Patents by Inventor Tadashi Kai

Tadashi Kai 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: 11856791
    Abstract: A nonvolatile storage device includes first interconnections extending in a first direction and second interconnections extending in a second direction intersecting the first direction. Memory cells are formed at intersections between first and second interconnections. Each memory cell includes a resistance change element and a selector. In the arrangement of memory cells, all memory cells that are connected to any particular first interconnection are aligned along that first interconnection, and all memory cells connected to any particular second interconnection are alternately staggered in the first direction across a width of that second interconnection.
    Type: Grant
    Filed: May 20, 2022
    Date of Patent: December 26, 2023
    Assignee: Kioxia Corporation
    Inventors: Masahiko Nakayama, Kazumasa Sunouchi, Gaku Sudo, Tadashi Kai
  • Publication number: 20230380183
    Abstract: A magnetic memory device including a first memory cell which includes a first stacked structure including a magnetic layer and a second memory cell which is provided on the first memory cell and includes a second stacked structure including a magnetic layer. Each of the first stacked structure and the second stacked structure includes a first magnetic layer having a variable magnetization direction, a second magnetic layer having a fixed magnetization direction, and a nonmagnetic layer provided between the first magnetic layer and the second magnetic layer. A concentration of iron (Fe) contained in the first magnetic layer included in the first stacked structure and a concentration of iron (Fe) contained in the first magnetic layer included in the second stacked structure are different from each other.
    Type: Application
    Filed: August 1, 2023
    Publication date: November 23, 2023
    Applicant: Kioxia Corporation
    Inventors: Masayoshi IWAYAMA, Tatsuya KISHI, Masahiko NAKAYAMA, Toshihiko NAGASE, Daisuke WATANABE, Tadashi KAI
  • Patent number: 11758739
    Abstract: A magnetic memory device including a first memory cell which includes a first stacked structure including a magnetic layer and a second memory cell which is provided on the first memory cell and includes a second stacked structure including a magnetic layer. Each of the first stacked structure and the second stacked structure includes a first magnetic layer having a variable magnetization direction, a second magnetic layer having a fixed magnetization direction, and a nonmagnetic layer provided between the first magnetic layer and the second magnetic layer. A concentration of iron (Fe) contained in the first magnetic layer included in the first stacked structure and a concentration of iron (Fe) contained in the first magnetic layer included in the second stacked structure are different from each other.
    Type: Grant
    Filed: July 9, 2021
    Date of Patent: September 12, 2023
    Assignee: Kioxia Corporation
    Inventors: Masayoshi Iwayama, Tatsuya Kishi, Masahiko Nakayama, Toshihiko Nagase, Daisuke Watanabe, Tadashi Kai
  • Patent number: 11502125
    Abstract: A magnetoresistive memory device according to one embodiment includes: first and second layer stacks, each of which includes: a first ferromagnetic layer having a magnetization directed in a first direction; a non-magnetic first conductive layer above the first ferromagnetic layer, a second ferromagnetic layer provided above the first conductive layer and having a magnetization directed in a second direction different from the first direction, a first insulating layer on an upper surface of the second ferromagnetic layer, and a third ferromagnetic layer above the first insulating layer. The second ferromagnetic layer of the second layer stack is thicker than the second ferromagnetic layer of the first layer stack.
    Type: Grant
    Filed: March 12, 2020
    Date of Patent: November 15, 2022
    Assignee: KIOXIA CORPORATION
    Inventors: Masaru Toko, Tadaomi Daibou, Junichi Ito, Taichi Igarashi, Tadashi Kai
  • Publication number: 20220278168
    Abstract: A nonvolatile storage device includes first interconnections extending in a first direction and second interconnections extending in a second direction intersecting the first direction. Memory cells are formed at intersections between first and second interconnections. Each memory cell includes a resistance change element and a selector. In the arrangement of memory cells, all memory cells that are connected to any particular first interconnection are aligned along that first interconnection, and all memory cells connected to any particular second interconnection are alternately staggered in the first direction across a width of that second interconnection.
    Type: Application
    Filed: May 20, 2022
    Publication date: September 1, 2022
    Inventors: Masahiko NAKAYAMA, Kazumasa SUNOUCHI, Gaku SUDO, Tadashi KAI
  • Patent number: 11367748
    Abstract: A nonvolatile storage device includes first interconnections extending in a first direction and second interconnections extending in a second direction intersecting the first direction. Memory cells are formed at intersections between first and second interconnections. Each memory cell includes a resistance change element and a selector. In the arrangement of memory cells, all memory cells that are connected to any particular first interconnection are aligned along that first interconnection, and all memory cells connected to any particular second interconnection are alternately staggered in the first direction across a width of that second interconnection.
    Type: Grant
    Filed: March 19, 2021
    Date of Patent: June 21, 2022
    Assignee: KIOXIA CORPORATION
    Inventors: Masahiko Nakayama, Kazumasa Sunouchi, Gaku Sudo, Tadashi Kai
  • Patent number: 11355694
    Abstract: According to one embodiment, a magnetic memory device includes a stacked structure including a first magnetic layer having a variable magnetization direction, a second magnetic layer having a fixed magnetization direction, and a nonmagnetic layer provided between the first magnetic layer and the second magnetic layer, and containing magnesium (Mg) and oxygen (O). The nonmagnetic layer further contains an additive element selected from fluorine (F), sulfur (S), hydrogen (H) and lithium (Li).
    Type: Grant
    Filed: September 13, 2019
    Date of Patent: June 7, 2022
    Assignee: KIOXIA CORPORATION
    Inventors: Tadaomi Daibou, Yasushi Nakasaki, Tadashi Kai, Hiroki Kawai, Takamitsu Ishihara, Junichi Ito
  • Patent number: 11316101
    Abstract: A stack of the embodiment includes: a first magnetic substance; a second magnetic substance; and a first nonmagnetic substance which is disposed between the first magnetic substance and the second magnetic substance and contains at least one first metal element (M1) selected from the group consisting of ruthenium (Ru) and osmium (Os) and at least one second metal element (M2) selected from the group consisting of rhodium (Rh) and iridium (Ir). A magnetic device of the embodiment includes: a third magnetic substance; the stack; and a second nonmagnetic substance which is disposed between the third magnetic substance and the stack.
    Type: Grant
    Filed: March 5, 2020
    Date of Patent: April 26, 2022
    Assignee: KIOXIA CORPORATION
    Inventors: Rina Nomoto, Takayuki Tsukagoshi, Yasushi Nakasaki, Masaru Toko, Tadashi Kai, Takamitsu Ishihara
  • Patent number: 11316097
    Abstract: According to one embodiment, a memory device includes a first wiring extending in a first direction, and a second wiring extending in a second direction that intersects the first direction. A memory cell is between the first wiring and the second wiring and includes a resistive memory element and a switching element that are connected in series between the first wiring and the second wiring. An insulating region surrounds side surfaces of the memory cell. The insulating region includes a first insulating part adjacent to a side surface of the resistive memory element and a second insulating part adjacent to a side surface of the switching element. The second insulating part has a higher thermal conductivity than the first insulating part.
    Type: Grant
    Filed: August 26, 2020
    Date of Patent: April 26, 2022
    Assignee: KIOXIA CORPORATION
    Inventors: Taichi Igarashi, Tadaomi Daibou, Junichi Ito, Tadashi Kai, Shogo Itai, Toshiyuki Enda
  • Publication number: 20220013579
    Abstract: According to one embodiment, a magnetic memory device including a stacked structure including a first magnetic layer having a variable magnetization direction, a second magnetic layer having a fixed magnetization direction, and a nonmagnetic layer provided between the first magnetic layer and the second magnetic layer, and containing magnesium (Mg) and oxygen (O). The nonmagnetic layer further contains a first additive element and a second additive element, the first additive element is at least one element selected from sulfur (S), gallium (Ga), aluminum (Al), titanium (Ti), vanadium (V), hydrogen (H), fluorine (F), manganese (Mg), lithium (Li), nitrogen (N) and magnesium (Mg), and the second additive element is lithium (Li).
    Type: Application
    Filed: September 23, 2021
    Publication date: January 13, 2022
    Applicant: Kioxia Corporation
    Inventors: Tadaomi DAIBOU, Yasushi NAKASAKI, Tadashi KAI, Hiroki KAWAI, Takamitsu ISHIHARA, Junichi ITO
  • Patent number: 11171175
    Abstract: According to one embodiment, a magnetic device includes a stacked body including a first magnetic layer, a second magnetic layer, and a non-magnetic layer between the first magnetic layer and the second magnetic layer. The stacked body has a quadrangular planar shape, the stacked body has a first side dimension in a first direction parallel to a surface of a substrate and a thickness in a second direction perpendicular to the surface of the substrate, and a ratio of the first side dimension to the thickness is in a range of 0.10 to 4.0.
    Type: Grant
    Filed: August 30, 2019
    Date of Patent: November 9, 2021
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventors: Tadashi Kai, Masahiko Nakayama, Jyunichi Ozeki, Shogo Itai
  • Publication number: 20210335888
    Abstract: A magnetic memory device including a first memory cell which includes a first stacked structure including a magnetic layer and a second memory cell which is provided on the first memory cell and includes a second stacked structure including a magnetic layer. Each of the first stacked structure and the second stacked structure includes a first magnetic layer having a variable magnetization direction, a second magnetic layer having a fixed magnetization direction, and a nonmagnetic layer provided between the first magnetic layer and the second magnetic layer. A concentration of iron (Fe) contained in the first magnetic layer included in the first stacked structure and a concentration of iron (Fe) contained in the first magnetic layer included in the second stacked structure are different from each other.
    Type: Application
    Filed: July 9, 2021
    Publication date: October 28, 2021
    Applicant: TOSHIBA MEMORY CORPORATION
    Inventors: Masayoshi IWAYAMA, Tatsuya KISHI, Masahiko NAKAYAMA, Toshihiko NAGASE, Daisuke WATANABE, Tadashi KAI
  • Patent number: 11133456
    Abstract: According to one embodiment, a magnetic storage device includes: a magnetoresistive effect element including a non-magnet, and a stacked structure on the non-magnet, the stacked structure including: a first ferromagnet on the non-magnet; an anti-ferromagnet being exchange-coupled with the first ferromagnet; and a second ferromagnet between the first ferromagnet and the anti-ferromagnet. The stacked structure is configured to: have a first resistance value in response to a first current flowing through the stacked structure in a first direction, and have a second resistance value different from the first resistance value in response to a second current flowing through the stacked structure in a second direction opposite to the first direction.
    Type: Grant
    Filed: March 13, 2019
    Date of Patent: September 28, 2021
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventors: Takeshi Iwasaki, Akiyuki Murayama, Tadashi Kai, Tadaomi Daibou, Masaki Endo, Shumpei Omine, Taichi Igarashi, Junichi Ito
  • Publication number: 20210296568
    Abstract: According to one embodiment, a memory device includes a first wiring extending in a first direction, and a second wiring extending in a second direction that intersects the first direction. A memory cell is between the first wiring and the second wiring and includes a resistive memory element and a switching element that are connected in series between the first wiring and the second wiring. An insulating region surrounds side surfaces of the memory cell. The insulating region includes a first insulating part adjacent to a side surface of the resistive memory element and a second insulating part adjacent to a side surface of the switching element. The second insulating part has a higher thermal conductivity than the first insulating part.
    Type: Application
    Filed: August 26, 2020
    Publication date: September 23, 2021
    Inventors: Taichi IGARASHI, Tadaomi DAIBOU, Junichi ITO, Tadashi KAI, Shogo ITAI, Toshiyuki ENDA
  • Patent number: 11094743
    Abstract: According to one embodiment, a magnetic memory device includes a first memory cell which includes a first stacked structure including a magnetic layer, and a second memory cell which is provided on the first memory cell and includes a second stacked structure including a magnetic layer, wherein each of the first stacked structure and the second stacked structure has a structure in which a plurality of layers including a predetermined layer are stacked, and the predetermined layer included in the first stacked structure and the predetermined layer included in the second stacked structure have different thicknesses.
    Type: Grant
    Filed: March 14, 2019
    Date of Patent: August 17, 2021
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventors: Masayoshi Iwayama, Tatsuya Kishi, Masahiko Nakayama, Toshihiko Nagase, Daisuke Watanabe, Tadashi Kai
  • Publication number: 20210210549
    Abstract: A nonvolatile storage device includes first interconnections extending in a first direction and second interconnections extending in a second direction intersecting the first direction. Memory cells are formed at intersections between first and second interconnections. Each memory cell includes a resistance change element and a selector. In the arrangement of memory cells, all memory cells that are connected to any particular first interconnection are aligned along that first interconnection, and all memory cells connected to any particular second interconnection are alternately staggered in the first direction across a width of that second interconnection.
    Type: Application
    Filed: March 19, 2021
    Publication date: July 8, 2021
    Inventors: Masahiko NAKAYAMA, Kazumasa SUNOUCHI, Gaku SUDO, Tadashi KAI
  • Patent number: 10985209
    Abstract: A nonvolatile storage device includes first interconnections extending in a first direction and second interconnections extending in a second direction intersecting the first direction. Memory cells are formed at intersections between first and second interconnections. Each memory cell includes a resistance change element and a selector. In the arrangement of memory cells, all memory cells that are connected to any particular first interconnection are aligned along that first interconnection, and all memory cells connected to any particular second interconnection are alternately staggered in the first direction across a width of that second interconnection.
    Type: Grant
    Filed: September 3, 2019
    Date of Patent: April 20, 2021
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventors: Masahiko Nakayama, Kazumasa Sunouchi, Gaku Sudo, Tadashi Kai
  • Patent number: 10978636
    Abstract: According to one embodiment, a storage device includes a magnetoresistive effect element comprising a nonmagnetic layer and a stacked body on the nonmagnetic layer. The stacked body includes a first ferromagnetic layer on the nonmagnetic layer, a second ferromagnetic layer exchange-coupled with the first ferromagnetic layer, and a magnetic layer between the first ferromagnetic layer and the second ferromagnetic layer. The magnetic layer includes a magnetic material and at least one compound selected from among a carbide, a nitride, and a boride.
    Type: Grant
    Filed: March 1, 2019
    Date of Patent: April 13, 2021
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventors: Takeshi Iwasaki, Akiyuki Murayama, Tadashi Kai, Tadaomi Daibou, Masaki Endo, Shumpei Omine, Taichi Igarashi, Junichi Ito
  • Publication number: 20210082999
    Abstract: A magnetoresistive memory device according to one embodiment includes: first and second layer stacks, each of which includes: a first ferromagnetic layer having a magnetization directed in a first direction; a non-magnetic first conductive layer above the first ferromagnetic layer, a second ferromagnetic layer provided above the first conductive layer and having a magnetization directed in a second direction different from the first direction, a first insulating layer on an upper surface of the second ferromagnetic layer, and a third ferromagnetic layer above the first insulating layer. The second ferromagnetic layer of the second layer stack is thicker than the second ferromagnetic layer of the first layer stack.
    Type: Application
    Filed: March 12, 2020
    Publication date: March 18, 2021
    Applicant: KIOXIA CORPORATION
    Inventors: Masaru TOKO, Tadaomi DAIBOU, Junichi ITO, Taichi IGARASHI, Tadashi KAI
  • Publication number: 20200403150
    Abstract: A stack of the embodiment includes: a first magnetic substance; a second magnetic substance; and a first nonmagnetic substance which is disposed between the first magnetic substance and the second magnetic substance and contains at least one first metal element (M1) selected from the group consisting of ruthenium (Ru) and osmium (Os) and at least one second metal element (M2) selected from the group consisting of rhodium (Rh) and iridium (Ir). A magnetic device of the embodiment includes: a third magnetic substance; the stack; and a second nonmagnetic substance which is disposed between the third magnetic substance and the stack.
    Type: Application
    Filed: March 5, 2020
    Publication date: December 24, 2020
    Applicant: KIOXIA CORPORATION
    Inventors: Rina NOMOTO, Takayuki TSUKAGOSHI, Yasushi NAKASAKI, Masaru TOKO, Tadashi KAI, Takamitsu ISHIHARA