Patents by Inventor Goshi Biwa

Goshi Biwa 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: 20090008648
    Abstract: A GaN-based semiconductor element which can suppress a leakage current generated during reverse bias application, an optical device using the same, and an image display apparatus using the optical device are provided. The GaN-based semiconductor element has a first GaN-based compound layer including an n-type conductive layer; a second GaN-based compound layer including a p-type conductive layer; and an active layer provided between the first GaN-based compound layer and the second GaN-based compound layer. In this GaN-based semiconductor element, the first GaN-based compound layer includes an underlayer having an n-type impurity concentration in the range of 3×1018 to 3×1019/cm3, and when a reverse bias of 5 V is applied, a leakage current density, which is the density of a current flowing per unit area of the active layer, is 2×10?5 A/cm2 or less.
    Type: Application
    Filed: June 12, 2008
    Publication date: January 8, 2009
    Applicant: SONY CORPORATION
    Inventors: Goshi Biwa, Ippei Nishinaka, Hiroyuki Okuyama
  • Patent number: 7468528
    Abstract: A semiconductor light-emitting device is provided. The semiconductor light-emitting device includes a laminated semiconductor structure portion composed of at least a first conductivity type first cladding layer, an active layer and a second conductivity type second cladding layer, wherein an outer peripheral surface of this laminated semiconductor structure portion is formed as a curved surface shape which is protrusively curved or bent with respect to the outside of the laminated direction.
    Type: Grant
    Filed: January 10, 2006
    Date of Patent: December 23, 2008
    Assignee: Sony Corporation
    Inventors: Jun Suzuki, Masato Doi, Hiroyuki Okuyama, Goshi Biwa
  • Publication number: 20080273566
    Abstract: A semiconductor light-emitting element includes a nitride-based Group III-V compound semiconductor, wherein the semiconductor light-emitting element has a structure in which an active layer including one or a plurality of well layers is sandwiched between a p-side cladding layer and an n-side cladding layer, and the composition of at least one of the well layers of the active layer is modulated in the direction perpendicular to the thickness direction of the least one of the well layers.
    Type: Application
    Filed: March 19, 2008
    Publication date: November 6, 2008
    Applicant: SONY CORPORATION
    Inventors: Ippei Nishinaka, Goshi Biwa
  • Publication number: 20080121904
    Abstract: There is obtained a semiconductor light-emitting device capable of obtaining a high light reflectance through the use of a high-reflection metal layer formed on the side of an electrode on one side and capable of preventing migration of atoms from the high-reflectance metal layer. Semiconductor layers of the opposite conduction types are formed on the opposite sides of an active layer, and an ohmic contact layer being a thin film for contriving a decrease in contact resistance, a transparent and conductive layer, and a high-reflection metal layer for reflecting light generated in the active layer are sequentially layered on one of the semiconductor layers. Since the transparent conductive layer functions also as a barrier layer and it transmits light, a high light take-out efficiency can be obtained through the reflection at the high-reflectance metal layer.
    Type: Application
    Filed: March 31, 2005
    Publication date: May 29, 2008
    Applicant: SONY CORPORATION
    Inventors: Jun Suzuki, Masato Doi, Hiroyuki Okuyama, Goshi Biwa
  • Patent number: 7364805
    Abstract: A crystal foundation having dislocations is used to obtain a crystal film of low dislocation density, a crystal substrate, and a semiconductor device. One side of a growth substrate (11) is provided with a crystal layer (13) with a buffer layer (12) in between. The crystal layer (13) has spaces (13a), (13b) in an end of each threading dislocation D1 elongating from below. The threading dislocation D1 is separated from the upper layer by the spaces (13a), (13b), so that each threading dislocation D1 is blocked from propagating to the upper layer. When the displacement of the threading dislocation D1 expressed by Burgers vector is preserved to develop another dislocation, the spaces (13a), (13b) vary the direction of its displacement. As a result, the upper layer above the spaces (13a), (13b) turns crystalline with a low dislocation density.
    Type: Grant
    Filed: January 18, 2002
    Date of Patent: April 29, 2008
    Assignee: Sony Corporation
    Inventors: Etsuo Morita, Yousuke Murakami, Goshi Biwa, Hiroyuki Okuyama, Masato Doi, Toyoharu Oohata
  • Publication number: 20080054822
    Abstract: A method for driving a light-emitting diode includes the step of modulating the luminance of the light-emitting diode with current density within the range of 20 A/cm2 or less. The light-emitting diode includes a p-type layer, an n-type layer, and a light-emitting layer disposed therebetween and having an indium-containing quantum well structure. Each of the p-type layer, the n-type layer, and the light-emitting layer includes a nitride-based group III-V compound semiconductor crystal having a wurtzite structure. The light-emitting layer has a main surface inclined at an angle of 0.25° to 2° with respect to a c-plane.
    Type: Application
    Filed: August 9, 2007
    Publication date: March 6, 2008
    Applicant: Sony Corporation
    Inventor: Goshi Biwa
  • Publication number: 20080048195
    Abstract: A GaN-based semiconductor light-emitting element capable of suppressing the occurrence of piezoelectric spontaneous polarization in the thickness direction of an active layer and reducing the driving voltage of a light-emitting diode is provided. The GaN-based semiconductor light-emitting element has a structure with a first GaN-based compound semiconductor layer 21 having the top face parallel to the a-plane and having a first conductivity type, an active layer 22 having the top face parallel to the a-plane, a second GaN-based compound semiconductor layer 23 having the top face parallel to the a-plane and having a second conductivity type, and a contact layer 24 composed of a GaN-based compound semiconductor and having the top face parallel to the a-plane, stacked in that order. The GaN-based semiconductor light-emitting element further includes a first electrode 25 disposed on the first GaN-based compound semiconductor layer 21 and a second electrode 26 disposed on the contact layer 24.
    Type: Application
    Filed: December 26, 2005
    Publication date: February 28, 2008
    Applicant: SONY CORPORATION
    Inventors: Hiroyuki Okuyama, Goshi Biwa
  • Publication number: 20080050599
    Abstract: A crystal foundation having dislocations is used to obtain a crystal film of low dislocation density, a crystal substrate, and a semiconductor device. One side of a growth substrate (11) is provided with a crystal layer (13) with a buffer layer (12) in between. The crystal layer (13) has spaces (13a), (13b) in an end of each threading dislocation D1 elongating from below. The threading dislocation D1 is separated from the upper layer by the spaces (13a), (13b), so that each threading dislocation D1 is blocked from propagating to the upper layer. When the displacement of the threading dislocation D1 expressed by Burgers vector is preserved to develop another dislocation, the spaces (13a), (13b) vary the direction of its displacement. As a result, the upper layer above the spaces (13a), (13b) turns crystalline with a low dislocation density.
    Type: Application
    Filed: October 23, 2007
    Publication date: February 28, 2008
    Applicant: Sony Corporation
    Inventors: Etsuo Morita, Yousuke Murakami, Goshi Biwa, Hiroyuki Okuyama, Masato Doi, Toyoharu Oohata
  • Publication number: 20070284564
    Abstract: A GaN-based semiconductor light-emitting device includes (A) a first GaN-based compound semiconductor layer 13 having n-type conductivity, (B) an active layer 15 having a multi-quantum well structure including well layers and barrier layers for separating between the well layers, and (C) a second GaN-based compound semiconductor layer 17 having p-type conductivity. The well layers are disposed in the active layer 15 so as to satisfy the relation d1<d2 wherein d1 is the well layer density on the first GaN-based compound semiconductor layer side in the active layer and d2 is the well layer density on the second GaN-based compound semiconductor layer side.
    Type: Application
    Filed: September 8, 2006
    Publication date: December 13, 2007
    Applicant: SONY CORPORATION
    Inventors: Goshi Biwa, Hiroyuki Okuyama
  • Publication number: 20070187704
    Abstract: A semiconductor light emitting element, manufacturing method. thereof, integrated semiconductor light emitting device, manufacturing method thereof, illuminating device, and manufacturing method thereof are provided. An n-type GaN layer is grown on a sapphire substrate, and a growth mask of SiN, for example, is formed thereon. On the n-type GaN layer exposed through an opening in the growth mask, a six-sided steeple-shaped n-type GaN layer is selectively grown, which has inclined crystal planes each composed of a plurality of crystal planes inclined from the major surface of the sapphire substrate by different angles of inclination to exhibit a convex plane as a whole. On the n-type GaN layer, an active layer and a p-type GaN layer are grown to make a light emitting element structure. Thereafter, a p-side electrode and an n-side electrode are formed.
    Type: Application
    Filed: March 26, 2007
    Publication date: August 16, 2007
    Applicant: SONY CORPORATION
    Inventors: Hiroyuki Okuyama, Masato Doi, Goshi Biwa, Jun Suzuki, Toyoharu Oohata
  • Publication number: 20070190677
    Abstract: A semiconductor light emitting element, manufacturing method thereof, integrated semiconductor light emitting device, manufacturing method thereof, illuminating device, and manufacturing method thereof are provided. An n-type GaN layer is grown on a sapphire substrate, and a growth mask of SiN, for example, is formed thereon. On the n-type GaN layer exposed through an opening in the growth mask, a six-sided steeple-shaped n-type GaN layer is selectively grown, which has inclined crystal planes each composed of a plurality of crystal planes inclined from the major surface of the sapphire substrate by different angles of inclination to exhibit a convex plane as a whole. On the n-type GaN layer, an active layer and a p-type GaN layer are grown to make a light emitting element structure. Thereafter, a p-side electrode and an n-side electrode are formed.
    Type: Application
    Filed: March 26, 2007
    Publication date: August 16, 2007
    Applicant: SONY CORPORATION
    Inventors: Hiroyuki Okuyama, Masato Doi, Goshi Biwa, Jun Suzuki, Toyoharu Oohata
  • Patent number: 7250320
    Abstract: A semiconductor light emitting element, manufacturing method thereof, integrated semiconductor light emitting device, manufacturing method thereof, illuminating device, and manufacturing method thereof are provided. An n-type GaN layer is grown on a sapphire substrate, and a growth mask of SiN, for example, is formed thereon. On the n-type GaN layer exposed through an opening in the growth mask, a six-sided steeple-shaped n-type GaN layer is selectively grown, which has inclined crystal planes each composed of a plurality of crystal planes inclined from the major surface of the sapphire substrate by different angles of inclination to exhibit a convex plane as a whole. On the n-type GaN layer, an active layer and a p-type GaN layer are grown to make a light emitting element structure. Thereafter, a p-side electrode and an n-side electrode are formed.
    Type: Grant
    Filed: February 19, 2004
    Date of Patent: July 31, 2007
    Assignee: Sony Corporation
    Inventors: Hiroyuki Okuyama, Masato Doi, Goshi Biwa, Jun Suzuki, Toyoharu Oohata
  • Publication number: 20070147453
    Abstract: An n-type GaN layer is grown onto a sapphire substrate and a hexagonal etching mask is formed onto the n-type GaN layer as provided. The n-type GaN layer is etched to a predetermined depth by using the etching mask by the RIE method. A hexagonal prism portion whose upper surface is a C plane is formed. After the etching mask was removed, an active layer and a p-type GaN layer are sequentially grown onto the whole surface of the substrate so as to cover the hexagonal prism portion, thereby forming a light emitting device structure. After that, a p-side electrode is formed onto the p-type GaN layer of the hexagonal prism portion and an n-side electrode is formed onto the n-type GaN layer.
    Type: Application
    Filed: March 6, 2007
    Publication date: June 28, 2007
    Applicant: SONY CORPORATION
    Inventors: Toyoharu Oohata, Hiroyuki Okuyama, Masato Doi, Goshi Biwa, Jun Suzuki
  • Publication number: 20070125996
    Abstract: A crystal foundation having dislocations is used to obtain a crystal film of low dislocation density, a crystal substrate, and a semiconductor device. One side of a growth substrate (11) is provided with a crystal layer (13) with a buffer layer (12) in between. The crystal layer (13) has spaces (13a), (13b) in an end of each threading dislocation D1 elongating from below. The threading dislocation D1 is separated from the upper layer by the spaces (13a), (13b), so that each threading dislocation D1 is blocked from propagating to the upper layer. When the displacement of the threading dislocation D1 expressed by Burgers vector is preserved to develop another dislocation, the spaces (13a), (13b) vary the direction of its displacement. As a result, the upper layer above the spaces (13a), (13b) turns crystalline with a low dislocation density.
    Type: Application
    Filed: January 31, 2007
    Publication date: June 7, 2007
    Applicant: Sony Corporation
    Inventors: Etsuo Morita, Yousuke Murakami, Goshi Biwa, Hiroyuki Okuyama, Masato Doi, Toyoharu Oohata
  • Patent number: 7227189
    Abstract: Nitride semiconductor devices and methods of producing same are provided. The present invention includes forming a nitride semiconductor layer on a base body of the nitride semiconductor under selective and controlled crystal growth conditions. For example, the crystal growth rate, the supply of crystal growth source material and/or the crystal growth area can be varied over time, thus resulting in a nitride semiconductor device with enhanced properties.
    Type: Grant
    Filed: June 15, 2004
    Date of Patent: June 5, 2007
    Assignee: Sony Corporation
    Inventors: Goshi Biwa, Hiroyuki Okuyama, Masato Doi, Toyoharu Oohata
  • Patent number: 7221001
    Abstract: Semiconductor light-emitting devices are provided. The semiconductor light-emitting devices include a substrate and a crystal layer selectively grown thereon at least a portion of the crystal layer is oriented along a plane that slants to or diagonally intersect a principal plane of orientation associated with the substrate thereby for example, enhancing crystal properties, preventing threading dislocations, and facilitating device miniaturization and separation during manufacturing and use thereof.
    Type: Grant
    Filed: February 24, 2005
    Date of Patent: May 22, 2007
    Assignee: Sony Corporation
    Inventors: Hiroyuki Okuyama, Masato Doi, Goshi Biwa, Toyoharu Oohata, Tomoyuki Kikutani
  • Publication number: 20070085087
    Abstract: A semiconductor light-emitting device is provided. The semiconductor light-emitting device includes: a substrate having a substrate surface oriented along a substrate surface plane; a first grown layer including a first grown layer conductivity type formed on the substrate; a masking layer formed on the first grown layer; a second grown layer of a second grown layer conductivity type formed by selective growth through an opening in the masking layer and including a crystal surface oriented along a crystal surface plane; a first cladding layer including a first cladding layer conductivity type formed along at least a portion of the crystal surface plane; an active layer; and a second cladding layer including a second cladding layer conductivity type. At least one of the first cladding layer, the active layer, and the second cladding layer cover the masking layer surrounding the opening.
    Type: Application
    Filed: November 9, 2006
    Publication date: April 19, 2007
    Applicant: Sony Corporation
    Inventors: Hiroyuki Okuyama, Masato Doi, Goshi Biwa, Toyoharu Oohata, Tomoyuki Kikutani
  • Patent number: 7205168
    Abstract: An n-type GaN layer is grown onto a sapphire substrate and a hexagonal etching mask is formed onto the n-type GaN layer as provided. The n-type GaN layer is etched to a predetermined depth by using the etching mask by the RIE method. A hexagonal prism portion whose upper surface is a C plane is formed. After the etching mask was removed, an active layer and a p-type GaN layer are sequentially grown onto the whole surface of the substrate so as to cover the hexagonal prism portion, thereby forming a light emitting device structure. After that, a p-side electrode is formed onto the p-type GaN layer of the hexagonal prism portion and an n-side electrode is formed onto the n-type GaN layer.
    Type: Grant
    Filed: September 8, 2003
    Date of Patent: April 17, 2007
    Assignee: Sony Corporation
    Inventors: Toyoharu Oohata, Hiroyuki Okuyama, Masato Doi, Goshi Biwa, Jun Suzuki
  • Publication number: 20070077674
    Abstract: A process for producing a semiconductor light-emitting device is provided. The process includes providing a substrate including a substrate surface oriented along a substrate surface plane, forming a crystal seed layer on the substrate surface, forming a masking layer on the crystal seed layer, wherein the masking layer includes an opening, forming a crystal layer by selective growth of the crystal seed layer through the opening of the masking layer, wherein the crystal layer includes a crystal layer surface oriented along a crystal layer plane that diagonally intersects the substrate surface, and forming each of a first conductive layer, an active layer, and a second conductive layer along at least a portion of the crystal layer surface.
    Type: Application
    Filed: November 9, 2006
    Publication date: April 5, 2007
    Applicant: Sony Corporation
    Inventors: Hiroyuki Okuyama, Masato Doi, Goshi Biwa, Toyoharu Oohata, Tomoyuki Kikutani
  • Publication number: 20070037308
    Abstract: A method for manufacturing a GaN semiconductor light-emitting element is provided. The method for manufacturing a GaN semiconductor light-emitting element includes forming, by crystal growth, a first GaN compound semiconductor layer of a first conductivity type, the top face of which corresponds to the A plane, an active layer composed of InxGa(1?x)N, the top face of which corresponds to the A plane, and a second GaN compound semiconductor layer of a second conductivity type, the top face of which corresponds to the A plane, in that order on a base which is a nonpolar plane, wherein the active layer is formed at a crystal growth rate of 0.3 nm/sec or more.
    Type: Application
    Filed: August 8, 2006
    Publication date: February 15, 2007
    Applicant: SONY CORPORATION
    Inventors: Hiroyuki Okuyama, Goshi Biwa