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.

公开(公告)号：US11054463B2

公开(公告)日：2021-07-06

申请号：US16087781

申请日：2017-03-22

Applicant: TOHOKU UNIVERSITY

Inventor： Kenchi Ito ,  Tetsuo Endoh ,  Hideo Sato ,  Takashi Saito ,  Masakazu Muraguchi ,  Hideo Ohno

IPC: G01R31/28 ,  H01L27/22 ,  H01L43/12 ,  G01R27/00 ,  H01L21/66 ,  H01L21/8239

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.

公开(公告)号：US10658572B2

公开(公告)日：2020-05-19

申请号：US16179461

申请日：2018-11-02

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 ,  H01L27/22 ,  H01F10/16 ,  H01F10/32 ,  H01L27/105 ,  H01L29/82 ,  G11C11/16 ,  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 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.