Patents by Inventor Yoshihiko Saito

Yoshihiko Saito 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: 7224022
    Abstract: As and B are implanted to side surfaces of trenches 3 by a rotation ion implanting method, and by using a difference between these impurities in diffusion coefficient, the structure in which an n?-type epitaxial Si layer is interposed between trenches 3 is converted into a semiconductor structure consisting of n-type pillar layer 5/p-type pillar layer 4/n-type pillar layer 5 lining up. The structure can function substantially the same role as that of a super junction structure.
    Type: Grant
    Filed: March 19, 2004
    Date of Patent: May 29, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Keinichi Tokano, Yoshihiko Saito, Shigeo Kouzuki, Yasunori Usui, Masaru Izumisawa, Takahiro Kawano
  • Publication number: 20070025403
    Abstract: A graded SiGe buffer layer 12 and a SiGe buffer layer 13 are formed on a Si substrate 11. A strained Si layer 14 having a critical film thickness or less is formed to decrease a stress applied to an interface between the strained Si layer 14 and the SiGe buffer layer 13, thereby obtaining a strained Si layer 14, in which a crystal defect density is low. Furthermore, the surface of the strained Si layer 14 is covered by a SiGe cap layer 21, which has a lattice constant greater than Si, thereby preventing the strained Si layer 14 from disappearing due to the sacrifice oxidation performed in the later steps, and enabling a gate oxide layer to be formed thereon. Thus, it is possible to obtain a high-quality strained Si wafer.
    Type: Application
    Filed: July 27, 2006
    Publication date: February 1, 2007
    Inventors: Hajime Nagano, Yoshihiko Saito
  • Publication number: 20060145230
    Abstract: A semiconductor element of this invention includes a drift layer of a first conductivity type formed on a semiconductor substrate of the first conductivity type, a well layer of a second conductivity type selectively formed in the surface of the drift layer, a source layer of the first conductivity type selectively formed in the surface of the well layer, a trench formed to reach at least the inside of the drift layer from the surface of the source layer through the well layer, a buried electrode formed in the trench through a first insulating film, and a control electrode formed on the drift layer, the well layer, and the source layer through a second insulating film.
    Type: Application
    Filed: December 5, 2005
    Publication date: July 6, 2006
    Inventors: Ichiro Omura, Wataru Saito, Tsuneo Ogura, Hiromichi Ohashi, Yoshihiko Saito, Kenichi Tokano
  • Patent number: 7067870
    Abstract: A semiconductor element of this invention includes a drift layer of a first conductivity type formed on a semiconductor substrate of the first conductivity type, a well layer of a second conductivity type selectively formed in the surface of the drift layer, a source layer of the first conductivity type selectively formed in the surface of the well layer, a trench formed to reach at least the inside of the drift layer from the surface of the source layer through the well layer, a buried electrode formed in the trench through a first insulating film, and a control electrode formed on the drift layer, the well layer, and the source layer through a second insulating film.
    Type: Grant
    Filed: February 3, 2004
    Date of Patent: June 27, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ichiro Omura, Wataru Saito, Tsuneo Ogura, Hiromichi Ohashi, Yoshihiko Saito, Kenichi Tokano
  • Publication number: 20060046441
    Abstract: According to the present invention, there is provided a selectivity monitoring method in a selective film growth method of selectively growing a film in a predetermined region on a semiconductor substrate, comprising: selectively growing the film on a surface of the semiconductor substrate while measuring temperature of the surface of the semiconductor substrate by at least one pyrometer placed in a non-contact state above the surface of the semiconductor substrate; and determining that selectivity of the growth of the film has decreased, when the temperature changes from a predetermined value or changes from a predetermined angle in a graph showing change of the temperature during film formation.
    Type: Application
    Filed: August 26, 2005
    Publication date: March 2, 2006
    Inventors: Kiyotaka Miyano, Akihito Yamamoto, Yoshihiko Saito
  • Patent number: 6984669
    Abstract: The present invention provides a fluorinated cation exchange membrane comprising at least two layers, a first layer made of a fluoropolymer having sulfonic acid groups and a second layer made of a fluoropolymer having carboxylic acid groups on the cathode side thereof, wherein when an electrolytic soda process is conducted using the cation exchange membrane as a diaphragm between an anode compartment and a cathode compartment, the water transport number through the cation exchange membrane is at least 4.8 mol/F (F: Faraday) under operating conditions such that the brine concentration in the anode compartment is 200 g/L, the sodium hydroxide concentration in the cathode compartment is 32 mass %, the current density is 5 kA/m2, and the temperature is 90° C. The fluorinated cation exchange membrane of the present invention gives an excellent effect such that a uniform catholyte concentration can be maintained even when installed in an electrolytic cell having no special circulating means.
    Type: Grant
    Filed: November 10, 2003
    Date of Patent: January 10, 2006
    Assignee: Asahi Glass Company, Limited
    Inventors: Takuo Nishio, Yoshihiko Saito, Tetsuji Shimohira
  • Publication number: 20050202266
    Abstract: A laminate film has a clear layer (B) comprising an acrylic-based polymer (B1) having at least one longer unsaturated double bond group and at least one shorter unsaturated double bond group as side chains, and having a weight-average molecular weight not less than 50,000 but not more than 500,000, the longer unsaturated double bond group introduced in the acrylic-based polymer (B1) by a long-chain unsaturated carboxylic acid having a molecular weight of 150 or more, and the shorter unsaturated double bond group introduced in the acrylic-based polymer (B1) by a short-chain unsaturated carboxylic acid having a molecular weight of less than 150. Compared with laminate films prepared by spray coating, dip coating, or other coating methods, this laminate film is excellent in processability, coating film properties, and ornamental properties. Thus, an article can be excellently decorated with the laminate film provided by the present invention.
    Type: Application
    Filed: March 9, 2005
    Publication date: September 15, 2005
    Inventors: Takakazu Hase, Yoshihiko Saito, Koichi Takahashi, Yasushi Kojima, Kenichi Shinya, Keishi Hamada
  • Publication number: 20040238844
    Abstract: A semiconductor device includes a first conductivity type semiconductor substrate, a vertical unit cell and a separating member. The unit cell includes a second conductivity type semiconductor layer and two first conductivity type semiconductor layers to interpose the second conductivity type semiconductor layer from both side surfaces. A pn junction boundary between the second and first conductivity type semiconductor layer is substantially vertical to the main surface of the semiconductor substrate. A second conductivity type base layer on an upper surface of the second conductivity type semiconductor layer has an impurity concentration higher than the second conductivity type semiconductor layer. A first conductivity type source diffusion layer is on a surface of the base layer. A gate insulating film is formed on the base layer interposed between the source diffusion layer and the first conductivity type semiconductor layer. A gate electrode is formed on the gate insulating film.
    Type: Application
    Filed: March 19, 2004
    Publication date: December 2, 2004
    Inventors: Kenichi Tokano, Yoshihiko Saito, Shigeo Kouzuki, Yasunori Usui, Masaru Izumisawa, Takahiro Kawano
  • Publication number: 20040155287
    Abstract: A semiconductor element of this invention includes a drift layer of a first conductivity type formed on a semiconductor substrate of the first conductivity type, a well layer of a second conductivity type selectively formed in the surface of the drift layer, a source layer of the first conductivity type selectively formed in the surface of the well layer, a trench formed to reach at least the inside of the drift layer from the surface of the source layer through the well layer, a buried electrode formed in the trench through a first insulating film, and a control electrode formed on the drift layer, the well layer, and the source layer through a second insulating film.
    Type: Application
    Filed: February 3, 2004
    Publication date: August 12, 2004
    Inventors: Ichiro Omura, Wataru Saito, Tsuneo Ogura, Hiromichi Ohashi, Yoshihiko Saito, Kenichi Tokano
  • Patent number: 6750508
    Abstract: A semiconductor element of this invention includes a drift layer of a first conductivity type formed on a semiconductor substrate of the first conductivity type, a well layer of a second conductivity type selectively formed in the surface of the drift layer, a source layer of the first conductivity type selectively formed in the surface of the well layer, a trench formed to reach at least the inside of the drift layer from the surface of the source layer through the well layer, a buried electrode formed in the trench through a first insulating film, and a control electrode formed on the drift layer, the well layer, and the source layer through a second insulating film.
    Type: Grant
    Filed: June 28, 2001
    Date of Patent: June 15, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ichiro Omura, Wataru Saito, Tsuneo Ogura, Hiromichi Ohashi, Yoshihiko Saito, Kenichi Tokano
  • Publication number: 20040092611
    Abstract: The present invention provides a fluorinated cation exchange membrane comprising at least two layers, a first layer made of a fluoropolymer having sulfonic acid groups and a second layer made of a fluoropolymer having carboxylic acid groups on the cathode side thereof, wherein when an electrolytic soda process is conducted using the cation exchange membrane as a diaphragm between an anode compartment and a cathode compartment, the water transport number through the cation exchange membrane is at least 4.8 mol/F (F: Faraday) under operating conditions such that the brine concentration in the anode compartment is 200 g/L, the sodium hydroxide concentration in the cathode compartment is 32 mass %, the current density is 5 kA/m2, and the temperature is 90° C. The fluorinated cation exchange membrane of the present invention gives an excellent effect such that a uniform catholyte concentration can be maintained even when installed in an electrolytic cell having no special circulating means.
    Type: Application
    Filed: November 10, 2003
    Publication date: May 13, 2004
    Applicant: ASAHI GLASS COMPANY LIMITED
    Inventors: Takuo Nishio, Yoshihiko Saito, Tetsuji Shimohira
  • Publication number: 20020030237
    Abstract: A semiconductor element of this invention includes a drift layer of a first conductivity type formed on a semiconductor substrate of the first conductivity type, a well layer of a second conductivity type selectively formed in the surface of the drift layer, a source layer of the first conductivity type selectively formed in the surface of the well layer, a trench formed to reach at least the inside of the drift layer from the surface of the source layer through the well layer, a buried electrode formed in the trench through a first insulating film, and a control electrode formed on the drift layer, the well layer, and the source layer through a second insulating film.
    Type: Application
    Filed: June 28, 2001
    Publication date: March 14, 2002
    Inventors: Ichiro Omura, Wataru Saito, Tsuneo Ogura, Hiromichi Ohashi, Yoshihiko Saito, Kenichi Tokano
  • Patent number: 6258889
    Abstract: An object of the present invention is to provide an emulsion and its production process, which is used for coating of plastic materials such as polyolefin and has enough coating and adhesion to polyolefin materials and is excellent in compatibility with an acrylic resin and other resins and has high storage stability. An emulsion includes: A styrene-acryl-acid grafted polyolefin chloride, which includes a polyolefin chloride structure moiety (1), an acid anhydride and/or carboxylic acid structure moiety (2) bonded to the moiety (1) and a styrene-acryl based polymerization chain moiety (3) bonded to the moiety (2) excluding some of the acid anhydride groups and/or carboxylic acid groups, wherein a ratio of the moiety (2) to a sum of the moiety (1) and the moiety (2) is 1-10 weight %; an emulsifier; a basic substance made of at least one of amine compound and ammonia; and water.
    Type: Grant
    Filed: March 9, 1999
    Date of Patent: July 10, 2001
    Assignee: Nippon Bee Chemical Co., Ltd.
    Inventors: Katsumi Mizuguchi, Yukiko Iida, Takeshi Nakasuka, Yoshihiko Saito
  • Patent number: 5716504
    Abstract: A cation exchange membrane for electrolysis, which comprises at least 2 layers of fluorine-containing polymer films having sulfonic acid groups, wherein a first layer facing a cathode is made of a three component polymer of the following monomers (A), (B) and (C) and has a thickness of from 50 to 150 .mu.m, and a second layer has a thickness of from 50 to 300 .mu.m:(A) CF.sub.2 =CF(OCF.sub.2 CFCF.sub.3).sub.m O(CF.sub.2).sub.n SO.sub.3 Mwherein m=0 or 1, n=1 to 5, and M is hydrogen or an alkali metal, ##STR1## wherein m=0 or 1, and Rf is a C.sub.1-10 perfluoroalkyl group.
    Type: Grant
    Filed: June 20, 1996
    Date of Patent: February 10, 1998
    Assignee: Asahi Glass Company Ltd.
    Inventors: Yoshihiko Saito, Tetsuji Shimohira, Haruhisa Miyake
  • Patent number: 5149403
    Abstract: A fluorine-containing cation exchange membrane for electrolysis, which comprises a multi-layered structure prepared by integrally laminating (i) the first ion exchange layer having --COOM groups (M is hydrogen or an alkali metal) in an ion exchange capacity of from 0.6 to 2.0 meq/g dry resin and having a thickness of from 5 to 300 .mu.m, (ii) the second ion exchange layer present on the anode side of the first ion exchange layer, the second ion exchange layer having a smaller specific resistance and a larger thickness than the first ion exchange layer, and (iii) a hydrophilic asymmetric porous layer present on the cathode side of the first ion exchange layer, the porous layer having a water-permeability which becomes smaller in proportion as closer to the cathode side, and a process for producing an alkali metal hydroxide by using the above fluorine-containing cation exchange membrane.
    Type: Grant
    Filed: December 7, 1990
    Date of Patent: September 22, 1992
    Assignee: Asahi Glass Company Ltd.
    Inventors: Tetsuji Shimohira, Yoshiaki Higuchi, Yoshihiko Saito, Kohji Suzuki
  • Patent number: 5138421
    Abstract: The semiconductor substrate according to the present invention comprises a first semiconductor layer, an insulation layer formed on said first semiconductor layer, a buffer layer formed on said insulation layer having at least one of getter ability and layer distortion buffering ability, and a second semiconductor layer formed on said buffer layer.
    Type: Grant
    Filed: October 16, 1990
    Date of Patent: August 11, 1992
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Yoshihiko Saito
  • Patent number: 4956392
    Abstract: A process for producing methanol or mixed alcohol which comprises reacting a synthesis gas containing hydrogen and carbon monoxide and/or carbon dioxide in a fluidized catalyst bed.Catalyst particles having an average particle diameter of not more than 150 microns and a particle density of at least 1.7 g/cm.sup.3 are used as the fluidized catalyst.The catalyst particles are contacted with the synthesis gas at a superficial linear velocity of at least 0.2 m/sec. under a pressure of 40 to 200 atmospheres.
    Type: Grant
    Filed: November 17, 1989
    Date of Patent: September 11, 1990
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Yoshihiko Saito, Osamu Hashimoto, Masaaki Kuwa, Takashi Kojima, Kinya Tsuji
  • Patent number: 4894349
    Abstract: A process for forming a vapor-phase epitaxial growth layer on a silicon wafer having a buried layer of a high As or B concentration. This vapor-phase epitaxial growth process is performed in two steps of (i) performing a vapor-phase epitaxial growth at a relatively low temperature by using a reaction gas containing at least one kind selected from a group consisting of SiH.sub.x F.sub.4-x (x=0 to 3) and Si.sub.2 H.sub.x F.sub.6-x (x=0-5) and at least one kind selected from a group consisting of SiH.sub.4 and Si.sub.2 H.sub.6, and (ii) performing a vapor-phase epitaxial growth under a condition which allows a higher growth rate that in the step (i) by using a reaction gas containing SiH.sub.4 or Si.sub.2 H.sub.6 which may or may not be accompanied with silane fluoride.
    Type: Grant
    Filed: December 15, 1988
    Date of Patent: January 16, 1990
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshihiko Saito, Yoshiaki Matsushita
  • Patent number: 4872958
    Abstract: An ion exchange membrane for electrolysis comprising a first layer of a fluoropolymer having carboxylic acid groups as its ion exchange groups and facing a cathode, a second layer of a fluoropolymer having ion exchange groups, a specific resistance lower than that of the first layer and a thickness of at least 50% of the total thickness of the membrane, and a third layer of a fluoropolymer having ion exchange groups, a swelling degree higher by at least 5% than that of the second layer and a specific resistance lower by at least 30 .OMEGA..cm than that of the second layer, the first, second and third layers being laminated in this order.
    Type: Grant
    Filed: June 15, 1988
    Date of Patent: October 10, 1989
    Assignee: Asahi Glass Company, Ltd.
    Inventors: Koji Suzuki, Tetsuro Tsukada, Yoshihiko Saito, Kiyotaka Arai, Hiroshi Mori
  • Patent number: 4787997
    Abstract: An etching solution used for evaluating crystal defects in a silicon wafer is disclosed. The etching solution is characterized by consisting of acetic acid, hydrofluoric acid, nitric acid, silver nitrate, and copper nitrate, and is very advantageous in consideration of the operator's health, since it does not contain Cr.sup.6+. The etching solution has a sufficiently high etching rate and detection properties.
    Type: Grant
    Filed: March 2, 1988
    Date of Patent: November 29, 1988
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshihiko Saito, Yoshiaki Matsushita