formed by stacking a p-type nitride semiconductor layer, an active layer having a multiquantum well structure of a nitride semiconductor, and an n-type nitride semiconductor layer in this order; forming an n-electrode on an upper face of the n-type nitride semiconductor layer; and forming a concave-convex region on the upper face of the n-type nitride semiconductor layer by performing wet etching on the upper face of the n-type nitride semiconductor layer with the use of an alkaline solution, except for a region in which the n-electrode is formed.
    Type: Application
    Filed: October 31, 2012
    Publication date: March 7, 2013
    Inventors: Kotaro Zaima, Toru Gotoda, Toshiyuki Oka, Shinya Nunoue
  • Patent number: 8390012
    Abstract: A semiconductor light emitting device has a support substrate, a light emitting element, and underfill material. The light emitting element includes a nitride-based group III-V compound semiconductor layer contacted via a bump on the support substrate. The underfill material is disposed between the support substrate and the light emitting element, the underfill material comprising a rib portion disposed outside of an end face of the light emitting element to surround the end surface of the light emitting element.
    Type: Grant
    Filed: September 2, 2010
    Date of Patent: March 5, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toru Gotoda, Hajime Nago, Toshiyuki Oka, Kotaro Zaima, Shinya Nunoue