Patents by Inventor Soichi Oikawa
Soichi Oikawa 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: 11980104Abstract: According to one embodiment, a magnetic memory device includes a magnetoresistance effect element including a first magnetic layer having a variable magnetization direction, a second magnetic layer having a variable magnetization direction, a third magnetic layer having a fixed magnetization direction and a nonmagnetic layer, the first magnetic layer being provided between the second and third magnetic layers, and the nonmagnetic layer being provided between the first and third magnetic layers. The second magnetic layer has a superlattice structure in which first element layers and second element layers are alternately stacked. The first element is Co, and the second element is selected from Pt, Ni and Pd, and the second magnetic layer contains Cr as a third element.Type: GrantFiled: December 10, 2020Date of Patent: May 7, 2024Assignee: Kioxia CorporationInventors: Masaru Toko, Hideyuki Sugiyama, Soichi Oikawa, Masahiko Nakayama
-
Publication number: 20230079445Abstract: According to one embodiment, a memory device includes a first memory cell, a second memory cell adjacent to the first memory cell in a first direction, and a third memory cell adjacent to the first memory cell in a second direction, each of the first, second, and third memory cells including a resistance change memory element and a switching element. The switching element includes first and second electrodes, and a switching material layer between the first and second electrodes, the first and second electrodes overlap each other when viewed from the first direction, the first electrodes in the first and second memory cells are apart from each other, and the switching material layers in the first and second memory cells are continuously provided.Type: ApplicationFiled: March 11, 2022Publication date: March 16, 2023Applicant: Kioxia CorporationInventors: Kenji FUKUDA, Hideyuki SUGIYAMA, Masahiko NAKAYAMA, Hiroyuki KANAYA, Soichi OIKAWA
-
Publication number: 20220302371Abstract: A magnetic storage device includes a magnetoresistance effect element including a first magnetic layer having a variable magnetization direction, a second magnetic layer having a fixed magnetization direction, and a non-magnetic layer between the first and second magnetic layers. The first magnetic layer includes a first layer that is magnetic, a second layer that is magnetic and farther from the non-magnetic layer than the first layer, and a third layer between the first and second layers. The third layer includes a first portion formed of an insulating material or a semiconductor material and a plurality of second portions surrounded by the first portion and formed of a conductive material.Type: ApplicationFiled: August 31, 2021Publication date: September 22, 2022Inventors: Katsuhiko KOUI, Masaru TOKO, Soichi OIKAWA, Hideyuki SUGIYAMA
-
Publication number: 20220085276Abstract: According to one embodiment, a magnetic memory device includes a magnetoresistance effect element including a first magnetic layer having a variable magnetization direction, a second magnetic layer having a variable magnetization direction, a third magnetic layer having a fixed magnetization direction and a nonmagnetic layer, the first magnetic layer being provided between the second and third magnetic layers, and the nonmagnetic layer being provided between the first and third magnetic layers. The second magnetic layer has a superlattice structure in which first element layers and second element layers are alternately stacked. The first element is Co, and the second element is selected from Pt, Ni and Pd, and the second magnetic layer contains Cr as a third element.Type: ApplicationFiled: December 10, 2020Publication date: March 17, 2022Applicant: Kioxia CorporationInventors: Masaru TOKO, Hideyuki SUGIYAMA, Soichi OIKAWA, Masahiko NAKAYAMA
-
Patent number: 11017826Abstract: According to one embodiment, a magnetic memory device includes a conductive member, a first magnetic layer, a first counter magnetic layer, and a first nonmagnetic layer. The conductive member includes a first portion, a second portion, and a third portion between the first portion and the second portion. The first counter magnetic layer is provided between the third portion and the first magnetic layer in a first direction crossing a second direction. The second direction is from the first portion toward the second portion. The first nonmagnetic layer is provided between the first magnetic layer and the first counter magnetic layer. The third portion includes a first position, and a second position between the first position and the first counter magnetic layer in the first direction. A second concentration of boron at the second position is lower than a first concentration of boron at the first position.Type: GrantFiled: November 27, 2019Date of Patent: May 25, 2021Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Yushi Kato, Soichi Oikawa, Hiroaki Yoda
-
Patent number: 10897007Abstract: According to one embodiment, a magnetic memory device includes a first magnetic region, a first counter magnetic region, and a first nonmagnetic region provided between the first magnetic region and the first counter magnetic region. The first magnetic region includes a first magnetic film, a second magnetic film, and an intermediate film. The first magnetic film is provided between the second magnetic film and the first nonmagnetic region. The intermediate film includes Ru and is provided between the first magnetic film and the second magnetic film. A distance along a first direction between the first magnetic film and the second magnetic film is not less than 1.8 nm and not more than 2.2 nm. The first direction is from the first counter magnetic region toward the first magnetic region.Type: GrantFiled: November 27, 2019Date of Patent: January 19, 2021Assignee: Kabushiki Kaisha ToshibaInventors: Soichi Oikawa, Yushi Kato, Hiroaki Yoda
-
Patent number: 10734053Abstract: According to one embodiment, a magnetic memory device includes a conductive member, a first magnetic layer, a second magnetic layer, and a first nonmagnetic layer. The conductive member includes a first layer. The first layer includes at least one selected from the group consisting of HfN having a NaCl structure, HfN having a fcc structure, and HfC having a NaCl structure. The first magnetic layer is separated from the first layer in a first direction. The second magnetic layer is provided between the first layer and the first magnetic layer. The first nonmagnetic layer is provided between the first magnetic layer and the second magnetic layer.Type: GrantFiled: February 11, 2019Date of Patent: August 4, 2020Assignee: Kabushiki Kaisha ToshibaInventors: Mizue Ishikawa, Yushi Kato, Soichi Oikawa, Hiroaki Yoda
-
Publication number: 20200168260Abstract: According to one embodiment, a magnetic memory device includes a conductive member, a first magnetic layer, a first counter magnetic layer, and a first nonmagnetic layer. The conductive member includes a first portion, a second portion, and a third portion between the first portion and the second portion. The first counter magnetic layer is provided between the third portion and the first magnetic layer in a first direction crossing a second direction. The second direction is from the first portion toward the second portion. The first nonmagnetic layer is provided between the first magnetic layer and the first counter magnetic layer. The third portion includes a first position, and a second position between the first position and the first counter magnetic layer in the first direction. A second concentration of boron at the second position is lower than a first concentration of boron at the first position.Type: ApplicationFiled: November 27, 2019Publication date: May 28, 2020Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yushi KATO, Soichi OIKAWA, Hiroaki YODA
-
Publication number: 20200168790Abstract: According to one embodiment, a magnetic memory device includes a first magnetic region, a first counter magnetic region, and a first nonmagnetic region provided between the first magnetic region and the first counter magnetic region. The first magnetic region includes a first magnetic film, a second magnetic film, and an intermediate film. The first magnetic film is provided between the second magnetic film and the first nonmagnetic region. The intermediate film includes Ru and is provided between the first magnetic film and the second magnetic film. A distance along a first direction between the first magnetic film and the second magnetic film is not less than 1.8 nm and not more than 2.2 nm. The first direction is from the first counter magnetic region toward the first magnetic region.Type: ApplicationFiled: November 27, 2019Publication date: May 28, 2020Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Soichi OIKAWA, Yushi KATO, Hiroaki YODA
-
Publication number: 20200058338Abstract: According to one embodiment, a magnetic memory device includes a conductive member, a first magnetic layer, a second magnetic layer, and a first nonmagnetic layer. The conductive member includes a first layer. The first layer includes at least one selected from the group consisting of HfN having a NaCl structure, HfN having a fcc structure, and HfC having a NaCl structure. The first magnetic layer is separated from the first layer in a first direction. The second magnetic layer is provided between the first layer and the first magnetic layer. The first nonmagnetic layer is provided between the first magnetic layer and the second magnetic layer.Type: ApplicationFiled: February 11, 2019Publication date: February 20, 2020Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Mizue ISHIKAWA, Yushi KATO, Soichi OIKAWA, Hiroaki YODA
-
Patent number: 10490736Abstract: A magnetic memory according to an embodiment includes: first to third terminals; a nonmagnetic conductive layer including first to third regions, the second region being disposed between the first and third regions, the first region being electrically connected to the first terminal, and the third region being electrically connected to the second terminal; and a magnetoresistive element disposed to correspond to the second region, including a first magnetic layer electrically connected to the third terminal, a second magnetic layer disposed between the first magnetic layer and the second region, and a nonmagnetic layer disposed between the first and second magnetic layers, the conductive layer including at least one of an alloy including Ir and Ta, an alloy including Ir and V, an alloy including Au and V, an alloy including Au and Nb, or an alloy including Pt and V, each of the alloys having an fcc structure.Type: GrantFiled: March 6, 2018Date of Patent: November 26, 2019Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Yoshiaki Saito, Tomoaki Inokuchi, Yushi Kato, Soichi Oikawa, Mizue Ishikawa, Hiroaki Yoda
-
Patent number: 10453513Abstract: According to one embodiment, a magnetic memory device includes a conductive layer, a first magnetic layer, a second magnetic layer, a first nonmagnetic layer, and a controller. The conductive layer includes first and second portions, and a third portion between the first and second portions. The conductive layer includes a first metal and boron. The first magnetic layer is separated from the third portion in a first direction crossing a second direction. The second magnetic layer is provided between the third portion and the first magnetic layer. The first nonmagnetic layer is provided between the first and second magnetic layers. The controller is electrically connected to the first and second portions. The controller supplies a current to the conductive layer. The first metal includes at least one selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.Type: GrantFiled: March 12, 2018Date of Patent: October 22, 2019Assignee: Kabushiki Kaisha ToshibaInventors: Yushi Kato, Yoshiaki Saito, Mizue Ishikawa, Soichi Oikawa, Hiroaki Yoda
-
Patent number: 10374150Abstract: According to one embodiment, a magnetic memory device includes a conductive layer, first and second magnetic layers, a first nonmagnetic layer and a controller. The conductive layer includes first and second portions, and a third portion positioned between the first and second portions. The conductive layer includes a first metal. The first magnetic layer is separated from the third portion. The second magnetic layer is provided between the third portion and the first magnetic layer. The first nonmagnetic layer is provided between the first and second magnetic layers. The controller is electrically connected to the first and second portions. The second magnetic layer has first and second lattice lengths. The first lattice length is longer than the second lattice length. The controller implements a first operation of supplying a first current to the conductive layer, and a second operation of supplying a second current to the conductive layer.Type: GrantFiled: February 26, 2018Date of Patent: August 6, 2019Assignee: Kabushiki Kaisha ToshibaInventors: Yushi Kato, Yoshiaki Saito, Soichi Oikawa, Mizue Ishikawa, Hiroaki Yoda
-
Patent number: 10360960Abstract: According to one embodiment, a magnetic memory device includes a conductive layer, a first magnetic layer, a second magnetic layer, a first nonmagnetic layer, and a controller. The conductive layer includes a first portion, a second portion, and a third portion between the first and second portions. The first magnetic layer is separated from the third portion. The second magnetic layer is provided between the third portion and the first magnetic layer. The first nonmagnetic layer is provided between the first and second magnetic layers. The controller is electrically connected to the first and second portions. The third portion includes a first region and a second region. The second region is provided between the first region and the second magnetic layer. The controller implements a first operation of supplying a first current to the conductive layer, and a second operation of supplying a second current to the conductive layer.Type: GrantFiled: September 11, 2017Date of Patent: July 23, 2019Assignee: Kabushiki Kaisha ToshibaInventors: Yushi Kato, Soichi Oikawa, Mizue Ishikawa, Yoshiaki Saito, Hiroaki Yoda
-
Patent number: 10262711Abstract: A magnetic memory of an embodiment includes: first through third terminals; a conductive layer including first through third portions, the first portion being located between the second and third portions, the second and third portions being electrically connected to the first and second terminals respectively; and a magnetoresistive element including: a first magnetic layer electrically connected to the third terminal; a second magnetic layer disposed between the first magnetic layer and the first portion; a first nonmagnetic layer disposed between the first magnetic layer and the second magnetic layer; a third magnetic layer disposed between the first nonmagnetic layer and the second magnetic layer; and a second nonmagnetic layer disposed between the second magnetic layer and the third magnetic layer, a sign of a spin Hall angle of the second nonmagnetic layer being different from a sign of a spin Hall angle of the conductive layer.Type: GrantFiled: August 31, 2017Date of Patent: April 16, 2019Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Mizue Ishikawa, Yushi Kato, Yoshiaki Saito, Soichi Oikawa, Hiroaki Yoda
-
Publication number: 20190088860Abstract: A magnetic memory according to an embodiment includes: first to third terminals; a nonmagnetic conductive layer including first to third regions, the second region being disposed between the first and third regions, the first region being electrically connected to the first terminal, and the third region being electrically connected to the second terminal; and a magnetoresistive element disposed to correspond to the second region, including a first magnetic layer electrically connected to the third terminal, a second magnetic layer disposed between the first magnetic layer and the second region, and a nonmagnetic layer disposed between the first and second magnetic layers, the conductive layer including at least one of an alloy including Ir and Ta, an alloy including Ir and V, an alloy including Au and V, an alloy including Au and Nb, or an alloy including Pt and V, each of the alloys having an fcc structure.Type: ApplicationFiled: March 6, 2018Publication date: March 21, 2019Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yoshiaki Saito, Tomoaki Inokuchi, Yushi Kato, Soichi Oikawa, Mizue Ishikawa, Hiroaki Yoda
-
Publication number: 20190080741Abstract: According to one embodiment, a magnetic memory device includes a conductive layer, a first magnetic layer, a second magnetic layer, a first nonmagnetic layer, and a controller. The conductive layer includes first and second portions, and a third portion between the first and second portions. The conductive layer includes a first metal and boron. The first magnetic layer is separated from the third portion in a first direction crossing a second direction. The second magnetic layer is provided between the third portion and the first magnetic layer. The first nonmagnetic layer is provided between the first and second magnetic layers. The controller is electrically connected to the first and second portions. The controller supplies a current to the conductive layer. The first metal includes at least one selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.Type: ApplicationFiled: March 12, 2018Publication date: March 14, 2019Applicant: Kabushiki Kaisha ToshibaInventors: Yushi KATO, Yoshiaki SAITO, Mizue ISHIKAWA, Soichi OIKAWA, Hiroaki YODA
-
Publication number: 20190051818Abstract: According to one embodiment, a magnetic memory element includes a conductive layer, a first magnetic layer, a second magnetic layer, and a first nonmagnetic layer. The first magnetic layer is separated from the conductive layer. The second magnetic layer includes iron, platinum, and boron and is provided between the conductive layer and the first magnetic layer. The first nonmagnetic layer is provided between the first magnetic layer and the second magnetic layer. The conductive layer includes a first region and a second region. The second region includes a first metal and boron and is provided between the first region and the second magnetic layer. The first region does not include boron, or a first concentration of boron in the first region is lower than a second concentration of boron in the second region.Type: ApplicationFiled: February 15, 2018Publication date: February 14, 2019Applicant: Kabushiki Kaisha ToshibaInventors: Soichi OIKAWA, Yushi Kato, Mizue Ishikawa, Yoshiaki Saito, Hiroaki Yoda
-
Publication number: 20180366639Abstract: According to one embodiment, a magnetic memory device includes a conductive layer, first and second magnetic layers, a first nonmagnetic layer and a controller. The conductive layer includes first and second portions, and a third portion positioned between the first and second portions. The conductive layer includes a first metal. The first magnetic layer is separated from the third portion. The second magnetic layer is provided between the third portion and the first magnetic layer. The first nonmagnetic layer is provided between the first and second magnetic layers. The controller is electrically connected to the first and second portions. The second magnetic layer has first and second lattice lengths. The first lattice length is longer than the second lattice length. The controller implements a first operation of supplying a first current to the conductive layer, and a second operation of supplying a second current to the conductive layer.Type: ApplicationFiled: February 26, 2018Publication date: December 20, 2018Applicant: Kabushiki Kaisha ToshibaInventors: Yushi Kato, Yoshiaki Saito, Soichi Oikawa, Mizue Ishikawa, Hiroaki Yoda
-
Publication number: 20180268886Abstract: A magnetic memory of an embodiment includes: first through third terminals; a conductive layer including first through third portions, the first portion being located between the second and third portions, the second and third portions being electrically connected to the first and second terminals respectively; and a magnetoresistive element including: a first magnetic layer electrically connected to the third terminal; a second magnetic layer disposed between the first magnetic layer and the first portion; a first nonmagnetic layer disposed between the first magnetic layer and the second magnetic layer; a third magnetic layer disposed between the first nonmagnetic layer and the second magnetic layer; and a second nonmagnetic layer disposed between the second magnetic layer and the third magnetic layer, a sign of a spin Hall angle of the second nonmagnetic layer being different from a sign of a spin Hall angle of the conductive layer.Type: ApplicationFiled: August 31, 2017Publication date: September 20, 2018Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Mizue ISHIKAWA, Yushi KATO, Yoshiaki SAITO, Soichi OIKAWA, Hiroaki YODA