Patents by Inventor Hiromi Fuke

Hiromi Fuke 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: 6816347
    Abstract: A first layer region of a magnetically pinned layer in a spin valve structure, which is relatively remoter from a non-magnetic intermediate layer, is made of a ferromagnetic material containing at least one element selected from the group consisting of Cr (chrome), Rh (rhodium), Os (osmium), Re (rhenium), Si (silicon), Al (aluminum), Be (beryllium), Ga (gallium), Ge (germanium), Te (tellurium), B (boron), V (vanadium), Ru (ruthenium), Ir (iridium), W (tungsten), Mo (molybdenum), Au (gold), Pt (platinum), Ag (silver) and Cu (copper). Thereby, it is possible to provide a structure of the magnetically pinned layer, which can be readily made using a conventional deposition method and can ensure a sufficient electron reflecting effect on the part of the magnetically pinned layer, and to provide a magnetoresistive element using a spin valve film including the particular structure.
    Type: Grant
    Filed: December 28, 2000
    Date of Patent: November 9, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Katsuhiko Koi, Hitoshi Iwasaki, Yuzo Kamiguchi, Hiromi Fuke, Hideaki Fukuzawa
  • Publication number: 20040121185
    Abstract: Disclosed are a high-sensitivity and high-reliability magnetoresistance effect device (MR device) in which bias point designing is easy, and also a magnetic head, a magnetic head assembly and a magnetic recording/reproducing system incorporating the MR device. In the MR device incorporating a spin valve film, the magnetization direction of the free layer is at a certain angle to the magnetization direction of a second ferromagnetic layer therein when the applied magnetic field is zero. In this, the pinned magnetic layer comprises a pair of ferromagnetic films as antiferromagnetically coupled to each other via a coupling film existing therebetween.
    Type: Application
    Filed: October 10, 2001
    Publication date: June 24, 2004
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Yuzo Kamiguchi, Katsuhiko Koui, Shin-ichi Nakamura, Hitoshi Iwasaki, Kazuhiro Saito, Hiromi Fuke, Masatshi Yoshikawa, Susumu Hashimoto, Masashi Sahashi
  • Patent number: 6690553
    Abstract: A magnetoresistance effect device comprises a magnetic multi-layer film having at least an antiferromagnetic film, a first ferromagnetic film, a non-magnetic film, and a second ferromagnetic film formed in the order on the front surface portion of the substrate, the magnetic multi-layer film having giant magnetoresistance effect, at least the second ferromagnetic film having a shape corresponding to a magnetic field detecting portion. The bias magnetic field applying films are disposed on a conductive film of the magnetic multi-layer film at outer portions of both edge portions of the magnetic field detecting portion of the magnetoresistance effective film. Alternatively, the second ferromagnetic film has a first portion corresponding to the magnetic field detecting portion and a second portion corresponding to the outer portions of both the edge portions of the magnetic field detecting portion, the film thickness of the second portion being smaller than the film thickness of the first portion.
    Type: Grant
    Filed: April 19, 2001
    Date of Patent: February 10, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hitoshi Iwasaki, Yuzo Kamiguchi, Hiromi Fuke, Kazuhiro Saito, Masashi Sahashi
  • Patent number: 6636399
    Abstract: A magnetoresistance effect device comprises a magnetic multi-layer film having at least an antiferromagnetic film, a first ferromagnetic film, a non-magnetic film, and a second ferromagnetic film formed in the order on the front surface portion of the substrate, the magnetic multi-layer film having giant magnetoresistance effect, at least the second ferromagnetic film having a shape corresponding to a magnetic field detecting portion. The bias magnetic field applying films are disposed on a conductive film of the magnetic multi-layer film at outer portions of both edge portions of the magnetic field detecting portion of the magnetoresistance effective film. Alternatively, the second ferromagnetic film has a first portion corresponding to the magnetic field detecting portion and a second portion corresponding to the outer portions of both the edge portions of the magnetic field detecting portion, the film thickness-of the second portion being smaller than the film thickness of the first portion.
    Type: Grant
    Filed: August 13, 2001
    Date of Patent: October 21, 2003
    Assignee: Kabushiki Kaishia Toshiba
    Inventors: Hitoshi Iwasaki, Yuzo Kamiguchi, Hiromi Fuke, Kazuhiro Saito, Masashi Sahashi
  • Patent number: 6483673
    Abstract: A GMR element part is formed of a laminated structure which comprises at least one pair of ferromagnetic layers and a nonmagnetic intermediate layer interposed between the pair of ferromagnetic layers. Signal magnetic field detecting ferromagnetic layers will be optionally disposed one each outside the pair of ferromagnetic layers. The GMR element part consists of a laminated structure which is provided with one pair of GMR ferromagnetic layers opposed to each other across a nonmagnetic intermediate layer or a laminated structure which is provided with one pair of GMR ferromagnetic layer opposed to each other across a nonmagnetic intermediate layer and at least one low-permeability ferromagnetic layer disposed there between through the medium of a nonmagnetic intermediate layer.
    Type: Grant
    Filed: May 28, 1998
    Date of Patent: November 19, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hitoshi Iwasaki, Yuichi Ohsawa, Reiko Kondoh, Yuzo Kamiguchi, Susumu Hashimoto, Tomomi Funayama, Hiromi Fuke, Junichi Akiyama, Kazuhiro Saito
  • Patent number: 6455178
    Abstract: An exchange coupling film comprises a ferromagnetic film and an antiferromagnetic film laminated on the ferromagnetic film, wherein at least a portion of the antiferromagnetic film has a face-centered cubic crystal structure and the antiferromagnetic film comprises an IrMn alloy represented by the general formula of IrxMn100−x, wherein x stands for a value by atomic % satisfying the expression, 2≦x≦80.
    Type: Grant
    Filed: December 23, 1999
    Date of Patent: September 24, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Fuke, Yuuzo Kamiguchi, Susumu Hashimoto, Tomomi Funayama, Kazuhiro Saito, Hitoshi Iwasaki, Masashi Sahashi
  • Patent number: 6395388
    Abstract: The present invention provides an exchange coupling film having a stacked-film-structure consisting of a ferromagnetic film made of at least one material of Fe, Co and Ni, and an antiferromagnetic film, wherein the exchange coupling film made of a ferromagnetic material to which an element is added, is provided at the interface between the ferromagnetic film and the antiferromagnetic film so as to improve the lattice matching, which results in the enhancement of the exchange coupling force, and a magnetoresistance effect element including such an exchange coupling film as described above, and an electrode for supplying a current to the ferromagnetic film which constitutes the exchange coupling film.
    Type: Grant
    Filed: November 17, 1999
    Date of Patent: May 28, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hitoshi Iwasaki, Yuichi Ohsawa, Reiko Kondoh, Susumu Hashimoto, Atsuhito Sawabe, Yuzo Kamiguchi, Masashi Sahashi, Hiromi Fuke
  • Publication number: 20020048690
    Abstract: Disclosed are a high-sensitivity and high-reliability magnetoresistance effect device (MR device) in which bias point designing is easy, and also a magnetic head, a magnetic head assembly and a magnetic recording/reproducing system incorporating the MR device. In the MR device incorporating a spin valve film, the magnetization direction of the free layer is at a certain angle to the magnetization direction of a second ferromagnetic layer therein when the applied magnetic field is zero. In this, the pinned magnetic layer comprises a pair of ferromagnetic films as antiferromagnetically coupled to each other via a coupling film existing therebetween.
    Type: Application
    Filed: October 10, 2001
    Publication date: April 25, 2002
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Yuzo Kamiguchi, Katsuhiko Koui, Shin-ichi Nakamura, Hitoshi Iwasaki, Kazuhiro Saito, Hiromi Fuke, Masatoshi Yoshikawa, Susumu Hashimoto, Masashi Sahashi
  • Publication number: 20020048127
    Abstract: There are provided a magnetoresistance effect element, a magnetic head, a magnetic head assembly and a magnetic recording system, which have high sensitivity and high reliability. The magnetoresistance effect element has two ferromagnetic layers, a non-magnetic layer provided between the ferromagnetic layers, and a layer containing an oxide or nitride as a principal component, wherein the layer containing the oxide or nitride as the principal component contains a magnetic transition metal element which does not bond to oxygen and nitrogen and which is at least one of Co, Fe and Ni.
    Type: Application
    Filed: September 4, 2001
    Publication date: April 25, 2002
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hideaki Fukuzawa, Katsuhiko Koi, Hiromi Fuke, Hiroshi Tomita, Hitoshi Iwasaki, Masashi Sahashi
  • Patent number: 6368706
    Abstract: The present invention provides an exchange coupling film having a stacked-film-structure consisting of a ferromagnetic film made of at least one material of Fe, Co and Ni, and an antiferromagnetic film, wherein the exchange coupling film made of a ferromagnetic material to which an element is added, is provided at the interface between the ferromagnetic film and the antiferromagnetic film so as to improve the lattice matching, which results in the enhancement of the exchange coupling force, and a magnetoresistance effect element including such an exchange coupling film as described above, and an electrode for supplying a current to the ferromagnetic film which constitutes the exchange coupling film.
    Type: Grant
    Filed: July 8, 1998
    Date of Patent: April 9, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hitoshi Iwasaki, Yuichi Ohsawa, Reiko Kondoh, Susumu Hashimoto, Atsuhito Sawabe, Yuzo Kamiguchi, Masashi Sahashi, Hiromi Fuke
  • Publication number: 20020015269
    Abstract: A magnetoresistance effect device comprises a magnetic multi-layer film having at least an antiferromagnetic film, a first ferromagnetic film, a non-magnetic film, and a second ferromagnetic film formed in the order on the front surface portion of the substrate, the magnetic multi-layer film having giant magnetoresistance effect, at least the second ferromagnetic film having a shape corresponding to a magnetic field detecting portion. The bias magnetic field applying films are disposed on a conductive film of the magnetic multi-layer film at outer portions of both edge portions of the magnetic field detecting portion of the magnetoresistance effective film. Alternatively, the second ferromagnetic film has a first portion corresponding to the magnetic field detecting portion and a second portion corresponding to the outer portions of both the edge portions of the magnetic field detecting portion, the film thickness-of the second portion being smaller than the film thickness of the first portion.
    Type: Application
    Filed: August 13, 2001
    Publication date: February 7, 2002
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hitoshi Iwasaki, Yuzo Kamiguchi, Hiromi Fuke, Kazuhiro Saito, Masashi Sahashi
  • Patent number: 6338899
    Abstract: Disclosed are a high-sensitivity and high-reliability magnetoresistance effect device (MR device) in which bias point designing is easy, and also a magnetic head, a magnetic head assembly and a magnetic recording/reproducing system incorporating the MR device. In the MR device incorporating a spin valve film, the magnetization direction of the free layer is at a certain angle to the magnetization direction of a second ferromagnetic layer therein when the applied magnetic field is zero. In this, the pinned magnetic layer comprises a pair of ferromagnetic films as antiferromagnetically coupled to each other via a coupling film existing therebetween.
    Type: Grant
    Filed: June 14, 1999
    Date of Patent: January 15, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Yuzo Kamiguchi, Katsuhiko Koui, Shin-ichi Nakamura, Hitoshi Iwasaki, Kazuhiro Saito, Hiromi Fuke, Masatoshi Yoshikawa, Susumu Hashimoto, Masashi Sahashi
  • Publication number: 20010043448
    Abstract: A magnetoresistance effect device comprises a magnetic multi-layer film having at least an antiferromagnetic film, a first ferromagnetic film, a non-magnetic film, and a second ferromagnetic film formed in the order on the front surface portion of the substrate, the magnetic multi-layer film having giant magnetoresistance effect, at least the second ferromagnetic film having a shape corresponding to a magnetic field detecting portion. The bias magnetic field applying films are disposed on a conductive film of the magnetic multi-layer film at outer portions of both edge portions of the magnetic field detecting portion of the magnetoresistance effective film. Alternatively, the second ferromagnetic film has a first portion corresponding to the magnetic field detecting portion and a second portion corresponding to the outer portions of both the edge portions of the magnetic field detecting portion, the film thickness of the second portion being smaller than the film thickness of the first portion.
    Type: Application
    Filed: April 19, 2001
    Publication date: November 22, 2001
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hitoshi Iwasaki, Yuzo Kamiguchi, Hiromi Fuke, Kazuhiro Saito, Masashi Sahashi
  • Patent number: 6313973
    Abstract: A magnetoresistive element comprises an exchange coupling film having a under layer, an antiferromagnetic film and a ferromagnetic film, which are laminated in that order, the under layer including a metal having a face centered cubic crystal structure or hexagonal closest packing crystal structure which have a longer nearest neighbor atomic distance than that of the antiferromagnetic film. With this construction, it is possible to improve the exchange coupling field and to satisfy a stable output over a long period of time. A magnetoresistive element having a dual spin valve structure has a magnetization adjusting layer, which is antiferromagnetically connected to a pinned layer via an anti-parallel connection layer, to adjust the value of the product of the saturation magnetization of each of the magnetization adjusting layer and the pinned layer by the thickness thereof.
    Type: Grant
    Filed: June 30, 1999
    Date of Patent: November 6, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Fuke, Kazuhiro Saito, Katsuhiko Koui, Hideaki Fukuzawa, Akiko Saito, Hitoshi Iwasaki
  • Publication number: 20010013999
    Abstract: A first layer region of a magnetically pinned layer in a spin valve structure, which is relatively remoter from a non-magnetic intermediate layer, is made of a ferromagnetic material containing at least one element selected from the group consisting of Cr (chrome), Rh (rhodium), Os (osmium), Re (rhenium), Si (silicon), Al (aluminum), Be (beryllium), Ga (gallium), Ge (germanium), Te (tellurium), B (boron), V (vanadium), Ru (ruthenium), Ir (iridium), W (tungsten), Mo (molybdenum), Au (gold), Pt (platinum), Ag (silver) and Cu (copper). Thereby, it is possible to provide a structure of the magnetically pinned layer, which can be readily made using a conventional deposition method and can ensure a sufficient electron reflecting effect on the part of the magnetically pinned layer, and to provide a magnetoresistive element using a spin valve film including the particular structure.
    Type: Application
    Filed: December 28, 2000
    Publication date: August 16, 2001
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Katsuhiko Koi, Hitoshi Iwasaki, Yuzo Kamiguchi, Hiromi Fuke, Hideaki Fukuzawa
  • Patent number: 6165607
    Abstract: A sputtering target consisting essentially of Mn and at least one kind of R element selected from a group of Ni, Pd, Pt, Co, Rh, Ir, V, Nb, Ta, Cu, Ag, Au, Ru, Os, Cr, Mo, W, and Re. The sputtering target, at least as a part of target texture, comprises one member selected from a group of an alloy phase and a compound phase formed between the R element and Mn. In addition, oxygen content in the target is 1 weight % or less (including 0). With such a sputtering target, an anti-ferromagnetic material film consisting of RMn alloy excellent in corrosion resistivity and thermal performance can be stabilized in its film composition and film quality. By employing the anti-ferromagnetic material film, when an exchange coupling film is formed by stacking the anti-ferromagnetic material film and the ferromagnetic material film, sufficient exchange coupling force is obtained stably. Such an exchange coupling film can be used in a magneto-resistance effect element and the like.
    Type: Grant
    Filed: July 17, 1998
    Date of Patent: December 26, 2000
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takashi Yamanobe, Naomi Fujioka, Takashi Ishigami, Nobuo Katsui, Hiromi Fuke, Kazuhiro Saito, Hitoshi Iwasaki, Masashi Sahashi, Takashi Watanabe
  • Patent number: 6159593
    Abstract: The present invention provides an exchange coupling film having a stacked-film-structure consisting of a ferromagnetic film made of at least one material of Fe, Co and Ni, and an antiferromagnetic film, wherein the exchange coupling film made of a ferromagnetic material to which an element is added, is provided at the interface between the ferromagnetic film and the antiferromagnetic film so as to improve the lattice matching, which results in the enhancement of the exchange coupling force, and a magnetoresistance effect element including such an exchange coupling film as described above, and an electrode for supplying a current to the ferromagnetic film which constitutes the exchange coupling film.
    Type: Grant
    Filed: April 16, 1998
    Date of Patent: December 12, 2000
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hitoshi Iwasaki, Yuichi Ohsawa, Reiko Kondoh, Susumu Hashimoto, Atsuhito Sawabe, Yuzo Kamiguchi, Masashi Sahashi, Hiromi Fuke
  • Patent number: 6088195
    Abstract: A magnetoresistance effect element is provided with a laminated film which is composed of a first ferromagnetic conductive layer, a non-magnetic conductive layer superposed on the first ferromagnetic film, and a second ferromagnetic conductive layer superposed on the non-magnetic conductor layer, and which is provided with a pair of electrodes formed on the laminated film, wherein at least one of the first and second magnetic conductive layers comprises at least a first ferromagnetic layer and a second ferromagnetic film, for example, Co alloy films whose directions of axis of easy magnetization are different from each other.
    Type: Grant
    Filed: March 27, 1997
    Date of Patent: July 11, 2000
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuzo Kamiguchi, Kazuhiro Saito, Hideaki Fukuzawa, Hiromi Fuke, Hitoshi Iwasaki, Masashi Sahashi
  • Patent number: 6057049
    Abstract: An exchange coupling film comprises a ferromagnetic film and an antiferromagnetic film laminated on the ferromagnetic film, wherein at least a portion of the antiferromagnetic film has a face-centered cubic crystal structure and the antiferromagnetic film comprises an IrMn alloy represented by the general formula of Ir.sub.x Mn.sub.100-x, wherein x stands for a value by atomic % satisfying the expression, 2.ltoreq.x.ltoreq.80.
    Type: Grant
    Filed: December 13, 1995
    Date of Patent: May 2, 2000
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Fuke, Yuuzo Kamiguchi, Susumu Hashimoto, Tomomi Funayama, Kazuhiro Saito, Hitoshi Iwasaki, Masashi Sahashi
  • Patent number: 5999378
    Abstract: A magnetoresistance effect head comprises a giant magnetoresistance effect film, a pair of leads to supply an electric current to the giant magnetoresistance effect head, and upper and lower magnetic shielding layers made of a crystalline soft magnetic film and disposed to hold the giant magnetoresistance effect film therebetween with a magnetic gap film intervened, wherein the surface roughness of an under layer of the giant magnetoresistance effect film is determined so that a center period L of the surface roughness satisfies L>70 nm.
    Type: Grant
    Filed: December 1, 1997
    Date of Patent: December 7, 1999
    Assignees: Kabushiki Kaisha Toshiba, TDK Corporation
    Inventors: Kazuhiro Saito, Hiromi Fuke, Hitoshi Iwasaki, Yuzo Kamiguchi, Masashi Sahashi, Hiroaki Kawashima, Taro Oike, Koichi Terunuma, Haruyuki Morita