Patents by Inventor Masaru TOKO
Masaru TOKO 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).
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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
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Patent number: 11502125Abstract: 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: GrantFiled: March 12, 2020Date of Patent: November 15, 2022Assignee: KIOXIA CORPORATIONInventors: Masaru Toko, Tadaomi Daibou, Junichi Ito, Taichi Igarashi, Tadashi Kai
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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
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Patent number: 11316101Abstract: 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: GrantFiled: March 5, 2020Date of Patent: April 26, 2022Assignee: KIOXIA CORPORATIONInventors: Rina Nomoto, Takayuki Tsukagoshi, Yasushi Nakasaki, Masaru Toko, Tadashi Kai, Takamitsu Ishihara
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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
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Publication number: 20210082999Abstract: 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: ApplicationFiled: March 12, 2020Publication date: March 18, 2021Applicant: KIOXIA CORPORATIONInventors: Masaru TOKO, Tadaomi DAIBOU, Junichi ITO, Taichi IGARASHI, Tadashi KAI
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Patent number: 10910032Abstract: A memory device includes a magnetoresistive element including first and second magnetic layers and a non-magnetic layer provided between the first and second magnetic layers. The memory device also includes a write circuit which controls a first writing setting magnetization of the first and second magnetic layers in a parallel state and a second writing setting the magnetization of the first and second magnetic layers in an antiparallel state, and applies a write current to the magnetoresistive element. A first write current in the first writing includes a first pulse and a second pulse added to the first pulse. A width of the second pulse is smaller than a width of the first pulse, and a current level of the second pulse is different from a current level of the first pulse.Type: GrantFiled: May 1, 2019Date of Patent: February 2, 2021Assignee: TOSHIBA MEMORY CORPORATIONInventors: Tatsuya Kishi, Tsuneo Inaba, Daisuke Watanabe, Masahiko Nakayama, Nobuyuki Ogata, Masaru Toko, Hisanori Aikawa, Jyunichi Ozeki, Toshihiko Nagase, Young Min Eeh, Kazuya Sawada
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Publication number: 20200403150Abstract: 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: ApplicationFiled: March 5, 2020Publication date: December 24, 2020Applicant: KIOXIA CORPORATIONInventors: Rina NOMOTO, Takayuki TSUKAGOSHI, Yasushi NAKASAKI, Masaru TOKO, Tadashi KAI, Takamitsu ISHIHARA
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Patent number: 10622545Abstract: According to one embodiment, a magnetic memory device includes a first magnetic layer having a variable magnetization direction, a first non-magnetic layer provided on the first magnetic layer, and a second magnetic layer provided on the first magnetic layer and having a fixed magnetization direction and provided on the first magnetic layer. The second magnetic layer includes a non-magnetic metal including at least one of Mo (molybdenum), Ta (tantalum), W (tungsten), Hf (hafnium), Nb (niobium) and Ti (titanium).Type: GrantFiled: September 12, 2017Date of Patent: April 14, 2020Assignee: TOSHIBA MEMORY CORPORATIONInventors: Masaru Toko, Keiji Hosotani, Hisanori Aikawa, Tatsuya Kishi
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Patent number: 10573802Abstract: According to one embodiment, a magnetic memory device includes a stacked structure that 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, wherein the entire first magnetic layer exhibits a parallel or antiparallel magnetization direction to the second magnetic layer, and has an anisotropic magnetic field Hk_film within a range from ?1 kOe to +1 kOe.Type: GrantFiled: September 12, 2018Date of Patent: February 25, 2020Assignee: TOSHIBA MEMORY CORPORATIONInventors: Tatsuya Kishi, Youngmin Eeh, Kazuya Sawada, Masaru Toko
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Publication number: 20190288184Abstract: According to one embodiment, a magnetic memory device includes a stacked structure that 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, wherein the entire first magnetic layer exhibits a parallel or antiparallel magnetization direction to the second magnetic layer, and has an anisotropic magnetic field Hk_film within a range from ?1 kOe to +1 kOe.Type: ApplicationFiled: September 12, 2018Publication date: September 19, 2019Applicant: TOSHIBA MEMORY CORPORATIONInventors: Tatsuya KISHI, Youngmin EEH, Kazuya SAWADA, Masaru TOKO
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Publication number: 20190259438Abstract: A memory device includes a magnetoresistive element including first and second magnetic layers and a non-magnetic layer provided between the first and second magnetic layers. The memory device also includes a write circuit which controls a first writing setting magnetization of the first and second magnetic layers in a parallel state and a second writing setting the magnetization of the first and second magnetic layers in an antiparallel state, and applies a write current to the magnetoresistive element. A first write current in the first writing includes a first pulse and a second pulse added to the first pulse. A width of the second pulse is smaller than a width of the first pulse, and a scurrent level of the second pulse is different from a current level of the first pulse.Type: ApplicationFiled: May 1, 2019Publication date: August 22, 2019Applicant: TOSHIBA MEMORY CORPORATIONInventors: Tatsuya KISHI, Tsuneo INABA, Daisuke WATANABE, Masahiko NAKAYAMA, Nobuyuki OGATA, Masaru TOKO, Hisanori AIKAWA, Jyunichi OZEKI, Toshihiko NAGASE, Young Min EEH, Kazuya SAWADA
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Patent number: 10325640Abstract: According to one embodiment, a memory device includes: a magnetoresistive element including first and second magnetic layers and a non-magnetic layer provided between the first and second magnetic layers; and a write circuit which controls a first writing setting magnetization of the first and second magnetic layers in a parallel state and a second writing setting the magnetization of the first and second magnetic layers in an antiparallel state, and applies a current pulse to the magnetoresistive element. A first pulse pattern used in the first writing is different from a second pulse pattern used in the second writing.Type: GrantFiled: March 10, 2017Date of Patent: June 18, 2019Assignee: TOSHIBA MEMORY CORPORATIONInventors: Tatsuya Kishi, Tsuneo Inaba, Daisuke Watanabe, Masahiko Nakayama, Nobuyuki Ogata, Masaru Toko, Hisanori Aikawa, Jyunichi Ozeki, Toshihiko Nagase, Young Min Eeh, Kazuya Sawada
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Patent number: 10311929Abstract: According to an embodiment, a resistance change memory includes a semiconductor substrate, a transistor having a control terminal, a first terminal and a second terminal, the transistor provided on the semiconductor substrate, an insulating layer covering the transistor, a first conductive line connected to the first terminal and provided on the insulating layer, a second conductive line provided on the insulating layer, and a resistance change element connected between the second terminal and the second conductive line. The first conductive line has a width greater than a width of the second conductive line in a direction in which the first and second conductive lines are arranged.Type: GrantFiled: December 8, 2017Date of Patent: June 4, 2019Assignees: TOSHIBA MEMORY CORPORATION, SK HYNIX INC.Inventors: Hisanori Aikawa, Tatsuya Kishi, Keisuke Nakatsuka, Satoshi Inaba, Masaru Toko, Keiji Hosotani, Jae Yun Yi, Hong Ju Suh, Se Dong Kim
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Patent number: 10230042Abstract: A magnetoresistive effect element according to one embodiment includes: a first magnetic layer; a nonmagnetic layer; a second magnetic layer; a metal layer; and a third magnetic layer. An area of a bottom of the third magnetic layer is larger than an area of a top of the third magnetic layer. An angle between the top of the third magnetic layer and a side of the third magnetic layer is larger than an angle between a top of the second magnetic layer and a side of the second magnetic layer, or an angle between the bottom of the third magnetic layer and a side of the third magnetic layer is smaller than an angle between the bottom of the second magnetic layer and a side of the second magnetic layer.Type: GrantFiled: September 9, 2016Date of Patent: March 12, 2019Assignee: TOSHIBA MEMORY CORPORATIONInventors: Masatoshi Yoshikawa, Hisanori Aikawa, Kazuhiro Tomioka, Shuichi Tsubata, Masaru Toko, Katsuya Nishiyama, Yutaka Hashimoto, Tatsuya Kishi
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Publication number: 20180277744Abstract: According to one embodiment, a magnetic memory device includes a first magnetic layer having a variable magnetization direction, a first non-magnetic layer provided on the first magnetic layer, and a second magnetic layer provided on the first magnetic layer and having a fixed magnetization direction and provided on the first magnetic layer. The second magnetic layer includes a non-magnetic metal including at least one of Mo (molybdenum), Ta (tantalum), W (tungsten), Hf (hafnium), Nb (niobium) and Ti (titanium).Type: ApplicationFiled: September 12, 2017Publication date: September 27, 2018Applicant: TOSHIBA MEMORY CORPORATIONInventors: Masaru TOKO, Keiji HOSOTANI, Hisanori AIKAWA, Tatsuya KISHI
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Publication number: 20180102156Abstract: According to an embodiment, a resistance change memory includes a semiconductor substrate, a transistor having a control terminal, a first terminal and a second terminal, the transistor provided on the semiconductor substrate, an insulating layer covering the transistor, a first conductive line connected to the first terminal and provided on the insulating layer, a second conductive line provided on the insulating layer, and a resistance change element connected between the second terminal and the second conductive line. The first conductive line has a width greater than a width of the second conductive line in a direction in which the first and second conductive lines are arranged.Type: ApplicationFiled: December 8, 2017Publication date: April 12, 2018Applicants: TOSHIBA MEMORY CORPORATION, SK HYNIX INC.Inventors: Hisanori AIKAWA, Tatsuya KISHI, Keisuke NAKATSUKA, Satoshi INABA, Masaru TOKO, Keiji HOSOTANI, Jae Yun YI, Hong Ju SUH, Se Dong KIM
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Publication number: 20180075895Abstract: According to one embodiment, a memory device includes: a magnetoresistive element including first and second magnetic layers and a non-magnetic layer provided between the first and second magnetic layers; and a write circuit which controls a first writing setting magnetization of the first and second magnetic layers in a parallel state and a second writing setting the magnetization of the first and second magnetic layers in an antiparallel state, and applies a current pulse to the magnetoresistive element. A first pulse pattern used in the first writing is different from a second pulse pattern used in the second writing.Type: ApplicationFiled: March 10, 2017Publication date: March 15, 2018Applicant: TOSHIBA MEMORY CORPORATIONInventors: Tatsuya KISHI, Tsuneo INABA, Daisuke WATANABE, Masahiko NAKAYAMA, Nobuyuki OGATA, Masaru TOKO, Hisanori AIKAWA, Jyunichi OZEKI, Toshihiko NAGASE, Young Min EEH, Kazuya SAWADA
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Publication number: 20170256706Abstract: According to one embodiment, a magnetic storage device includes a first and a second magnetoresistive effect element, which are disposed in an arrangement pattern including a plurality of arrangement areas, and in each of which a second ferromagnetic layer and a third ferromagnetic layer are antiferromagnetically coupled. A magnetization orientation of the third ferromagnetic layer of the first magnetoresistive effect element is antiparallel to a magnetization orientation of the third ferromagnetic layer of the second magnetoresistive effect element. The first magnetoresistive effect element is disposed in an arrangement area randomly positioned with respect to an arrangement area in which the second magnetoresistive effect element is disposed.Type: ApplicationFiled: September 9, 2016Publication date: September 7, 2017Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Masaru TOKO, Keiji HOSOTANI, Hisanori AIKAWA, Tatsuya KISHI
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Publication number: 20170256705Abstract: A magnetoresistive effect element according to one embodiment includes: a first magnetic layer; a nonmagnetic layer; a second magnetic layer; a metal layer; and a third magnetic layer. An area of a bottom of the third magnetic layer is larger than an area of a top of the third magnetic layer. An angle between the top of the third magnetic layer and a side of the third magnetic layer is larger than an angle between a top of the second magnetic layer and a side of the second magnetic layer, or an angle between the bottom of the third magnetic layer and a side of the third magnetic layer is smaller than an angle between the bottom of the second magnetic layer and a side of the second magnetic layer.Type: ApplicationFiled: September 9, 2016Publication date: September 7, 2017Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Masatoshi YOSHIKAWA, Hisanori AIKAWA, Kazuhiro TOMIOKA, Shuichi TSUBATA, Masaru TOKO, Katsuya NISHIYAMA, Yutaka HASHIMOTO, Tatsuya KISHI