Patents by Inventor Minoru Ikarashi

Minoru Ikarashi 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: 20100314673
    Abstract: A memory device includes: a memory layer that retains information based on a magnetization state of a magnetic material, a first intermediate layer and a second intermediate layer that are provided to sandwich the memory layer and are each formed of an insulator, a first fixed magnetic layer disposed on an opposite side of the first intermediate layer from the memory layer, a second fixed magnetic layer disposed on an opposite side of the second intermediate layer from the memory layer, and a nonmagnetic conductive layer provided between either the first intermediate layer or the second intermediate layer and the memory layer, the memory device being configured so that spin-polarized electrons are injected thereinto in a stacking direction to change the magnetization direction of the memory layer, thereby storing information in the memory layer.
    Type: Application
    Filed: June 9, 2010
    Publication date: December 16, 2010
    Applicant: SONY CORPORATION
    Inventors: Kazutaka Yamane, Masanori Hosomi, Hiroshi Kano, Hiroyuki Ohmori, Minoru Ikarashi, Tetsuya Yamamoto, Kazuhiro Bessho, Yutaka Higo, Yuki Oishi, Shinichiro Kusunoki
  • Publication number: 20100200939
    Abstract: A memory is provided that is capable of improving the thermal stability without increasing the write current. The memory is configured to include: a storage element which has a storage layer that holds information according to a magnetization state of a magnetic substance and in which a magnetization fixed layer is provided on the storage layer with an intermediate layer 16 interposed therebetween, the intermediate layer is formed of an insulator, the direction of magnetization of the storage layer is changed by injecting electrons spin-polarized in a lamination direction such that the information is recorded in the storage layer, and distortion is applied to the storage layer from an insulating layer which exists around the storage layer and has a smaller coefficient of thermal expansion than the storage layer. A wiring line for supplying a current flowing in the lamination direction of the storage element.
    Type: Application
    Filed: June 30, 2008
    Publication date: August 12, 2010
    Applicant: SONY CORPORATION
    Inventors: Masanori Hosomi, Hiroyuki Ohmori, Minoru Ikarashi, Tetsuya Yamamoto, Yutaka Higo, Kazutaka Yamane, Yuki Oishi, Hiroshi Kano
  • Publication number: 20100135068
    Abstract: A resistance-change memory device is provided and includes a stack constituting a tunnel magnetoresistance effect element that has a magnetic layer in which a direction of magnetization is switchable and that is formed on a conductive layer, and the stack is included in a resistance-change memory cell performing data writing utilizing a spin transfer effect caused by current injection. The stack is formed such that a line connecting centers of respective layers of the stack is tilted with respect to a direction perpendicular to a surface of the conductive layer having the stack formed thereon.
    Type: Application
    Filed: December 2, 2009
    Publication date: June 3, 2010
    Applicant: SONY CORPORATION
    Inventors: Minoru Ikarashi, Yutaka Higo, Masanori Hosomi, Hiroshi Kano, Shinichiro Kusunoki, Hiroyuki Ohmori, Yuki Oishi, Tetsuya Yamamoto, Kazutaka Yamane
  • Publication number: 20100135069
    Abstract: A resistance variable memory device is provided and includes a resistance variable memory cell that writes data by utilizing a spin transfer effect based on an injection current. The memory device also includes a driving circuit that generates a combined pulse of a plurality of write pulses and an offset pulse defining the level between the write pulses and supplies the combined pulse to the memory cell at the time of the writing.
    Type: Application
    Filed: December 2, 2009
    Publication date: June 3, 2010
    Applicant: SONY CORPORATION
    Inventors: Minoru Ikarashi, Yutaka Higo, Masanori Hosomi, Hiroshi Kano, Shinichiro Kusunoki, Hiroyuki Ohmori, Yuki Oishi, Tetsuya Yamamoto, Kazutaka Yamane
  • Patent number: 7633796
    Abstract: A storage element includes a storage layer for holding information depending on a magnetization state of a magnetic material; and a magnetization fixed layer in which magnetization direction is fixed, that is arranged relative to the storage layer through a nonmagnetic layer. The magnetization direction of the storage layer is changed with application of an electric current in a laminating direction to enable information to be recorded to the storage layer. A plurality of magnetization regions respectively having magnetization components in laminating directions and having magnetizations in different directions from each other are formed in the magnetization fixed layer or on an opposite side of the magnetization fixed layer relative to the storage layer.
    Type: Grant
    Filed: January 14, 2008
    Date of Patent: December 15, 2009
    Assignee: Sony Corporation
    Inventors: Kazutaka Yamane, Minoru Ikarashi, Masanori Hosomi, Hiroyuki Ohmori, Tetsuya Yamamoto, Yutaka Higo, Yuki Oishi, Hiroshi Kano
  • Patent number: 7529122
    Abstract: A storage element and memory are provided. The storage element includes a storage layer that stores information based on a magnetic state of a magnetic material; and a fixed magnetization layer a magnetization direction of which is fixed and which is provided for the storage layer with a nonmagnetic layer in between. Information is recorded in the storage layer by applying a current in a stacking direction to change the magnetization direction of the storage layer. The fixed magnetization layer includes a plurality of ferromagnetic layers that are stacked with nonmagnetic layers in between, and the fixed magnetization layer includes magnetization regions having magnetic components in the stacking direction and magnetizations in respectively opposite directions. The magnetization regions are formed at both ends of at least one ferromagnetic layer that is disposed closest to the storage layer out of the plurality of ferromagnetic layers.
    Type: Grant
    Filed: October 15, 2007
    Date of Patent: May 5, 2009
    Assignee: Sony Corporation
    Inventor: Minoru Ikarashi
  • Patent number: 7502250
    Abstract: A memory device includes a memory element, a first wiring and a second wiring. The memory element includes a memory layer retaining information based on a magnetization state of a magnetic material and a magnetization pinned layer in which a magnetization direction is pinned and which is provided for the memory layer through a non-magnetic layer, in which current flows in a stacking direction to change a magnetization direction of the memory layer. The first wiring supplies current flowing in the stacking direction of the memory element, and the second wiring supplies current to apply a current magnetic field to the memory element. When information is recorded in the memory device, a first pulse current is supplied to the first wiring, a second pulse current is supplied to the second wiring, and the second pulse current falls at least 10 picoseconds after the first pulse current falls.
    Type: Grant
    Filed: June 28, 2007
    Date of Patent: March 10, 2009
    Assignee: Sony Corporation
    Inventor: Minoru Ikarashi
  • Publication number: 20080197433
    Abstract: Disclosed is a memory device including a memory layer retaining information thereon based on a magnetization state of a magnetic body, a fixed-magnetization layer having a fixed-magnetization direction formed on the memory layer through a non-magnetic layer, and two metal wiring lines formed adjacent to both ends of the fixed-magnetization layer, in the memory, the magnetization direction of the memory layer is changed by passing an electric current therethrough in a stacked direction to record the information on the memory layer.
    Type: Application
    Filed: February 20, 2008
    Publication date: August 21, 2008
    Applicant: Sony Corporation
    Inventors: Yutaka Higo, Minoru Ikarashi, Masanori Hosomi, Hiroyuki Ohmori, Tetsuya Yamamoto, Kazutaka Yamane, Yuki Oishi, Hiroshi Kano
  • Publication number: 20080197434
    Abstract: A magnetic memory device in which an MRAM element is magnetically shielded from large external magnetic fields. The magnetic memory device includes: a substrate; a magnetic random access memory mounted on the substrate, the magnetic random access memory including a memory element having a magnetized pinned layer with fixed direction of magnetization and a magnetic layer with changeable direction of magnetization stacked on one another; another element mounted on the substrate; and a pair of magnetic shielding layers which magnetically shield the memory element, the magnetic shielding layers located relatively above and below the memory element and within a region corresponding to an area occupied by the memory element.
    Type: Application
    Filed: April 11, 2008
    Publication date: August 21, 2008
    Applicant: SONY CORPORATION
    Inventors: Yoshihiro Kato, Katsumi Okayama, Kaoru Kobayashi, Tetsuya Yamamoto, Minoru Ikarashi
  • Publication number: 20080180992
    Abstract: A storage element includes a storage layer for holding information depending on a magnetization state of a magnetic material; and a magnetization fixed layer in which magnetization direction is fixed, that is arranged relative to the storage layer through a nonmagnetic layer. The magnetization direction of the storage layer is changed with application of an electric current in a laminating direction to enable information to be recorded to the storage layer. A plurality of magnetization regions respectively having magnetization components in laminating directions and having magnetizations in different directions from each other are formed in the magnetization fixed layer or on an opposite side of the magnetization fixed layer relative to the storage layer.
    Type: Application
    Filed: January 14, 2008
    Publication date: July 31, 2008
    Applicant: SONY CORPORATION
    Inventors: Kazutaka Yamane, Minoru Ikarashi, Masanori Hosomi, Hiroyuki Ohmori, Tetsuya Yamamoto, Yutaka Higo, Yuki Oishi, Hiroshi Kano
  • Publication number: 20080151607
    Abstract: Disclosed is a storage element having a storage layer retaining information based on a magnetization state of a magnetic material; a fixed-magnetization layer having a ferromagnetic layer; and an intermediate layer interposed between the storage layer and the fixed-magnetization layer. In the storage element, spin-polarized electrons are injected in a stacking direction to change a magnetization direction of the storage layer so that information is recorded in the storage layer, and resistivity of the ferromagnetic layer forming the storage layer is 8×10?7 ?m or more.
    Type: Application
    Filed: November 15, 2007
    Publication date: June 26, 2008
    Applicant: SONY CORPORATION
    Inventors: Masanori Hosomi, Hiroyuki Ohmori, Minoru Ikarashi, Tetsuya Yamamoto, Yutaka Higo, Kazutaka Yamane, Yuki Oishi, Hiroshi Kano
  • Publication number: 20080112215
    Abstract: A storage element and memory are provided. The storage element includes a storage layer that stores information based on a magnetic state of a magnetic material; and a fixed magnetization layer a magnetization direction of which is fixed and which is provided for the storage layer with a nonmagnetic layer in between. Information is recorded in the storage layer by applying a current in a stacking direction to change the magnetization direction of the storage layer. The fixed magnetization layer includes a plurality of ferromagnetic layers that are stacked with nonmagnetic layers in between, and the fixed magnetization layer includes magnetization regions having magnetic components in the stacking direction and magnetizations in respectively opposite directions. The magnetization regions are formed at both ends of at least one ferromagnetic layer that is disposed closest to the storage layer out of the plurality of ferromagnetic layers.
    Type: Application
    Filed: October 15, 2007
    Publication date: May 15, 2008
    Applicant: SONY CORPORATION
    Inventor: Minoru Ikarashi
  • Patent number: 7345367
    Abstract: A magnetic memory device exhibits improved writing characteristics by providing a magnetic flux concentrator which efficiently applies the magnetic field, which is generated by the writing word line, to the memory layer of the TMR element. The magnetic memory device (1) is composed of the TMR element (13), the writing word line (the first wiring) (11) which is electrically insulated from the TMR element (13), and the bit line (the second wiring) (12) which is electrically connected to the TMR element (13) and intersecting three-dimensionally with the writing word line (11), with the TMR element (13) interposed therebetween. The magnetic memory device (1) is characterized as follows. The magnetic flux concentrator (51) of high-permeability layer is formed along at least the lateral sides of the writing word line (11) and the side of the writing word line (11) which is opposite to the side facing the TMR element (13).
    Type: Grant
    Filed: March 26, 2003
    Date of Patent: March 18, 2008
    Assignee: Sony Corporation
    Inventors: Makoto Motoyoshi, Minoru Ikarashi
  • Publication number: 20080043517
    Abstract: A memory device includes a memory element, a first wiring and a second wiring. The memory element includes a memory layer retaining information based on a magnetization state of a magnetic material and a magnetization pinned layer in which a magnetization direction is pinned and which is provided for the memory layer through a non-magnetic layer, in which current flows in a stacking direction to change a magnetization direction of the memory layer. The first wiring supplies current flowing in the stacking direction of the memory element, and the second wiring supplies current to apply a current magnetic field to the memory element. When information is recorded in the memory device, a first pulse current is supplied to the first wiring, a second pulse current is supplied to the second wiring, and the second pulse current falls at least 10 picoseconds after the first pulse current falls.
    Type: Application
    Filed: June 28, 2007
    Publication date: February 21, 2008
    Applicant: SONY CORPORATION
    Inventor: Minoru Ikarashi
  • Patent number: 7173791
    Abstract: A unit element of a magnetic device or a ferroelectric device and magnetic particles of a magnetic recording medium are provided. The outline of the unit element and the magnetic particles is arranged so as to have a portion topologically identical to one of a letter-C shape and a letter-S shape that correspond to the magnetization or polarization distribution immediately before the rotation of magnetization or polarization.
    Type: Grant
    Filed: December 1, 2004
    Date of Patent: February 6, 2007
    Assignee: Sony Corporation
    Inventor: Minoru Ikarashi
  • Patent number: 7119419
    Abstract: A memory device is proposed which enables to guarantee the operation of MRAM elements being magnetically shielded against a large external magnetic fields without being affected by an internal leakage magnetic field. The MRAM elements 30 which are shielded by magnetic shield layers 33, 34 are placed at an intermediate region 41 avoiding an edge region 43 and a center region 42 of the magnetic shield layers 33, 34 so that the MRAM element is secured to operate normally without being affected by the internal leakage magnetic field avoiding the edge region 43 where the magnetic shield effect is reduced by the exterior magnetic field, and avoiding the central region 42 where the internal leakage magnetic field is large.
    Type: Grant
    Filed: December 19, 2003
    Date of Patent: October 10, 2006
    Assignee: Sony Corporation
    Inventors: Yoshihiro Kato, Katsumi Okayama, Kaoru Kobayashi, Tetsuya Yamamoto, Minoru Ikarashi
  • Patent number: 6992342
    Abstract: A magnetic memory device, in which a tunnel magneto resistance element that establishes a connection between a write word line (first interconnection) and a bit line (second interconnection) is provided within a region in which the write word line and the bit line cross in a grade-separated manner. The magnetic memory device comprises a through hole that is provided in such a manner that is insulated from the write word line and also extending through the write word line so as to establish a connection between the tunnel magneto resistance element and a second landing pad (interconnection layer) lower than the write word line, and a contact that is formed in the through hole through a side wall barrier film so as to establish a connection between the tunnel magneto resistance element and the second landing pad.
    Type: Grant
    Filed: July 2, 2003
    Date of Patent: January 31, 2006
    Assignee: Sony Corporation
    Inventors: Makoto Motoyoshi, Minoru Ikarashi
  • Publication number: 20050226030
    Abstract: A magnetic memory device in which an MRAM element is magnetically shielded from a large external magnetic field in an satisfactory manner, making it possible to surely achieve an operation free of problems in a magnetic field generated by the environment in which the MRAM element is used. A magnetic random access memory (MRAM) (30) is constituted by a TMR element (10) having a magnetized pinned layer (4), (6) with fixed direction of magnetization and a magnetic layer (memory layer) (2) with changeable direction of magnetization stacked on one another, mounted on a substrate together with another element (38), such as a DRAM, wherein a magnetic shielding layer (33), (34) is formed in a region corresponding to an area occupied by the MRAM element (30) or/and a magnetic shielding layer (33), (34) is with a distance of 15 mm or less between the opposite sides (especially, a length or a width).
    Type: Application
    Filed: December 12, 2003
    Publication date: October 13, 2005
    Inventors: Yoshihiro Kato, Katsumi Okayama, Kaoru Kobayashi, Tetsuya Yamamoto, Minoru Ikarashi
  • Patent number: 6934130
    Abstract: A unit element of a magnetic device or a ferroelectric device and magnetic particles of a magnetic recording medium are provided. The outline of the unit element and the magnetic particles is arranged so as to have a portion topologically identical to one of a letter-C shape and a letter-S shape that correspond to the magnetization or polarization distribution immediately before the rotation of magnetization or polarization.
    Type: Grant
    Filed: September 2, 2002
    Date of Patent: August 23, 2005
    Assignee: Sony Corporation
    Inventor: Minoru Ikarashi
  • Publication number: 20050162970
    Abstract: A magnetic memory device exhibits improved writing characteristics by providing a magnetic flux concentrator which efficiently applies the magnetic field, which is generated by the writing word line, to the memory layer of the TMR element. The magnetic memory device (1) is composed of the TMR element (13), the writing word line (the first wiring) (11) which is electrically insulated from the TMR element (13), and the bit line (the second wiring) (12) which is electrically connected to the TMR element (13) and intersecting three-dimensionally with the writing word line (11), with the TMR element (13) interposed therebetween. The magnetic memory device (1) is characterized as follows. The magnetic flux concentrator (51) of high-permeability layer is formed along at least the lateral sides of the writing word line (11) and the side of the writing word line (11) which is opposite to the side facing the TMR element (13).
    Type: Application
    Filed: March 26, 2003
    Publication date: July 28, 2005
    Inventors: Makoto Motoyoshi, Minoru Ikarashi