Patents by Inventor Akihiko Namba

Akihiko Namba 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: 7710013
    Abstract: The present invention relates to an electron emitting device having a structure for efficiently emitting electrons. The electron emitting device has a substrate comprised of an n-type diamond, and a pointed projection provided on the substrate. The projection comprises a base provided on the substrate side, and an electron emission portion provided on the base and emitting electrons from the tip thereof. The base is comprised of an n-type diamond. The electron emission portion is comprised of a p-type diamond. The length from the tip of the projection (electron emission portion) to the interface between the base and the electron emission portion is preferably 100 nm or less.
    Type: Grant
    Filed: August 13, 2007
    Date of Patent: May 4, 2010
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Natsuo Tatsumi, Akihiko Namba, Yoshiki Nishibayashi, Takahiro Imai
  • Patent number: 7476895
    Abstract: An n-type diamond epitaxial layer 20 is formed by processing a single-crystalline {100} diamond substrate 10 so as to form a {111} plane, and subsequently by causing diamond to epitaxially grow while n-doping the diamond {111} plane. Further, a combination of the n-type semiconductor diamond, p-type semiconductor diamond, and non-doped diamond, obtained in the above-described way, as well as the use of p-type single-crystalline {100} diamond substrate allow for a pn junction type, a pnp junction type, an npn junction type and a pin junction type semiconductor diamond to be obtained.
    Type: Grant
    Filed: January 10, 2007
    Date of Patent: January 13, 2009
    Assignee: Sumitomo Electric Industries., Ltd.
    Inventors: Akihiko Namba, Takahiro Imai, Yoshiki Nishibayashi
  • Patent number: 7390695
    Abstract: A manufacturing method for a large-scale diamond substrate and the produced substrate that is suitable for semiconductor lithography processing and large-scale optical parts, semiconductor materials, thermal-release substrate, semiconductor wafer processing, back-feed devices, and others. The manufacturing method of the present invention includes: preparing a substrate having a main face including a first region which is a concave and a second region which surrounds the first region, and mounting, on the first region, a single crystalline diamond seed substrate having a plate thickness thicker than the concave depth of the first region; forming a CVD diamond layer from the single crystalline diamond seed substrate using a chemical vapor deposition, and mutually connecting by forming a CVD diamond layer on the second region at the same time; and polishing to substantially flatten both the CVD diamond layers and on the second region by mechanically polishing.
    Type: Grant
    Filed: March 28, 2006
    Date of Patent: June 24, 2008
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Kiichi Meguro, Keisuke Tanizaki, Akihiko Namba, Yoshiyuki Yamamoto, Takahiro Imai
  • Publication number: 20080113686
    Abstract: A high-frequency amplifier inserted between a television input terminal and a first filter and having a current control input for controlling a current value is provided, together with a current control unit for controlling the current of the high-frequency amplifier, and the current of the high-frequency amplifier is set larger while the portable telephone is sending a transmission signal.
    Type: Application
    Filed: November 6, 2007
    Publication date: May 15, 2008
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masaaki Noda, Masaharu Iwasa, Akihiko Namba
  • Patent number: 7370396
    Abstract: An electronic component includes a substrate; a piezoelectric material layer supported directly or indirectly by the substrate; a first electrode arranged on a surface of the piezoelectric material layer on an opposite side of the substrate; and a second electrode arranged on a surface of the piezoelectric material layer on the substrate side. The piezoelectric material layer is sandwiched between the first electrode and the second electrode. The first electrode has a smaller surface area than the piezoelectric material layer. A portion where the piezoelectric material layer is exposed from the first electrode includes a portion that is thinner than a thickness of the piezoelectric material layer between the first electrode and the second electrode.
    Type: Grant
    Filed: November 28, 2006
    Date of Patent: May 13, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Akihiko Namba, Keiji Onishi, Katsu Takeda
  • Publication number: 20080042144
    Abstract: The present invention relates to an electron emitting device having a structure for efficiently emitting electrons. The electron emitting device has a substrate comprised of an n-type diamond, and a pointed projection provided on the substrate. The projection comprises a base provided on the substrate side, and an electron emission portion provided on the base and emitting electrons from the tip thereof. The base is comprised of an n-type diamond. The electron emission portion is comprised of a p-type diamond. The length from the tip of the projection (electron emission portion) to the interface between the base and the electron emission portion is preferably 100 nm or less.
    Type: Application
    Filed: August 13, 2007
    Publication date: February 21, 2008
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, INC.
    Inventors: Natsuo Tatsumi, Akihiko Namba, Yoshiki Nishibayashi, Takahiro Imai
  • Patent number: 7323812
    Abstract: A method for production includes a step for forming concave molds on a surface of a substrate and a step for growing a diamond heteroepitaxially on the substrate in an atmosphere containing a doping material. The crystal structure of the slope of the concave molds of the substrate can have the cubic system crystal orientation (111), and the doping material is phosphorous. Further, the substrate is Si, and the slope of the molds can be the Si(111) face. The diamond electron emission device contains projection parts on the surface thereof, where a slope of the projection parts 1 contains a diamond (111) face, and flat parts 2, which are not the projection parts, contain face orientations other than (100) face or (110) face and grain boundaries.
    Type: Grant
    Filed: September 29, 2004
    Date of Patent: January 29, 2008
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Natsuo Tatsumi, Akihiko Namba, Yoshiki Nishibayashi, Takahiro Imai
  • Publication number: 20080004819
    Abstract: A method for measuring electric circuit parameters of a 2-terminal circuit having first and second terminals, includes steps of: terminating one of the first and second terminals with a terminal impedance Z1, to measure reflection characteristics al for the other terminal; terminating one of the first and second terminals with a terminal impedance Z2 different from the terminal impedance Z1, to measure reflection characteristics (2 for the other terminal; terminating one of the first and second terminals with a terminal impedance Z3 different from the terminal impedances Z1 and Z2, to measure reflection characteristics ?3 for the other terminal; and calculating electric circuit parameters of the 2-terminal circuit based on the resultant reflection characteristics ?1, ?2 and ?3, whereby measuring electric circuit parameters, such as S-parameters, Z-parameters or the like, even of a DUT having a weak ground, in a simple way with high accuracy and low cost.
    Type: Application
    Filed: May 13, 2005
    Publication date: January 3, 2008
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Akihiko Namba, Tetsuyoshi Ogura, Toru Yamada
  • Patent number: 7307377
    Abstract: The present invention relates to an electron emitting device having a structure for efficiently emitting electrons. The electron emitting device has a substrate comprised of an n-type diamond, and a pointed projection provided on the substrate. The projection comprises a base provided on the substrate side, and an electron emission portion provided on the base and emitting electrons from the tip thereof. The base is comprised of an n-type diamond. The electron emission portion is comprised of a p-type diamond. The length from the tip of the projection (electron emission portion) to the interface between the base and the electron emission portion is preferably 100 nm or less.
    Type: Grant
    Filed: September 29, 2004
    Date of Patent: December 11, 2007
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Natsuo Tatsumi, Akihiko Namba, Yoshiki Nishibayashi, Takahiro Imai
  • Publication number: 20070272929
    Abstract: The present invention relates to a diamond n-type semiconductor in which the amount of change in carrier concentration is fully reduced in a wide temperature range. The diamond n-type semiconductor comprises a diamond substrate, and a diamond semiconductor formed on a main surface thereof and turned out to be n-type. The diamond semiconductor exhibits a carrier concentration (electron concentration) negatively correlated with temperature in a part of a temperature region in which it is turned out to be n-type, and a Hall coefficient positively correlated with temperature. The diamond n-type semiconductor having such a characteristic is obtained, for example, by forming a diamond semiconductor doped with a large amount of a donor element while introducing an impurity other than the donor element onto the diamond substrate.
    Type: Application
    Filed: November 17, 2004
    Publication date: November 29, 2007
    Inventors: Akihiko Namba, Yoshiki Nishibayashi, Takahiro Imai
  • Patent number: 7255744
    Abstract: Concerns lithium-doped diamond: Low-resistivity n-type semiconductor diamond doped with lithium and nitrogen, and a method of manufacturing such diamond are provided. Low-resistivity n-type semiconductor diamond containing 1017 cm?3 or more of lithium atoms and nitrogen atoms together, in which are respectively doped lithium atoms into carbon-atom interstitial lattice sites, and nitrogen atoms into carbon-atom substitutional sites, with the lithium and the nitrogen holding arrangements that neighbor each other. To obtain low-resistivity n-type semiconductor diamond, in a method for the vapor synthesis of diamond, photodissociating source materials by photoexcitation utilizing vacuum ultraviolet light and irradiating a lithium source material with an excimer laser to scatter and supply lithium atoms enables the diamond to be produced.
    Type: Grant
    Filed: December 22, 2003
    Date of Patent: August 14, 2007
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Akihiko Namba, Takahiro Imai, Hisao Takeuchi
  • Patent number: 7246421
    Abstract: A surface acoustic wave device which occupies a small mounting area and has a low profile, yet having an improved reliability, and can be made available at low cost. The surface acoustic wave device comprises a piezoelectric substrate, a function region formed of comb-like electrodes for exciting surface acoustic wave provided on a main surface of the piezoelectric substrate, a space formation member covering the function region, a plurality of bump electrodes provided on a main surface of the piezoelectric substrate and a terminal electrode provided opposed to the main surface of piezoelectric substrate. The bump electrode and the terminal electrode are having a direct electrical connection, and a space between piezoelectric substrate and terminal electrode is filled with resin.
    Type: Grant
    Filed: September 7, 2005
    Date of Patent: July 24, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Akihiko Namba, Keiji Onishi, Yasuhiro Sugaya, Katsunori Moritoki
  • Publication number: 20070090731
    Abstract: An electronic component includes a substrate; a piezoelectric material layer supported directly or indirectly by the substrate; a first electrode arranged on a surface of the piezoelectric material layer on an opposite side of the substrate; and a second electrode arranged on a surface of the piezoelectric material layer on the substrate side. The piezoelectric material layer is sandwiched between the first electrode and the second electrode. The first electrode has a smaller surface area than the piezoelectric material layer. A portion where the piezoelectric material layer is exposed from the first electrode includes a portion that is thinner than a thickness of the piezoelectric material layer between the first electrode and the second electrode.
    Type: Application
    Filed: November 28, 2006
    Publication date: April 26, 2007
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Akihiko NAMBA, Keiji Onishi, Katsu Takeda
  • Patent number: 7172957
    Abstract: An n-type diamond epitaxial layer 20 is formed by processing a single-crystalline {100} diamond substrate 10 so as to form a {111} plane, and subsequently by causing diamond to epitaxially grow while n-doping the diamond {111} plane. Further, a combination of the n-type semiconductor diamond, p-type semiconductor diamond, and non-doped diamond, obtained in the above-described way, as well as the use of p-type single-crystalline {100} diamond substrate allow for a pn junction type, a pnp junction type, an npn junction type and a pin junction type semiconductor diamond to be obtained.
    Type: Grant
    Filed: December 17, 2004
    Date of Patent: February 6, 2007
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Akihiko Namba, Takahiro Imai, Yoshiki Nishibayashi
  • Patent number: 7170215
    Abstract: An electronic component includes a substrate; a piezoelectric material layer supported directly or indirectly by the substrate; a first electrode arranged on a surface of the piezoelectric material layer on an opposite side of the substrate; and a second electrode arranged on a surface of the piezoelectric material layer on the substrate side. The piezoelectric material layer is sandwiched between the first electrode and the second electrode. The first electrode has a smaller surface area than the piezoelectric material layer. A portion where the piezoelectric material layer is exposed from the first electrode includes a portion that is thinner than a thickness of the piezoelectric material layer between the first electrode and the second electrode.
    Type: Grant
    Filed: June 10, 2004
    Date of Patent: January 30, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Akihiko Namba, Keiji Onishi, Katsu Takeda
  • Publication number: 20060220514
    Abstract: A method for production includes a step for forming concaved molds on a surface of a substrate and a step for growing a diamond heteroepitaxially on the substrate in an atmosphere containing a doping material. The crystal structure of the slope of the concaved molds of the substrate can have the cubic system crystal orientation (111), and the doping material is phosphorous. Further, the substrate is Si, and the slope of the molds can be the Si (111) face. The diamond electron emission device contains projection parts on the surface thereof, where a slope of the projection parts 1 contains a diamond (111) face, and flat parts 2, which are not the projection parts, contain face orientations other than (100) face or (110) face and grain boundaries.
    Type: Application
    Filed: September 29, 2004
    Publication date: October 5, 2006
    Inventors: Natsuo Tatsumi, Akihiko Namba, Yoshiki Nishibayashi, Takahiro Imai
  • Publication number: 20060213428
    Abstract: The present invention provides a manufacturing method for a large-scale diamond substrate and a substrate produced by the method suitable for semiconductor lithography processing and large-scale optical parts, semiconductor materials, thermal-release substrate, semiconductor wafer processing, and back-feed devices, and others.
    Type: Application
    Filed: March 28, 2006
    Publication date: September 28, 2006
    Inventors: Kiichi Meguro, Keisuke Tanizaki, Akihiko Namba, Yoshiyuki Yamamoto, Takahiro Imai
  • Publication number: 20060177962
    Abstract: A method of manufacturing n-type semiconductor diamond by the present invention is characterized in producing diamond incorporating Li and N by implanting Li ions into, so that 10 ppm thereof will be contained in, single-crystal diamond incorporating 10 ppm or more N, or else, in doping single-crystal diamond with Li and N ions, by implanting the ions so that ion-implantation depths at which the post-implantation Li and N concentrations each are 10 ppm or more will overlap, and thereafter annealing the diamond in a temperature range of from 800° C. or more to less than 1800° C. to electrically activate the Li and N and restore the diamond crystalline structure. In the present invention, n-type semiconductor diamond incorporates, from the surface of the crystal to the same depth, 10 ppm or more of each of Li and N, wherein its sheet resistance is 107 ?/? or less.
    Type: Application
    Filed: December 22, 2003
    Publication date: August 10, 2006
    Applicant: Sumitomo Electric Industries, Ltd.
    Inventors: Akihiko Namba, Yoshiyuki Yamamoto, Hitoshi Sumiya, Yoshiki Nishibayashi, Takahiro Imai
  • Patent number: 6998687
    Abstract: A surface acoustic wave (SAW) device having improved moisture resistance is provided. The device includes a piezoelectric substrate, an interdigital transducer (IDT) electrode on a first surface of the piezoelectric substrate, and a resin coating for covering the IDT electrode. After a piece of resin material of the resin coating is dipped in an amount of pure water as solvent having a mass as 10 times great as the piece of resin material at 120° C. under 2 atom pressure for twenty hours, a concentration of chlorine ion in the solvent is not higher than 50 ppm.
    Type: Grant
    Filed: January 24, 2002
    Date of Patent: February 14, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Takashi Inoue, Satoshi Matsuo, Akihiko Namba
  • Publication number: 20060006760
    Abstract: A surface acoustic wave device which occupies a small mounting area and has a low profile, yet having an improved reliability, and can be made available at low cost. The surface acoustic wave device comprises a piezoelectric substrate, a function region formed of comb-like electrodes for exciting surface acoustic wave provided on a main surface of the piezoelectric substrate, a space formation member covering the function region, a plurality of bump electrodes provided on a main surface of the piezoelectric substrate and a terminal electrode provided opposed to the main surface of piezoelectric substrate. The bump electrode and the terminal electrode are having a direct electrical connection, and a space between piezoelectric substrate and terminal electrode is filled with resin.
    Type: Application
    Filed: September 7, 2005
    Publication date: January 12, 2006
    Inventors: Akihiko Namba, Keiji Onishi, Yasuhiro Sugaya, Katsunori Moritoki