Patents by Inventor Tatsuya Kishi

Tatsuya Kishi 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: 20050042478
    Abstract: A magnetoresistance effect element includes a first ferromagnetic layer (1), insulating layer (3) overlying the first ferromagnetic layer, and second ferromagnetic layer (2) overlying the insulating layer. The insulating layer has formed a through hole (A) having an opening width not larger than 20 nm, and the first and second ferromagnetic layers are connected to each other via the through hole.
    Type: Application
    Filed: September 8, 2004
    Publication date: February 24, 2005
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Shiho Okuno, Yuichi Ohsawa, Shigeru Haneda, Yuzo Kamiguchi, Tatsuya Kishi
  • Publication number: 20050024930
    Abstract: A magnetic memory device includes first wiring which runs in the first direction, second wiring which runs in the second direction, a magneto-resistance element which is arranged at an intersection between the first and second wirings, a first yoke main body which covers at least either of the lower surface and two side surfaces of the first wring, a second yoke main body which covers at least either of the upper surface and two side surfaces of the second wiring, first and second yoke tips which are arranged on two sides of the magneto-resistance element in the first direction at an interval from the magneto-resistance element, and third and fourth yoke tips which are arranged on two sides of the magneto-resistance element in the second direction at an interval from the magneto-resistance element.
    Type: Application
    Filed: August 26, 2004
    Publication date: February 3, 2005
    Inventors: Hiroaki Yoda, Yoshiaki Asao, Tomomasa Ueda, Minoru Amano, Tatsuya Kishi, Keiji Hosotani, Junichi Miyamoto
  • Publication number: 20050018478
    Abstract: An MTJ element has two magnetic layers and a nonmagnetic layer. The resistance of the MTJ element, which varies depending on whether the two magnetic layers are magnetized parallel or antiparallel. In an MRAM adapted to write data into the MTJ element by causing a write wiring to generate induced magnetic flux and consequently changing the direction of magnetization of the recording layer, the MTJ element is a perpendicular MTJ element in which each of the two magnetic layers is magnetized in a direction perpendicular to its plane. The write wiring is placed in a direction perpendicular to the direction of the thickness of the MTJ element and applies a generated magnetic field to the magnetic layers of the MTJ element in the direction in which they are magnetized. Magnetic yokes hold the MTJ element in the direction of its thickness.
    Type: Application
    Filed: June 8, 2004
    Publication date: January 27, 2005
    Inventors: Toshihiko Nagase, Hiroaki Yoda, Masatoshi Yoshikawa, Tadashi Kai, Tatsuya Kishi, Hisanori Aikawa, Tomomasa Ueda
  • Patent number: 6839206
    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: Grant
    Filed: March 11, 2002
    Date of Patent: January 4, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiaki Saito, Masayuki Sagoi, Minoru Amano, Kentaro Nakajima, Shigeki Takahashi, Tatsuya Kishi
  • Publication number: 20040257866
    Abstract: A highly reliable magnetic memory exhibits enhanced data-holding stability at high storage density in a storage layer of a magnetoresistive effect element used for memory cells. A magnetic memory includes a memory cell array having first wirings, second wirings intersecting the first wirings and memory cells each provided at an intersection area of the corresponding first and second wirings. Each memory cell is selected when the corresponding first and second wirings are selected.
    Type: Application
    Filed: July 20, 2004
    Publication date: December 23, 2004
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Minoru Amano, Tatsuya Kishi, Hiroaki Yoda, Yoshiaki Saito, Shigeki Takahashi, Tomomasa Ueda, Katsuya Nishiyama, Yoshiaki Asao, Yoshihisa Iwata
  • Patent number: 6831855
    Abstract: A magnetic memory includes: a magnetoresistance effect element having a magnetic recording layer; a first writing wiring extending in a first direction on or below the magnetoresistance effect element, a center of gravity of an axial cross section of the wiring being apart from a center of thickness at the center of gravity, and the center of gravity being eccentric toward the magnetoresistance effect element; and a writing circuit configured to pass a current through the first writing wiring in order to record an information in the magnetic recording layer by a magnetic field generated by the current.
    Type: Grant
    Filed: January 16, 2003
    Date of Patent: December 14, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tatsuya Kishi, Minoru Amano, Yoshiaki Saito, Shigeki Takahashi, Katsuya Nishiyama, Yoshiaki Asao, Hiroaki Yoda, Tomomasa Ueda, Yoshihisa Iwata
  • Patent number: 6831857
    Abstract: A highly reliable magnetic memory exhibits enhanced data-holding stability at high storage density in a storage layer of a magnetoresistive effect element used for memory cells. A magnetic memory includes a memory cell array having first wirings, second wirings intersecting the first wirings and memory cells each provided at an intersection area of the corresponding first and second wirings. Each memory cell is selected when the corresponding first and second wirings are selected.
    Type: Grant
    Filed: December 27, 2002
    Date of Patent: December 14, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Minoru Amano, Tatsuya Kishi, Hiroaki Yoda, Yoshiaki Saito, Shigeki Takahashi, Tomomasa Ueda, Katsuya Nishiyama, Yoshiaki Asao, Yoshihisa Iwata
  • Publication number: 20040223382
    Abstract: There are provided at least one wire, a magnetoresistive effect element having a storage layer whose magnetization direction varies according to a current magnetic field generated by causing a current to flow in the wire, and first yokes provided so as to be spaced from at least one pair of opposed side faces of the magnetoresistive effect element to form a magnetic circuit in cooperation with the magnetoresistive effect element when a current is caused to flow in the wire. Each of the first yokes has at least two soft magnetic layers which are stacked via a non-magnetic layer.
    Type: Application
    Filed: June 10, 2004
    Publication date: November 11, 2004
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yoshiaki Saito, Tomomasa Ueda, Tatsuya Kishi, Minoru Amano
  • Patent number: 6807094
    Abstract: A magnetic memory includes a magnetoresistance effect element having a magnetic recording layer, a first wiring extending in a first direction on or below the magnetoresistance effect element, a covering layer provided on at least both sides of the first wiring, and a writing circuit configured to pass a current through the first wiring in order to record information in the magnetic recording layer by a magnetic field generated by the current. The covering layer is made of magnetic material and has a uniaxial anisotropy in the first direction, along which a magnetization of the covering layer occurs.
    Type: Grant
    Filed: February 3, 2004
    Date of Patent: October 19, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiaki Saito, Katsuya Nishiyama, Shigeki Takahashi, Minoru Amano, Tomomasa Ueda, Hiroaki Yoda, Yoshiaki Asao, Yoshihisa Iwata, Tatsuya Kishi
  • Publication number: 20040195602
    Abstract: A recording layer of an MTJ element is constituted by using a high crystal magnetic anisotropic material. A write wiring used to write data into the MTJ element is covered with a magnetic layer, and the write wiring and the magnetic layer are exchange-coupled with each other. A sum of a magnetic volume of the magnetic layer at a part opposed to the recording layer of the MTJ element and that of the recording layer is set smaller than a magnetic volume of the magnetic layer at any other part.
    Type: Application
    Filed: November 12, 2003
    Publication date: October 7, 2004
    Inventors: Hiroaki Yoda, Tomomasa Ueda, Hisanori Aikawa, Tatsuya Kishi, Takeshi Kajiyama, Yoshiaki Asao
  • Patent number: 6797536
    Abstract: A magnetic memory device includes first wiring which runs in the first direction, second wiring which runs in the second direction, a magneto-resistance element which is arranged at an intersection between the first and second wirings, a first yoke main body which covers at least either of the lower surface and two side surfaces of the first wring, a second yoke main body which covers at least either of the upper surface and two side surfaces of the second wiring, first and second yoke tips which are arranged on two sides of the magneto-resistance element in the first direction at an interval from the magneto-resistance element, and third and fourth yoke tips which are arranged on two sides of the magneto-resistance element in the second direction at an interval from the magneto-resistance element.
    Type: Grant
    Filed: February 2, 2004
    Date of Patent: September 28, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroaki Yoda, Yoshiaki Asao, Tomomasa Ueda, Minoru Amano, Tatsuya Kishi, Keiji Hosotani, Junichi Miyamoto
  • Publication number: 20040179393
    Abstract: A write wiring for writing information in an MTJ device is covered with a magnetic layer. The magnetic layer has a structure in which the growing direction of columnar grains is 30° or less from the normal-line direction of sidewalls, a structure in which grains are deposited like a layer, or a structure in which grains are amorphously deposited.
    Type: Application
    Filed: September 29, 2003
    Publication date: September 16, 2004
    Inventors: Hiroaki Yoda, Hisanori Aikawa, Tomomasa Ueda, Tatsuya Kishi, Takeshi Kajiyama, Yoshiaki Asao
  • Publication number: 20040175596
    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: March 11, 2004
    Publication date: September 9, 2004
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Koichiro Inomata, Kentaro Nakajima, Yoshiaki Saito, Masayuki Sagoi, Tatsuya Kishi
  • Publication number: 20040169963
    Abstract: A magnetoresistance effect element includes a first ferromagnetic layer (1), insulating layer (3) overlying the first ferromagnetic layer, and second ferromagnetic layer (2) overlying the insulating layer. The insulating layer has formed a through hole (A) having an opening width not larger than 20 nm, and the first and second ferromagnetic layers are connected to each other via the through hole.
    Type: Application
    Filed: March 10, 2004
    Publication date: September 2, 2004
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Shiho Okuno, Yuichi Ohsawa, Shigeru Haneda, Yuzo Kamiguchi, Tatsuya Kishi
  • Publication number: 20040156232
    Abstract: A magnetic memory includes: a magnetoresistance effect element having a magnetic recording layer; a first wiring extending in a first direction on or below the magnetoresistance effect element; a covering layer provided at least both sides of the first wiring, the covering layer being made of magnetic material, and the covering layer having a uniaxial anisotropy in the first direction along which a magnetization of the covering layer occurs easily; and a writing circuit configured to pass a current through the first wiring in order to record an information in the magnetic recording layer by a magnetic field generated by the current.
    Type: Application
    Filed: February 3, 2004
    Publication date: August 12, 2004
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yoshiaki Saito, Katsuya Nishiyama, Shigeki Takahashi, Minoru Amano, Tomomasa Ueda, Hiroaki Yoda, Yoshiaki Asao, Yoshihisa Iwata, Tatsuya Kishi
  • Publication number: 20040156231
    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 5, 2004
    Publication date: August 12, 2004
    Inventors: Yoshiaki Saito, Koichiro Inomata, Minoru Amano, Kentaro Nakajima, Masayuki Sagoi, Tatsuya Kishi, Shigeki Takahashi
  • Publication number: 20040152227
    Abstract: A magnetic memory device includes first wiring which runs in the first direction, second wiring which runs in the second direction, a magneto-resistance element which is arranged at an intersection between the first and second wirings, a first yoke main body which covers at least either of the lower surface and two side surfaces of the first wring, a second yoke main body which covers at least either of the upper surface and two side surfaces of the second wiring, first and second yoke tips which are arranged on two sides of the magneto-resistance element in the first direction at an interval from the magneto-resistance element, and third and fourth yoke tips which are arranged on two sides of the magneto-resistance element in the second direction at an interval from the magneto-resistance element.
    Type: Application
    Filed: February 2, 2004
    Publication date: August 5, 2004
    Inventors: Hiroaki Yoda, Yoshiaki Asao, Tomomasa Ueda, Minoru Amano, Tatsuya Kishi, Keiji Hosotani, Junichi Miyamoto
  • Publication number: 20040141367
    Abstract: The magnetic memory includes a plurality of memory cells, each memory cell including: at least one writing wire; at least one data storage portion, provided on at least one portion of an outer periphery of the writing wire, which comprises a ferromagnetic material whose magnetization direction can be inverted by causing a current to flow in the writing wire; and at least one magneto-resistance effect element, disposed in the vicinity of the data storage portion, which senses the magnetization direction of the data storage portion.
    Type: Application
    Filed: October 30, 2003
    Publication date: July 22, 2004
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Minoru Amano, Tatsuya Kishi, Sumio Ikegawa, Yoshiaki Saito, Hiroaki Yoda
  • Patent number: 6765821
    Abstract: There are provided at least one wire, a magnetoresistive effect element having a storage layer whose magnetization direction varies according to a current magnetic field generated by causing a current to flow in the wire, and first yokes provided so as to be spaced from at least one pair of opposed side faces of the magnetoresistive effect element to form a magnetic circuit in cooperation with the magnetoresistive effect element when a current is caused to flow in the wire. Each of the first yokes has at least two soft magnetic layers which are stacked via a non-magnetic layer.
    Type: Grant
    Filed: September 16, 2003
    Date of Patent: July 20, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiaki Saito, Tomomasa Ueda, Tatsuya Kishi, Minoru Amano
  • Patent number: 6765824
    Abstract: There is provided a magnetoresistance element in which a shape of a free ferromagnetic layer includes a first portion with a parallelogrammic contour, and second portions that protrude from a pair of opposite corners of the first portion respectively in a main direction parallel to a pair of opposite sides of the first portion, the shape is asymmetric with respect to a line that passes through a center of the first portion and is parallel to the main direction, and an axis of easy magnetization of the free ferromagnetic layer falls within a range defined by an acute angle that a first direction makes with a second direction, the first direction being substantially parallel to the main direction and the second direction being substantially parallel to the longest line segment that joins contours of the second portions.
    Type: Grant
    Filed: March 19, 2003
    Date of Patent: July 20, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tatsuya Kishi, Yoshiaki Saito, Minoru Amano, Shigeki Takahashi, Katsuya Nishiyama, Tomomasa Ueda