Patents by Inventor Hiroaki Honjou

Hiroaki Honjou 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: 9478309
    Abstract: Provided is a magnetic domain wall displacement memory cell, including a recording layer including a magnetic film, the recording layer including: a magnetization reversal region in which magnetization is reversible; and first and second magnetization fixed regions that supply a spin-polarized electron to the magnetization reversal region. The magnetic domain wall displacement memory cell is configured so that a first region in which magnetization reversal occurs due to a first current flowing in a direction parallel to a film surface of the recording layer and a first magnetic field component in the direction parallel to the film surface of the recording layer is formed, and a second region in which no magnetization reversal occurs is formed.
    Type: Grant
    Filed: September 13, 2013
    Date of Patent: October 25, 2016
    Assignees: NEC CORPORATION, TOHOKU UNIVERSITY
    Inventors: Ryusuke Nebashi, Noboru Sakimura, Tadahiko Sugibayashi, Yukihide Tsuji, Ayuka Tada, Hiroaki Honjou, Hideo Ohno
  • Patent number: 9406869
    Abstract: A semiconductor device includes: a first magnetic layer (1) disposed on a flat substrate surface; a second magnetic layer (3) disposed above the first magnetic layer (1) and magnetically coupled to the first magnetic layer (1) by magnetostatic coupling or exchange coupling; and a third thin film layer (8) formed between the first magnetic layer (1) and the second magnetic layer (3), the third thin film layer (8) having such a thickness as to avoid inhibiting the magnetic coupling between the first magnetic layer (1) and the second magnetic layer (3).
    Type: Grant
    Filed: April 24, 2013
    Date of Patent: August 2, 2016
    Assignees: NEC CORPORATION, TOHOKU UNIVERSITY
    Inventors: Hiroaki Honjou, Keizo Kinoshita, Hideo Ohno
  • Publication number: 20150248939
    Abstract: Provided is a magnetic domain wall displacement memory cell, including a recording layer including a magnetic film, the recording layer including: a magnetization reversal region in which magnetization is reversible; and first and second magnetization fixed regions that supply a spin-polarized electron to the magnetization reversal region. The magnetic domain wall displacement memory cell is configured so that a first region in which magnetization reversal occurs due to a first current flowing in a direction parallel to a film surface of the recording layer and a first magnetic field component in the direction parallel to the film surface of the recording layer is formed, and a second region in which no magnetization reversal occurs is formed.
    Type: Application
    Filed: September 13, 2013
    Publication date: September 3, 2015
    Applicants: NEC Corporation, Tohoku University
    Inventors: Ryusuke Nebashi, Noboru Sakimura, Tadahiko Sugibayashi, Yukihide Tsuji, Ayuka Tada, Hiroaki Honjou, Hideo Ohno
  • Publication number: 20150200354
    Abstract: A semiconductor device includes: a first magnetic layer (1) disposed on a flat substrate surface; a second magnetic layer (3) disposed above the first magnetic layer (1) and magnetically coupled to the first magnetic layer (1) by magnetostatic coupling or exchange coupling; and a third thin film layer (8) formed between the first magnetic layer (1) and the second magnetic layer (3), the third thin film layer (8) having such a thickness as to avoid inhibiting the magnetic coupling between the first magnetic layer (1) and the second magnetic layer (3).
    Type: Application
    Filed: April 24, 2013
    Publication date: July 16, 2015
    Applicants: TOHOKU UNIVERSITY, NEC CORPORATION
    Inventors: Hiroaki Honjou, Keizo Kinoshita, Hideo Ohno
  • Patent number: 8908423
    Abstract: A magnetoresistive effect element includes: a magnetization free layer having an invertible magnetization; an insulating layer being adjacent to the magnetization free layer; and a magnetization fixed layer being adjacent to the insulation layer and in an opposite side of the insulation layer to the magnetization free layer. The magnetization free layer includes: a first magnetization free layer being adjacent to the insulating layer and comprising Fe or Co; and a second magnetization free layer being adjacent to the first magnetization layer and comprising NiFeB.
    Type: Grant
    Filed: November 22, 2010
    Date of Patent: December 9, 2014
    Assignee: NEC Corporation
    Inventor: Hiroaki Honjou
  • Publication number: 20130075847
    Abstract: A magnetic memory has: a pinning layer being a perpendicular magnetic film whose magnetization direction is fixed; an underlayer formed on the pinning layer; and a data storage layer being a perpendicular magnetic film formed on the underlayer. The data storage layer has: a magnetization free region whose magnetization direction is reversible; and a magnetization fixed region magnetically coupled with the pinning layer through the underlayer. A magnetization direction of the magnetization fixed region is fixed by the magnetic coupling. The underlayer has a magnetic underlayer made of a magnetic material.
    Type: Application
    Filed: March 16, 2011
    Publication date: March 28, 2013
    Applicant: NEC CORPORATION
    Inventor: Hiroaki Honjou
  • Publication number: 20120281463
    Abstract: A magnetoresistive effect element includes: a magnetization free layer having an invertible magnetization; an insulating layer being adjacent to the magnetization free layer; and a magnetization fixed layer being adjacent to the insulation layer and in an opposite side of the insulation layer to the magnetization free layer. The magnetization free layer includes: a first magnetization free layer being adjacent to the insulating layer and comprising Fe or Co; and a second magnetization free layer being adjacent to the first magnetization layer and comprising NiFeB.
    Type: Application
    Filed: November 22, 2010
    Publication date: November 8, 2012
    Applicant: NEC CORPORATION
    Inventor: Hiroaki Honjou
  • Patent number: 8300456
    Abstract: An MRAM has a pinned layer and a magnetic recording layer connected to the pinned layer through a tunnel barrier layer. The magnetic recording layer has a first free layer, a second free layer being in contact with the tunnel barrier layer, and an intermediate layer provided between the first free layer and the second free layer. The first free layer includes a magnetization switching region whose magnetization direction can be switched by domain wall motion method. The second free layer has no domain wall. The intermediate layer is formed to cover at least the magnetization switching region. The magnetization switching region and the second free layer are magnetically coupled to each other through the intermediate layer.
    Type: Grant
    Filed: October 22, 2007
    Date of Patent: October 30, 2012
    Assignee: NEC Corporation
    Inventors: Hiroaki Honjou, Tetsuhiro Suzuki, Norikazu Ohshima
  • Publication number: 20100046288
    Abstract: An MRAM according to the present invention has a pinned layer 60 and a magnetic recording layer 40 connected to the pinned layer 60 through a tunnel barrier layer 50. The magnetic recording layer 40 has a first free layer 10, a second free layer 30 being in contact with the tunnel barrier layer 50, and an intermediate layer 20 provided between the first free layer 10 and the second free layer 30. The first free layer 10 includes a magnetization switching region 13, a first magnetization fixed region 11 and a second magnetization fixed region 12. The magnetization switching region 13 has reversible magnetization and overlaps the second free layer 30. The first magnetization fixed region 11 is connected to a first boundary B1 of the magnetization switching region 13 and its magnetization orientation is fixed in a first direction.
    Type: Application
    Filed: October 22, 2007
    Publication date: February 25, 2010
    Inventors: Hiroaki Honjou, Tetsuhiro Suzuki, Norikazu Ohshima
  • Patent number: 7372673
    Abstract: In a magnetoresistive effect transducer including a pinning layer, a pinned layer, a free layer and a non-magnetic layer inserted between the pinned layer and the free layer, a longitudinal bias layer is connected directly to a part of the free layer to apply a bias magnetic field to the free layer, thus biasing a magnetization direction of the free layer so that the magnetization direction of the free layer coincides with that of the longitudinal bias layer.
    Type: Grant
    Filed: May 31, 2005
    Date of Patent: May 13, 2008
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Tsutomu Ishi, Hiroaki Honjou, Kunihiko Ishihara, Jun-Ichi Fujikata, Hisao Matsutera, Hisanao Tsuge, Atsushi Kamijo
  • Publication number: 20050219772
    Abstract: In a magnetoresistive effect transducer including a pinning layer, a pinned layer, a free layer and a non-magnetic layer inserted between the pinned layer and the free layer, a longitudinal bias layer is connected directly to a part of the free layer to apply a bias magnetic field to the free layer, thus biasing a magnetization direction of the free layer so that the magnetization direction of the free layer coincides with that of the longitudinal bias layer.
    Type: Application
    Filed: May 31, 2005
    Publication date: October 6, 2005
    Applicant: NEC Corporation
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Tsutomu Ishi, Hiroaki Honjou, Kunihiko Ishihara, Jun-Ichi Fujikata, Hisao Matsutera, Hisanao Tsuge, Atsushi Kamijo
  • Patent number: 6950290
    Abstract: In a magnetoresistive effect transducer including a pinning layer, a pinned layer, a free layer and a non-magnetic layer inserted between the pinned layer and the free layer, a longitudinal bias layer is connected directly to a part of the free layer to apply a bias magnetic field to the free layer, thus biasing a magnetization direction of the free layer so that the magnetization direction of the free layer coincides with that of the longitudinal bias layer.
    Type: Grant
    Filed: September 12, 2002
    Date of Patent: September 27, 2005
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Tsutomu Ishi, Hiroaki Honjou, Kunihiko Ishihara, Jun-Ichi Fujikata, Hisao Matsutera, Hisanao Tsuge, Atsushi Kamijo
  • Patent number: 6798626
    Abstract: A magnetoresistive effect element which is easy to manufacture and in which a sense current is prevented from bypassing a barrier layer is provided. Also provided are a method for manufacturing the element and a magnetic recording apparatus utilizing the element. This magnetoresistive effect element utilizes an MTJ film which comprises, for forming its basic structure, a free layer, a barrier layer, a pinned layer and a pinning layer, wherein an oxide or a nitride layer is formed by oxidizing or nitriding metallic materials constituting the pinned layer and pinning layer.
    Type: Grant
    Filed: February 3, 2003
    Date of Patent: September 28, 2004
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Eizo Fukami, Kiyokazu Nagahara, Hiroaki Honjou, Shinsaku Saitoh
  • Patent number: 6624987
    Abstract: A magnetoresistive effect head which is easy to manufacture and in which a sense current is prevented from bypassing a barrier layer is provided. Also provided are a method for manufacturing the head and a magnetic recording apparatus utilizing the head. This magnetoresistive effect head utilizes an MTJ film which comprises, for forming its basic structure, a free layer, a barrier layer, a pinned layer and a pinning layer, wherein an oxide or a nitride layer is formed by oxidizing or nitriding metallic materials constituting the pinned layer and pinning layer.
    Type: Grant
    Filed: May 31, 2000
    Date of Patent: September 23, 2003
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Eizo Fukami, Kiyokazu Nagahara, Hiroaki Honjou, Shinsaku Saitoh
  • Publication number: 20030151859
    Abstract: A magnetoresistive effect element which is easy to manufacture and in which a sense current is prevented from bypassing a barrier layer is provided. Also provided are a method for manufacturing the element and a magnetic recording apparatus utilizing the element. This magnetoresistive effect element utilizes an MTJ film which comprises, for forming its basic structure, a free layer, a barrier layer, a pinned layer and a pinning layer, wherein an oxide or a nitride layer is formed by oxidizing or nitriding metallic materials constituting the pinned layer and pinning layer.
    Type: Application
    Filed: February 3, 2003
    Publication date: August 14, 2003
    Applicant: NEC CORPORATION
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Eizo Fukami, Kiyokazu Nagahara, Hiroaki Honjou, Shinsaku Saitoh
  • Patent number: 6542342
    Abstract: In a magnetoresistive effect transducer including a pinning layer, a pinned layer, a free layer and a non-magnetic layer inserted between the pinned layer and the free layer, a longitudinal bias layer is connected directly to a part of the free layer to apply a bias magnetic field to the free layer, thus biasing a magnetization direction of the free layer so that the magnetization direction of the free layer coincides with that of the longitudinal bias layer.
    Type: Grant
    Filed: November 29, 1999
    Date of Patent: April 1, 2003
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Tsutomu Ishi, Hiroaki Honjou, Kunihiko Ishihara, Jun-Ichi Fujikata, Hisao Matsutera, Hisanao Tsuge, Atsushi Kamijo
  • Patent number: 6538861
    Abstract: A magnetoresistive head whose operation depends on a magnetoresistive effect is configured using a ferromagnetic tunnel junction (MTJ) film, which is arranged between a lower electrode and an upper electrode. The ferromagnetic tunnel junction film is basically configured using a set of a free layer, a barrier layer and a fixing layer, which are sequentially formed and laminated on the lower electrode. Herein, the ferromagnetic tunnel junction film is designed to avoid electrostatic destruction in manufacture by prescribed measures. For example, the barrier layer is reduced in thickness at a terminal portion as compared with a center portion. Or, the barrier layer has a defect at the terminal portion. In addition, it is possible to provide a conductor in connection with the barrier layer in proximity to its terminal portion.
    Type: Grant
    Filed: June 19, 2000
    Date of Patent: March 25, 2003
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Masafumi Nakada, Eizo Fukami, Kiyokazu Nagahara, Hiroaki Honjou, Kunihiko Ishihara, Tamaki Toba, Hisanao Tsuge, Atsushi Kamijo
  • Publication number: 20030035256
    Abstract: In a magnetoresistive effect transducer including a pinning layer, a pinned layer, a free layer and a non-magnetic layer inserted between the pinned layer and the free layer, a longitudinal bias layer is connected directly to a part of the free layer to apply a bias magnetic field to the free layer, thus biasing a magnetization direction of the free layer so that the magnetization direction of the free layer coincides with that of the longitudinal bias layer.
    Type: Application
    Filed: September 12, 2002
    Publication date: February 20, 2003
    Applicant: NEC Corporation
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Tsutomu Ishi, Hiroaki Honjou, Kunihiko Ishihara, Jun-Ichi Fujikata, Hisao Matsutera, Hisanao Tsuge, Atsushi Kamijo