Patents by Inventor Shunsuke Fukami

Shunsuke Fukami 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: 8787076
    Abstract: A magnetic memory according to the present invention has: a first underlayer; a second underlayer so formed on the first underlayer as to be in contact with the first underlayer; and a data storage layer so formed on the second underlayer as to be in contact with the second underlayer. The data storage layer is made of a ferromagnetic material having perpendicular magnetic anisotropy. A magnetization state of the data storage layer is changed by current driven domain wall motion.
    Type: Grant
    Filed: August 13, 2009
    Date of Patent: July 22, 2014
    Assignee: NEC Corporation
    Inventors: Shunsuke Fukami, Nobuyuki Ishiwata, Tetsuhiro Suzuki, Kiyokazu Nagahara, Norikazu Ohshima
  • Publication number: 20140159121
    Abstract: Provided is a nonvolatile magnetic device that is capable of realizing low power consumption by performing writing with a voltage and is also excellent in retention characteristics. The nonvolatile magnetic device includes a nonvolatile magnetic element. The nonvolatile magnetic element includes: a first free layer made of a ferromagnetic substance; a first insulating layer made of an insulator, the first insulating layer being provided to be connected to the first free layer; a charged layer provided adjacent to the first insulating layer; a second insulating layer made of an insulator, the second insulating layer being provided adjacent to the charged layer; and an injection layer provided adjacent to the second insulating layer. The charged layer is smaller in electric resistivity than both of the first insulating layer and the second insulating layer. The injection layer is smaller in electric resistivity than the second insulating layer.
    Type: Application
    Filed: June 13, 2012
    Publication date: June 12, 2014
    Inventors: Shunsuke Fukami, Daichi Chiba
  • Publication number: 20140097509
    Abstract: A disclosed magnetic memory element includes: a magnetization free layer formed of a ferromagnetic substance having perpendicular magnetic anisotropy; a response layer provided so as to be opposed to the magnetization free layer and formed of a ferromagnetic substance having perpendicular magnetic anisotropy; a non-magnetic layer provided so as to be opposed to the response layer on a side opposite to the magnetization free layer and formed of a non-magnetic substance; and a reference layer provided so as to be opposed to the non-magnetic layer on a side opposite to the response layer and formed of a ferromagnetic substance having perpendicular magnetic anisotropy. The magnetization free layer includes a first magnetization fixed region and a second magnetization fixed region which have magnetization fixed in directions antiparallel to each other, and a magnetization free region in which a magnetization direction is variable.
    Type: Application
    Filed: April 19, 2012
    Publication date: April 10, 2014
    Applicant: TOHOKU UNIVERSITY
    Inventors: Shunsuke Fukami, Nobuyuki Ishiwata, Tadahiko Sugibayashi, Hideo Ohno, Shoji Ikeda, Michihiko Yamanouchi
  • Patent number: 8687414
    Abstract: A magnetic memory cell includes: a magnetization recording layer; and a magnetic tunneling junction section. The magnetization recording layer includes a ferromagnetic layer with perpendicular magnetic anisotropy. The magnetic tunneling junction section is used for reading information in the magnetization recording layer. The magnetization recording layer includes two domain wall moving areas.
    Type: Grant
    Filed: December 24, 2009
    Date of Patent: April 1, 2014
    Assignee: NEC Corporation
    Inventors: Kiyokazu Nagahara, Shunsuke Fukami, Nobuyuki Ishiwata, Tetsuhiro Suzuki, Norikazu Ohshima
  • Patent number: 8625327
    Abstract: A domain wall motion type MRAM has: a magnetic recording layer 10 being a ferromagnetic layer having perpendicular magnetic anisotropy; a pair of current supply terminals 14a and 14b connected to the magnetic recording layer 10 for supplying a current to the magnetic recording layer 10; and an anti-ferromagnetic layer 45 being in contact with a first region R1 of the magnetic recording layer 10. The first region R1 includes a part of a current supply region RA of the magnetic recording layer 10 that is between the pair of current supply terminals 14a and 14b.
    Type: Grant
    Filed: July 2, 2009
    Date of Patent: January 7, 2014
    Assignee: NEC Corporation
    Inventors: Tetsuhiro Suzuki, Shunsuke Fukami, Kiyokazu Nagahara, Norikazu Oshima, Nobuyuki Ishiwata
  • Patent number: 8592930
    Abstract: A magnetic memory element includes: a first magnetization free layer; a non-magnetic layer; a reference layer; a first magnetization fixed layer group; and a first blocking layer. The first magnetization free layer is composed of ferromagnetic material with perpendicular magnetic anisotropy and includes a first magnetization fixed region, a second magnetization fixed region and a magnetization free region. The non-magnetic layer is provided near the first magnetization free layer. The reference layer is composed of ferromagnetic material and provided on the non-magnetic layer. The first magnetization fixed layer group is provided near the first magnetization fixed region. The first blocking layer is provided being sandwiched between the first magnetization fixed layer group and the first magnetization fixed region or in the first magnetization fixed layer group.
    Type: Grant
    Filed: October 21, 2010
    Date of Patent: November 26, 2013
    Assignee: NEC Corporation
    Inventors: Shunsuke Fukami, Tetsuhiro Suzuki, Kiyokazu Nagahara, Norikazu Ohshima, Nobuyuki Ishiwata
  • Publication number: 20130285700
    Abstract: A non-volatile logic operation device includes an operation unit that is connected to a first input terminal, a second input terminal, and an output terminal, includes an operation layer, a first non-magnetic layer, and a reference layer, and outputs from the output terminal a result of a logic operation on signals applied at the first input terminal and the second input terminal, and a control unit that is connected to a third input terminal, and includes a control layer. The control unit is arranged in the vicinity of the operation unit.
    Type: Application
    Filed: January 5, 2012
    Publication date: October 31, 2013
    Inventors: Shunsuke Fukami, Nobuyuki Ishiwata
  • Patent number: 8565011
    Abstract: An initialization method is provided for a magnetic memory element including: a data recording layer having perpendicular magnetic anisotropy which includes: a first magnetization fixed region, a second magnetization fixed region, and a magnetization free region coupled to the first magnetization fixed region and the second magnetization fixed region, the data recording layer being structure so that the coercive force of the first magnetization fixed region being different from that of the second magnetization fixed region. The initialization method includes steps of: directing the magnetizations of the first magnetization fixed region, the second magnetization fixed region and the magnetization free region in the same direction; and applying a magnetic field having both components perpendicular to and parallel to the magnetic anisotropy of the data recording layer to the data recording layer.
    Type: Grant
    Filed: October 29, 2009
    Date of Patent: October 22, 2013
    Assignee: NEC Corporation
    Inventors: Shunsuke Fukami, Kiyokazu Nagahara, Tetsuhiro Suzuki, Nobuyuki Ishiwata, Norikazu Ohshima
  • Patent number: 8559214
    Abstract: A magnetic memory cell is provided with a magnetization record layer and a magnetic tunnel junction section. The magnetization record layer is a ferromagnetic layer having a perpendicular magnetic anisotropy. The magnetic tunnel junction section is used to read data from the magnetization record layer. The magnetization record layer has a plurality of domain wall motion regions.
    Type: Grant
    Filed: December 24, 2009
    Date of Patent: October 15, 2013
    Assignee: NEC Corporation
    Inventors: Shunsuke Fukami, Kiyokazu Nagahara, Tetsuhiro Suzuki, Nobuyuki Ishiwata, Norikazu Ohshima
  • Patent number: 8537604
    Abstract: A magnetoresistance element is provided with: a magnetization recording layer that is a ferromagnetic layer. The magnetization recording layer includes: a magnetization reversal region having a reversible magnetization; a first magnetization fixed region connected to a first boundary of the magnetization reversal region and having a magnetization direction fixed in a first direction; and a second magnetization fixed region connected to a second boundary of the magnetization reversal region and having a magnetization direction fixed in a second direction. At least one magnetization reversal facilitation structure which is a structure in which a magnetization is reversed more easily than the remaining portion is provided for a portion of the second magnetization fixed region.
    Type: Grant
    Filed: October 16, 2009
    Date of Patent: September 17, 2013
    Assignee: NEC Corporation
    Inventors: Tetsuhiro Suzuki, Shunsuke Fukami, Kiyokazu Nagahara, Norikazu Ohshima, Nobuyuki Ishiwata
  • Patent number: 8514616
    Abstract: A magnetoresistive effect element includes: a magnetization free layer; a non-magnetic insertion layer provided adjacent to the magnetization free layer; a magnetic insertion layer provided adjacent to the non-magnetic insertion layer and opposite to the magnetization free layer with respect to the non-magnetic insertion layer; a spacer layer provided adjacent to the magnetic insertion layer and opposite to the non-magnetic insertion layer with respect to the magnetic insertion layer; and a first magnetization fixed layer provided adjacent to the spacer layer and opposite to the magnetic insertion layer with respect to the spacer layer. The magnetization free layer and the first magnetization fixed layer have magnetization components in directions approximately perpendicular to a film surface. The magnetization free layer includes two magnetization fixed portions and a domain wall motion portion arranged between the two magnetization fixed portions.
    Type: Grant
    Filed: February 15, 2010
    Date of Patent: August 20, 2013
    Assignee: NEC Corporation
    Inventors: Nobuyuki Ishiwata, Norikazu Ohshima, Shunsuke Fukami, Kiyokazu Nagahara, Tetsuhiro Suzuki
  • Patent number: 8503222
    Abstract: A non-volatile logic circuit includes an input section, a control section and an output section. The input section has perpendicular magnetic anisotropy and has a ferromagnetic layer whose magnetization state is changeable. The control section includes a ferromagnetic layer. The output section is provided in a neighborhood of the input section and the control section and includes a magnetic tunnel junction element whose magnetization state is changeable. The magnetization state of the input section is changed based on the magnetization state. A magnetization state of the magnetic tunnel junction element of the output section which state is changed based on the magnetization state of the ferromagnetic material of the control section and the magnetization state of the ferromagnetic material of the input section.
    Type: Grant
    Filed: January 21, 2010
    Date of Patent: August 6, 2013
    Assignee: NEC Corporation
    Inventors: Tetsuhiro Suzuki, Shunsuke Fukami, Kiyokazu Nagahara, Nobuyuki Ishiwata, Tadahiko Sugibayashi, Noboru Sakimura, Ryusuke Nebashi
  • Publication number: 20130175645
    Abstract: A magnetoresistive effect element of the present invention includes: a domain wall motion layer, a spacer layer and a reference layer. The domain wall motion layer is made of ferromagnetic material with perpendicular magnetic anisotropy. The spacer layer is formed on the domain wall motion layer and made of non-magnetic material. The reference layer is formed on the spacer layer and made of ferromagnetic material, magnetization of the reference layer being fixed. The domain wall motion layer includes at least one domain wall, and stores data corresponding to a position of the domain wall. An anisotropy magnetic field of the domain wall motion layer is larger than a value in which the domain wall motion layer can hold the perpendicular magnetic anisotropy, and smaller than an essential value of an anisotropy magnetic field of the ferromagnetic material of the domain wall motion layer.
    Type: Application
    Filed: December 14, 2010
    Publication date: July 11, 2013
    Applicant: NEC CORPORATION
    Inventors: Tadahiko Sugibayashi, Eiji Kariyada, Kaoru Mori, Norikazu Ohshima, Shunsuke Fukami, Tetsuhiro Suzuki, Hironobu Tanigawa, Sadahiko Miura, Nobuyuki Ishiwata
  • Publication number: 20130140660
    Abstract: In a perpendicular magnetization domain wall motion MRAM in which the magnetizations of both ends of a magnetization free layer are pinned by magnetization pinned layers, the increase of a write current due to leakage magnetic field from the magnetization pinned layer is prevented. A first displacement is present between a first boundary line and a first vertical line, where a curve portion, which crosses a first magnetization free layer, of an outer circumferential line of a first magnetization pinned layer is the first boundary line, a segment which links a center of a magnetization free region and a center of a first magnetization pinned region is a first segment, and a segment, which is a vertical line of the first segment, and which comes in contact with the first boundary line is the first vertical line.
    Type: Application
    Filed: June 16, 2011
    Publication date: June 6, 2013
    Inventors: Shunsuke Fukami, Tetsuhiro Suzuki, Kiyokazu Nagahara, Nobuyuki Ishiwata, Norikazu Ohshima
  • Publication number: 20130113058
    Abstract: A magnetic memory element includes: a first magnetization free layer configured to be composed of ferromagnetic material with perpendicular magnetic anisotropy; a reference layer configured to be provided near the first magnetization free layer; a non-magnetic layer configured to be provided adjacent to the reference layer; and a step formation layer configured to be provided under the first magnetization free layer. The first magnetization free layer includes: a first magnetization fixed region of which magnetization is fixed, a second magnetization fixed region of which magnetization is fixed, and a magnetization free region configured to be connected with the first magnetization fixed region and the second magnetization fixed region. The first magnetization free layer has at least one of a step, a groove and a protrusion inside.
    Type: Application
    Filed: March 9, 2011
    Publication date: May 9, 2013
    Applicant: NEC CORPORATION
    Inventors: Shunsuke Fukami, Kiyokazu Nagahara, Tetsuhiro Suzuki
  • Patent number: 8416611
    Abstract: A magnetoresistance effect element includes: a magnetization free layer; a spacer layer provided adjacent to the magnetization free layer; a first magnetization fixed layer provided adjacent to the spacer layer on a side opposite to the magnetization free layer; and at least two second magnetization fixed layers provided adjacent to the magnetization free layer. The magnetization free layer, the first magnetization fixed layer, and the second magnetization free layers respectively have magnetization components in a direction substantially perpendicular to film surfaces thereof. The magnetization free layer includes: two magnetization fixed portions; and a domain wall motion portion arranged between the two magnetization fixed portions. Magnetizations of the two magnetization fixed portions constituting the magnetization free layer are fixed substantially antiparallel to each other in directions substantially perpendicular to the film surface.
    Type: Grant
    Filed: June 16, 2008
    Date of Patent: April 9, 2013
    Assignee: NEC Corporation
    Inventors: Shunsuke Fukami, Nobuyuki Ishiwata
  • Patent number: 8379429
    Abstract: A domain wall motion element has a magnetic recording layer 10 that is formed of a ferromagnetic film and has a domain wall DW. The magnetic recording layer 10 has: a pair of end regions 11-1 and 11-2 whose magnetization directions are fixed; and a center region 12 sandwiched between the pair of end regions 11-1 and 11-2, in which the domain wall. DW moves. A first trapping site TS1 by which the domain wall DW is trapped is formed at a boundary between the end region 11-1, 11-2 and the center region 12. Furthermore, at least one second trapping site TS2 by which the domain wall DW is trapped is formed within the center region 12.
    Type: Grant
    Filed: January 13, 2009
    Date of Patent: February 19, 2013
    Assignee: NEC Corporation
    Inventors: Nobuyuki Ishiwata, Tetsuhiro Suzuki, Norikazu Ohshima, Kiyokazu Nagahara, Shunsuke Fukami
  • Patent number: 8363461
    Abstract: A magnetic memory includes a magnetization recording layer, a first terminal, a second terminal, a magnetization pinned layer and a non-magnetic layer. The magnetization recording layer has a vertical magnetic anisotropy and includes a ferromagnetic layer. The first terminal is connected to one end of a first region in the magnetization recording layer. The second terminal is connected to the other end of the first region. The non-magnetic layer is arranged on the first region. The magnetization pinned layer is arranged on the non-magnetic layer and is located on the side opposite to the first region. The magnetization recording layer includes: a first extension portion located outside the first terminal in the magnetization recording layer; and a property changing structure that is arranged in the first extension portion and substantially changes a magnetization switching property of the magnetization recording layer.
    Type: Grant
    Filed: June 26, 2009
    Date of Patent: January 29, 2013
    Assignee: NEC Corporation
    Inventors: Tetsuhiro Suzuki, Shunsuke Fukami, Kiyokazu Nagahara, Norikazu Ohshima, Nobuyuki Ishiwata
  • Publication number: 20120278582
    Abstract: A magnetic memory element includes: a first magnetization free layer; a non-magnetic layer; a reference layer; a first magnetization fixed layer group; and a first blocking layer. The first magnetization free layer is composed of ferromagnetic material with perpendicular magnetic anisotropy and includes a first magnetization fixed region, a second magnetization fixed region and a magnetization free region. The non-magnetic layer is provided near the first magnetization free layer. The reference layer is composed of ferromagnetic material and provided on the non-magnetic layer. The first magnetization fixed layer group is provided near the first magnetization fixed region. The first blocking layer is provided being sandwiched between the first magnetization fixed layer group and the first magnetization fixed region or in the first magnetization fixed layer group.
    Type: Application
    Filed: October 21, 2010
    Publication date: November 1, 2012
    Applicant: NEC CORPORATION
    Inventors: Shunsuke Fukami, Tetsuhiro Suzuki, Kiyokazu Nagahara, Norikazu Ohshima, Nobuyuki Ishiwata
  • Patent number: 8194436
    Abstract: A magnetic random access memory includes: a first ferromagnetic layer; an insulating layer provided adjacent to the first ferromagnetic layer; and a first magnetization pinned layer provided adjacent to the insulating layer on a side opposite to the first ferromagnetic layer. The first ferromagnetic layer includes a magnetization free region, a first magnetization pinned region, and a second magnetization pinned region. The magnetization free region has reversible magnetization, and overlaps with the second ferromagnetic layer. The first magnetization pinned region has first pinned magnetization, and is connected to a part of the magnetization free region. The second magnetization pinned region has second pinned magnetization, and is connected to a part of the magnetization free region. The first ferromagnetic layer has magnetic anisotropy in a direction perpendicular to a film surface.
    Type: Grant
    Filed: July 7, 2008
    Date of Patent: June 5, 2012
    Assignee: NEC Corporation
    Inventors: Shunsuke Fukami, Tetsuhiro Suzuki, Kiyokazu Nagahara, Norikazu Ohshima, Nobuyuki Ishiwata