Patents by Inventor Masatoshi Yoshikawa
Masatoshi Yoshikawa 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: 10388854Abstract: According to one embodiment, a magnetic memory device includes a stacked structure, the 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, wherein the nonmagnetic layer comprises a structure in which a first oxide layer formed of a first metal oxide and a second oxide layer formed of a second metal oxide having a relative dielectric constant greater than a relative dielectric constant of the first metal oxide are stacked.Type: GrantFiled: March 12, 2018Date of Patent: August 20, 2019Assignee: TOSHIBA MEMORY CORPORATIONInventors: Masatoshi Yoshikawa, Shuichi Tsubata
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Patent number: 10388855Abstract: According to one embodiment, a magnetic memory device includes a stacked structure including a first magnetic layer having a variable magnetization direction, a nonmagnetic layer provided on the first magnetic layer, and a second magnetic layer provided on the nonmagnetic layer and having a fixed magnetization direction, wherein as viewed in a direction parallel to a stacked direction of the stacked structure, a pattern of a lower surface of the first magnetic layer is located inside a pattern of an upper surface of the first magnetic layer, and a pattern of an upper surface of the second magnetic layer is located inside a pattern of a lower surface of the second magnetic layer or substantially conforms to the pattern of the lower surface of the second magnetic layer.Type: GrantFiled: August 30, 2017Date of Patent: August 20, 2019Assignee: TOSHIBA MEMORY CORPORATIONInventors: Shuichi Tsubata, Masatoshi Yoshikawa, Kenji Noma
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Patent number: 10304509Abstract: According to an embodiment, a magnetic storage device includes a memory cell including a magnetoresistive element, a selector, a first end, and a second end. The magnetoresistive element includes a first ferromagnetic layer, a second ferromagnetic layer, a third ferromagnetic layer, a first nonmagnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer, and a second nonmagnetic layer disposed between the second ferromagnetic layer and the third ferromagnetic layer to couple the second ferromagnetic layer with the third ferromagnetic layer in an antiferromagnetic manner. The first ferromagnetic layer has a film thickness larger than a film thickness of the second ferromagnetic layer.Type: GrantFiled: September 12, 2017Date of Patent: May 28, 2019Assignee: TOSHIBA MEMORY CORPORATIONInventors: Masatoshi Yoshikawa, Kuniaki Sugiura
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Publication number: 20190088856Abstract: According to one embodiment, a magnetic memory device includes a stacked structure, the 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, wherein the nonmagnetic layer comprises a structure in which a first oxide layer formed of a first metal oxide and a second oxide layer formed of a second metal oxide having a relative dielectric constant greater than a relative dielectric constant of the first metal oxide are stacked.Type: ApplicationFiled: March 12, 2018Publication date: March 21, 2019Applicant: TOSHIBA MEMORY CORPORATIONInventors: Masatoshi YOSHIKAWA, Shuichi TSUBATA
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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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Patent number: 10193057Abstract: A magnetic memory device includes a stacked structure including a magnetic element, a protective insulating film covering the stacked structure, and an interface layer provided at an interface between the stacked structure and the protective insulating film. The interface layer contains a predetermined element which is not contained in the magnetic element or the protective insulating film.Type: GrantFiled: January 6, 2017Date of Patent: January 29, 2019Assignee: TOSHIBA MEMORY CORPORATIONInventors: Masatoshi Yoshikawa, Hiroaki Yoda, Shuichi Tsubata, Kenji Noma, Tatsuya Kishi, Satoshi Seto, Kazuhiro Tomioka
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Patent number: 10177302Abstract: According to one embodiment, a magnetic memory device includes a stacked structure including a magnetic layer, and an upper structure provided on the stacked structure, and including a first portion and a second portion surrounding the first portion and formed of material different from that of the first portion.Type: GrantFiled: March 14, 2016Date of Patent: January 8, 2019Assignee: TOSHIBA MEMORY CORPORATIONInventors: Shuichi Tsubata, Masatoshi Yoshikawa
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Publication number: 20190006580Abstract: A method of manufacturing a magnetic memory device includes forming a stacked structure including a magnetic element, forming a metal film which covers the stacked structure, and forming a protective insulating film formed of a metallic oxide by oxidizing the metal film. A metal element contained in the metallic oxide is selected from yttrium (Y), aluminum (Al), magnesium (Mg), calcium (Ca), zirconium (Zr) and hafnium (Hf).Type: ApplicationFiled: September 9, 2018Publication date: January 3, 2019Applicant: TOSHIBA MEMORY CORPORATIONInventors: Masatoshi YOSHIKAWA, Hiroaki YODA, Shuichi TSUBATA, Kenji NOMA, Tatsuya KISHI, Satoshi SETO, Kazuhiro TOMIOKA
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Patent number: 10147761Abstract: According to one embodiment, a semiconductor memory device includes a magnetoresistive element and an insulating layer. The magnetoresistive element includes a first magnetic layer, a nonmagnetic layer, and a second magnetic layer and. The magnetoresistive element is capable of storing data according to a direction of magnetization in the first magnetic layer. The insulating layer covers a side surface of the magnetoresistive element. The first magnetic layer includes a first region and a second region. Each of the first and second regions includes a magnetic material and a nonmagnetic material. A concentration ratio of the nonmagnetic material to the magnetic material is higher in the second region than in the first region.Type: GrantFiled: March 13, 2017Date of Patent: December 4, 2018Assignee: TOSHIBA MEMORY CORPORATIONInventors: Masatoshi Yoshikawa, Shuichi Tsubata
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Publication number: 20180269386Abstract: According to one embodiment, a magnetic memory device includes a stacked structure including a first magnetic layer having a variable magnetization direction, a nonmagnetic layer provided on the first magnetic layer, and a second magnetic layer provided on the nonmagnetic layer and having a fixed magnetization direction, wherein as viewed in a direction parallel to a stacked direction of the stacked structure, a pattern of a lower surface of the first magnetic layer is located inside a pattern of an upper surface of the first magnetic layer, and a pattern of an upper surface of the second magnetic layer is located inside a pattern of a lower surface of the second magnetic layer or substantially conforms to the pattern of the lower surface of the second magnetic layer.Type: ApplicationFiled: August 30, 2017Publication date: September 20, 2018Applicant: TOSHIBA MEMORY CORPORATIONInventors: Shuichi TSUBATA, Masatoshi YOSHIKAWA, Kenji NOMA
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Publication number: 20180261270Abstract: According to an embodiment, a magnetic storage device includes a memory cell including a magnetoresistive element, a selector, a first end, and a second end. The magnetoresistive element includes a first ferromagnetic layer, a second ferromagnetic layer, a third ferromagnetic layer, a first nonmagnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer, and a second nonmagnetic layer disposed between the second ferromagnetic layer and the third ferromagnetic layer to couple the second ferromagnetic layer with the third ferromagnetic layer in an antiferromagnetic manner. The first ferromagnetic layer has a film thickness larger than a film thickness of the second ferromagnetic layer.Type: ApplicationFiled: September 12, 2017Publication date: September 13, 2018Applicant: TOSHIBA MEMORY CORPORATIONInventors: Masatoshi YOSHIKAWA, Kuniaki SUGIURA
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Patent number: 10043853Abstract: According to one embodiment, a magnetic memory device includes a first insulating film provided on a semiconductor region, and having a portion located in a memory cell array area and thicker than a portion located in a peripheral circuit area, a plurality of conductive plugs located in the memory cell array area and provided in the first insulating film, stacked structures located in the memory cell array area, provided on the conductive plugs, and each having layers including a magnetic layer, and transistors located in the peripheral circuit area, and each including a gate electrode provided on the semiconductor region and covered with the first insulating film, wherein a thickness t0 from a main surface of the semiconductor region to a lower surface of each stacked structure is greater than a predetermined value.Type: GrantFiled: March 20, 2017Date of Patent: August 7, 2018Assignee: TOSHIBA MEMORY CORPORATIONInventors: Kuniaki Sugiura, Masahiko Hasunuma, Masatoshi Yoshikawa
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Patent number: 10020444Abstract: According to one embodiment, a magnetic memory device includes an interlayer insulating film, a bottom electrode formed in the interlayer insulating film, a buffer layer formed on the bottom electrode, and a stacked structure formed on the buffer layer and including a first magnetic layer functioning as a magnetic storage layer, wherein a portion of the buffer layer located on a central portion of the bottom electrode is thicker than a portion of the buffer layer located on a peripheral portion of the bottom electrode.Type: GrantFiled: March 3, 2015Date of Patent: July 10, 2018Assignee: TOSHIBA MEMORY CORPORATIONInventors: Shuichi Tsubata, Masatoshi Yoshikawa, Satoshi Seto
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Publication number: 20180076263Abstract: According to one embodiment, a magnetic memory device includes a first insulating film provided on a semiconductor region, and having a portion located in a memory cell array area and thicker than a portion located in a peripheral circuit area, a plurality of conductive plugs located in the memory cell array area and provided in the first insulating film, stacked structures located in the memory cell array area, provided on the conductive plugs, and each having layers including a magnetic layer, and transistors located in the peripheral circuit area, and each including a gate electrode provided on the semiconductor region and covered with the first insulating film, wherein a thickness t0 from a main surface of the semiconductor region to a lower surface of each stacked structure is greater than a predetermined value.Type: ApplicationFiled: March 20, 2017Publication date: March 15, 2018Applicant: Toshiba Memory CorporationInventors: Kuniaki SUGIURA, Masahiko HASUNUMA, Masatoshi YOSHIKAWA
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Publication number: 20180076261Abstract: According to one embodiment, a semiconductor memory device includes a magnetoresistive element and an insulating layer. The magnetoresistive element includes a first magnetic layer, a nonmagnetic layer, and a second magnetic layer and. The magnetoresistive element is capable of storing data according to a direction of magnetization in the first magnetic layer. The insulating layer covers a side surface of the magnetoresistive element. The first magnetic layer includes a first region and a second region. Each of the first and second regions includes a magnetic material and a nonmagnetic material. A concentration ratio of the nonmagnetic material to the magnetic material is higher in the second region than in the first region.Type: ApplicationFiled: March 13, 2017Publication date: March 15, 2018Applicant: TOSHIBA MEMORY CORPORATIONInventors: Masatoshi YOSHIKAWA, Shuichi TSUBATA
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Patent number: 9893121Abstract: According to one embodiment, a magnetic memory includes a first metal layer including a first metal, a second metal layer on the first metal layer, the second metal layer including a second metal which is more easily oxidized than the first metal, the second metal layer having a first sidewall portion which contacts the first metal layer, and the second metal layer having a second sidewall portion above the first sidewall portion, the second sidewall portion which steps back from the first sidewall portion, a magnetoresistive element on the second metal layer, a third metal layer on the magnetoresistive element, and a first material which contacts a sidewall portion of the magnetoresistive element and the second sidewall portion of the second metal layer, the first material including an oxide of the second metal.Type: GrantFiled: September 6, 2016Date of Patent: February 13, 2018Assignees: Toshiba Memory Corporation, SK Hynix, Inc.Inventors: Yasuyuki Sonoda, Masahiko Nakayama, Min Suk Lee, Masatoshi Yoshikawa, Kuniaki Sugiura, Ji Hwan Hwang
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Patent number: 9777883Abstract: The present invention is such that a main body neither drops out nor is destroyed. A plurality of brackets (4), provided on a side surface of a main body (2) in which a superconducting magnet is mounted internally in a state in which each protrudes therefrom, are each supported by a stand (3) from the bottom, and enclosing members (5) are attached to the side surface of the main body (2) with a prescribed space (a) opened from the bottom of the brackets (4). At least part of the inside surface of an enclosing member (5) surrounds a stand (3) in a non-contact state.Type: GrantFiled: March 7, 2014Date of Patent: October 3, 2017Assignee: JAPAN SUPERCONDUCTOR TECHNOLOGY INC.Inventors: Kazuhito Tago, Yoshio Okui, Masatoshi Yoshikawa
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Publication number: 20170263858Abstract: According to one embodiment, a magnetic memory device includes a stacked structure including a first magnetic layer, a second magnetic layer and a nonmagnetic layer between the first magnetic layer and the second magnetic layer, and a sidewall insulating layer provided on a side surface of the stacked structure and containing boron (B).Type: ApplicationFiled: September 16, 2016Publication date: September 14, 2017Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yasuyuki SONODA, Daisuke WATANABE, Masatoshi YOSHIKAWA, Youngmin EEH, Shuichi TSUBATA, Toshihiko NAGASE, Yutaka HASHIMOTO, Kazuya SAWADA, Kazuhiro TOMIOKA, Kenichi YOSHINO, Tadaaki OIKAWA
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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
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Patent number: 9698338Abstract: According to one embodiment, a method of manufacturing a magnetic memory device includes a stack structure formed of a plurality of layers including a magnetic layer, the method includes forming a lower structure film including at least one layer, etching the lower structure film to form a lower structure of the stack structure, forming an upper structure film including at least one layer on a region including the lower structure, and etching the upper structure film to form an upper structure of the stack structure on the lower structure.Type: GrantFiled: March 5, 2015Date of Patent: July 4, 2017Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Masatoshi Yoshikawa, Satoshi Seto, Shuichi Tsubata, Kazuhiro Tomioka