Patents by Inventor Hiromi Yuasa

Hiromi Yuasa 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).

  • Publication number: 20100092803
    Abstract: A method for manufacturing a magneto-resistance effect element is provided. The magneto-resistance effect element includes a first magnetic layer including a ferromagnetic material, a second magnetic layer including a ferromagnetic material and a spacer layer provided between the first magnetic layer and the second magnetic layer, the spacer layer having an insulating layer and a conductive portion penetrating through the insulating layer. The method includes: forming a film to be a base material of the spacer layer; performing a first treatment using a gas including at least one of oxygen molecules, oxygen atoms, oxygen ions, oxygen plasma and oxygen radicals on the film; and performing a second treatment using a gas including at least one of hydrogen molecules, hydrogen atoms, hydrogen ions, hydrogen plasma, hydrogen radicals, deuterium molecules, deuterium atoms, deuterium ions, deuterium plasma and deuterium radicals on the film submitted to the first treatment.
    Type: Application
    Filed: September 25, 2009
    Publication date: April 15, 2010
    Applicants: KABUSHIKI KAISHA TOSHIBA, TDK CORPORATION
    Inventors: Hiromi Yuasa, Hideaki Fukuzawa, Yoshihiko Fuji, Shuichi Murakami, Michiko Hara, Kunliang Zhang, Min Li, Erhard Schreck
  • Publication number: 20100091415
    Abstract: A method for manufacturing a magneto-resistance effect element is provided. The magneto-resistance effect element includes a first magnetic layer including a ferromagnetic material, a second magnetic layer including a ferromagnetic material and a spacer layer provided between the first magnetic layer and the second magnetic layer, the spacer layer having an insulating layer and a conductive portion penetrating through the insulating layer. The method includes: forming a film to be a base material of the spacer layer; performing a first treatment using a gas including at least one of oxygen molecules, oxygen atoms, oxygen ions, oxygen plasma and oxygen radicals on the film; and performing a second treatment using a gas including at least one of nitrogen ions, nitrogen atoms, nitrogen plasma, and nitrogen radicals on the film submitted to the first treatment.
    Type: Application
    Filed: September 25, 2009
    Publication date: April 15, 2010
    Applicants: KABUSHIKI KAISHA TOSHIBA, TDK CORPORATION
    Inventors: Hiromi Yuasa, Hideaki Fukuzawa, Yoshihiko Fuji, Shuichi Murakami, Michiko Hara, Kunliang Zhang, Min Li, Erhard Schreck
  • Publication number: 20090269618
    Abstract: There is provided a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers to be controlled, and a magnetic head and magnetic recording and/or reproducing system using the same. In a magnetoresistance effect element wherein a sense current is caused to flow in a direction perpendicular to the plane of the film, a resistance regulating layer is provided in at least one of a pinned layer, a free layer and an non-magnetic intermediate layer. The resistance regulating layer contains, as a principal component, an oxide, a nitride, a fluoride, a carbide or a boride. The resistance regulating layer may be a continuous film or may have pin holes. Thus, it is possible to provide a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers, while effectively utilizing the scattering effect depending on spin.
    Type: Application
    Filed: July 6, 2009
    Publication date: October 29, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yuuzo KAMIGUCHI, Hiromi Yuasa, Tomohiko Nagata, Hiroaki Yoda, Katsuhiko Koui, Masatoshi Yoshikawa, Hitoshi Iwasaki, Masashi Sahashi, Masayuki Takagishi
  • Patent number: 7602592
    Abstract: A magnetoresistive element includes at least three metallic magnetic layers, connection layers each provided between the metallic magnetic layers, and electrodes which supply a current perpendicularly to a plane of a stack of the metallic magnetic layers and the connection layers. A magnetization direction of a lowermost or uppermost metallic magnetic layer of the metallic magnetic layers is pinned, and a magnetization direction of an intermediate metallic magnetic layer is twisted such that magnetization directions of the lowermost and the uppermost metallic magnetic layers are made substantially orthogonal to each other at zero external field.
    Type: Grant
    Filed: May 26, 2006
    Date of Patent: October 13, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa, Hitoshi Iwasaki
  • Patent number: 7593195
    Abstract: A magnetoresistance effect element comprises a magnetoresistance effect film and a pair of electrode. The magnetoresistance effect film having a first magnetic layer whose direction of magnetization is substantially pinned in one direction; a second magnetic layer whose direction of magnetization changes in response to an external magnetic field; a nonmagnetic intermediate layer located between the first and second magnetic layers; and a film provided in the first magnetic layer, in the second magnetic layer, at a interface between the first magnetic layer and the nonmagnetic intermediate layer, and/or at a interface between the second magnetic layer and the nonmagnetic intermediate layer, the film having a thickness not larger than 3 nanometers, and the film has as least one selected from the group consisting of nitride, oxinitride, phosphide, and fluoride.
    Type: Grant
    Filed: December 12, 2006
    Date of Patent: September 22, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa, Hiromi Fuke, Hitoshi Iwasaki, Masashi Sahashi
  • Publication number: 20090225477
    Abstract: A magnetoresistance effect element comprises a magnetoresistance effect film and a pair of electrode. The magnetoresistance effect film having a first magnetic layer whose direction of magnetization is substantially pinned in one direction; a second magnetic layer whose direction of magnetization changes in response to an external magnetic field; a nonmagnetic intermediate layer located between the first and second magnetic layers; and a film provided in the first magnetic layer, in the second magnetic layer, at a interface between the first magnetic layer and the nonmagnetic intermediate layer, and/or at a interface between the second magnetic layer and the nonmagnetic intermediate layer, the film having a thickness not larger than 3 nanometers, and the film has as least one selected from the group consisting of oxide, nitride, oxinitride, phosphide, and fluoride.
    Type: Application
    Filed: May 19, 2009
    Publication date: September 10, 2009
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hideaki FUKUZAWA, Hiromi Yuasa, Hiromi Fuke, Hitoshi Iwasaki, Masashi Sahashi
  • Publication number: 20090190262
    Abstract: A magnetoresistive element includes a magnetoresistive film including a magnetization pinned layer, a magnetization free layer, an intermediate layer arranged between the magnetization pinned layer and the magnetization free layer, a cap layer arranged on the magnetization pinned layer or on the magnetization free layer, and a functional layer formed of an oxygen- or nitrogen-containing material and arranged in the magnetization pinned layer, or in the magnetization free layer, and a pair of electrodes which pass a current perpendicularly to a plane of the magnetoresistive film, in which a crystalline orientation plane of the functional layer is different from a crystalline orientation plane of its upper or lower adjacent layer.
    Type: Application
    Filed: January 30, 2009
    Publication date: July 30, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Shuichi Murakami, Hideaki Fukuzawa, Hiromi Yuasa, Yoshihiko Fuji
  • Publication number: 20090190264
    Abstract: A magnetoresistive element includes a magnetoresistive film including a magnetization pinned layer, a magnetization free layer, an intermediate layer arranged between the magnetization pinned layer and the magnetization free layer, a cap layer arranged on the magnetization pinned layer or on the magnetization free layer, and a functional layer arranged in the magnetization pinned layer, in the magnetization free layer, in the interface between the magnetization pinned layer and the intermediate layer, in the interface between the intermediate layer and the magnetization free layer, or in the interface between the magnetization pinned layer or the magnetization free layer and the cap layer, and a pair of electrodes which pass a current perpendicularly to a plane of the magnetoresistive film, in which the functional layer is formed of a layer including nitrogen and a metal material containing 5 atomic % or more of Fe.
    Type: Application
    Filed: January 30, 2009
    Publication date: July 30, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hideaki Fukuzawa, Shuichi Murakami, Hiromi Yuasa, Yoshihiko Fuji
  • Patent number: 7561383
    Abstract: There is provided a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers to be controlled, and a magnetic head and magnetic recording and/or reproducing system using the same. In a magnetoresistance effect element wherein a sense current is caused to flow in a direction perpendicular to the plane of the film, a resistance regulating layer is provided in at least one of a pinned layer, a free layer and an non-magnetic intermediate layer. The resistance regulating layer contains, as a principal component, an oxide, a nitride, a fluoride, a carbide or a boride. The resistance regulating layer may be a continuous film or may have pin holes. Thus, it is possible to provide a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers, while effectively utilizing the scattering effect depending on spin.
    Type: Grant
    Filed: September 17, 2008
    Date of Patent: July 14, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuuzo Kamiguchi, Hiromi Yuasa, Tomohiko Nagata, Hiroaki Yoda, Katsuhiko Koui, Masatoshi Yoshikawa, Hitoshi Iwasaki, Masashi Sahashi, Masayuki Takagishi
  • Publication number: 20090162698
    Abstract: A magnetoresistive effect element is produced by forming a first magnetic layer, a spacer layer including an insulating layer and a conductive layer which penetrates through the insulating layer and passes a current, on the first magnetic layer, and a second magnetic layer all of which or part of which is treated with ion, plasma or heat, on the formed spacer layer.
    Type: Application
    Filed: December 20, 2006
    Publication date: June 25, 2009
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa, Yoshihiko Fuji, Hitoshi Iwasaki
  • Publication number: 20090141408
    Abstract: A magnetoresistance effect element comprises a magnetoresistance effect film and a pair of electrode. The magnetoresistance effect film having a first magnetic layer whose direction of magnetization is substantially pinned in one direction; a second magnetic layer whose direction of magnetization changes in response to an external magnetic field; a nonmagnetic intermediate layer located between the first and second magnetic layers; and a film provided in the first magnetic layer, in the second magnetic layer, at a interface between the first magnetic layer and the nonmagnetic intermediate layer, and/or at a interface between the second magnetic layer and the nonmagnetic intermediate layer, the film having a thickness not larger than 3 nanometers, and the film has as least one selected from the group consisting of nitride, oxinitride, phosphide, and fluoride.
    Type: Application
    Filed: February 6, 2009
    Publication date: June 4, 2009
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa, Hiromi Fuke, Hitoshi Iwasaki, Masashi Sahashi
  • Patent number: 7542248
    Abstract: There is provided a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers to be controlled, and a magnetic head and magnetic recording and/or reproducing system using the same. In a magnetoresistance effect element wherein a sense current is caused to flow in a direction perpendicular to the plane of the film, if a pinned layer and a free layer have a stacked construction of a magnetic layer and a non-magnetic layer or a stacked construction of a magnetic layer and a magnetic layer, it is possible to provide a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers, while effectively utilizing the scattering effect depending on spin.
    Type: Grant
    Filed: November 23, 2007
    Date of Patent: June 2, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuuzo Kamiguchi, Hiromi Yuasa, Tomohiko Nagata, Hiroaki Yoda
  • Patent number: 7525776
    Abstract: A magnetoresistive element has a magnetization pinned layer a magnetization direction of which is substantially pinned in one direction, a magnetization free layer a magnetization direction of which varies depending on an external field, and a spacer layer including an insulating layer provided between the magnetization pinned layer and the magnetization free layer and current paths penetrating the insulating layer, the magnetization pinned layer or magnetization free layer located under the spacer layer comprising crystal grains separated by grain boundaries extending across a thickness thereof, in which, supposing that an in-plane position of one end of each of the crystal grains is set to 0 and an in-plane position of a grain boundary adjacent to the other end of the crystal grain is set to 100, the current path corresponding the crystal grain is formed on a region in a range between 20 and 80 of the in-plane position.
    Type: Grant
    Filed: November 9, 2005
    Date of Patent: April 28, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa, Katsuhiko Koui, Hitoshi Iwasaki
  • Publication number: 20090104475
    Abstract: A method for manufacturing a magneto-resistance effect element includes: forming a first magnetic layer; forming a first metallic layer, on the first magnetic layer, mainly containing an element selected from the group consisting of Cu, Au, Ag; forming a functional layer, on the first metallic layer, mainly containing an element selected from the group consisting of Si, Hf, Ti, Mo, W, Nb, Mg, Cr and Zr; forming a second metallic layer, on the functional layer, mainly containing Al; treating the second metallic layer by means of oxidizing, nitriding or oxynitiriding so as to form a current confined layer including an insulating layer and a current path with a conductor passing a current through the insulating layer; and forming, on the current confined layer, a second magnetic layer.
    Type: Application
    Filed: December 17, 2008
    Publication date: April 23, 2009
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yoshihiko Fuji, Hideaki Fukuzawa, Hiromi Yuasa
  • Patent number: 7522390
    Abstract: A spin-valve magnetoresistive effect film includes a magnetization fixed layer, a magnetization free layer, and an intermediate layer interposed therebetween. The intermediate layer has a conduction part disposed in an insulation layer and made of a magnetic metal material. The ferromagnetic film stacked on an upper side of the intermediate layer, out of ferromagnetic films constituting the magnetization fixed layer and the magnetization free layer has a perpendicular orientation part which is disposed above the conduction part and whose crystal growth direction is substantially perpendicular to a film plane, and a non-perpendicular orientation part which exists in a portion other than the perpendicular orientation part. A magnetoresistive effect element has a pair of electrodes passing a sense current in a direction perpendicular to the film plane of the magnetoresistive effect film.
    Type: Grant
    Filed: October 13, 2005
    Date of Patent: April 21, 2009
    Assignees: Kabushiki Kaisha Toshiba, TDK Corporation
    Inventors: Hiromi Yuasa, Hideaki Fukuzawa, Hitoshi Iwasaki
  • Publication number: 20090097166
    Abstract: A magnetoresistive element has a first magnetic layer and a second magnetic layer separate from each other, the first magnetic layer and the second magnetic layer each having a magnetization whose direction is substantially pinned, and a non-magnetic conductive layer formed in contact with the first magnetic layer and the second magnetic layer and electrically connecting the first and second magnetic layers, the non-magnetic conductive layer forming a path of spin-polarized electrons from one of the magnetic layer to the other magnetic layer, the non-magnetic conductive layer comprising a portion located between the first magnetic layer and the second magnetic layer, the portion being a sensing area.
    Type: Application
    Filed: December 5, 2008
    Publication date: April 16, 2009
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa, Susumu Hashimoto, Hitoshi Iwasaki
  • Publication number: 20090091865
    Abstract: A novel CCP scheme is disclosed for a CPP-GMR sensor in which an amorphous metal/alloy layer such as Hf is inserted between a lower Cu spacer and an oxidizable layer such as Al, Mg, or AlCu prior to performing a pre-ion treatment (PIT) and ion assisted oxidation (IAO) to transform the amorphous layer into a first metal oxide template and the oxidizable layer into a second metal oxide template both having Cu metal paths therein. The amorphous layer promotes smoothness and smaller grain size in the oxidizable layer to minimize variations in the metal paths and thereby improves dR/R, R, and dR uniformity by 50% or more. An amorphous Hf layer may be used without an oxidizable layer, or a thin Cu layer may be inserted in the CCP scheme to form a Hf/PIT/IAO or Hf/Cu/Al/PIT/IAO configuration. A double PIT/IAO process may be used as in Hf/PIT/IAO/Al/PIT/IAO or Hf/PIT/IAO/Hf/PIT/IAO schemes.
    Type: Application
    Filed: October 3, 2007
    Publication date: April 9, 2009
    Inventors: Kunliang Zhang, Min Li, Yue Liu, Hideaki Fukuzawa, Hiromi Yuasa
  • Patent number: 7515386
    Abstract: There is provided a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers to be controlled, and a magnetic head and magnetic recording and/or reproducing system using the same. In a magnetoresistance effect element wherein a sense current is caused to flow in a direction perpendicular to the plane of the film, a resistance regulating layer is provided in at least one of a pinned layer, a free layer and an non-magnetic intermediate layer. The resistance regulating layer contains, as a principal component, an oxide, a nitride, a fluoride, a carbide or a boride. The resistance regulating layer may be a continuous film or may have pin holes. Thus, it is possible to provide a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers, while effectively utilizing the scattering effect depending on spin.
    Type: Grant
    Filed: March 27, 2006
    Date of Patent: April 7, 2009
    Assignee: Kabushiki Kaisa Toshiba
    Inventors: Yuuzo Kamiguchi, Hiromi Yuasa, Tomohiko Nagata, Hiroaki Yoda, Katsuhiko Koui, Masatoshi Yoshikawa, Hitoshi Iwasaki, Masashi Sahashi, Masayuki Takagishi
  • Patent number: 7515387
    Abstract: A spin-valve magnetoresistive effect film includes a magnetization fixed layer, a magnetization free layer, and a nonmagnetic intermediate layer interposed therebetween. The nonmagnetic intermediate layer has a conduction part disposed in an insulation layer and made of a nonmagnetic metal material. The ferromagnetic film stacked on an upper side of the nonmagnetic intermediate layer, out of ferromagnetic films constituting the magnetization fixed layer and the magnetization free layer has a perpendicular orientation part which is disposed above the conduction part and whose crystal growth direction is substantially perpendicular to a film plane, and a non-perpendicular orientation part which exists in a portion other than the perpendicular orientation part. A magnetoresistive effect element has a pair of electrodes passing a sense current in a direction perpendicular to the film plane of the spin-valve magnetoresistive effect film.
    Type: Grant
    Filed: October 13, 2005
    Date of Patent: April 7, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Yuasa, Hideaki Fukuzawa, Hitoshi Iwasaki
  • Patent number: 7514117
    Abstract: The present invention relates to a method for manufacturing a magnetoresistive element having a magnetization pinned layer, a magnetization free layer, and a spacer layer including an insulating layer provided between the magnetization pinned layer and the magnetization free layer and current paths penetrating into the insulating layer. A process of forming the spacer layer in the method includes depositing a first metal layer forming the metal paths, depositing a second metal layer on the first metal layer, performing a pretreatment of irradiating the second metal layer with an ion beam or a RF plasma of a rare gas, and converting the second metal layer into the insulating layer by means of supplying an oxidation gas or a nitriding gas.
    Type: Grant
    Filed: August 9, 2005
    Date of Patent: April 7, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Katsuhiko Koui, Hiromi Yuasa, Susumu Hashimoto, Hitoshi Iwasaki