Patents by Inventor Takahiko Machita

Takahiko Machita 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: 20090135529
    Abstract: The invention provides a magneto-resistive effect device of the CPP (current perpendicular to plane) structure, comprising a magneto-resistive effect unit, and a first shield layer and a second shield layer located and formed such that the magneto-resistive effect unit is sandwiched between them, with a sense current applied in a stacking direction. The magneto-resistive effect unit comprises a nonmagnetic intermediate layer, and a first ferromagnetic layer and a second ferromagnetic layer stacked and formed such that the nonmagnetic intermediate layer is interposed between them.
    Type: Application
    Filed: November 28, 2007
    Publication date: May 28, 2009
    Applicant: TDK Corporation
    Inventors: Koji Shimazawa, Daisuke Miyauchi, Yoshihiro Tsuchiya, Takahiko Machita, Shinji Hara
  • Publication number: 20090128965
    Abstract: A magnetic field detecting element has a stack which includes a NiCr layer, a first magnetic layer whose magnetization direction varies in accordance with an external magnetic field, a non-magnetic spacer layer, and a second magnetic layer whose magnetization direction varies in accordance with the external magnetic field, said NiCr layer, said first magnetic layer, said spacer layer and said second magnetic layer being disposed in this order and being arranged in contact with each other, wherein a sense current is adapted to flow in a direction that is perpendicular to a film surface of said stack; and a bias magnetic layer which is disposed on a side of said stack, said side being opposite to an air bearing surface of said stack, wherein said bias magnetic layer is adapted to apply a bias magnetic field to said stack in a direction that is perpendicular to said air bearing surface.
    Type: Application
    Filed: November 15, 2007
    Publication date: May 21, 2009
    Inventors: Tomohito MIZUNO, Yoshihiro TSUCHIYA, Shinji HARA, Koji SHIMAZAWA, Daisuke MIYAUCHI, Takahiko MACHITA, Tsutomu CHOU, Toshiyuki AYUKAWA, Hironobu MATSUZAWA, Tsuyoshi ICHIKI
  • Publication number: 20090109580
    Abstract: A magnetic field detecting element comprises; a stack including an upper magnetic layer and a lower magnetic layer, and a non-magnetic intermediate layer sandwiched between said upper magnetic layer and said lower magnetic layer, wherein magnetization of said upper magnetic layer and said lower magnetic layer changes in accordance with an external magnetic field; an upper shield electrode layer and a lower shield electrode layer which is provided to sandwich said stack therebetween in a direction of the stacking of said stack, wherein said upper shield electrode layer and said lower shield electrode layer supply sense current in the direction of stacking, and magnetically shield said stack; a bias magnetic layer which is provided on a surface of said stack opposite to an air bearing surface, and wherein said bias magnetic layer applies a bias magnetic field to said upper magnetic layer and said lower magnetic layer in a direction perpendicular to the air bearing surface; and insulating layers which are provid
    Type: Application
    Filed: October 26, 2007
    Publication date: April 30, 2009
    Inventors: Toshiyuki AYUKAWA, Daisuke MIYAUCHI, Koji SHIMAZAWA, Takahiko MACHITA
  • Publication number: 20090086383
    Abstract: The invention provides a giant magneto-resistive effect device of the CPP (current perpendicular to plane) structure (CPP-GMR device) comprising a spacer layer, and a first ferromagnetic layer and a second ferromagnetic layer stacked together with said spacer layer sandwiched between them, with a sense current passed in the stacking direction, wherein the first ferromagnetic layer and the second ferromagnetic layer function such that the angle made between the directions of magnetizations of both layers change relatively depending on an external magnetic field, said spacer layer contains a semiconductor oxide layer, and a nitrogen element-interface protective layer is provided at a position where the semiconductor oxide layer forming the whole or a part of said spacer layer contacts an insulating layer.
    Type: Application
    Filed: October 1, 2007
    Publication date: April 2, 2009
    Applicant: TDK CORPORATION
    Inventors: Shinji Hara, Daisuke Miyauchi, Koji Shimazawa, Yoshihiro Tsuchiya, Tomohito Mizuno, Takahiko Machita
  • Publication number: 20090067099
    Abstract: An MR element includes an MR stack including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer disposed between the first and the second ferromagnetic layer. The MR stack has an outer surface, and the spacer layer has a periphery located in the outer surface of the MR stack. The magnetoresistive element further includes a layered film that touches the periphery of the spacer layer. The spacer layer includes a semiconductor layer formed using an oxide semiconductor as a material. The layered film includes a first layer, a second layer, and a third layer stacked in this order. The first layer is formed of the same material as the semiconductor layer, and touches the periphery of the spacer layer. The second layer is a metal layer that forms a Schottky barrier at the interface between the first layer and the second layer. The third layer is an insulating layer.
    Type: Application
    Filed: September 11, 2007
    Publication date: March 12, 2009
    Applicant: TDK CORPORATION
    Inventors: Yoshihiro Tsuchiya, Koji Shimazawa, Tomohito Mizuno, Shinji Hara, Daisuke Miyauchi, Takahiko Machita
  • Publication number: 20090059443
    Abstract: An MR element includes a stack of layers including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer disposed between the first and the second ferromagnetic layer. The stack of layers has an outer surface, and the spacer layer has a periphery located in the outer surface of the stack of layers. The magnetoresistive element further includes an insulating film that touches the periphery of the spacer layer. The spacer layer includes a layer made of an oxide semiconductor composed of an oxide of a first metal. The insulating film includes a contact film that touches the periphery of the spacer layer and that is made of an oxide of a second metal having a Pauling electronegativity lower than that of the first metal by 0.1 or more.
    Type: Application
    Filed: August 27, 2007
    Publication date: March 5, 2009
    Applicant: TDK CORPORATION
    Inventors: Yoshihiro Tsuchiya, Tomohito Mizuno, Shinji Hara, Daisuke Miyauchi, Takahiko Machita
  • Publication number: 20090034132
    Abstract: A magnetic field detecting element comprising: a stack including an upper magnetic layer, a lower magnetic layer and a non-magnetic intermediate layer sandwiched between said upper magnetic layer and said lower magnetic layer, wherein magnetization directions of said upper magnetic layer and said lower magnetic layer change in accordance with an external magnetic field; an upper shield electrode layer and a lower shield electrode layer which are provided in a manner that they sandwich said stack therebetween in a direction of stacking of said stack, wherein said upper shield electrode layer and said lower shield electrode layer supply sense current in the direction of stacking and magnetically shield said stack; a bias magnetic layer which is provided on a surface of said stack, the surface being opposite to an air bearing surface of said stack, wherein said bias magnetic layer applies a bias magnetic field to said upper magnetic layer and to said lower magnetic layer in a direction perpendicular to the air b
    Type: Application
    Filed: July 30, 2007
    Publication date: February 5, 2009
    Inventors: Daisuke MIYAUCHI, Takahiko MACHITA
  • Publication number: 20090034133
    Abstract: A magnetic field detecting element comprising: a stack including an upper magnetic layer, a lower magnetic layer and a non-magnetic intermediate layer sandwiched between said upper magnetic layer and said lower magnetic layer, wherein magnetization directions of said upper magnetic layer and said lower magnetic layer change in accordance with an external magnetic field; an upper shield electrode layer and a lower shield electrode layer which are provided in a manner that they sandwich said stack therebetween in a direction of stacking of said stack, wherein said upper shield electrode layer and said lower shield electrode layer supply sense current in the direction of stacking and magnetically shield said stack; a bias magnetic layer which is provided on a surface of said stack, the surface being opposite to an air bearing surface of said stack, wherein said bias magnetic layer applies a bias magnetic field to said upper magnetic layer and to said lower magnetic layer in a direction perpendicular to the air b
    Type: Application
    Filed: July 30, 2007
    Publication date: February 5, 2009
    Inventors: Daisuke MIYAUCHI, Takahiko MACHITA
  • Publication number: 20090002897
    Abstract: The invention provides a giant magneto-resistive effect device (CPP-GMR device) having a CPP (current perpendicular to plane) structure comprising a multilayer device assembly comprising a fixed magnetization layer, a spacer layer, a free layer and a cap layer stacked one upon another in order, with a sense current applied in a stacking direction of the multilayer device assembly. In the rear of the multilayer device assembly, there is a refilled insulation layer formed, which is in contact with the rear end face of the multilayer device assembly and extends rearward, wherein the uppermost position P of the refilled insulation layer that is in contact with the rear end face of said multilayer device assembly lies at a rear end face of the cap layer and is set in such a way as to satisfy a relation: 0.2?(T2/T1)<1 where T1 is the thickness of the cap layer, and T2 is the absolute value of a distance from the uppermost portion of the cap layer down to the position P as viewed in a thickness direction.
    Type: Application
    Filed: June 26, 2007
    Publication date: January 1, 2009
    Applicant: TDK CORPORATION
    Inventors: Takahiko Machita, Daisuke Miyauchi
  • Publication number: 20080226948
    Abstract: A magnetoresistance effect element (MR element) for use in a thin-film magnetic head has a buffer layer, an antiferromagnetic layer, a pinned layer, a spacer layer, a free layer, and a cap layer that are successively stacked. A sense current flows in a direction perpendicular to layer surfaces via a lower shield layer and an upper shield layer. The pinned layer comprises an outer layer having a fixed magnetization direction, a nonmagnetic intermediate layer, and an inner layer in the form of a ferromagnetic layer. The spacer layer comprises a first nonmagnetic metal layer, a semiconductor layer made of ZnO, and a second nonmagnetic metal layer. The inner layer or the outer layer includes a diffusion blocking layer made of an oxide of an element whose electronegativity is equal to or smaller than Zn, e.g., ZnO, TaO, ZrO, MgO, TiO, or HfO, or made of RuO.
    Type: Application
    Filed: March 12, 2007
    Publication date: September 18, 2008
    Inventors: Tomohito MIZUNO, Takahiko MACHITA, Kei HIRATA, Yoshihiro TSUCHIYA, Shinji HARA
  • Publication number: 20080204942
    Abstract: A magnetic thin film has a pinned layer whose magnetization direction is fixed with respect to an external magnetic field, a free layer whose magnetization direction is changed according to the external magnetic field, and a spacer layer which is sandwiched between said pinned layer and said free layer. Sense current is configured to flow in a direction that is perpendicular to film surfaces of said pinned layer, said spacer layer, and said free layer. Said spacer layer has a CuZn metal alloy which includes an oxide region, said oxide region consisting of an oxide of any of Al, Si, Cr, Ti, Hf, Zr, Zn, and Mg.
    Type: Application
    Filed: February 23, 2007
    Publication date: August 28, 2008
    Inventors: Takahiko MACHITA, Tomohito MIZUNO, Yoshihiro TSUCHIYA, Daisuke MIYAUCHI, Shinji HARA
  • Publication number: 20080198515
    Abstract: A thin film magnetic head has: a spin valve having a pinned layer whose magnetization direction is fixed relative to an external magnetic field, a first nonmagnetic intermediate layer which is disposed on said pinned layer, and a free layer whose magnetization direction is changed according to the external magnetic field, said free layer being disposed on said first nonmagnetic intermediate layer; and bias magnetic layers for applying a bias magnetic field to said free layer, said bias magnetic layers being provided on both sides of said spin valve with regard to a track width direction thereof. The pinned layer has a hard magnetic layer, a second nonmagnetic intermediate layer which is disposed on said hard magnetic layer, and a ferromagnetic layer which is disposed on said second nonmagnetic intermediate layer. The bias magnetic layer has a bias antiferromagnetic layer, and a bias ferromagnetic layer which is disposed on said bias antiferromagnetic layer.
    Type: Application
    Filed: February 20, 2007
    Publication date: August 21, 2008
    Inventors: Daisuke MIYAUCHI, Shinji HARA, Takahiko MACHITA
  • Publication number: 20080040915
    Abstract: Using a beam of xenon ions together with a suitable mask, a stack is ion milled until a part of it, no more than about 0.1 microns thick, has been removed so that a pedestal having sidewalls, including a vertical section and a shortened taper portion, has been formed. This is followed by formation of conductive lead layers as needed. Using xenon as the sputtering gas enables the point at which milling is terminated to be more precisely controlled.
    Type: Application
    Filed: October 18, 2007
    Publication date: February 21, 2008
    Inventors: Stuart Kao, Chunping Luo, Chaopeng Chen, Takahiko Machita, Daisuke Miyauchi, Jeiwei Chang
  • Publication number: 20080043378
    Abstract: We describe a family of magnetic read heads that each includes a GMR or MTJ stack. A part, no more than about 0.1 microns thick, has been removed from this stack a to form a pedestal having sidewalls comprising a vertical section that includes all of the free layer.
    Type: Application
    Filed: October 18, 2007
    Publication date: February 21, 2008
    Inventors: Stuart Kao, Chunping Luo, Chaopeng Chen, Takahiko Machita, Daisuke Miyauchi, Jei-Wei Chang
  • Publication number: 20080040914
    Abstract: Using a beam of xenon ions together with a suitable mask, a GMR stack is ion milled until a part of it, no more than about 0.1 microns thick, has been removed so that a pedestal, having sidewalls comprising a vertical section that includes all of the free layer, has been formed. This is followed by formation of the longitudinal bias and conductive lead layers in the usual way. Using xenon as the sputtering gas enables the point at which milling is terminated to be more precisely controlled.
    Type: Application
    Filed: October 18, 2007
    Publication date: February 21, 2008
    Inventors: Stuart Kao, Chunping Luo, Chaopeng Chen, Takahiko Machita, Daisuke Miyauchi, Jeiwei Chang
  • Publication number: 20080034576
    Abstract: Using a beam of xenon ions together with a suitable mask, a MTJ stack is ion milled until a part of it, no more than about 0.1 microns thick, has been removed so that a pedestal, having sidewalls comprising a vertical section that includes all of the free layer, has been formed. This is followed by formation of the longitudinal bias and conductive lead layers in the usual way. Using xenon as the sputtering gas enables the point at which milling is terminated to be more precisely controlled.
    Type: Application
    Filed: October 18, 2007
    Publication date: February 14, 2008
    Inventors: Stuart Kao, Chunping Luo, Chaopeng Chen, Takahiko Machita, Daisuke Miyauchi, Jeiwei Chang
  • Patent number: 7320170
    Abstract: Using a beam of xenon ions together with a suitable mask, a GMR stack is ion milled until a part of it, no more than about 0.1 microns thick, has been removed so that a pedestal, having sidewalls comprising a vertical section that includes all of the free layer, has been formed. This is followed by formation of the longitudinal bias and conductive lead layers in the usual way. Using xenon as the sputtering gas enables the point at which milling is terminated to be more precisely controlled.
    Type: Grant
    Filed: April 20, 2004
    Date of Patent: January 22, 2008
    Assignees: Headway Technologies, Inc., TDK Corporation
    Inventors: Stuart Kao, Chunping Luo, Chaopeng Chen, Takahiko Machita, Daisuke Miyauchi, Jei-Wei Chang
  • Publication number: 20080013223
    Abstract: In the GMR device of the CPP structure using the synthetic pinned layer as the fixed magnetization layer (pinned layer), the width W1 of the inner pin layer is set at 50 nm or less; the fixed magnetization layer is configured in such a way as to have a given angle range of tapers at both its ends as viewed from the medium opposite plane; the magnetic volume ratio between the inner and the outer pin layer is allowed to lie in the range of 0.9 to 1.1; and the magnetic thickness ratio between the inner and the outer pin layer is set at 0.8 or less. It is thus possible to make the outer pin layer thin at no cost of the thickness of the inner pin layer forming a part of the synthetic pinned layer yet without doing damage to the function of the synthetic pinned layer itself, viz., resistance to an external magnetic field.
    Type: Application
    Filed: July 5, 2007
    Publication date: January 17, 2008
    Applicant: TDK CORPORATION
    Inventors: Daisuke Miyauchi, Takahiko Machita
  • Publication number: 20070279809
    Abstract: A magneto-resistance effect element comprises a stacked body which comprises a pinned layer having a fixed magnetization direction, a free layer having a magnetization direction that varies according to an external magnetic field, and a nonmagnetic spacer layer which is interposed between the pinned layer and the free layer. The stacked body having a constricted shape in which at least one part of the spacer layer is constricted when viewed from at least one direction perpendicular to a stacked direction of the stacked body.
    Type: Application
    Filed: April 5, 2007
    Publication date: December 6, 2007
    Applicant: TDK Corporation
    Inventors: Daisuke Myiauchi, Kazuki Sato, Takayasu Kanaya, Takahiko Machita
  • Publication number: 20070242396
    Abstract: In an MR element, each of a pinned layer and a free layer includes a Heusler alloy layer. The Heusler alloy layer has two surfaces that are quadrilateral in shape and face toward opposite directions. The Heusler alloy layer includes one crystal grain that touches four sides of one of the two surfaces. In a method of manufacturing the MR element, a layered film to be the MR element is formed and patterned, and then heat treatment is performed on the layered film patterned, so that crystal grains included in a film to be the Heusler alloy layer in the layered film grow and one crystal grain that touches four sides of one of the surfaces of the film to be the Heusler alloy layer is thereby formed.
    Type: Application
    Filed: March 8, 2007
    Publication date: October 18, 2007
    Applicant: TDK CORPORATION
    Inventors: Koji Shimazawa, Yoshihiro Tsuchiya, Tomohito Mizuno, Daisuke Miyauchi, Shinji Hara, Takahiko Machita