Patents by Inventor Toshihiko Nagase

Toshihiko Nagase 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: 8665639
    Abstract: According to one embodiment, a magnetoresistive element includes a first magnetic layer with a perpendicular and variable magnetization, a second magnetic layer with a perpendicular and invariable magnetization, and a first nonmagnetic layer between the first and second magnetic layer. The first magnetic layer has a laminated structure of first and second ferromagnetic materials. A magnetization direction of the first magnetic layer is changed by a current which pass through the first magnetic layer, the first nonmagnetic layer and the second magnetic layer. A perpendicular magnetic anisotropy of the second ferromagnetic material is smaller than that of the first ferromagnetic material. A film thickness of the first ferromagnetic material is thinner than that of the second ferromagnetic material.
    Type: Grant
    Filed: February 28, 2012
    Date of Patent: March 4, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshihiko Nagase, Tadashi Kai, Katsuya Nishiyama, Eiji Kitagawa, Tadaomi Daibou, Masahiko Nakayama, Makoto Nagamine, Shigeto Fukatsu, Masatoshi Yoshikawa, Hiroaki Yoda
  • Patent number: 8659103
    Abstract: According to one embodiment, a magnetoresistive element includes the following configuration. A first magnetic layer has an invariable magnetization. A second magnetic layer has a variable magnetization. A nonmagnetic layer is provided between the first and the second magnetic layers. The first magnetic layer has a structure in which first, second and third magnetic material films and a nonmagnetic material film are stacked. The first magnetic material film is provided in contact with the nonmagnetic layer, the nonmagnetic material film is provided in contact with the first magnetic material film, the second magnetic material film is provided in contact with the nonmagnetic material film, and the third magnetic material film is provided in contact with the second magnetic material film. The second magnetic material film has a Co concentration higher than that of the first magnetic material film.
    Type: Grant
    Filed: March 19, 2012
    Date of Patent: February 25, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Daisuke Watanabe, Katsuya Nishiyama, Toshihiko Nagase, Koji Ueda, Tadashi Kai
  • Publication number: 20130299929
    Abstract: A magnetoresistive element includes a first magnetic layer having an axis of magnetization perpendicular to the film surface and a fixed magnetization orientation; a second magnetic layer having an axis of magnetization perpendicular to the film surface and a changeable magnetization orientation; a first nonmagnetic layer arranged between the first and second magnetic layers; and a third magnetic layer having an axis of magnetization perpendicular to the film surface and a fixed magnetization orientation opposite that of the first magnetic layer. The first magnetic layer has a first magnetic material film in contact with the first nonmagnetic layer, a nonmagnetic material film in contact with the first magnetic material film, and a second magnetic material film containing Co100-xWx (0<x<40 at %) and in contact with the nonmagnetic material film. As current flows via the nonmagnetic layer, the magnetization orientation of the second magnetic layer changes.
    Type: Application
    Filed: March 5, 2013
    Publication date: November 14, 2013
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Daisuke WATANABE, Katsuya NISHIYAMA, Toshihiko NAGASE, Koji UEDA, Tadashi KAI
  • Publication number: 20130288397
    Abstract: According to one embodiment, a magnetoresistive effect element includes a first magnetic layer including perpendicular anisotropy to a film surface and an invariable magnetization direction, the first magnetic layer having a magnetic film including an element selected from a first group including Tb, Gd, and Dy and an element selected from a second group including Co and Fe, a second magnetic layer including perpendicular magnetic anisotropy to the film surface and a variable magnetization direction, and a nonmagnetic layer between the first magnetic layer and the second magnetic layer. The magnetic film includes amorphous phases and crystals whose particle sizes are 0.5 nm or more.
    Type: Application
    Filed: July 1, 2013
    Publication date: October 31, 2013
    Inventors: Eiji Kitagawa, Tadaomi Daibou, Yutaka Hashimoto, Masaru Tokou, Tadashi Kai, Makato Nagamine, Toshihiko Nagase, Katsuya Nishiyama, Koji Ueda, Hiroaki Yoda, Kay Yakushiji, Shinji Yuasa, Hitoshi Kubota, Taro Nagahama, Akio Fukushima, Koji Ando
  • Patent number: 8547737
    Abstract: A magnetoresistive element according to an embodiment includes: a first ferromagnetic layer having an axis of easy magnetization in a direction perpendicular to a film plane; a second ferromagnetic layer having an axis of easy magnetization in a direction perpendicular to a film plane; a nonmagnetic layer placed between the first ferromagnetic layer and the second ferromagnetic layer; a first interfacial magnetic layer placed between the first ferromagnetic layer and the nonmagnetic layer; and a second interfacial magnetic layer placed between the second ferromagnetic layer and the nonmagnetic layer. The first interfacial magnetic layer includes a first interfacial magnetic film, a second interfacial magnetic film placed between the first interfacial magnetic film and the nonmagnetic layer and having a different composition from that of the first interfacial magnetic film, and a first nonmagnetic film placed between the first interfacial magnetic film and the second interfacial magnetic film.
    Type: Grant
    Filed: September 27, 2012
    Date of Patent: October 1, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tadaomi Daibou, Eiji Kitagawa, Yutaka Hashimoto, Masaru Tokou, Toshihiko Nagase, Katsuya Nishiyama, Koji Ueda, Makoto Nagamine, Tadashi Kai, Hiroaki Yoda
  • Publication number: 20130249025
    Abstract: According to one embodiment, a magnetoresistive element includes a bottom electrode, a first magnetic layer with an magnetic axis substantially perpendicular to a film plane thereof, a first interface layer, an MgO insulating layer, a second interface layer, a second magnetic layer with an magnetic axis nearly perpendicular to a film plane thereof, and a top electrode. The magnetoresistive element has a diffusion barrier layer between the first magnetic layer and the first interface layer when the first magnetic layer contains Pt or Pd, and a diffusion barrier layer between the second magnetic layer and the second interface layer when the second magnetic layer contains Pt or Pd. The diffusion barrier layer is an Hf film of thickness 0.6 nm to 0.8 nm.
    Type: Application
    Filed: September 8, 2012
    Publication date: September 26, 2013
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Katsuaki NATORI, Toshihiko Nagase, Eiji Kitagawa, Tadashi Kai
  • Patent number: 8502331
    Abstract: According to one embodiment, a magnetoresistive effect element includes a first magnetic layer including perpendicular anisotropy to a film surface and an invariable magnetization direction, the first magnetic layer having a magnetic film including an element selected from a first group including Tb, Gd, and Dy and an element selected from a second group including Co and Fe, a second magnetic layer including perpendicular magnetic anisotropy to the film surface and a variable magnetization direction, and a nonmagnetic layer between the first magnetic layer and the second magnetic layer. The magnetic film includes amorphous phases and crystals whose particle sizes are 0.5 nm or more.
    Type: Grant
    Filed: September 16, 2011
    Date of Patent: August 6, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Eiji Kitagawa, Tadaomi Daibou, Yutaka Hashimoto, Masaru Tokou, Tadashi Kai, Makoto Nagamine, Toshihiko Nagase, Katsuya Nishiyama, Koji Ueda, Hiroaki Yoda, Kay Yakushiji, Shinji Yuasa, Hitoshi Kubota, Taro Nagahama, Akio Fukushima, Koji Ando
  • Patent number: 8476266
    Abstract: A compound represented by formula (I), wherein R1 represents a hydrogen atom, etc., R2 and R3 each independently represents a hydrogen atom, optionally oxidized C1-4 alkyl group or optionally protected hydroxyl group, or R2 and R3 taken together represent optionally oxidized C2-5 alkylene group, R4 represents an optionally oxidized C1-6 alkyl group, etc., R5 represents an optionally oxidized C1-6 alkyl group, etc., R6 represents an optionally oxidized C1-6 alkyl group, etc., m represents 0 or an integer from 1 to 3, n represents 0 or an integer from 1 to 4, and i represents 0 or an integer from 1 to 7.
    Type: Grant
    Filed: September 26, 2012
    Date of Patent: July 2, 2013
    Assignee: Ono Pharmaceutical Co., Ltd.
    Inventors: Atsushi Naganawa, Toshihiko Nagase
  • Publication number: 20130056349
    Abstract: Provided are a sputtering target including a target main body 10 that has MgO as a main component and a thickness of 3 mm or smaller, and a method of manufacturing a magnetic memory using the sputtering target which improves an MR ratio.
    Type: Application
    Filed: August 31, 2012
    Publication date: March 7, 2013
    Inventors: Eiji KITAGAWA, Tadaomi DAIBOU, Kenji NOMA, Tadashi KAI, Koji YAMAKAWA, Toshihiko NAGASE, Katsuya NISHIYAMA, Koji UEDA, Daisuke WATANABE, Hiroaki YODA, Satoru SANO, Yoshihiro NISHIMURA, Takayuki WATANABE, Yuzo KATO, Akira UEKI
  • Patent number: 8378437
    Abstract: A magnetoresistive effect element includes a reference layer, a recording layer, and a nonmagnetic layer. The reference layer is made of a magnetic material, has an invariable magnetization which is perpendicular to a film surface. The recording layer is made of a magnetic material, has a variable magnetization which is perpendicular to the film surface. The nonmagnetic layer is arranged between the reference layer and the recording layer. A critical diameter which is determined by magnetic anisotropy, saturation magnetization, and switched connection of the recording layer and has a single-domain state as a unique stable state or a critical diameter which has a single-domain state as a unique stable state and is inverted while keeping the single-domain state in an inverting process is larger than an element diameter of the magnetoresistive effect element.
    Type: Grant
    Filed: October 9, 2008
    Date of Patent: February 19, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masahiko Nakayama, Kay Yakushiji, Sumio Ikegawa, Shinji Yuasa, Tadashi Kai, Toshihiko Nagase, Minoru Amano, Hisanori Aikawa, Tatsuya Kishi, Hiroaki Yoda
  • Patent number: 8363462
    Abstract: A magnetoresistive element which records information by supplying spin-polarized electrons to a magnetic material, includes a first pinned layer which is made of a magnetic material and has a first magnetization directed in a direction perpendicular to a film surface, a free layer which is made of a magnetic material and has a second magnetization directed in the direction perpendicular to the film surface, the direction of the second magnetization reversing by the spin-polarized electrons, and a first nonmagnetic layer which is provided between the first pinned layer and the free layer. A saturation magnetization Ms of the free layer satisfies a relationship 0?Ms<?{square root over ( )}{Jw/(6?At)}. Jw is a write current density, t is a thickness of the free layer, A is a constant.
    Type: Grant
    Filed: September 15, 2011
    Date of Patent: January 29, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshihiko Nagase, Masatoshi Yoshikawa, Eiji Kitagawa, Masahiko Nakayama, Tadashi Kai, Tatsuya Kishi, Hiroaki Yoda
  • Publication number: 20130020659
    Abstract: A magnetoresistive element according to an embodiment includes: a first ferromagnetic layer having an axis of easy magnetization in a direction perpendicular to a film plane; a second ferromagnetic layer having an axis of easy magnetization in a direction perpendicular to a film plane; a nonmagnetic layer placed between the first ferromagnetic layer and the second ferromagnetic layer; a first interfacial magnetic layer placed between the first ferromagnetic layer and the nonmagnetic layer; and a second interfacial magnetic layer placed between the second ferromagnetic layer and the nonmagnetic layer. The first interfacial magnetic layer includes a first interfacial magnetic film, a second interfacial magnetic film placed between the first interfacial magnetic film and the nonmagnetic layer and having a different composition from that of the first interfacial magnetic film, and a first nonmagnetic film placed between the first interfacial magnetic film and the second interfacial magnetic film.
    Type: Application
    Filed: September 27, 2012
    Publication date: January 24, 2013
    Inventors: Tadaomi Daibou, Eiji Kitagawa, Yutaka Hashimoto, Masaru Tokou, Toshihiko Nagase, Katsuya Nishiyama, Koji Ueda, Makoto Nagamine, Tadashi Kai, Hiroaki Yoda
  • Publication number: 20130010532
    Abstract: According to one embodiment, a magnetoresistive element includes first and second magnetic layers and a first nonmagnetic layer. The first magnetic layer has an axis of easy magnetization perpendicular to a film plane, and a variable magnetization. The second magnetic layer has an axis of easy magnetization perpendicular to a film plane, and an invariable magnetization. The first nonmagnetic layer is provided between the first and second magnetic layers. The second magnetic layer includes third and fourth magnetic layers, and a second nonmagnetic layer formed between the third and fourth magnetic layers. The third magnetic layer is in contact with the first nonmagnetic layer and includes Co and at least one of Zr, Nb, Mo, Hf, Ta, and W.
    Type: Application
    Filed: March 22, 2012
    Publication date: January 10, 2013
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Toshihiko Nagase, Eiji Kitagawa, Katsuya Nishiyama, Tadashi Kai, Koji Ueda, Daisuke Watanabe
  • Publication number: 20130009259
    Abstract: According to one embodiment, a magnetoresistive element includes the following configuration. A first magnetic layer has an invariable magnetization. A second magnetic layer has a variable magnetization. A nonmagnetic layer is provided between the first and the second magnetic layers. The first magnetic layer has a structure in which first, second and third magnetic material films and a nonmagnetic material film are stacked. The first magnetic material film is provided in contact with the nonmagnetic layer, the nonmagnetic material film is provided in contact with the first magnetic material film, the second magnetic material film is provided in contact with the nonmagnetic material film, and the third magnetic material film is provided in contact with the second magnetic material film. The second magnetic material film has a Co concentration higher than that of the first magnetic material film.
    Type: Application
    Filed: March 19, 2012
    Publication date: January 10, 2013
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Daisuke WATANABE, Katsuya NISHIYAMA, Toshihiko NAGASE, Koji UEDA, Tadashi KAI
  • Publication number: 20130001714
    Abstract: According to one embodiment, a magnetoresistive element includes a storage layer having a perpendicular and variable magnetization, a reference layer having a perpendicular and invariable magnetization, a shift adjustment layer having a perpendicular and invariable magnetization in a direction opposite to a magnetization of the reference layer, a first nonmagnetic layer between the storage layer and the reference layer, and a second nonmagnetic layer between the reference layer and the shift adjustment layer. A switching magnetic field of the reference layer is equal to or smaller than a switching magnetic field of the storage layer, and a magnetic relaxation constant of the reference layer is larger than a magnetic relaxation constant of the storage layer.
    Type: Application
    Filed: March 19, 2012
    Publication date: January 3, 2013
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Katsuya Nishiyama, Hisanori Aikawa, Tadashi Kai, Toshihiko Nagase, Koji Ueda, Hiroaki Yoda
  • Publication number: 20130001713
    Abstract: According to one embodiment, a magnetoresistive element includes the following configuration. First nonmagnetic layer is provided between the first magnetic layer (storage layer) and the second magnetic layer (reference layer). Third magnetic layer is formed on a surface of the storage layer, which is opposite to a surface on which the first nonmagnetic layer is formed. Fourth magnetic layer is formed on a surface of the reference layer, which is opposite to a surface on which the first nonmagnetic layer is formed. The third and fourth magnetic layers have a magnetization antiparallel to the magnetization of the storage layer. Second nonmagnetic layer is located between the storage and third magnetic layers. Third nonmagnetic layer is located between the reference and fourth magnetic layers. The thickness of the fourth magnetic layer is smaller than that of the third magnetic layer.
    Type: Application
    Filed: March 19, 2012
    Publication date: January 3, 2013
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Koji Ueda, Katsuya Nishiyama, Toshihiko Nagase, Daisuke Watanabe, Eiji Kitagawa, Tadashi Kai
  • Patent number: 8318729
    Abstract: A compound represented by formula (I), wherein R1 represents a hydrogen atom, etc., R2 and R3 each independently represents a hydrogen atom, optionally oxidized C1-4 alkyl group or optionally protected hydroxyl group, or R2 and R3 taken together represent optionally oxidized C2-5 alkylene group, R4 represents an optionally oxidized C1-6 alkyl group, etc., R5 represents an optionally oxidized C1-6 alkyl group, etc., R6 represents an optionally oxidized C1-6 alkyl group, etc., m represents 0 or an integer from 1 to 3, n represents 0 or an integer from 1 to 4, and i represents 0 or an integer from 1 to 7.
    Type: Grant
    Filed: August 11, 2008
    Date of Patent: November 27, 2012
    Assignee: Ono Pharmaceutical Co., Ltd.
    Inventors: Atsushi Naganawa, Toshihiko Nagase
  • Patent number: 8305801
    Abstract: A magnetoresistive element according to an embodiment includes: a first ferromagnetic layer having an axis of easy magnetization in a direction perpendicular to a film plane; a second ferromagnetic layer having an axis of easy magnetization in a direction perpendicular to a film plane; a nonmagnetic layer placed between the first ferromagnetic layer and the second ferromagnetic layer; a first interfacial magnetic layer placed between the first ferromagnetic layer and the nonmagnetic layer; and a second interfacial magnetic layer placed between the second ferromagnetic layer and the nonmagnetic layer. The first interfacial magnetic layer includes a first interfacial magnetic film, a second interfacial magnetic film placed between the first interfacial magnetic film and the nonmagnetic layer and having a different composition from that of the first interfacial magnetic film, and a first nonmagnetic film placed between the first interfacial magnetic film and the second interfacial magnetic film.
    Type: Grant
    Filed: March 8, 2011
    Date of Patent: November 6, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tadaomi Daibou, Eiji Kitagawa, Yutaka Hashimoto, Masaru Tokou, Toshihiko Nagase, Katsuya Nishiyama, Koji Ueda, Makoto Nagamine, Tadashi Kai, Hiroaki Yoda
  • Patent number: 8299552
    Abstract: A magnetoresistive element includes a first underlying layer having an NaCl structure and containing a nitride orienting in a (001) plane, a first magnetic layer provided on the first underlying layer, having magnetic anisotropy perpendicular to a film surface, having an L10 structure, and containing a ferromagnetic alloy orienting in a (001) plane, a first nonmagnetic layer provided on the first magnetic layer, and a second magnetic layer provided on the first nonmagnetic layer and having magnetic anisotropy perpendicular to a film surface.
    Type: Grant
    Filed: September 18, 2008
    Date of Patent: October 30, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshihiko Nagase, Masatoshi Yoshikawa, Eiji Kitagawa, Katsuya Nishiyama, Tadaomi Daibou, Tatsuya Kishi, Hiroaki Yoda
  • Patent number: 8218355
    Abstract: A magnetoresistive element includes an underlying layer having a cubic or tetragonal crystal structure oriented in a (001) plane, a first magnetic layer provided on the underlying layer, having perpendicular magnetic anisotropy, and having an fct structure oriented in a (001) plane, a non-magnetic layer provided on the first magnetic layer, and a second magnetic layer provided on the non-magnetic layer, and having perpendicular magnetic anisotropy. An in-plane lattice constant a1 of the underlying layer and an in-plane lattice constant a2 of the first magnetic layer satisfy the following equation in which b is a magnitude of Burgers vector of the first magnetic layer, ? is an elastic modulus of the first magnetic layer, and hc is a thickness of the first magnetic layer. |?{square root over (2)}×a1/2?a2|/a2<b×{ln (hc/b)+1}/{2?×hc×(1+?)}.
    Type: Grant
    Filed: March 24, 2009
    Date of Patent: July 10, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Eiji Kitagawa, Masatoshi Yoshikawa, Toshihiko Nagase, Tadaomi Daibou, Makoto Nagamine, Katsuya Nishiyama, Tatsuya Kishi, Hiroaki Yoda