Patents by Inventor Hideo Ohno

Hideo Ohno 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: 20190304526
    Abstract: A magnetic tunnel junction element with a high MR ratio, and can prevent a recording layer from being damaged, and magnetic memory. A reference layer includes a ferromagnetic body, and has magnetization direction fixed in the vertical direction. A barrier layer includes non-magnetic body, and disposed on one surface side of the reference layer. A recording layer is disposed to sandwich barrier layer between itself and reference layer. The recording layer includes a first ferromagnetic layer including at least one of Co and Fe, and having a magnetization direction variable in vertical direction; a first non-magnetic layer including at least one of Mg, MgO, C, Li, Al, and Si, second non-magnetic layer including at least one of Ta, Hf, W, Mo, Nb, Zr, Y, Sc, Ti, V, and Cr, and second ferromagnetic layer including at least one of Co and Fe, and having a magnetization direction variable in vertical direction.
    Type: Application
    Filed: May 19, 2017
    Publication date: October 3, 2019
    Applicant: TOHOKU UNIVERSITY
    Inventors: Hiroaki HONJO, Shoji IKEDA, Hideo SATO, Tetsuo ENDOH, Hideo OHNO
  • Patent number: 10424725
    Abstract: A spintronics element including a ferromagnetic layer containing boron, and a diffusion stopper film covering a side face of the ferromagnetic layer partially or entirely, the side face in direct contact with diffusion stopper film, so as to prevent out-diffusion of the boron contained in the ferromagnetic layer. The diffusion stopper film contains boron at a concentration higher than a concentration of the boron in a portion of the ferromagnetic layer where the ferromagnetic layer contacts the diffusion stopper film.
    Type: Grant
    Filed: June 20, 2018
    Date of Patent: September 24, 2019
    Assignee: TOHOKU UNIVERSITY
    Inventors: Soshi Sato, Masaaki Niwa, Hiroaki Honjo, Shoji Ikeda, Hideo Sato, Hideo Ohno, Tetsuo Endoh
  • Patent number: 10410703
    Abstract: A magnetoresistance effect element includes a recording layer containing a ferromagnetic body, and including a first fixed and second magnetization regions having magnetization components fixed substantially in a direction antiparallel to the in-plane direction to each other, and a free magnetization region disposed between the first and second fixed magnetization regions and having a magnetization component invertible in the in-plane direction, a domain wall disposed between the first fixed magnetization region and the free magnetization region, and being movable within the free magnetization region, and a magnetic nanowire having a width of 40 nm or less. The thickness of the recording layer is 40 nm or less and at least half but no more than twofold the width of the magnetic nanowire. The element further includes a barrier layer disposed on the recording layer, and a reference layer disposed on the barrier layer and containing a ferromagnetic body.
    Type: Grant
    Filed: November 13, 2017
    Date of Patent: September 10, 2019
    Assignee: TOHOKU UNIVERSITY
    Inventors: Shunsuke Fukami, Toru Iwabuchi, Hideo Ohno, Tetsuo Endoh
  • Patent number: 10396274
    Abstract: A method of manufacturing a spintronics element from laminated layers. The method includes (a) forming a plurality of laminated layers in manufacturing equipment, (b) forming a wafer in the manufacturing equipment, including applying a protection layer directly on a non-magnetic uppermost layer of the laminated layers so that the protection layer prevents alteration of characteristics of the uppermost layer, and (c) exposing the wafer, outside of the manufacturing equipment, to an atmosphere that includes H2O having a partial pressure in the atmosphere equal to or larger than 10?4 Pa.
    Type: Grant
    Filed: March 8, 2016
    Date of Patent: August 27, 2019
    Assignee: TOHOKU UNIVERSITY
    Inventors: Soshi Sato, Masaaki Niwa, Hiroaki Honjo, Shoji Ikeda, Hideo Ohno, Tetsuo Endo
  • Publication number: 20190243929
    Abstract: A circuit design support system, a circuit design support method, a circuit design support program, and a recording medium having the program recorded thereon are provided by which a design can be performed in consideration of the stochastic operation of the stochastic operation element and the influence caused by the stochastic operation of the stochastic operation element on the operation reliability of the circuit can be evaluated.
    Type: Application
    Filed: August 3, 2017
    Publication date: August 8, 2019
    Applicant: TOHOKU UNIVERSITY
    Inventors: Masanori NATSUI, Akira TAMAKOSHI, Takahiro HANYU, Akira MOCHIZUKI, Tetsuo ENDOH, Hiroki KOIKE, Hideo OHNO
  • Publication number: 20190229262
    Abstract: A magnetic tunnel junction element configured by stacking, in a following stack order, a fixed layer formed of a ferromagnetic body and in which a magnetization direction is fixed, a magnetic coupling layer formed of a nonmagnetic body, a reference layer formed of a ferromagnetic body and in which the magnetization direction is fixed, a barrier layer formed of a nonmagnetic body, and a recording layer formed of a ferromagnetic body, a barrier layer formed of a nonmagnetic body, and a recording layer formed by sandwiching an insertion layer formed of a nonmagnetic body between first and second ferromagnetic layers, wherein the magnetic coupling layer is formed using a sputtering gas in which a value of a ratio in which a mass number of an element used in the magnetic coupling layer divided by the mass number of the sputtering gas itself is 2.2 or smaller.
    Type: Application
    Filed: March 17, 2017
    Publication date: July 25, 2019
    Applicant: TOHOKU UNIVERSITY
    Inventors: Hiroaki Honjo, Shoji Ikeda, Hideo Sato, Tetsuo Endoh, Hideo Ohno
  • Publication number: 20190219633
    Abstract: A method and a system for measuring the thermal stability factor of a magnetic tunnel junction device, a semiconductor integrated circuit, and a production management method for the semiconductor integrated circuit, capable of measuring the thermal stability factors of individual devices in a relatively short period of time and quickly performing quality control during material development and at a production site. A meter measures change in resistance value of an evaluation MTJ for a predetermined period while causing a predetermined current to flow into the evaluation MTJ maintained at a predetermined temperature. An analyzer calculates a time constant in which a low-resistance state is maintained and a time constant in which a high-resistance state is maintained from the measured change in resistance value. A thermal stability factor of the evaluation MTJ is calculated on the basis of the calculated time constants and the predetermined current flowing into the evaluation MTJ.
    Type: Application
    Filed: March 22, 2017
    Publication date: July 18, 2019
    Applicant: TOHOKU UNIVERSITY
    Inventors: Kenchi ITO, Tetsuo ENDOH, Hideo SATO, Takashi SAITO, Masakazu MURAGUCHI, Hideo OHNO
  • Publication number: 20190198755
    Abstract: A method for producing a magnetic memory includes: forming a magnetic film having a non-magnetic layer between a first magnetic layer and a second magnetic layer on a substrate having an electrode layer; performing annealing treatment at a first treatment temperature in a state where a magnetic field is applied in a direction perpendicular to a film surface of the first or the second magnetic layer in vacuum; forming a magnetic tunnel junction element; forming a protective film protecting the magnetic tunnel junction element; a formation accompanied by thermal history, in which a constituent element of a magnetic memory is formed after the protective film formation on the substrate; and implementing annealing treatment at a second treatment temperature lower than the first treatment temperature on the substrate in an annealing treatment chamber, in vacuum or inert gas wherein no magnetic field is applied.
    Type: Application
    Filed: August 28, 2017
    Publication date: June 27, 2019
    Inventors: Kenchi ITO, Tetsuo ENDOH, Shoji IKEDA, Hideo SATO, Hideo OHNO, Sadahiko MIURA, Masaaki NIWA, Hiroaki HONJO
  • Publication number: 20190189917
    Abstract: A magnetic tunnel junction element includes, in a following stack order, an underlayer formed of a metal material, a fixed layer formed of a ferromagnetic body, a magnetic coupling layer formed of a nonmagnetic body, a reference layer formed of a ferromagnetic body, a barrier layer formed of a nonmagnetic body, and a recording layer formed of a ferromagnetic body, or alternatively, the magnetic tunnel junction element includes, in a following stack order, a recording layer formed of a ferromagnetic body, a barrier layer formed of a nonmagnetic body, a reference layer formed of a ferromagnetic body, a magnetic coupling layer formed of a nonmagnetic body, an underlayer formed of a metal material, and a fixed layer formed of a ferromagnetic body, wherein the fixed layer is formed and stacked after performing plasma treatment to a surface of the underlayer having been formed.
    Type: Application
    Filed: March 21, 2017
    Publication date: June 20, 2019
    Applicant: TOHOKU UNIVERSITY
    Inventors: Hiroaki Honjo, Tetsuo Endoh, Shoji Ikeda, Hideo Sato, Hideo Ohno
  • Patent number: 10263180
    Abstract: A magnetoresistance effect element includes a reference layer made of a ferromagnetic material, a recording layer made of a ferromagnetic material, and a barrier layer disposed between the reference layer and the recording layer. The reference layer and the recording layer have an in-plane magnetization direction parallel to a surface of the layers. The recording layer has a shape that has short axis and long axis perpendicular to the short axis in plan view. A first value obtained by dividing a thickness of the recording layer by a length of the short axis of the recording layer is greater than 0.3 and smaller than 1.
    Type: Grant
    Filed: July 22, 2017
    Date of Patent: April 16, 2019
    Assignee: TOHOKU UNIVERSITY
    Inventors: Hideo Sato, Shinya Ishikawa, Shunsuke Fukami, Shoji Ikeda, Fumihiro Matsukura, Hideo Ohno, Tetsuo Endoh
  • Publication number: 20190074433
    Abstract: A magnetoresistance effect element includes first and second magnetic layers having a perpendicular magnetization direction, and a first non-magnetic layer disposed adjacent to the first magnetic layer and on a side opposite to a side on which the second magnetic layer is disposed. An interfacial perpendicular magnetic anisotropy exists at an interface between the first magnetic layer and the first non-magnetic layer, and the anisotropy causes the first magnetic layer to have a magnetization direction perpendicular to the surface of the layers. An atomic fraction of all magnetic elements to all magnetic and non-magnetic elements included in the second magnetic layer is smaller than that of the first magnetic layer.
    Type: Application
    Filed: November 2, 2018
    Publication date: March 7, 2019
    Applicant: TOHOKU UNIVERSITY
    Inventors: Hideo SATO, Shoji IKEDA, Mathias BERSWEILER, Hiroaki HONJO, Kyota WATANABE, Shunsuke FUKAMI, Fumihiro MATSUKURA, Kenchi ITO, Masaaki NIWA, Tetsuo ENDOH, Hideo OHNO
  • Publication number: 20190019944
    Abstract: A magnetic tunnel junction element (10) includes a configuration in which a reference layer (14) that includes a ferromagnetic material, a barrier layer (15) that includes O, a recording layer (16) that includes a ferromagnetic material including Co or Fe, a first protective layer (17) that includes O, and a second protective layer (18) that includes at least one of Pt, Ru, Co, Fe, CoB, FeB, or CoFeB are layered.
    Type: Application
    Filed: November 18, 2016
    Publication date: January 17, 2019
    Inventors: Hideo Sato, Yoshihisa Horikawa, Shunsuke Fukami, Shoji Ikeda, Fumihiro Matsukura, Hideo Ohno, Tetsuo Endoh, Hiroaki Honjo
  • Patent number: 10164174
    Abstract: A magnetoresistance effect element includes first and second magnetic layers having a perpendicular magnetization direction, and a first non-magnetic layer disposed adjacent to the first magnetic layer and on a side opposite to a side on which the second magnetic layer is disposed. An interfacial perpendicular magnetic anisotropy exists at an interface between the first magnetic layer and the first non-magnetic layer, and the anisotropy causes the first magnetic layer to have a magnetization direction perpendicular to the surface if the layers. The second magnetic layer has a saturation magnetization lower than that of the first magnetic layer, and an interfacial magnetic anisotropy energy density (Ki) at the interface between the first magnetic layer and the first non-magnetic layer is greater than that of an interface between the first non-magnetic layer and second magnetic layers if being disposed adjacent each other.
    Type: Grant
    Filed: January 16, 2018
    Date of Patent: December 25, 2018
    Assignee: TOHOKU UNIVERSITY
    Inventors: Hideo Sato, Shoji Ikeda, Mathias Bersweiler, Hiroaki Honjo, Kyota Watanabe, Shunsuke Fukami, Fumihiro Matsukura, Kenchi Ito, Masaaki Niwa, Tetsuo Endoh, Hideo Ohno
  • Patent number: 10127957
    Abstract: A control method for a magnetoresistance effect element and a control device for the magnetoresistance effect element that provide a higher writing speed and lower power consumption. When the magnetization direction of a second magnetic layer is nearly parallel to the magnetization direction of a first magnetic layer, a first voltage is applied across the first and second magnetic layer so that the magnetization direction of the second magnetic layer is reversed by modifying the direction of the magnetization easy axis thereof, followed by the application of a second voltage. When the magnetization direction of the second magnetic layer is nearly antiparallel to the magnetization direction of the first magnetic layer, a third voltage is applied across the first magnetic layer and the second magnetic layer, followed by the application of a fourth voltage so that current flows from the second magnetic layer toward the first magnetic layer.
    Type: Grant
    Filed: November 13, 2014
    Date of Patent: November 13, 2018
    Assignee: TOHOKU UNIVERSITY
    Inventors: Shun Kanai, Fumihiro Matsukura, Hideo Ohno, Michihiko Yamanouchi, Shoji Ikeda, Hideo Sato
  • Publication number: 20180301621
    Abstract: A spintronics element including a ferromagnetic layer containing boron, and a diffusion stopper film covering a side face of the ferromagnetic layer partially or entirely, the side face in direct contact with diffusion stopper film, so as to prevent out-diffusion of the boron contained in the ferromagnetic layer. The diffusion stopper film contains boron at a concentration higher than a concentration of the boron in a portion of the ferromagnetic layer where the ferromagnetic layer contacts the diffusion stopper film.
    Type: Application
    Filed: June 20, 2018
    Publication date: October 18, 2018
    Applicant: TOHOKU UNIVERSITY
    Inventors: Soshi SATO, Masaaki NIWA, Hiroaki HONJO, Shoji IKEDA, Hideo SATO, Hideo OHNO, Tetsuo ENDOH
  • Patent number: 10037789
    Abstract: In order to stably write data into a magnetic memory that uses in-plane current-induced perpendicular switching of magnetization to write data, the magnetic memory includes a recording layer formed as a perpendicular magnetization film, an adjacent layer joined to an upper surface or a lower surface of the recording layer, an external magnetic field application part configured to apply a first external magnetic field to the recording layer in a first direction which is an in-plane direction of the recording layer, and a current application part configured to allow a write current to flow through the adjacent layer in the first direction or a second direction which is opposite to the first direction. The external magnetic field application part is configured to switch a direction of a second external magnetic field applied in a direction perpendicular to the first direction in accordance with a direction of the write current.
    Type: Grant
    Filed: August 31, 2015
    Date of Patent: July 31, 2018
    Assignees: NEC CORPORATION, TOHOKU UNIVERSITY
    Inventors: Ryusuke Nebashi, Noboru Sakimura, Yukihide Tsuji, Ayuka Tada, Hideo Ohno
  • Patent number: 10020039
    Abstract: A magnetoresistive device includes a magnetic free layer having first and second surfaces, the magnetic free layer being comprised of a ferromagnetic material having a perpendicular magnetic anisotropy, a spin current generation layer contacting the first surface of the magnetic free layer, a tunnel barrier layer having one surface contacting the second surface of the magnetic free layer, a reference layer contacting another surface of the tunnel barrier layer, and a leakage field generation layer including first and second leakage field generation layers each of which is comprised of a ferromagnetic material and generates a leakage field, an in-plane component of the leakage field at an part of the magnetic free layer is formed generating a domain wall having an in-plane magnetization component in the magnetic free layer.
    Type: Grant
    Filed: May 2, 2016
    Date of Patent: July 10, 2018
    Assignee: TOHOKU UNIVERSITY
    Inventors: Shunsuke Fukami, Michihiko Yamanouchi, Hideo Ohno
  • Publication number: 20180175286
    Abstract: A magnetoresistance effect element includes first and second magnetic layers having a perpendicular magnetization direction, and a first non-magnetic layer disposed adjacent to the first magnetic layer and on a side opposite to a side on which the second magnetic layer is disposed. An interfacial perpendicular magnetic anisotropy exists at an interface between the first magnetic layer and the first non-magnetic layer, and the anisotropy causes the first magnetic layer to have a magnetization direction perpendicular to the surface if the layers. The second magnetic layer has a saturation magnetization lower than that of the first magnetic layer, and an interfacial magnetic anisotropy energy density (Ki) at the interface between the first magnetic layer and the first non-magnetic layer is greater than that of an interface between the first non-magnetic layer and second magnetic layers if being disposed adjacent each other.
    Type: Application
    Filed: January 16, 2018
    Publication date: June 21, 2018
    Applicant: TOHOKU UNIVERSITY
    Inventors: Hideo SATO, Shoji IKEDA, Mathias BERSWEILER, Hiroaki HONJO, Kyota WATANABE, Shunsuke FUKAMI, Fumihiro MATSUKURA, Kenchi ITO, Masaaki NIWA, Tetsuo ENDOH, Hideo OHNO
  • Publication number: 20180108390
    Abstract: A magnetoresistance effect element includes a recording layer containing a ferromagnetic body, and including a first fixed and second magnetization regions having magnetization components fixed substantially in a direction antiparallel to the in-plane direction to each other, and a free magnetization region disposed between the first and second fixed magnetization regions and having a magnetization component invertible in the in-plane direction, a domain wall disposed between the first fixed magnetization region and the free magnetization region, and being movable within the free magnetization region, and a magnetic nanowire having a width of 40 nm or less. The thickness of the recording layer is 40 nm or less and at least half but no more than twofold the width of the magnetic nanowire. The element further includes a barrier layer disposed on the recording layer, and a reference layer disposed on the barrier layer and containing a ferromagnetic body.
    Type: Application
    Filed: November 13, 2017
    Publication date: April 19, 2018
    Applicant: TOHOKU UNIVERSITY
    Inventors: Shunsuke FUKAMI, Toru IWABUCHI, Hideo OHNO, Tetsuo ENDOH
  • Patent number: 9941468
    Abstract: A magnetoresistance effect element (100) includes a heavy metal layer (11) that includes a heavy metal and that is formed to extend in a first direction, a recording layer (12) that includes a ferromagnetic material and that is provided adjacent to the heavy metal layer (11), a barrier layer (13) that includes an insulating material and that is provided on the recording layer (12) with being adjacent to a surface of the recording layer (12) opposite to the heavy metal layer (11), and a reference layer (14) that includes a ferromagnetic material and that is provided adjacent to a surface of the barrier layer (13), the surface being opposite to the recording layer (12). The direction of the magnetization of the reference layer (14) has a component substantially fixed in the first direction, and the direction of the magnetization of the recording layer (12) has a component variable in the first direction.
    Type: Grant
    Filed: July 29, 2015
    Date of Patent: April 10, 2018
    Assignee: Tohoku University
    Inventors: Shunsuke Fukami, Chaoling Zhang, Tetsuro Anekawa, Hideo Ohno, Tetsuo Endoh