Patents Assigned to Showa Denko Kabushiki Kaisha
  • Patent number: 6774402
    Abstract: A pn-junction type compound semiconductor light-emitting device having a substrate formed of a crystal, a first barrier layer provided on the substrate and formed of an undoped boron phosphide-base semiconductor of first conduction type, and a light-emitting layer of a first or a second conduction type provided on the first barrier layer including a plurality of superposed constituent layers formed of group III nitride semiconductors each having a different band gap. The constituent layer of the light-emitting layer provided closest to the first barrier layer is a first light-emitting constituent layer formed of a group III nitride semiconductor containing phosphorus (P). A method for producing the semiconductor light-emitting device is also disclosed.
    Type: Grant
    Filed: March 11, 2003
    Date of Patent: August 10, 2004
    Assignee: Showa Denko Kabushiki Kaisha
    Inventor: Takashi Udagawa
  • Patent number: 6761982
    Abstract: A magnetic recording medium containing a non-magnetic substrate, an orientation-determining layer for causing the non-magnetic undercoat layer assume to have a predominant orientation plane of (200), a non-magnetic undercoat layer, a magnetic layer, and a protective layer, in order, is disclosed. The non-magnetic undercoat layer 3 has a bcc structure; the orientation-determining layer has a crystal structure in which columnar fine crystal grains are inclined in a radial direction; and the ratio of a coercive force in a circumferential direction of the magnetic layer (Hcc) to a coercive force in a radial direction of the magnetic layer 4 (Hcr)is more than 1. The magnetic layer includes a plurality of magnetic films and having an hcp structure and a predominant orientation plane of (110), and permits antiferromagnetic bonding to be formed therebetween.
    Type: Grant
    Filed: December 28, 2001
    Date of Patent: July 13, 2004
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Akira Sakawaki, Hiroshi Sakai
  • Patent number: 6759442
    Abstract: An object of the present invention is to provide a packing material for solid phase extraction, ensuring excellent recovery of not only a hydrophobic substance but also an ionic substance by having hydrophobicity and an ion exchange group at the same time, and a solid phase extraction method, a packing apparatus, and a method for treating a sample, using the packing apparatus. A packing material for solid phase extraction of the present invention is a particle obtained by copolymerizing a hydrophobic monomer (A) and a hydrophilic monomer (B) and introducing thereinto an ion exchange group, in which the ion exchange group is introduced without impairing the hydrophobic site. The present invention also provides a solid phase extraction method, a packing apparatus for solid phase extraction and a method for treating a sample, using the packing material.
    Type: Grant
    Filed: June 4, 2001
    Date of Patent: July 6, 2004
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Ryuji Takahashi, Hiroshi Suzuki
  • Patent number: 6740589
    Abstract: A polishing composition for polishing copper and tantalum or a tantalum compound provided on a semiconductor wafer, including an aqueous solvent and at least one amino acid having two or more nitrogen atoms.
    Type: Grant
    Filed: November 30, 2001
    Date of Patent: May 25, 2004
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Yoshitomo Shimazu, Hajime Sato
  • Patent number: 6733553
    Abstract: The present invention can provide an abrasive composition for polishing a semiconductor device which composition contains water, microparticles of an abrasive, and a chelating agent, wherein the abrasive is cerium oxide; the microparticles of cerium oxide have an average particle size of 0.01-1.0 &mgr;m and which composition is used for suitably forming a shallow trench isolation structure in a well-controlled manner during planarization of a semiconductor device including element-isolated structure. The invention also provides a method for producing the semiconductor device by use of the abrasive composition.
    Type: Grant
    Filed: April 12, 2001
    Date of Patent: May 11, 2004
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Takanori Kido, Fumio Tsujino
  • Patent number: 6730941
    Abstract: A boron-phosphide-based semiconductor light-emitting device having a semiconductor substrate of a first conduction type having, on its bottom surface, a bottom electrode; a first boron-phosphide-based semiconductor layer of a first conductive type provided on the substrate; a Group III-V compound semiconductor active layer provided on the first boron-phosphide-based semiconductor layer; a second boron-phosphide-based semiconductor layer of second conduction type provided on the active layer; and a top electrode provided on the surface of the second boron-phosphide-based semiconductor layer.
    Type: Grant
    Filed: January 29, 2003
    Date of Patent: May 4, 2004
    Assignee: Showa Denko Kabushiki Kaisha
    Inventor: Takashi Udagawa
  • Patent number: 6727010
    Abstract: A magnetic recording medium comprising, in order, a non-metallic substrate; an amorphous metallic film having an amorphous structure; a crystal-structure-regulating film of NiP-based alloy; and a non-magnetic undercoat film and a magnetic film; and wherein the crystal-structure-regulating film has a film thickness of 50 nm or less, and a total film thickness of the amorphous metallic film and the crystal-structure-regulating film is at least 60 nm is disclosed.
    Type: Grant
    Filed: December 27, 2001
    Date of Patent: April 27, 2004
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Kenzo Hanawa, Hiroshi Ohsawa
  • Patent number: 6719842
    Abstract: Ammonia for use in the manufacture of a GaN-type compound semiconductor, filled in a charging container 18 such that at least a part of the ammonia is liquid and the liquid phase ammonia has a water concentration determined by a Fourier-transform infrared spectroscopy (FT-IR) of 0.5 vol ppm or less, is introduced in the gaseous state into a reaction chamber 11 housing therein a substrate 1, and a layer comprising a GaN-type compound started from this ammonia is formed on the substrate 1.
    Type: Grant
    Filed: December 29, 1999
    Date of Patent: April 13, 2004
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Hideki Hayashida, Taizo Ito, Yasuyuki Sakaguchi
  • Patent number: 6706078
    Abstract: A solid electrolytic capacitor is obtained by mounting a plurality of single plate capacitor elements within a chip by employing a stacking structure such as parallel stacking, opposing stacking, each layer-opposing stacking or closest stacking. As a result, a compact and high-capacitance element can be easily manufactured. The single plate capacitor element is preferably an element having an unfolded fan-like shape.
    Type: Grant
    Filed: March 13, 2002
    Date of Patent: March 16, 2004
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Hiroshi Nitoh, Atsushi Sakai, Wataru Minamida, Yuji Furuta
  • Patent number: 6699582
    Abstract: A fine carbon fiber having an outer diameter of about 1 to about 80 nm and an aspect ratio of 10 to 30,000, comprising a hollow center portion and a multi-layer sheath structure of a plurality of carbon layers, the layers forming annual rings, wherein the sheath-forming carbon layers form an incomplete sheath, i.e., the carbon layers are partially broken or disrupted in a longitudinal direction, and the outer diameter of the carbon fiber and/or the diameter of the hollow center portion are not uniform in a longitudinal direction. The carbon fiber is obtained by instantaneously reacting a carrier gas at a high temperature and an organic compound gas kept at a temperature below the decomposition temperature of the transition metal compound and has a conductivity equivalent to that of a conventional vapor phase method and is useful as a filler material in resins, rubbers, paints and the like.
    Type: Grant
    Filed: September 26, 2002
    Date of Patent: March 2, 2004
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Toshio Morita, Hitoshi Inoue, Kunio Nishimura, Yutaka Suhara, Satoshi Ohshima, Motoo Yumura
  • Patent number: 6689185
    Abstract: An object of the present invention is to provide a niobium sintered body free of reduction in the CV value, a niobium powder for use in the manufacture of the niobium sintered body, and a capacitor using the niobium sintered body. A niobium powder of the present invention has niobium and tantalum, where the tantalum is present in an amount at most of about 700 ppm by mass. A sintered body and a capacitor each is manufactured using the niobium powder.
    Type: Grant
    Filed: December 19, 2002
    Date of Patent: February 10, 2004
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Kazumi Naito, Kazuhiro Omori
  • Patent number: 6688154
    Abstract: A forging die for forging a cylindrical rotor having a plurality of vane-accommodating grooves which extend toward the axis of the rotor, includes an upper die; a lower die having a mold cavity in its center portion, and a plurality of vane-accommodating-groove-forming portions which protrude inward from an inner wall which defines the mold cavity; and a spacer having a plurality of shell segments for determining a shape of a side wall of the cylindrical rotor which is segmented by the vane-accommodating grooves, and a flange for joining the shell segments is disclosed. The spacer is provided in the interior of the mold cavity of the lower die. A forging production system for producing the rotor; a method for producing the rotor; and the rotor are also disclosed.
    Type: Grant
    Filed: July 16, 2002
    Date of Patent: February 10, 2004
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Yoshiyuki Anazawa, Hidemi Yamada, Keiichi Yokoi
  • Patent number: 6686072
    Abstract: A magnetic recording medium which exhibits excellent magnetic characteristics and which can be easily produced is disclosed. A magnetic recording medium containing a non-metallic substrate 1, a non-magnetic undercoat film 3, a cobalt alloy hexagonal closed packed (hcp) (110) textured magnetic film 4, and a protective film 5 formed on the substrate. An orientation-determining film 2, which determines the crystal orientation of an undercoat film provided directly thereon to cause the texture of the undercoat film to be (200), is formed between the substrate 1 and the undercoat film 3. The orientation-determining film 2 has a crystal structure such that columnar fine crystal grains 2a are inclined in a radial direction of the substrate 1, and the ratio of a coercive force in a circumferential direction of the medium (Hcc) to a coercive force in a radial direction of the medium (Hcr); i.e., Hcc/Hcr, is more than 1.
    Type: Grant
    Filed: August 29, 2001
    Date of Patent: February 3, 2004
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Akira Sakawaki, Masato Kokubu, Hiroshi Sakai
  • Patent number: 6680133
    Abstract: A magnetic recording medium comprising a non-metallic substrate, a non-magnetic undercoat film, a magnetic film, and a protective film are formed, wherein an orientation-determining film, which determines crystalline orientation of a film provided directly on the orientation-determining film when subjected to surface-texturing, is formed between the non-metallic substrate and the non-magnetic undercoat film. The orientation-determining film comprises NiPX and X has a melting point of 600-2000° C.
    Type: Grant
    Filed: December 8, 2000
    Date of Patent: January 20, 2004
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Akira Sakawaki, Masakazu Kobayashi, Hiroshi Sakai
  • Patent number: 6680112
    Abstract: A process for producing a magnetic recording medium, which comprises the steps of forming a non-magnetic undercoat film and a magnetic film on a non-magnetic substrate; forming a carbonaceous protective film thereon through plasma CVD to produce a disk D; etching the surface of a carbonaceous protective film in an etching apparatus 2 by use of plasma generated from an etching gas; and forming a lubricating film on the carbonaceous protective film surface.
    Type: Grant
    Filed: June 14, 2000
    Date of Patent: January 20, 2004
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Mikio Suzuki, Kimie Takagi, Wenqiang Lu, Hiroshi Daio
  • Patent number: 6677061
    Abstract: A magnetic recording medium exhibiting excellent recording and reproduction characteristics is disclosed. A magnetic recording medium includes a non-magnetic substrate 1; a soft magnetic undercoat film 2; an orientation-regulating film 3; a perpendicular magnetic film 4; and a protective film 5, the films being formed on the substrate 1. The soft magnetic undercoat film 2 contains a material represented by the following composition: aFe-bCo-cM-dX1-fN where M is one or more elements selected from Ti, Zr, Nb, Hf, Ta, V, and Mo; X1 is one or more elements selected from Cr, Ga, Al, Si, and Ni; and a, b, c, d, and f represent atomic percentages and satisfy the following relations: 60≦a+b≦90, 30≦a≦90, 5≦c≦20, 0.1≦d≦7, and 3≦f≦30.
    Type: Grant
    Filed: May 23, 2002
    Date of Patent: January 13, 2004
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Kenji Shimizu, Akira Sakawaki, Hiroshi Sakai
  • Patent number: 6673491
    Abstract: The present invention provides a cathode electroactive material comprising a composite oxide comprising &bgr;-MnO2 and a spinel oxide predominantly comprising lithium, manganese, and oxygen. The present invention provides a process for producing said material, which process comprises acid treatment of a composite oxide comprising a spinel oxide predominantly comprising lithium, manganese, and oxygen, and heat treatment of the resultant composite oxide at a temperature of about 200° C. or higher and lower than about 400° C. The thus-produced oxide is employed as a cathode electroactive material in a non-aqueous secondary cell.
    Type: Grant
    Filed: January 22, 2001
    Date of Patent: January 6, 2004
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Akihiko Shirakawa, Takao Noda
  • Patent number: 6671164
    Abstract: An object of the present invention is to provide a niobium powder for producing a capacitor exhibiting excellent reliability; a sintered body formed from the powder; and a capacitor including the sintered body. Even when niobium exhibiting high affinity to oxygen is employed, the niobium powder is obtained by regulating the amount of oxygen contained in the powder. By employing niobium powder which has undergone partial oxidation and partial nitridation, in which the mass ratio of the nitrogen content to the oxygen content is about 1/45 or more, a capacitor exhibiting excellent reliability can be obtained.
    Type: Grant
    Filed: April 24, 2001
    Date of Patent: December 30, 2003
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Kazumi Naito, Nobuyuki Nagato
  • Patent number: 6669852
    Abstract: In order to provide a method for effectively separating red mud generated during alumina-extraction treatment of an alumina ore containing goethite as an iron component, the alumina ore containing goethite as an iron component is treated with an alkaline solution at 110-160° C., to thereby take up alumina components through extraction, and a settling aid formed of a water-soluble polymer including, as an effective component, a copolymer containing, as a monomer component, a vinylhydroxamic acid compound or a salt thereof (A) and having an average molecular weight of at least 2,000 is added to the resultant extract, to thereby settle the red mud for separation thereof.
    Type: Grant
    Filed: October 30, 2001
    Date of Patent: December 30, 2003
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Isao Ishikawa, Haruo Washikita, Yasuo Kawai, Koyuki Mesuda
  • Patent number: 6664575
    Abstract: A GaInP stacked layer structure 1 having a GaAs single crystal substrate 10 having stacked on the surface thereof at least a buffer layer 11, an electron channel layer 12 composed of GaXIn1-XAs (0≦X≦1), a spacer layer 13 composed of GaInP and an electron supply layer 14 composed of GaInP is disclosed. The electron channel layer 12 contains a compositional gradient region imparted with a gradient by increasing the indium composition ratio (1-X) in the direction of the layer thickness increasing toward the junction interface 12b with the electron supply layer 14 side.
    Type: Grant
    Filed: December 5, 2001
    Date of Patent: December 16, 2003
    Assignee: Showa Denko Kabushiki Kaisha
    Inventor: Takashi Udagawa