Patents by Inventor Daisuke Saida

Daisuke Saida 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: 20160118098
    Abstract: A magnetic memory according to an embodiment includes at least one MTJ element, the MTJ element including: a magnetic multilayer structure including a first magnetic layer in which a direction of magnetization is fixed, a second magnetic layer in which a direction of magnetization is changeable, and a tunnel barrier layer located between the first and second magnetic layers; a first electrode provided on a first surface of the magnetic multilayer structure; a second electrode provided on a second surface of the magnetic multilayer structure; an insulating film provided on a side surface of the magnetic multilayer structure; and a control electrode provided on the side surface of the magnetic multilayer structure with the insulating film located therebetween, a voltage being applied to the control electrode in a read operation, which increases an energy barrier for changing the magnetization of the second magnetic layer.
    Type: Application
    Filed: November 20, 2015
    Publication date: April 28, 2016
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Naoharu SHIMOMURA, Eiji KITAGAWA, Minoru AMANO, Daisuke SAIDA, Kay YAKUSHIJI, Takayuki NOZAKI, Shinji YUASA, Akio FUKUSHIMA, Hiroshi IMAMURA, Hitoshi KUBOTA
  • Patent number: 9299918
    Abstract: A magnetoresistive element according to an embodiment includes: a first to third ferromagnetic layers, and a first nonmagnetic layer, the first and second ferromagnetic layers each having an axis of easy magnetization in a direction perpendicular to a film plane, the third ferromagnetic layer including a plurality of ferromagnetic oscillators generating rotating magnetic fields of different oscillation frequencies from one another. Spin-polarized electrons are injected into the first ferromagnetic layer and induce precession movements in the plurality of ferromagnetic oscillators of the third ferromagnetic layer by flowing a current between the first and third ferromagnetic layers, the rotating magnetic fields are generated by the precession movements and are applied to the first ferromagnetic layer, and at least one of the rotating magnetic fields assists a magnetization switching in the first ferromagnetic layer.
    Type: Grant
    Filed: October 1, 2014
    Date of Patent: March 29, 2016
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tadaomi Daibou, Minoru Amano, Daisuke Saida, Junichi Ito, Yuichi Ohsawa, Chikayoshi Kamata, Saori Kashiwada, Hiroaki Yoda
  • Patent number: 9257168
    Abstract: An example magnetic recording device includes a magnetic recording section and a magnetization oscillator and a first nonmagnetic layer disposed between the magnetic recording section and the magnetization oscillator. The magnetic recording section includes a first ferromagnetic layer with a magnetization substantially fixed in a first direction; a second ferromagnetic layer with a variable magnetization direction; and a second nonmagnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer. The magnetization oscillator includes a third ferromagnetic layer with a variable magnetization direction; a fourth ferromagnetic layer with a magnetization substantially fixed in a second direction; and a third nonmagnetic layer disposed between the third ferromagnetic layer and the fourth ferromagnetic layer.
    Type: Grant
    Filed: November 12, 2013
    Date of Patent: February 9, 2016
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shiho Nakamura, Hirofumi Morise, Satoshi Yanagi, Daisuke Saida, Akira Kikitsu
  • Patent number: 9230628
    Abstract: A magnetic memory according to an embodiment includes at least one MTJ element, the MTJ element including: a magnetic multilayer structure including a first magnetic layer in which a direction of magnetization is fixed, a second magnetic layer in which a direction of magnetization is changeable, and a tunnel barrier layer located between the first and second magnetic layers; a first electrode provided on a first surface of the magnetic multilayer structure; a second electrode provided on a second surface of the magnetic multilayer structure; an insulating film provided on a side surface of the magnetic multilayer structure; and a control electrode provided on the side surface of the magnetic multilayer structure with the insulating film located therebetween, a voltage being applied to the control electrode in a read operation, which increases an energy barrier for changing the magnetization of the second magnetic layer.
    Type: Grant
    Filed: March 6, 2014
    Date of Patent: January 5, 2016
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Naoharu Shimomura, Eiji Kitagawa, Minoru Amano, Daisuke Saida, Kay Yakushiji, Takayuki Nozaki, Shinji Yuasa, Akio Fukushima, Hiroshi Imamura, Hitoshi Kubota
  • Patent number: 9082961
    Abstract: According to one embodiment, a method of manufacturing a multilayer film, the method includes forming a first layer, forming a second layer on the first layer, and transcribing a crystal information of one of the first and second layers to the other one of the first and second layers by executing a GCIB-irradiation to the second layer.
    Type: Grant
    Filed: September 7, 2011
    Date of Patent: July 14, 2015
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yuichi Ohsawa, Shigeki Takahashi, Junichi Ito, Daisuke Saida, Kyoichi Suguro, Hiroaki Yoda
  • Patent number: 9025368
    Abstract: A magnetic memory element includes a first stacked unit and a second stacked unit. The first stacked unit includes a first ferromagnetic layer, a second ferromagnetic layer, and a first nonmagnetic layer. The second ferromagnetic layer is stacked with the first ferromagnetic layer. The second ferromagnetic layer has a first and second portion. The first and second portion has a changeable direction of magnetization. The second portion is stacked with the first portion in a stacking direction of the first ferromagnetic layer and the second ferromagnetic layer. A magnetic resonance frequency of the second portion is lower than a magnetic resonance frequency of the first portion. The first nonmagnetic layer is provided between the first ferromagnetic layer and the second ferromagnetic layer. The second stacked unit is stacked with the first stacked unit in the stacking direction. The second stacked unit includes a third ferromagnetic layer.
    Type: Grant
    Filed: February 20, 2014
    Date of Patent: May 5, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Daisuke Saida, Minoru Amano, Hiroshi Imamura
  • Patent number: 9019757
    Abstract: A spin wave element includes a substrate, a multilayer, a detecting portion, and two or more input portions. The multilayer having a lamination direction thereof is formed on the substrate and includes a first ferromagnetic layer. The first ferromagnetic layer has magnetization whose direction is in the lamination direction. The detecting portion and the input portions are formed on the multilayer and separated from each other by a first nonmagnetic layer. In addition, a portion of an outer edge of the multilayer viewed from the lamination direction makes a portion of one ellipsoid. The detecting portion and one of the input portions are located on the long axis of the one ellipsoid. The portion of the one ellipsoid is located on a side of one of the input portions.
    Type: Grant
    Filed: September 13, 2010
    Date of Patent: April 28, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shiho Nakamura, Daisuke Saida, Hirofumi Morise, Tsuyoshi Kondo
  • Patent number: 8994131
    Abstract: According to one embodiment, a magnetic memory includes a first magnetoresistive element includes a storage layer with a perpendicular and variable magnetization, a tunnel barrier layer, and a reference layer with a perpendicular and invariable magnetization, and stacked in order thereof in a first direction, and a first shift corrective layer with a perpendicular and invariable magnetization, the first shift corrective layer and the storage layer arranged in a direction intersecting with the first direction. Magnetization directions of the reference layer and the first shift corrective layer are the same.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: March 31, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naoharu Shimomura, Eiji Kitagawa, Chikayoshi Kamata, Minoru Amano, Yuichi Ohsawa, Daisuke Saida, Megumi Yakabe, Hiroaki Maekawa
  • Patent number: 8937832
    Abstract: According to one embodiment, a magnetic memory includes a magnetoresistive element. The element includes a first magnetic film having a variable magnetization perpendicular to a film surface, a second magnetic film having an invariable magnetization perpendicular to the film surface, a nonmagnetic film between the first and second magnetic films, a magnetic field application layer including a third magnetic film having a magnetization parallel to the film surface. The third magnetic film applies a magnetic field parallel to the film surface to the first magnetic film. A magnitude of the magnetization of the third magnetic film when supplying a read current is larger than a magnitude of the magnetization of the third magnetic film when supplying a write current.
    Type: Grant
    Filed: September 18, 2012
    Date of Patent: January 20, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Eiji Kitagawa, Daisuke Saida, Naoharu Shimomura
  • Publication number: 20150014756
    Abstract: A magnetoresistive element according to an embodiment includes: a first to third ferromagnetic layers, and a first nonmagnetic layer, the first and second ferromagnetic layers each having an axis of easy magnetization in a direction perpendicular to a film plane, the third ferromagnetic layer including a plurality of ferromagnetic oscillators generating rotating magnetic fields of different oscillation frequencies from one another. Spin-polarized electrons are injected into the first ferromagnetic layer and induce precession movements in the plurality of ferromagnetic oscillators of the third ferromagnetic layer by flowing a current between the first and third ferromagnetic layers, the rotating magnetic fields are generated by the precession movements and are applied to the first ferromagnetic layer, and at least one of the rotating magnetic fields assists a magnetization switching in the first ferromagnetic layer.
    Type: Application
    Filed: October 1, 2014
    Publication date: January 15, 2015
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tadaomi DAIBOU, Minoru AMANO, Daisuke SAIDA, Junichi ITO, Yuichi OHSAWA, Chikayoshi KAMATA, Saori KASHIWADA, Hiroaki YODA
  • Patent number: 8928055
    Abstract: According to one embodiment, a magnetic memory element includes a stacked body and a conductive shield. The stacked body includes first and second stacked units. The first stacked unit includes first and second ferromagnetic layers and a first nonmagnetic layer. The first ferromagnetic layer has a fixed magnetization in a first direction. A magnetization direction of the second ferromagnetic layer is variable in a second direction. The first nonmagnetic layer is provided between the first and second ferromagnetic layers. The second stacked unit includes a third ferromagnetic layer stacked with the first stacked unit in a stacking direction of the first stacked unit. A magnetization direction of the third ferromagnetic layer is variable in a third direction. The conductive shield is opposed to at least a part of a side surface of the second stacked unit. An electric potential of the conductive shield is controllable.
    Type: Grant
    Filed: August 31, 2012
    Date of Patent: January 6, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Daisuke Saida, Minoru Amano, Junichi Ito
  • Patent number: 8878317
    Abstract: A magnetoresistive element according to an embodiment includes: a first to third ferromagnetic layers, and a first nonmagnetic layer, the first and second ferromagnetic layers each having an axis of easy magnetization in a direction perpendicular to a film plane, the third ferromagnetic layer including a plurality of ferromagnetic oscillators generating rotating magnetic fields of different oscillation frequencies from one another. Spin-polarized electrons are injected into the first ferromagnetic layer and induce precession movements in the plurality of ferromagnetic oscillators of the third ferromagnetic layer by flowing a current between the first and third ferromagnetic layers, the rotating magnetic fields are generated by the precession movements and are applied to the first ferromagnetic layer, and at least one of the rotating magnetic fields assists a magnetization switching in the first ferromagnetic layer.
    Type: Grant
    Filed: August 16, 2011
    Date of Patent: November 4, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tadaomi Daibou, Minoru Amano, Daisuke Saida, Junichi Ito, Yuichi Ohsawa, Chikayoshi Kamata, Saori Kashiwada, Hiroaki Yoda
  • Patent number: 8848433
    Abstract: According to one embodiment, a nonvolatile memory device includes: a magnetic memory element and a control unit. The magnetic memory element includes a stacked body, and a first and a second stacked units. The first stacked unit includes a first and second ferromagnetic layers and a first nonmagnetic layer provided between the first and the second ferromagnetic layers. The second stacked unit includes a third ferromagnetic layer and a nonmagnetic tunneling barrier layer stacked with the third ferromagnetic layer. The control unit is configured to implement a first operation of setting the magnetic memory element to be in a first state. The first operation includes a first preliminary operation of applying a first pulse voltage; and a first setting operation of applying a second pulse voltage having a second rising time to the magnetic memory element after the first preliminary operation.
    Type: Grant
    Filed: March 12, 2013
    Date of Patent: September 30, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Daisuke Saida, Minoru Amano, Naoharu Shimomura
  • Publication number: 20140269038
    Abstract: A magnetic memory according to an embodiment includes at least one MTJ element, the MTJ element including: a magnetic multilayer structure including a first magnetic layer in which a direction of magnetization is fixed, a second magnetic layer in which a direction of magnetization is changeable, and a tunnel barrier layer located between the first and second magnetic layers; a first electrode provided on a first surface of the magnetic multilayer structure; a second electrode provided on a second surface of the magnetic multilayer structure; an insulating film provided on a side surface of the magnetic multilayer structure; and a control electrode provided on the side surface of the magnetic multilayer structure with the insulating film located therebetween, a voltage being applied to the control electrode in a read operation, which increases an energy barrier for changing the magnetization of the second magnetic layer.
    Type: Application
    Filed: March 6, 2014
    Publication date: September 18, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Naoharu SHIMOMURA, Eiji KITAGAWA, Minoru AMANO, Daisuke SAIDA, Kay YAKUSHIJI, Takayuki NOZAKI, Shinji YUASA, Akio FUKUSHIMA, Hiroshi IMAMURA, Hitoshi KUBOTA
  • Publication number: 20140269037
    Abstract: A magnetic memory element includes a first stacked unit and a second stacked unit. The first stacked unit includes a first ferromagnetic layer, a second ferromagnetic layer, and a first nonmagnetic layer. The second ferromagnetic layer is stacked with the first ferromagnetic layer. The second ferromagnetic layer has a first and second portion. The first and second portion has a changeable direction of magnetization. The second portion is stacked with the first portion in a stacking direction of the first ferromagnetic layer and the second ferromagnetic layer. A magnetic resonance frequency of the second portion is lower than a magnetic resonance frequency of the first portion. The first nonmagnetic layer is provided between the first ferromagnetic layer and the second ferromagnetic layer. The second stacked unit is stacked with the first stacked unit in the stacking direction. The second stacked unit includes a third ferromagnetic layer.
    Type: Application
    Filed: February 20, 2014
    Publication date: September 18, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Daisuke SAIDA, Minoru Amano, Hiroshi Imamura
  • Patent number: 8787077
    Abstract: According to one embodiment, a nonvolatile memory device includes a memory unit and a control unit. The memory unit includes a magnetic memory element which includes: a first and second ferromagnetic layers; and a first nonmagnetic layer provided between the first and the second ferromagnetic layers. The memory unit includes a magnetic field application unit configured to apply a magnetic field to the second ferromagnetic layer, the magnetic field having a component in a first in-plane direction perpendicular to a stacking direction. The control unit is electrically connected to the magnetic memory element, and is configured to implement a setting operation of changing a voltage between the first and the second ferromagnetic layers from a first set voltage to a second set voltage. The magnetic field applied by the magnetic field application unit satisfies the condition of ? ? ? H > ( H u + H dx ) ? ( H u + H dx - H ext ) ( H u + H dx + H ext ) .
    Type: Grant
    Filed: March 18, 2013
    Date of Patent: July 22, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Daisuke Saida, Naoharu Shimomura, Minoru Amano, Eiji Kitagawa, Yoshishige Suzuki
  • Patent number: 8745120
    Abstract: According to an embodiment, an adder includes first and second wave computing units and a threshold wave computing unit. Each of the first and second wave computing units includes a pair of first input sections, a first wave transmission medium having a continuous film including a magnetic body connected to the first input sections, and a first wave detector outputting a result of computation by spin waves induced in the first wave transmission medium by the signals corresponding to the two bit values. The threshold wave computing unit includes a plurality of third input sections, a third wave transmission medium having a continuous film including a magnetic body connected to the third input sections, and a third wave detector a result of computation by spin waves induced in the third wave transmission medium.
    Type: Grant
    Filed: January 13, 2012
    Date of Patent: June 3, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hirofumi Morise, Shiho Nakamura, Daisuke Saida, Tsuyoshi Kondo
  • Patent number: 8737122
    Abstract: According to one embodiment, a nonvolatile memory device includes a magnetic memory element and a control unit. The magnetic memory element includes a stacked body including first and second stacked units. The first stacked unit includes a first ferromagnetic layer having a magnetization fixed, a second ferromagnetic layer having a magnetization variable and a first nonmagnetic layer provided between the first and second ferromagnetic layers. The second includes a third ferromagnetic layer having a magnetization rorated by a passed current to produce oscillation, a fourth ferromagnetic layer having a magnetization fixed and a second nonmagnetic layer provided between the third and fourth ferromagnetic layers stacked with each other. A frequency of the oscillation changes in accordance with the direction of the magnetization of the second ferromagnetic layer. The control unit includes a reading unit reading out the magnetization of the second ferromagnetic layer.
    Type: Grant
    Filed: March 9, 2012
    Date of Patent: May 27, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Daisuke Saida, Minoru Amano, Tazumi Nagasawa, Yuichi Ohsawa, Junichi Ito
  • Patent number: 8716817
    Abstract: According to one embodiment, a magnetic memory element includes a stacked body including first and second stacked units stacked with each other. The first stacked unit includes first and second ferromagnetic layers and a first nonmagnetic layer provided therebetween. The second stacked unit includes third and fourth ferromagnetic layers and a second nonmagnetic layer provided therebetween. Magnetization of the second and third ferromagnetic layers are variable. Magnetizations of the first and fourth ferromagnetic layers are fixed in a direction perpendicular to the layer surfaces. A cross-sectional area of the third ferromagnetic layer is smaller than a cross-sectional area of the first stacked unit when cut along a plane perpendicular to the stacking direction.
    Type: Grant
    Filed: March 9, 2012
    Date of Patent: May 6, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Daisuke Saida, Minoru Amano, Yuichi Ohsawa, Junichi Ito, Hiroaki Yoda
  • Patent number: 8716034
    Abstract: According to one embodiment, a method of manufacturing a magnetic memory, the method includes forming a first magnetic layer having a variable magnetization, forming a tunnel barrier layer on the first magnetic layer, forming a second magnetic layer on the tunnel barrier layer, the second magnetic layer having an invariable magnetization, forming a hard mask layer as a mask on the second magnetic layer, patterning the second magnetic layer by using the mask of the hard mask layer, and executing a GCIB-irradiation by using the mask of the hard mask layer, after the patterning.
    Type: Grant
    Filed: September 7, 2011
    Date of Patent: May 6, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuichi Ohsawa, Shigeki Takahashi, Junichi Ito, Daisuke Saida, Kyoichi Suguro, Hiroaki Yoda