公开(公告)号：US11264565B2

公开(公告)日：2022-03-01

申请号：US16843708

申请日：2020-04-08

Applicant: TOHOKU UNIVERSITY

Inventor： Hiroaki Honjo ,  Tetsuo Endoh ,  Hideo Sato ,  Shoji Ikeda

IPC: G11C11/15 ,  H01L27/22 ,  G11C11/16 ,  H01L43/08 ,  H01L43/10 ,  H01L43/02 ,  G01R33/09

Abstract: An object of the invention is to provide a magnetoresistance effect element which includes a reference layer having three or more magnetic layers and which improves a thermal stability factor Δ by decreasing a write error rate using an element structure that enables a wide margin to be secured between a current at which magnetization of the reference layer is reversed and a writing current Ic of a recording layer and by reducing an effect of a stray magnetic field from the reference layer.
The magnetoresistance effect element includes: a first recording layer (A1); a first non-magnetic layer (11); and a first reference layer (B1), wherein the first reference layer (B1) including n-number of a plurality of magnetic layers (21, 22, . . . , 2n) and (n−1)−number of a plurality of non-magnetic insertion layers (31, 32, . . . 3(n−1)) adjacently sandwiched by each of the plurality of magnetic layers, where n≥3.

公开(公告)号：US11121310B2

公开(公告)日：2021-09-14

申请号：US16513173

申请日：2019-07-16

Applicant: TOHOKU UNIVERSITY

Inventor： Soshi Sato ,  Masaaki Niwa ,  Hiroaki Honjo ,  Shoji Ikeda ,  Hideo Ohno ,  Tetsuo Endo

IPC: H01L43/08 ,  H01L43/12 ,  G11C11/16 ,  H01L21/66

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.

公开(公告)号：US11081641B2

公开(公告)日：2021-08-03

申请号：US16479153

申请日：2017-01-18

Applicant: TOHOKU UNIVERSITY

Inventor： Hiroaki Honjo ,  Tetsuo Endoh ,  Shoji Ikeda ,  Hideo Sato ,  Hideo Ohno

IPC: H01L43/02 ,  H01L43/10 ,  H01L43/12 ,  H01L27/22 ,  G11C11/16 ,  H01L27/12

Abstract: The present invention provides a magnetoresistance effect element which has a high thermal stability factor Δ 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.

公开(公告)号：US10586580B2

公开(公告)日：2020-03-10

申请号：US16308166

申请日：2017-05-19

Applicant: TOHOKU UNIVERSITY

Inventor： Hiroaki Honjo ,  Shoji Ikeda ,  Hideo Sato ,  Tetsuo Endoh ,  Hideo Ohno

IPC: G11C11/16 ,  H01L27/22 ,  H01L43/10 ,  H01L27/105 ,  H01L29/82 ,  H01L21/8239 ,  H01L43/02 ,  H01L43/08

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.

公开(公告)号：US10424725B2

公开(公告)日：2019-09-24

申请号：US16013093

申请日：2018-06-20

Applicant: TOHOKU UNIVERSITY

Inventor： Soshi Sato ,  Masaaki Niwa ,  Hiroaki Honjo ,  Shoji Ikeda ,  Hideo Sato ,  Hideo Ohno ,  Tetsuo Endoh

IPC: H01F10/32 ,  H01L43/10 ,  H01L43/08 ,  H01L43/02

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.

公开(公告)号：US20190229262A1

公开(公告)日：2019-07-25

申请号：US16320260

申请日：2017-03-17

Applicant: TOHOKU UNIVERSITY

Inventor： Hiroaki Honjo ,  Shoji Ikeda ,  Hideo Sato ,  Tetsuo Endoh ,  Hideo Ohno

IPC: H01L43/12 ,  C23C14/34 ,  H01L27/22 ,  H01L43/08 ,  H01L43/10 ,  C23C14/14

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.

公开(公告)号：US11765981B1

公开(公告)日：2023-09-19

申请号：US17264655

申请日：2019-06-21

Applicant: TOHOKU UNIVERSITY

Inventor： Sadahiko Miura ,  Hiroaki Honjo ,  Hideo Sato ,  Shoji Ikeda ,  Tetsuo Endoh

IPC: G11C11/00 ,  H10N50/10 ,  G11C11/16

CPC classification number: H10N50/10 ,  G11C11/161

Abstract: A magnetoresistance effect element with a small element size can be provided which achieves both an increase in a thermal stability factor Δ and a reduction in a writing current IC0 and which improves a performance index Δ/IC0(μA−1) obtained by dividing the thermal stability factor Δ by the writing current IC0. The magnetoresistance effect element includes a first reference layer (B1), a first junction layer (11), a first magnetic layer (21), a first non-magnetic coupling layer (31), a second magnetic layer (22), and a second junction layer (12), and a film thickness of the first non-magnetic coupling layer (31) is 0.1 nm or more and 0.3 nm or less.

公开(公告)号：US10749107B2

公开(公告)日：2020-08-18

申请号：US16320260

申请日：2017-03-17

Applicant: TOHOKU UNIVERSITY

Inventor： Hiroaki Honjo ,  Shoji Ikeda ,  Hideo Sato ,  Tetsuo Endoh ,  Hideo Ohno

IPC: H01L43/12 ,  C23C14/14 ,  C23C14/34 ,  H01L43/08 ,  H01L21/8239 ,  H01L27/105 ,  H01L27/22 ,  H01L43/10

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.

公开(公告)号：US10396274B2

公开(公告)日：2019-08-27

申请号：US15064586

申请日：2016-03-08

Applicant: TOHOKU UNIVERSITY

Inventor： Soshi Sato ,  Masaaki Niwa ,  Hiroaki Honjo ,  Shoji Ikeda ,  Hideo Ohno ,  Tetsuo Endo

IPC: G11C11/16 ,  H01L21/66 ,  H01L43/08 ,  H01L43/12

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.

公开(公告)号：US10164174B2

公开(公告)日：2018-12-25

申请号：US15872922

申请日：2018-01-16

Applicant: TOHOKU UNIVERSITY

Inventor： Hideo Sato ,  Shoji Ikeda ,  Mathias Bersweiler ,  Hiroaki Honjo ,  Kyota Watanabe ,  Shunsuke Fukami ,  Fumihiro Matsukura ,  Kenchi Ito ,  Masaaki Niwa ,  Tetsuo Endoh ,  Hideo Ohno

IPC: H01L43/08 ,  H01F10/16 ,  H01F10/32 ,  H01L27/105 ,  H01L29/82 ,  G11C11/16 ,  H01L27/22 ,  H01L43/10

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.