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: 8390007
    Abstract: A semiconductor light emitting device has a light emitting element, and first and second electrodes. The light emitting element has a nitride-based III-V compound semiconductor on a substrate. The first and second electrodes are disposed on both sides of the light emitting element, respectively. The light emitting element has a light emitting layer, a first conductive type semiconductor layer, and a second conductive type semiconductor layer. The first conductive type semiconductor layer is disposed between the light emitting layer and the first electrode. The second conductive type semiconductor layer is disposed between the light emitting layer and the second electrode. One surface of the first conductive type semiconductor layer contacts the first electrode and is a light extraction surface which is roughly processed so as to have two or more kinds of oblique angles.
    Type: Grant
    Filed: September 2, 2010
    Date of Patent: March 5, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toru Gotoda, Takahiro Sato, Toshiyuki Oka, Shinya Nunoue, Kotaro Zaima
  • Publication number: 20120319161
    Abstract: According to one embodiment, a method is disclosed for manufacturing a semiconductor light emitting device. The method can include forming a nitride semiconductor layer including a light emitting layer on a first substrate having an unevenness, bonding the nitride layer to a second substrate, and separating the first substrate from the nitride layer by irradiating the nitride layer with light. The forming the nitride layer includes leaving a cavity in a space inside a depression of the unevenness while forming a thin film on the depression. The film includes a same material as part of the nitride layer. The separating includes causing the film to absorb part of the light so that intensity of the light applied to a portion of the nitride layer facing the depression is made lower than intensity of the light applied to a portion facing a protrusion of the unevenness.
    Type: Application
    Filed: February 27, 2012
    Publication date: December 20, 2012
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Toru GOTODA, Toshiyuki Oka, Shinya Nunoue, Kotaro Zaima, Hiroshi Ono, Hajime Nago
  • Patent number: 8334153
    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. The light emitting element having a light extraction surface. The first electrode layer on the light extraction surface. The second electrode layer is provided on a surface opposite to the light extraction surface of the light emitting element. 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, a first conductive type semiconductor layer, and a second conductive type semiconductor layer.
    Type: Grant
    Filed: September 2, 2010
    Date of Patent: December 18, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toru Gotoda, Toshiyuki Oka, Shinya Nunoue, Kotaro Zaima
  • Patent number: 8314437
    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: September 2, 2010
    Date of Patent: November 20, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kotaro Zaima, Toru Gotoda, Toshiyuki Oka, Shinya Nunoue
  • Publication number: 20120217524
    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: Application
    Filed: August 10, 2011
    Publication date: August 30, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Taisuke Sato, Shigeya Kimura, Kotaro Zaima, Koichi Tachibana, Shinya Nunoue
  • Publication number: 20120199811
    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 18, 2012
    Publication date: August 9, 2012
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kotaro Zaima, Toru Gotoda, Toshiyuki Oka, Shinya Nunoue
  • Patent number: 8178891
    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: September 2, 2010
    Date of Patent: May 15, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kotaro Zaima, Toru Gotoda, Toshiyuki Oka, Shinya Nunoue
  • Publication number: 20120056154
    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: Application
    Filed: March 1, 2011
    Publication date: March 8, 2012
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kotaro ZAIMA, Toru Gotoda, Toshiyuki Oka, Shinya Nunoue
  • Publication number: 20120043550
    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: Application
    Filed: February 18, 2011
    Publication date: February 23, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Toshihide ITO, Toshiyuki Oka, Kotaro Zaima, Taisuke Sato, Shinya Nunoue
  • Publication number: 20110220934
    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: Application
    Filed: September 2, 2010
    Publication date: September 15, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Toru Gotoda, Hajime Nago, Toshiyuki Oka, Kotaro Zaima, Shinya Nunoue
  • Publication number: 20110220933
    Abstract: A semiconductor light emitting device has a light emitting element, and first and second electrodes. The light emitting element has a nitride-based III-V compound semiconductor on a substrate. The first and second electrodes are disposed on both sides of the light emitting element, respectively. The light emitting element has a light emitting layer, a first conductive type semiconductor layer, and a second conductive type semiconductor layer. The first conductive type semiconductor layer is disposed between the light emitting layer and the first electrode. The second conductive type semiconductor layer is disposed between the light emitting layer and the second electrode. One surface of the first conductive type semiconductor layer contacts the first electrode and is a light extraction surface which is roughly processed so as to have two or more kinds of oblique angles.
    Type: Application
    Filed: September 2, 2010
    Publication date: September 15, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Toru GOTODA, Takahiro Sato, Toshiyuki Oka, Shinya Nunoue, Kotaro Zaima
  • Publication number: 20110220935
    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. The light emitting element having a light extraction surface. The first electrode layer on the light extraction surface. The second electrode layer is provided on a surface opposite to the light extraction surface of the light emitting element. 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, a first conductive type semiconductor layer, and a second conductive type semiconductor layer.
    Type: Application
    Filed: September 2, 2010
    Publication date: September 15, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Toru GOTODA, Toshiyuki Oka, Shinya Nunoue, Kotaro Zaima
  • Publication number: 20110215293
    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: September 2, 2010
    Publication date: September 8, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kotaro Zaima, Toru Gotoda, Toshiyuki Oka, Shinya Nunoue
  • Publication number: 20110215292
    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: September 2, 2010
    Publication date: September 8, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kotaro Zaima, Toru Gotoda, Toshiyuki Oka, Shinya Nunoue
  • Patent number: 8004004
    Abstract: The present invention provides a semiconductor light emitting element with excellent color rendering properties, a method for manufacturing the semiconductor light emitting element, and a light emitting device. The semiconductor light emitting element includes: a semiconductor substrate that has a convex portion having a tilted surface as an upper face, and a concave portion formed on either side of the convex portion, the concave portion having a smaller width than the convex portion, a bottom face of the concave portion being located in a deeper position than the upper face of the convex portion; and a light emitting layer that is made of a nitride-based semiconductor and is formed on the semiconductor substrate so as to cover at least the convex portion.
    Type: Grant
    Filed: November 29, 2010
    Date of Patent: August 23, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hajime Nago, Koichi Tachibana, Kotaro Zaima, Shinji Saito, Shinya Nunoue, Toshiyuki Oka
  • Publication number: 20110068360
    Abstract: The present invention provides a semiconductor light emitting element with excellent color rendering properties, a method for manufacturing the semiconductor light emitting element, and a light emitting device. The semiconductor light emitting element includes: a semiconductor substrate that has a convex portion having a tilted surface as an upper face, and a concave portion formed on either side of the convex portion, the concave portion having a smaller width than the convex portion, a bottom face of the concave portion being located in a deeper position than the upper face of the convex portion; and a light emitting layer that is made of a nitride-based semiconductor and is formed on the semiconductor substrate so as to cover at least the convex portion.
    Type: Application
    Filed: November 29, 2010
    Publication date: March 24, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hajime NAGO, Koichi Tachibana, Kotaro Zaima, Shinji Saito, Shinya Nunoue, Toshiyuki Oka
  • Patent number: 7863637
    Abstract: The present invention provides a semiconductor light emitting element with excellent color rendering properties, a method for manufacturing the semiconductor light emitting element, and a light emitting device. The semiconductor light emitting element includes: a semiconductor substrate that has a convex portion having a tilted surface as an upper face, and a concave portion formed on either side of the convex portion, the concave portion having a smaller width than the convex portion, a bottom face of the concave portion being located in a deeper position than the upper face of the convex portion; and a light emitting layer that is made of a nitride-based semiconductor and is formed on the semiconductor substrate so as to cover at least the convex portion.
    Type: Grant
    Filed: February 26, 2008
    Date of Patent: January 4, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hajime Nago, Koichi Tachibana, Kotaro Zaima, Shinji Saito, Shinya Nunoue, Toshiyuki Oka
  • Publication number: 20080237569
    Abstract: The present invention provides a semiconductor light emitting element with excellent color rendering properties, a method for manufacturing the semiconductor light emitting element, and a light emitting device. The semiconductor light emitting element includes: a semiconductor substrate that has a convex portion having a tilted surface as an upper face, and a concave portion formed on either side of the convex portion, the concave portion having a smaller width than the convex portion, a bottom face of the concave portion being located in a deeper position than the upper face of the convex portion; and a light emitting layer that is made of a nitride-based semiconductor and is formed on the semiconductor substrate so as to cover at least the convex portion.
    Type: Application
    Filed: February 26, 2008
    Publication date: October 2, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hajime NAGO, Koichi Tachibana, Kotaro Zaima, Shinji Saito, Shinya Nunoue, Toshiyuki Oka