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).

  • Patent number: 10833256
    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: Grant
    Filed: March 21, 2017
    Date of Patent: November 10, 2020
    Assignee: TOHOKU UNIVERSITY
    Inventors: Hiroaki Honjo, Tetsuo Endoh, Shoji Ikeda, Hideo Sato, Hideo Ohno
  • Patent number: 10804457
    Abstract: A magnetoresistive element includes a reference layer having a fixed magnetization direction and including a ferromagnetic material containing Fe or Co, a recording layer having a variable magnetization direction and including a ferromagnetic material, and one non-magnetic layer that is formed between the reference layer and the recording layer and that contains oxygen. One of the reference layer and the recording layer contains Fe. The three layers are arranged so that a magnetization direction of the one of the reference layer and the recording layer becomes perpendicular to a layer surface by an interfacial perpendicular magnetic anisotropy at an interface between the one of the reference layer and the recording layer and the one non-magnetic layer resulting from the one of the reference layer and the recording layer having a predetermined thickness. The one of the reference layer and the recording layer has a bcc structure.
    Type: Grant
    Filed: August 30, 2016
    Date of Patent: October 13, 2020
    Assignee: TOHOKU UNIVERSITY
    Inventors: Hideo Ohno, Shoji Ikeda, Fumihiro Matsukura, Masaki Endoh, Shun Kanai, Katsuya Miura, Hiroyuki Yamamoto
  • Patent number: 10783936
    Abstract: In reading of a memory unit, an read failure operation due to variation in characteristic of a transistor in a dynamic load is reduced. A read circuit that reads a voltage obtained by a voltage division of a dynamic load unit and the memory unit as an output of the memory unit includes the dynamic load unit having one end connected to a side of a power supply and the other end connected to a side of the memory unit, and a feedback unit that, by a feedback of the voltage obtained by the voltage division that is divided between the dynamic load unit and the memory unit, holds the voltage obtained by the voltage division. The dynamic load unit has an array structure in which a plurality of resistive memory elements are connected in series, in parallel, or in series-parallel. The dynamic load unit has the array structure of the resistive memory elements and this structure can suppress the read failure operation due to the variation in dynamic load.
    Type: Grant
    Filed: December 8, 2017
    Date of Patent: September 22, 2020
    Assignee: TOHOKU UNIVERSITY
    Inventors: Takahiro Hanyu, Daisuke Suzuki, Hideo Ohno, Tetsuo Endoh
  • Patent number: 10783294
    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: Grant
    Filed: August 3, 2017
    Date of Patent: September 22, 2020
    Assignee: TOHOKU UNIVERSITY
    Inventors: Masanori Natsui, Akira Tamakoshi, Takahiro Hanyu, Akira Mochizuki, Tetsuo Endoh, Hiroki Koike, Hideo Ohno
  • Publication number: 20200286536
    Abstract: The magnetic memory element (100) includes: a conductive layer that includes a heavy metal layer (10) containing a 5d transition metal; a first ferromagnetic layer (20) that is adjacent to the conductive layer and contains a ferromagnetic layer having a reversible magnetization; a barrier layer (30) that is adjacent to the first ferromagnetic layer (20) and includes an insulating material; a reference layer (40) that is adjacent to the barrier layer (30) and has at least one second ferromagnetic layer (41) having a fixed magnetization direction; a cap layer (50) that is adjacent to the reference layer (40) and includes a conductive material; a first terminal (T1) that is capable of introducing a current into one end of the heavy metal layer (10) in the longitudinal direction; a second terminal (T2) that is capable of introducing a current into the other end of the heavy metal layer (10) in the longitudinal direction; and a third terminal (T3) that is capable of introducing a current into the cap layer (50).
    Type: Application
    Filed: March 21, 2017
    Publication date: September 10, 2020
    Inventors: Shunsuke FUKAMI, Chaoliang ZHANG, Ayato OHKAWARA, Kyota WATANABE, Hideo OHNO, Tetsuo ENDOH
  • Publication number: 20200265883
    Abstract: A memory circuit device includes multiple memory cells that are each constituted of a resistive memory element; a write circuit unit that is configured to write data to any one of the memory cells which is designated by cell designating information, and a read circuit unit that is configured to read out, from the memory cell designated by the cell designating information, data written in the memory cell. The memory circuit device has a configuration including a selection circuit unit that is shared by both of the write circuit unit and the read circuit unit and configured to select a memory cell to be activated from the multiple memory cells based on cell designating information, and a control circuit unit that is configured to selectively enable any one of writing of data by the write circuit unit and reading of data by the read circuit unit with respect to the memory cell selected by the selection circuit unit.
    Type: Application
    Filed: September 14, 2014
    Publication date: August 20, 2020
    Inventors: Takahiro Hanyu, Daisuke Suzuki, Hideo Ohno, Tetsuo Endoh
  • Patent number: 10749107
    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: Grant
    Filed: March 17, 2017
    Date of Patent: August 18, 2020
    Assignee: TOHOKU UNIVERSITY
    Inventors: Hiroaki Honjo, Shoji Ikeda, Hideo Sato, Tetsuo Endoh, Hideo Ohno
  • Patent number: 10706996
    Abstract: A magnetic material includes a structure in which a first magnetic layer 1 and a second magnetic layer 2 are stacked such that each layer is formed at least partially in a stacking direction by substantially one atomic layer. The first magnetic layer contains Co as a principal component. The second magnetic layer includes at least Ni. The magnetic material has magnetic anisotropy in the stacking direction. Preferably, an atomic arrangement within a film surface of the first magnetic layer and the second magnetic layer has six-fold symmetry.
    Type: Grant
    Filed: November 11, 2013
    Date of Patent: July 7, 2020
    Assignee: TOHOKU UNIVERSITY
    Inventors: Shunsuke Fukami, Hideo Sato, Michihiko Yamanouchi, Shoji Ikeda, Hideo Ohno
  • Publication number: 20200211611
    Abstract: A data write device for a resistive memory element, the resistive memory element including: a conductive electrode provided at one end of the memory element; and a reading electrode provided at the other end of the memory element being configured to vary a resistance of the memory element by applying a write current to the conductive electrode, the data write device for the resistive memory element further includes: a writing means, an output means, and a control means. The output means is provided between a power supply and the reading electrode. As output signals, a read signal from the memory element and a monitor signal to monitor a writing status of the memory element written by the writing means are output from the output means. By the monitor signal, a termination of data-writing into the resistive memory element is detected.
    Type: Application
    Filed: October 31, 2017
    Publication date: July 2, 2020
    Applicant: TOHOKU UNIVERSITY
    Inventors: Takahiro Hanyu, Daisuke Suzuki, Hideo Ohno, Tetsuo Endoh
  • Patent number: 10658572
    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: Grant
    Filed: November 2, 2018
    Date of Patent: May 19, 2020
    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: 10651369
    Abstract: Provided are a magneto resistive effect element with a stable magnetization direction perpendicular to a film plane and with a controlled magnetoresistance ratio, and a magnetic memory using the magneto resistive effect element. Ferromagnetic layers of the magneto resistive effect element are formed from a ferromagnetic material containing at least one type of 3d transition metal such that the magnetoresistance ratio is controlled, and the film thickness of the ferromagnetic layers is controlled on an atomic layer level such that the magnetization direction is changed from a direction in the film plane to a direction perpendicular to the film plane.
    Type: Grant
    Filed: December 28, 2016
    Date of Patent: May 12, 2020
    Assignee: TOHOKU UNIVERSITY
    Inventors: Hideo Ohno, Shoji Ikeda, Fumihiro Matsukura, Masaki Endoh, Shun Kanai, Hiroyuki Yamamoto, Katsuya Miura
  • Patent number: 10644234
    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: Grant
    Filed: August 28, 2017
    Date of Patent: May 5, 2020
    Assignee: TOHOKU UNIVERSITY
    Inventors: Kenchi Ito, Tetsuo Endoh, Shoji Ikeda, Hideo Sato, Hideo Ohno, Sadahiko Miura, Masaaki Niwa, Hiroaki Honjo
  • Patent number: 10622550
    Abstract: A magnetoresistance effect element includes a bias layer comprised of an antiferromagnetic material and having a shape in which a first length in a first direction greater than a second length in a second direction perpendicular to the first direction, a recording layer comprised of a ferromagnetic material and being disposed on the bias layer, a direction of magnetization of the recording layer being reversible, a barrier layer comprised of an insulation material and being disposed on the recording layer, and a reference layer comprised of a ferromagnetic material and being disposed on the barrier layer, a direction of magnetization of the reference layer being substantially fixed.
    Type: Grant
    Filed: September 28, 2017
    Date of Patent: April 14, 2020
    Assignee: TOHOKU UNIVERSITY
    Inventors: Shunsuke Fukami, Hideo Ohno, Tetsuo Endoh
  • Publication number: 20200090719
    Abstract: Provided is a magnetoresistance effect element in which the magnetization direction of the recording layer is perpendicular to the film surface and which has a high thermal stability factor ?, and a magnetic memory. A recording layer having a configuration of first magnetic layer/first non-magnetic coupling layer/first magnetic insertion layer/second non-magnetic coupling layer/second magnetic layer is sandwiched between the first and second non-magnetic layers and stacked so that a magnetic coupling force is generated between the first magnetic layer and the second magnetic layer.
    Type: Application
    Filed: December 28, 2017
    Publication date: March 19, 2020
    Inventors: Koichi NISHIOKA, Tetsuo ENDOH, Shoji IKEDA, Hiroaki HONJO, Hideo SATO, Hideo OHNO
  • Publication number: 20200082884
    Abstract: A data write circuit of a resistive memory element is provided, the device being capable of writing with low writing energy using a simple circuit. The data write circuit of the resistive memory element, includes: a complementary resistive memory element; writing means for making the complementary resistive memory element cause a resistance change; detection means for detecting a writing state in the complementary resistive memory element; and control means for controlling writing by the writing means, based on a detected signal of the detection means.
    Type: Application
    Filed: October 31, 2017
    Publication date: March 12, 2020
    Inventors: TAKAHIRO HANYU, DAISUKE SUZUKI, HIDEO OHNO, TETSUO ENDOH
  • Patent number: 10586580
    Abstract: A magnetic tunnel junction element with a high tunnel magnetic resistance ratio can prevent a recording layer from being damaged. 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 a 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 a vertical direction.
    Type: Grant
    Filed: May 19, 2017
    Date of Patent: March 10, 2020
    Assignee: TOHOKU UNIVERSITY
    Inventors: Hiroaki Honjo, Shoji Ikeda, Hideo Sato, Tetsuo Endoh, Hideo Ohno
  • Publication number: 20200044142
    Abstract: The present invention provides a magnetoresistance effect element which has a high thermal stability factor ? and in which a magnetization direction of a recording layer is a perpendicular direction with respect to a film surface, and a magnetic memory including the same. Magnetic layers of a recording layer of the magnetoresistance effect element are divided into at least two, and an Fe composition with respect to a sum total of atomic fractions of magnetic elements in each magnetic layer is changed before stacking the magnetic layers.
    Type: Application
    Filed: January 18, 2017
    Publication date: February 6, 2020
    Inventors: Hiroaki HONJO, Tetsuo ENDOH, Shoji IKEDA, Hideo SATO, Hideo OHNO
  • Publication number: 20190371370
    Abstract: In reading of a memory unit, an read failure operation due to variation in characteristic of a transistor in a dynamic load is reduced. A read circuit that reads a voltage obtained by a voltage division of a dynamic load unit and the memory unit as an output of the memory unit includes the dynamic load unit having one end connected to a side of a power supply and the other end connected to a side of the memory unit, and a feedback unit that, by a feedback of the voltage obtained by the voltage division that is divided between the dynamic load unit and the memory unit, holds the voltage obtained by the voltage division. The dynamic load unit has an array structure in which a plurality of resistive memory elements are connected in series, in parallel, or in series-parallel. The dynamic load unit has the array structure of the resistive memory elements and this structure can suppress the read failure operation due to the variation in dynamic load.
    Type: Application
    Filed: December 18, 2017
    Publication date: December 5, 2019
    Inventors: Takahiro Hanyu, Daisuke Suzuki, Hideo Ohno, Tetsuo Endoh
  • Publication number: 20190363245
    Abstract: A structure used in the formation of a spintronics element, the spintronics element to include a plurality of laminated layers, includes a substrate, a plurality of laminated layers formed on the substrate, an uppermost layer of the plurality of laminated layers being a non-magnetic layer containing oxygen, and a protection layer directly formed on the uppermost layer, the protection layer preventing alteration of characteristics of the uppermost layer while exposed in an atmosphere including H2O, a partial pressure of H2O in the atmosphere being equal to or larger than 10?4 Pa, no other layer being directly formed on the protection layer.
    Type: Application
    Filed: July 16, 2019
    Publication date: November 28, 2019
    Applicant: TOHOKU UNIVERSITY
    Inventors: Soshi SATO, Masaaki NIWA, Hiroaki HONJO, Shoji IKEDA, Hideo OHNO, Tetsuo ENDO
  • 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