Patents by Inventor Masayuki Sagoi

Masayuki Sagoi 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: 6707711
    Abstract: There is provided a magnetic memory including first and second wirings intersecting each other and disposed apart from each other, a magnetoresistance effect film positioned between the first and second wirings, and a first magnetic film including a first portion facing the magnetoresistance effect film with the first wiring interposed therebetween and a pair of second portions positioned on both sides of the first wiring and magnetically connected to the first portion, each of the first and second portions having either one of a high saturation magnetization soft magnetic material containing cobalt and a metal-nonmetal nano-granular film.
    Type: Grant
    Filed: February 4, 2003
    Date of Patent: March 16, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiaki Saito, Koichiro Inomata, Minoru Amano, Kentaro Nakajima, Masayuki Sagoi, Tatsuya Kishi, Shigeki Takahashi
  • Publication number: 20030197984
    Abstract: A magnetoresistive element has a ferromagnetic double tunnel junction having a stacked structure of a first antiferromagnetic layer/a first ferromagnetic layer/a first dielectric layer/a second ferromagnetic layer/a second dielectric layer/a third ferromagnetic layer/a second antiferromagnetic layer. The second ferromagnetic layer that is a free layer consists of a Co-based alloy or a three-layered film of a Co-based alloy/a Ni—Fe alloy/a Co-based alloy. A tunnel current is flowed between the first ferromagnetic layer and the third ferromagnetic layer.
    Type: Application
    Filed: May 23, 2003
    Publication date: October 23, 2003
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Koichiro Inomata, Kentaro Nakajima, Yoshiaki Saito, Masayuki Sagoi, Tatsuya Kishi
  • Patent number: 6611405
    Abstract: A magnetoresistive element has a ferromagnetic double tunnel junction having a stacked structure of a first antiferromagnetic layer/a first ferromagnetic layer/a first dielectric layer/a second ferromagnetic layer/a second dielectric layer/a third ferromagnetic layer/a second antiferromagnetic layer. The second ferromagnetic layer that is a free layer consists of a Co-based alloy or a three-layered film of a Co-based alloy/a Ni—Fe alloy/a Co-based alloy. A tunnel current is flowed between the first ferromagnetic layer and the third ferromagnetic layer.
    Type: Grant
    Filed: September 14, 2000
    Date of Patent: August 26, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichiro Inomata, Kentaro Nakajima, Yoshiaki Saito, Masayuki Sagoi, Tatsuya Kishi
  • Patent number: 6605836
    Abstract: Magnetoresistance effect devices for attaining magnetically stability and for reducing a switching magnetic field. One of the ferromagnetic layers of the magnetoresistance effect device has a plane shape in which a width of an end portions is wider than a center portion sandwiched by two end portions. The end portions are not symmetrical with respect to an easy magnetization axis or longer axis of the plane shape of ferromagnetic material layer, but are substantially rotationally symmetrical with a center of the plane shape as a pivot. The plane shape may have an S-shape where its magnetic domain is stabilized and the switching magnetic field is reduced. The magnetoresistance effect devices may be used in a magnetic memory apparatus, such as a random access memory, a personal digital assistance, a magnetic reproducing head, and a magnetic information reproducing apparatus.
    Type: Grant
    Filed: March 15, 2002
    Date of Patent: August 12, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tatsuya Kishi, Shigeki Takahashi, Kentaro Nakajima, Minoru Amano, Masayuki Sagoi, Yoshiaki Saito
  • Publication number: 20030137870
    Abstract: There is provided a magnetic memory including first and second wirings intersecting each other and disposed apart from each other, a magnetoresistance effect film positioned between the first and second wirings, and a first magnetic film including a first portion facing the magnetoresistance effect film with the first wiring interposed therebetween and a pair of second portions positioned on both sides of the first wiring and magnetically connected to the first portion, each of the first and second portions having either one of a high saturation magnetization soft magnetic material containing cobalt and a metal-nonmetal nano-granular film.
    Type: Application
    Filed: February 4, 2003
    Publication date: July 24, 2003
    Inventors: Yoshiaki Saito, Koichiro Inomata, Minoru Amano, Kentaro Nakajima, Masayuki Sagoi, Tatsuya Kishi, Shigeki Takahashi
  • Patent number: 6590803
    Abstract: A magnetic memory device includes a plurality of magnetoresistive elements arranged on a first plane in a matrix form, a plurality of first writing lines which are arranged on a second plane different from the first plane adjacent to the magnetoresistive elements, a first address decoder which selects a desired one from the plurality of first writing lines, a plurality of second writing lines crossing the plurality of first writing lines on a third plane different from the second plane and having parts adjacent to the plurality of magnetoresistive elements on the second plane and parallel to the plurality of first writing lines, and a second address decoder which selects a desired one from the plurality of second writing lines.
    Type: Grant
    Filed: March 22, 2002
    Date of Patent: July 8, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiaki Saito, Kentaro Nakajima, Masayuki Sagoi, Minoru Amano, Shigeki Takahashi, Tatsuya Kishi
  • Patent number: 6556473
    Abstract: There is provided a magnetic memory including first and second wirings intersecting each other and disposed apart from each other, a magnetoresistance effect film positioned between the first and second wirings, and a first magnetic film including a first portion facing the magnetoresistance effect film with the first wiring interposed therebetween and a pair of second portions positioned on both sides of the first wiring and magnetically connected to the first portion, each of the first and second portions having either one of a high saturation magnetization soft magnetic material containing cobalt and a metal-nonmetal nano-granular film.
    Type: Grant
    Filed: July 26, 2001
    Date of Patent: April 29, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiaki Saito, Koichiro Inomata, Minoru Amano, Kentaro Nakajima, Masayuki Sagoi, Tatsuya Kishi, Shigeki Takahashi
  • Publication number: 20020191451
    Abstract: A magnetoresistance effect devices having a magnetization free layer free to rotate in an applied magnetic field. The magnetization free layer may include first and second ferromagnetic material layers with a nonmagnetic material layer disposed between the two ferromagnetic material layers. Those ferromagnetic materials are antiferromagnetically coupled with each other at a magnetic coupling field J (−3 [kOe]≦J<0 [kOe]) or ferromagnetically coupled with each other. Alternatively, the magnetization free film includes a first ferromagnetic material layer including a center region having a first magnetization and edge regions having a second magnetization different from the first magnetization and a second ferromagnetic material layer including a center region having a third magnetization parallel to the first magnetization and edge regions having a fourth magnetization different from the third magnetization.
    Type: Application
    Filed: March 22, 2002
    Publication date: December 19, 2002
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tatsuya Kishi, Minoru Amano, Yoshiaki Saito, Shigeki Takahashi, Kentaro Nakajima, Masayuki Sagoi
  • Publication number: 20020159203
    Abstract: There is provided a magnetoresistance effect element including a first pinned ferromagnetic layer, a second pinned ferromagnetic layer facing the first pinned ferromagnetic layer, surface regions of the first and second pinned ferromagnetic layer facing each other being different from each other in composition, a free ferromagnetic layer intervening between the first and second pinned ferromagnetic layers, a first tunnel barrier layer intervening between the first pinned ferromagnetic layer and the free ferromagnetic layer, and a second tunnel barrier layer intervening between the second pinned ferromagnetic layer and the free ferromagnetic layer.
    Type: Application
    Filed: March 11, 2002
    Publication date: October 31, 2002
    Inventors: Yoshiaki Saito, Masayuki Sagoi, Minoru Amano, Kentaro Nakajima, Shigeki Takahashi, Tatsuya Kishi
  • Patent number: 6473336
    Abstract: A magnetic memory device comprises a memory cell assembled by first and second tunnel junction portions and a switch, each of the first and second tunnel junction portions being formed of a stack of a pinned layer in which a magnetization direction is fixed and a record layer in which a magnetization direction changes depending on an external magnetic field. A first data line is connected to a first end of the first tunnel junction portion. A second data line is connected to the first end of the second tunnel junction portion. A bit line is connected to the second end of the first tunnel junction portion and the second end of the second tunnel junction portion via the switch.
    Type: Grant
    Filed: December 14, 2000
    Date of Patent: October 29, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kentaro Nakajima, Koichiro Inomata, Yoshiaki Saito, Masayuki Sagoi
  • Publication number: 20020141232
    Abstract: A magnetic memory device includes a plurality of magnetoresistive elements arranged on a first plane in a matrix form, a plurality of first writing lines which are arranged on a second plane different from the first plane adjacent to the magnetoresistive elements, a first address decoder which selects a desired one from the plurality of first writing lines, a plurality of second writing lines crossing the plurality of first writing lines on a third plane different from the second plane and having parts adjacent to the plurality of magnetoresistive elements on the second plane and parallel to the plurality of first writing lines, and a second address decoder which selects a desired one from the plurality of second writing lines.
    Type: Application
    Filed: March 22, 2002
    Publication date: October 3, 2002
    Inventors: Yoshiaki Saito, Kentaro Nakajima, Masayuki Sagoi, Minoru Amano, Shigeki Takahashi, Tatsuya Kishi
  • Publication number: 20020130339
    Abstract: Magnetoresistance effect devices for attaining magnetically stability and for reducing a switching magnetic field. One of the ferromagnetic layers of the magnetoresistance effect device has a plane shape in which a width of an end portions is wider than a center portion sandwiched by two end portions. The end portions are not symmetrical with respect to an easy magnetization axis or longer axis of the plane shape of ferromagnetic material layer, but are substantially rotationally symmetrical with a center of the plane shape as a pivot. The plane shape may have an S-shape where its magnetic domain is stabilized and the switching magnetic field is reduced. The manufacturing method uses two linear mask patterns intersecting with each other to form sharp corners of a ferromagnetic tunnel junction. An electron beam (EB) drawing may be used to form the S-shape plane.
    Type: Application
    Filed: March 15, 2002
    Publication date: September 19, 2002
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tatsuya Kishi, Shigeki Takahashi, Kentaro Nakajima, Minoru Amano, Masayuki Sagoi, Yoshiaki Saito
  • Publication number: 20020034094
    Abstract: There is provided a magnetic memory including first and second wirings intersecting each other and disposed apart from each other, a magnetoresistance effect film positioned between the first and second wirings, and a first magnetic film including a first portion facing the magnetoresistance effect film with the first wiring interposed therebetween and a pair of second portions positioned on both sides of the first wiring and magnetically connected to the first portion, each of the first and second portions having either one of a high saturation magnetization soft magnetic material containing cobalt and a metal-nonmetal nano-granular film.
    Type: Application
    Filed: July 26, 2001
    Publication date: March 21, 2002
    Inventors: Yoshiaki Saito, Koichiro Inomata, Minoru Amano, Kentaro Nakajima, Masayuki Sagoi, Tatsuya Kishi, Shigeki Takahashi
  • Publication number: 20020006058
    Abstract: A magnetic memory device comprises a memory cell assembled by first and second tunnel junction portions and a switch, each of the first and second tunnel junction portions being formed of a stack of a pinned layer in which a magnetization direction is fixed and a record layer in which a magnetization direction changes depending on an external magnetic field. A first data line is connected to a first end of the first tunnel junction portion. A second data line is connected to the first end of the second tunnel junction portion. A bit line is connected to the second end of the first tunnel junction portion and the second end of the second tunnel junction portion via the switch.
    Type: Application
    Filed: December 14, 2000
    Publication date: January 17, 2002
    Inventors: Kentaro Nakajima, Koichiro Inomata, Yoshiaki Saito, Masayuki Sagoi
  • Patent number: 5126320
    Abstract: A method is disclosed which comprises setting a substrate within a mixed gas atmosphere containing 0.1 to 5% of oxygen gas and a balance as an inert gas, and sputtering a target member containing Ln, M, Cu and O within that atmosphere to obtain an oxygen-deficient perovskite type oxide superconducting thin-film of substantially Ln:M:Cu:O=1:2:3:(7-.delta.), where Ln represents at least one element selected from the rare earth elements and M represents at least one element selected from the group consisting of Ba, Sr, and Ca. The oxide superconducting thin-film of that composition ratio has a critical temperature of over 77K.
    Type: Grant
    Filed: June 26, 1991
    Date of Patent: June 30, 1992
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tadao Miura, Yoshiaki Terashima, Akio Hori, Masayuki Sagoi
  • Patent number: 4801481
    Abstract: A perpendicular magnetic recording floppy disk comprises a flexible plastic film substrate, a first magnetic recording layer formed on one side of the plastic film substrate and having an axis of easy magnetization in a direction perpendicular to the one side of the plastic film substrate, and a second magnetic recording layer formed on the other side of the plastic film substrate and having an axis of easy magnetization in a direction perpendicular to the above-mentioned other side of the plastic film substrate. The second magnetic recording layer has a thickness greater than a thickness of the first magnetic recording layer.
    Type: Grant
    Filed: June 17, 1983
    Date of Patent: January 31, 1989
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Masayuki Sagoi, Reiji Nishikawa
  • Patent number: 4761334
    Abstract: A magnetic recording medium in which a silicon nitride film is formed on a magnetic recording layer having an axis of easy magnetization in the direction essentially perpendicular to its own layer surface. The magnetic recording layer is a metallic magnetic film such as a Co-Cr containing alloy. The silicon nitride film is preferably in a state in which the number of nitrogen atoms is less than four thirds of the number of silicon atoms. A lubricant layer such as a layer of fluorocarbon can be formed on the silicon nitride film.
    Type: Grant
    Filed: July 1, 1985
    Date of Patent: August 2, 1988
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masayuki Sagoi, Noritsugu Kawashima, Yoichiro Tanaka, Kunio Sekine
  • Patent number: 4748073
    Abstract: A perpendicular magnetic floppy disk has a base layer on each side of which a recording layer is formed having an axis of easy magnetization in a direction perpendicular to its surface. A multilayered protective layer structure is provided on the recording layer. The protective layer structure includes double-stacked non-magnetic thin-film layer structures made of an Si-N-O-based film and silicon oxide film, respectively. The total thickness of the multilayered protective layer structure is smaller than 40 nanometers, which is thin enough to maximize an efficiency in perpendicular magnetic recording of data signal.
    Type: Grant
    Filed: June 26, 1986
    Date of Patent: May 31, 1988
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masayuki Sagoi, Yoichiro Tanaka
  • Patent number: 4701374
    Abstract: A magnetic recording medium obtained by forming a Si-N-O system film on a magnetic recording layer with perpendicular axis of easy magnetization. The magnetic recording layer is a metallic magnetic film such as Co-Cr system alloy film. The oxygen content in the Si-N-O system film is selected preferably to show a maximum absorption of infrared radiation in the range above 830 cm.sup.-1 and below 1100 cm.sup.-1 of 1/.lambda. (.lambda. is the wavelength of the infrared radiation). Through formation of the Si-N-O system film, the magnetic recording medium can satisfy simultaneously both of the durability and the perpendicular magnetic recording characteristics.
    Type: Grant
    Filed: July 1, 1985
    Date of Patent: October 20, 1987
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masayuki Sagoi, Yoichiro Tanaka, Hiroki Nakamura
  • Patent number: 4680197
    Abstract: A method of manufacturing a perpendicular magnetic recording floppy disk is disclosed. A first magnetic recording layer is formed by sputtering a perpendicularly magnetizable material on one side of a plastic film substrate. A second magnetic recording layer is formed by sputtering the perpendicularly magnetizable material on the other side of the plastic film substrate after forming the first magnetic recording layer. The second magnetic recording layer has a thickness greater than that of the first magnetic recording layer, when a curl of the first magnetic recording layer on the plastic film substrate, resulting from forming the first magnetic recording layer on the plastic film substrate, is to the outside. On the other hand, the second magnetic recording layer has a thickness lower than that of the first magnetic recording layer, when a curl of the first magnetic recording layer on the plastic film substrate is to the inside.
    Type: Grant
    Filed: December 2, 1985
    Date of Patent: July 14, 1987
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masayuki Sagoi, Reiji Nishikawa