Patents by Inventor Tadahiro Ohmi

Tadahiro Ohmi 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: 20130320477
    Abstract: A method of etching capable of rapidly and flatly performing wet etching on a Si substrate using fluonitric acid represented by HF(a)HNO3(b)H2O(c) (where the unit of a, b and c is wt % and a+b+c=100). The etching rate of an SiO2 layer with the highly concentrated fluonitric acid is significantly lowered by the appropriate selection of its composition as compared with the etching rate of the Si substrate, and etch the Si substrate until the SiO2 layer is exposed. In this way, it is possible to rapidly etch the Si substrate and significantly enhance the flatness of the etched surface.
    Type: Application
    Filed: October 28, 2011
    Publication date: December 5, 2013
    Applicant: TOHOKU UNIVERSITY
    Inventors: Tadahiro Ohmi, Tomotsugu Ohashi, Kazuhiro Yoshikawa, Tatsuro Yoshida, Teppei Uchimura, Kazuki Soeda, Shigetoshi Sugawa
  • Patent number: 8597584
    Abstract: This gas purifying process removes trace constituents from a mixed gas that includes a rare gas and nitrogen as main components, and at least one from among hydrogen, nitrogen and hydrogen reaction products, and water vapor as the trace constituent. This process sequentially carries out an adsorbing step for removing water vapor and nitrogen and hydrogen reaction products; a hydrogen oxidation step for converting the hydrogen into water vapor by means of a hydrogen oxidation catalytic reaction in the presence of oxygen; and a drying step for removing water vapor generated in the hydrogen oxidation step. When nitrogen oxides are included as a trace constituent, then a denitration step is carried out prior to the adsorbing step, to convert nitrogen oxides into nitrogen and water vapor by means of a catalytic denitration reaction in the presence of a reducing substance.
    Type: Grant
    Filed: May 19, 2010
    Date of Patent: December 3, 2013
    Assignees: Taiyo Nippon Sanso Corporation
    Inventors: Tadahiro Ohmi, Ryuichi Yazaki, Masato Kawai, Tetsuya Kimijima, Kunio Matsuda
  • Patent number: 8592810
    Abstract: It is an object of the present invention to stably form an N-doped ZnO-based compound thin film. In the present invention, a gas containing oxygen and nitrogen and a nitrogen gas together with an organometallic material gas are supplied into a low-electron-temperature high-density plasma which is excited by microwave, thereby forming the N-doped ZnO-based compound thin film on a substrate as a film forming object.
    Type: Grant
    Filed: October 7, 2010
    Date of Patent: November 26, 2013
    Assignees: National University Corporation Tohoku University, Rohm Co., Ltd.
    Inventors: Tadahiro Ohmi, Hirokazu Asahara, Atsutoshi Inokuchi
  • Publication number: 20130307404
    Abstract: With respect to a vacuum tube having a reduced pressure vessel containing an electric discharge gas sealed therein, problems such as the lowering of discharge efficiency owing to an organic material, moisture or oxygen remaining in the reduced pressure vessel have taken place conventionally. It has been now found that the selection of the number of water molecules, the number of molecules of an organic gas and the number of oxygen molecules remaining in the reduced pressure vessel, in a relation with the number of molecules of a gas contributing the electric discharge allows the reduction of the adverse effect by the above-mentioned remaining gas. Specifically, the selection of the number of molecules of the above electric discharge gas being about ten times that of the above-mentioned remaining gas or more can reduce the adverse effect by the above-mentioned remaining gas.
    Type: Application
    Filed: July 3, 2013
    Publication date: November 21, 2013
    Applicant: Foundation for Advancement of International Science
    Inventors: Tadahiro OHMI, Akihiro MORIMOTO
  • Publication number: 20130309828
    Abstract: Provided is a semiconductor device manufacturing method, comprising forming a first sacrificial layer that contacts at least a portion of a first semiconductor layer and has a higher solid solubility for impurities included in the first semiconductor layer than the first semiconductor layer; annealing the first sacrificial layer and the first semiconductor layer; removing the first sacrificial layer through a wet process; after removing the first sacrificial layer, performing at least one of forming an insulating layer that covers at least a portion of the first semiconductor layer and etching a portion of the first semiconductor layer; and forming an electrode layer that is electrically connected to the first semiconductor layer.
    Type: Application
    Filed: July 24, 2013
    Publication date: November 21, 2013
    Applicants: Tohoku University, Advanced Power Device Research Association
    Inventors: Hiroshi KAMBAYASHI, Akinobu TERAMOTO, Tadahiro OHMI
  • Publication number: 20130307092
    Abstract: A semiconductor device includes a gate electrode which is formed on a substrate, and contains Al and Zr, a gate insulating film which is formed to cover at least the upper surface of the gate electrode, and contains Al and Zr, and an insulator layer formed on the substrate to surround the gate electrode.
    Type: Application
    Filed: July 24, 2013
    Publication date: November 21, 2013
    Applicant: NATIONAL UNIVERSITY CORPORATION TOHOKU UNIVERSITY
    Inventor: Tadahiro Ohmi
  • Publication number: 20130307063
    Abstract: Provided is a method of manufacturing a gallium-nitride-based semiconductor device, comprising forming a first semiconductor layer of a gallium-nitride-based semiconductor; and forming a recessed portion by dry etching a portion of the first semiconductor layer via a microwave plasma process using a bromine-based gas.
    Type: Application
    Filed: July 24, 2013
    Publication date: November 21, 2013
    Applicants: TOHOKU UNIVERSITY, ADVANCED POWER DEVICE RESEARCH ASSOCIATION
    Inventors: Hiroshi KAMBAYASHI, Akinobu TERAMOTO, Tadahiro OHMI
  • Publication number: 20130300070
    Abstract: An annular metal gasket for sealing a space between members by being pressed in the vertical direction in a state of being mounted between the members, the metal gasket comprising an annular outer ring having a substantially C-shaped cross-section and having a circumferential-direction opening formed therein, and an annular inner ring fitted inside the outer ring. The inner ring is formed so as to have a polygonal cross-section. Bend parts having an inner angle larger than 180° are formed between the upper corner part and the inner- and outer-circumference-side corner parts; and between the lower corner part and the inner- and outer-circumference-side corner parts.
    Type: Application
    Filed: January 12, 2012
    Publication date: November 14, 2013
    Applicants: NIPPON VALQUA INDUSTRIES, LTD., TOHOKU UNIVERSITY
    Inventors: Tadahiro Ohmi, Yasuyuki Shirai, Koji Sato, Yoshinori Uchino, Masamichi Iwaki
  • Publication number: 20130302918
    Abstract: A plasma processing apparatus for processing an object to be processed using a plasma. The apparatus includes a processing chamber defining a processing cavity for containing an object to be processed and a process gas therein, a microwave radiating antenna having a microwave radiating surface for radiating a microwave in order to excite a plasma in the processing cavity, and a dielectric body provided so as to be opposed to the microwave radiating surface, in which the distance D between the microwave radiating surface and a surface of the dielectric body facing away from the microwave radiating surface, which is represented with the wavelength of the microwave being a distance unit, is determined to be in the range satisfying the inequality 0.7×n/4?D?1.3×n/4 (n being a natural number).
    Type: Application
    Filed: July 17, 2013
    Publication date: November 14, 2013
    Inventors: Tadahiro OHMI, Kazuhide Ino, Takahiro Arakawa
  • Publication number: 20130292700
    Abstract: A method for fabricating a semiconductor device including GaN (gallium nitride) that composes a semiconductor layer and includes forming a gate insulating film, in which at least one film selected from the group of a SiO2 film and an Al2O3 film is formed on a nitride layer containing GaN by using microwave plasma and the formed film is used as at least a part of the gate insulating film.
    Type: Application
    Filed: January 23, 2012
    Publication date: November 7, 2013
    Applicants: TOHOKU UNIVERSITY, TOKYO ELECTRON LIMTED, Advanced Power Device Research Association
    Inventors: Akinobu Teramoto, Hiroshi Kambayashi, Hirokazu Ueda, Yuichiro Morozumi, Katsushige Harada, Kazuhide Hasebe, Tadahiro Ohmi
  • Publication number: 20130295709
    Abstract: “The invention provides a photoelectric conversion element manufacturing apparatus that forms a semiconductor stack film on a substrate by using microwave plasma CVD. The apparatus includes a chamber which is a enclosed space containing a base, on which the a subject substrate for thin-film formation is mounted, a first gas supply unit which supplies plasma excitation gas to a plasma excitation region in the chamber, a pressure regulation unit which regulates pressure in the chamber, a second gas supply unit which supplies raw gas to a plasma diffusion region in the chamber, a microwave application unit which applies microwaves into the chamber, and a bias voltage application unit which selects and applies a substrate bias voltage to the substrate according to the type of gas.
    Type: Application
    Filed: May 23, 2013
    Publication date: November 7, 2013
    Inventors: Tadahiro OHMI, Akinobu TERAMOTO, Tetsuya GOTO, Kouji TANAKA
  • Patent number: 8573151
    Abstract: A conventional microwave plasma processing apparatus, even when krypton (Kr) is used as a plasma-generation gas, can only obtain an oxide film or a nitride film having the same level of characteristics as those obtained when a rare gas such as argon (Ar) is used as a plasma-generation gas. Accordingly, instead of forming a dielectric window of a microwave plasma processing apparatus with only a ceramic member, a planarization film capable of obtaining a stoichiometric SiO2 composition by thermal treatment is coated on one of a plurality of surfaces of the ceramic member, the surface facing a process space, and then thermally-treated, thereby forming a planarization insulation film having a very flat and dense surface. A corrosion-resistant film is formed on the planarization insulation film.
    Type: Grant
    Filed: February 26, 2009
    Date of Patent: November 5, 2013
    Assignees: Tokyo Electron Limited, Tohoku University
    Inventors: Tadahiro Ohmi, Masaki Hirayama, Tetsuya Goto, Yasuyuki Shirai, Masafumi Kitano, Kohei Watanuki, Takaaki Matsuoka, Shigemi Murakawa
  • Patent number: 8575023
    Abstract: A semiconductor device manufacturing method which achieves a contact of a low resistivity is provided. In a state where a first metal layer in contact with a semiconductor is covered with a second metal layer for preventing oxidation, only the first metal layer is silicided to form a silicide layer with no oxygen mixed therein. As a material of the first metal layer, a metal having a work function difference of a predetermined value from the semiconductor is used. As a material of the second metal layer, a metal which does not react with the first metal layer at an annealing temperature is used.
    Type: Grant
    Filed: October 23, 2009
    Date of Patent: November 5, 2013
    Assignees: National University Corporation Tohoku University, Foundation for Advancement of International Science
    Inventors: Tadahiro Ohmi, Akinobu Teramoto, Tatsunori Isogai, Hiroaki Tanaka
  • Patent number: 8568577
    Abstract: Provided is a magnetron sputtering apparatus that increases an instantaneous plasma density on a target to improve a film forming rate. The magnetron sputtering apparatus includes a substrate to be processed, a target installed to face the substrate and a rotary magnet installed at a side opposite to the substrate across the target. In the magnetron sputtering apparatus, plasma loops are formed on a target surface. The plasma loops are generated, move and disappear in an axis direction of the rotary magnet according to a rotation of the rotary magnet.
    Type: Grant
    Filed: April 4, 2008
    Date of Patent: October 29, 2013
    Assignees: National University Corporation Tohoku University, Tokyo Electron Limited
    Inventors: Tadahiro Ohmi, Tetsuya Goto, Takaaki Matsuoka
  • Patent number: 8568556
    Abstract: The plasma processing apparatus includes: a processing container including a metal; an electromagnetic wave source outputting an electromagnetic wave; a dielectric plate facing an inner wall of the processing container and transmitting the electromagnetic wave, which is output from the electromagnetic wave source, into the processing container; and a groove formed in an inner surface of the processing container and functioning as a propagation disturbing portion. If a low frequency microwave is supplied, the propagation of a conductor surface wave can be suppressed by the groove.
    Type: Grant
    Filed: June 11, 2008
    Date of Patent: October 29, 2013
    Assignees: Tokyo Electron Limited, Tohoku University
    Inventors: Masaki Hirayama, Tadahiro Ohmi
  • Patent number: 8562320
    Abstract: A resin molding device which molds a resin tube 1 from a molten resin has a tube molding portion 14 and a spindle 15 as jigs which define inner and outer diameters of the resin tube.
    Type: Grant
    Filed: March 18, 2008
    Date of Patent: October 22, 2013
    Assignees: National University Corporation Tohoku University, Nichias Corporation
    Inventors: Tadahiro Ohmi, Yasuyuki Shirai, Jiro Yamanaka, Kengo Iwahara, Kouji Fukae
  • Patent number: 8551830
    Abstract: There is provided a small-type semiconductor integrated circuit whose circuit area is small and whose wiring length is short. The semiconductor integrated circuit is constructed in a multi-layer structure and is provided with a first semiconductor layer, a first semiconductor layer transistor formed in the first semiconductor layer, a wiring layer which is deposited on the first semiconductor layer and in which metal wires are formed, a second semiconductor layer deposited on the wiring layer and a second semiconductor layer transistor formed in the second semiconductor layer. It is noted that insulation of a gate insulating film of the first semiconductor layer transistor is almost equal with that of a gate insulating film of the second semiconductor layer transistor and the gate insulating film of the second semiconductor layer transistor is formed by means of radical oxidation or radical nitridation.
    Type: Grant
    Filed: April 28, 2008
    Date of Patent: October 8, 2013
    Assignees: Advantest Corporation, National University Corporation Tohoku University
    Inventors: Tadahiro Ohmi, Koji Kotani, Kazuyuki Maruo, Takahiro Yamaguchi
  • Patent number: 8535494
    Abstract: Provided is a rotary magnet sputtering apparatus which includes a plasma shielding member and an outer wall connected to the ground and which has a series resonant circuit and a parallel resonant circuit between the plasma shielding member and the outer wall. The series resonant circuit has a very low impedance only at its resonant frequency while the parallel resonant circuit has a very high impedance only at its resonant frequency. With this configuration, the impedance between substrate RF power and the plasma shielding member becomes very high so that it is possible to suppress the generation of plasma between a substrate 10 to be processed and the plasma shielding member. Further, since a series resonant circuit is provided between a target and the ground, the RF power is efficiently supplied only to a region where the substrate passes under the target, so that a self-bias voltage is generated.
    Type: Grant
    Filed: March 2, 2009
    Date of Patent: September 17, 2013
    Assignees: National University Corporation Tohoku University, Tokyo Electron Limited
    Inventors: Tadahiro Ohmi, Tetsuya Goto, Takaaki Matsuoka
  • Publication number: 20130235545
    Abstract: In a multilayer wiring board 100 having a high-density wiring region and a high-frequency propagation region mounted in the same board, it is possible to propagate a signal frequency of 40 GHz or more in the high-frequency propagation region by using a resin material with a dissipation factor (tan ?) of less than 0.01 as a material of an insulating layer used at least in the high-frequency propagation region. The insulating layer is formed of a polymerizable composition which contains a cycloolefin monomer, a polymerization catalyst, a cross-linking agent, a bifunctional compound having two vinylidene groups, and a trifunctional compound having three vinylidene groups and in which the content ratio of the bifunctional compound and the trifunctional compound is 0.5 to 1.5 in terms of a weight ratio value (bifunctional compound/trifunctional compound).
    Type: Application
    Filed: November 10, 2011
    Publication date: September 12, 2013
    Applicants: ZEON CORPORATION, NATIONAL UNIVERSITY CORPORATION TOHOKU UNIVERSITY
    Inventors: Tadahiro Ohmi, Tetsuya Goto, Masakazu Hashimoto
  • Patent number: 8513137
    Abstract: A plasma processing apparatus for processing an object to be processed using a plasma. The apparatus includes a processing chamber defining a processing cavity for containing an object to be processed and a process gas therein, a microwave radiating antenna having a microwave radiating surface for radiating a microwave in order to excite a plasma in the processing cavity, and a dielectric body provided so as to be opposed to the microwave radiating surface, in which the distance D between the microwave radiating surface and a surface of the dielectric body facing away from the microwave radiating surface, which is represented with the wavelength of the microwave being a distance unit, is determined to be in the range satisfying the inequality 0.7×n/4?D?1.3×n/4 (n being a natural number).
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: August 20, 2013
    Assignees: Rohm Co., Ltd., Tadahiro Ohmi
    Inventors: Tadahiro Ohmi, Kazuhide Ino, Takahiro Arakawa