Patents by Inventor Akihiko Takeo

Akihiko Takeo 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: 20150179205
    Abstract: According to one embodiment, a pattern formation method includes steps of forming a layer to be processed on a substrate, forming a metal microparticle layer by coating the layer to be processed with a metal microparticle coating solution containing metal microparticles and a solvent, reducing a protective group amount around the metal microparticles by first etching, forming a protective layer by exposing the substrate to a gas containing C and F and adsorbing the gas around the metal microparticles to obtain a projection pattern, and transferring the projection pattern to the layer to be processed by second etching.
    Type: Application
    Filed: March 12, 2014
    Publication date: June 25, 2015
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kazutaka TAKIZAWA, Takeshi IWASAKI, Akihiko TAKEO
  • Publication number: 20150162042
    Abstract: According to one embodiment, a perpendicular magnetic recording medium includes a substrate, an underlayer formed on the substrate and a magnetic recording layer formed on the underlayer and having an easy axis in a direction perpendicular to a film surface. The underlayer includes a plurality of projecting portions arranged at a distance of 1 nm to 20 nm from one another. The magnetic recording layer is an amorphous magnetic recording layer including a plurality of magnetic grains each formed to expand towards a top end thereof from a surface of a respective projecting portion of the underlayer, at least those of the magnetic grains located on a respective projecting portion side being separated from each other.
    Type: Application
    Filed: September 25, 2014
    Publication date: June 11, 2015
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kaori Kimura, Soichi Oikawa, Kazutaka Takizawa, Akira Fujimoto, Akihiko Takeo
  • Patent number: 9028704
    Abstract: A manufacturing method of a magnetic recording medium includes follows: forming a magnetic recording layer on a substrate; forming an under layer and a metal release layer that forms an alloy with the under layer on the magnetic recording layer in this order and forming an alloyed release layer by alloying the under layer and the metal release layer; forming a mask layer on the alloyed release layer; forming a resist layer on the mask layer; providing a protrusion-recess pattern by patterning the resist layer; transferring the protrusion-recess pattern to the mask layer; transferring the protrusion-recess pattern to the alloyed release layer; transferring the protrusion-recess pattern to the magnetic recording layer; dissolving the alloyed release layer by using a stripping solution and removing a layer formed on the alloyed release layer from an upper side of the magnetic recording layer.
    Type: Grant
    Filed: October 24, 2012
    Date of Patent: May 12, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazutaka Takizawa, Akira Watanabe, Kaori Kimura, Takeshi Iwasaki, Akihiko Takeo
  • Patent number: 8995089
    Abstract: According to one embodiment, there is provided a magnetic recording medium which includes a base, a magnetic recording layer having convex-shaped magnetic layers, which is formed on the base, and a protective film formed on the magnetic recording layer. There are gaps in a region surrounded by the protective film, the surface of the base, and each side wall of each magnetic layer.
    Type: Grant
    Filed: July 17, 2013
    Date of Patent: March 31, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazutaka Takizawa, Akira Watanabe, Kaori Kimura, Tsuyoshi Onitsuka, Takeshi Iwasaki, Masahiro Takashita, Akihiko Takeo
  • Publication number: 20150074986
    Abstract: According to one embodiment, there is provided a spin torque oscillator including an oscillation layer formed of a magnetic material, a spin injection layer formed of a magnetic material and configured to inject a spin into the oscillation layer, and a current confinement layer including an insulating portion formed of an oxide or a nitride and a conductive portion formed of a nonmagnetic metal and penetrating the insulating portion in a direction of stacking. The conductive portion of the current confinement layer is positioned near a central portion of a plane of a device region including the oscillation layer and the spin injection layer.
    Type: Application
    Filed: November 21, 2014
    Publication date: March 19, 2015
    Inventors: Akihiko TAKEO, Satoshi SHIROTORI, Kenichiro YAMADA, Katsuhiko KOUI
  • Publication number: 20150072172
    Abstract: According to one embodiment, there is provided a pattern formation method including forming a target layer to be processed on a substrate, adding a second dispersion containing a polymer material including a polymer chain having a base metal at a terminal end and a second solvent to a first dispersion containing noble-metal microparticles and a first solvent, thereby preparing a noble-metal microparticle layer coating solution in which microparticles covered with the polymer material are dispersed, arranging the noble-metal microparticles covered with the polymer material on the target layer by using the noble-metal microparticle layer coating solution, and transferring a projections pattern of the noble-metal microparticles covered with the polymer material to the target layer.
    Type: Application
    Filed: January 10, 2014
    Publication date: March 12, 2015
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kazutaka TAKIZAWA, Kaori Kimura, Akihiko Takeo
  • Patent number: 8968526
    Abstract: There are provided a method for manufacturing a magnetic recording medium which is excellent in terms of both the recording and reproduction characteristics and the thermal fluctuation characteristics without reducing the density and hardness of the perpendicular magnetic layer; a magnetic recording medium; and a magnetic recording and reproducing apparatus with which an excellent recording density is achieved, wherein, in the method for manufacturing the magnetic recording medium, at least a portion of the perpendicular magnetic layer 4 is formed as a magnetic layer having a granular structure that contains Co as a major component and also contains an oxide of at least one nonmagnetic metal selected from the group consisting of Cr, Si, Ta, Al, Ti, W and Mg; a target for forming the perpendicular magnetic layer 4 by the sputtering process is prepared so as to include an oxide of Co and a compound of Co and at least one nonmagnetic metal selected from the group consisting of Cr, Si, Ta, Al, Ti, W and Mg, an
    Type: Grant
    Filed: January 22, 2010
    Date of Patent: March 3, 2015
    Assignees: Showa Denko K.K., Kabushiki Kaisha Toshiba, Tohoku University
    Inventors: Shingo Sasaki, Shin Saito, Migaku Takahashi, Atsushi Hashimoto, Yuzo Sasaki, Gohei Kurokawa, Tomoyuki Maeda, Akihiko Takeo
  • Publication number: 20150043106
    Abstract: According to one embodiment, a magnetic head includes a main pole configured to apply a recording magnetic field to a recording layer included in a recording medium, a trailing shield opposing the main pole in a down-track direction, with a write gap interposed therebetween, a pair of side shields opposing the main pole on opposite sides of the main pole in a cross-track direction, with respective gaps interposed therebetween, a recording coil configured to cause the main pole to generate a magnetic field, a first high-frequency oscillator interposed between the main pole and one of the side shields, and a second high-frequency oscillator interposed between the main pole and the other side shield.
    Type: Application
    Filed: October 25, 2013
    Publication date: February 12, 2015
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kenichiro YAMADA, Katsuhiko KOUI, Akihiko TAKEO
  • Patent number: 8929031
    Abstract: According to one embodiment, there is provided a spin torque oscillator including an oscillation layer formed of a magnetic material, a spin injection layer formed of a magnetic material and configured to inject a spin into the oscillation layer, and a current confinement layer including an insulating portion formed of an oxide or a nitride and a conductive portion formed of a nonmagnetic metal and penetrating the insulating portion in a direction of stacking. The conductive portion of the current confinement layer is positioned near a central portion of a plane of a device region including the oscillation layer and the spin injection layer.
    Type: Grant
    Filed: November 8, 2011
    Date of Patent: January 6, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akihiko Takeo, Satoshi Shirotori, Kenichiro Yamada, Katsuhiko Koui
  • Publication number: 20150004438
    Abstract: According to one embodiment, there is provided a method for forming a pattern including forming an island-like metal underlayer comprised of a first metal, a phase-separated release layer including a first metal, a second metal, and a metal oxide, a mask layer, and a resist layer on a processed layer in this order, forming a concave-convex pattern on the resist layer, transferring the pattern to the mask layer, the phase-separated release layer, and the processed layer in this order, dissolving the phase-separated release layer using a peeling liquid for dissolving the first metal and the second metal, and removing the mask layer from the processed layer to expose the concave-convex pattern.
    Type: Application
    Filed: October 22, 2013
    Publication date: January 1, 2015
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kazutaka Takizawa, Akira Watanabe, Kaori Kimura, Takeshi Iwasaki, Akihiko Takeo
  • Publication number: 20140376130
    Abstract: A magnetic head includes a plurality of reproducing elements so that the magnetic head can acquire reproduction signals from a plurality of tracks at the same time. The magnetic head includes a first reproducing element, a first magnetic film formed on a first side wall of the first reproducing element with a first side wall insulating film interposed therebetween, a second magnetic film formed on a second side wall of the first reproducing element with a second side wall insulating film interposed therebetween, a second reproducing element electrically isolated from the first reproducing element and formed on the first magnetic film, a third magnetic film formed on the first magnetic film, and a fourth magnetic film formed on the first reproducing element and electrically isolated from the second reproducing element.
    Type: Application
    Filed: January 10, 2014
    Publication date: December 25, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Akihiko TAKEO, Kazuto KASHIWAGI, Kenichiro YAMADA, Katsuhiko KOUI, Tomomi FUNAYAMA
  • Patent number: 8908329
    Abstract: According to one embodiment, a magnetic head manufacturing method includes forming a protective layer on the surfaces of a main magnetic pole layer, a processed spin torque oscillator, and a mask formed on the spin torque oscillator, and further performing ion beam etching on the main magnetic pole layer and the protective layer on the surface of the main magnetic pole layer through the mask such that the protective layer is left behind on the side surfaces of the spin torque oscillator and removed from the surface of the main magnetic pole layer, thereby processing the main magnetic pole layer such that its side surfaces have a shape tapered toward the substrate.
    Type: Grant
    Filed: October 22, 2012
    Date of Patent: December 9, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Satoshi Shirotori, Katsuhiko Koui, Shinobu Sugimura, Norihito Fujita, Akihiko Takeo
  • Patent number: 8858809
    Abstract: A manufacturing method of a magnetic recording medium includes steps of forming a magnetic recording layer, a first mask layer, a second mask layer containing silicon as primary component, a strip layer, a third mask layer, and a resist layer, a step of patterning the resist layer to provide a pattern, steps of transferring the pattern to the third mask layer, to the strip layer, and to the second mask layer, a step of removing the strip layer by wet etching and of stripping the third mask layer and the resist layer above the magnetic recording layer, steps of transferring the pattern to the first mask layer and to the magnetic recording layer, and a step of stripping the first mask layer remaining on the magnetic recording layer.
    Type: Grant
    Filed: September 7, 2012
    Date of Patent: October 14, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akira Watanabe, Kaori Kimura, Kazutaka Takizawa, Takeshi Iwasaki, Tsuyoshi Onitsuka, Akihiko Takeo
  • Publication number: 20140287265
    Abstract: According to one embodiment, a magnetic recording medium including a substrate and a magnetic recording layer formed on the substrate and including a plurality of projections is obtained. The array of the plurality of projections includes a plurality of domains in which the projections are regularly arranged, and a boundary region between the domains, in which the projections are irregularly arranged. The boundary region is formed along a perpendicular bisector of a line connecting the barycenters of adjacent projections.
    Type: Application
    Filed: July 12, 2013
    Publication date: September 25, 2014
    Inventors: Kaori Kimura, Kazutaka Takizawa, Akira Watanabe, Takeshi Iwasaki, Akihiko Takeo
  • Patent number: 8837087
    Abstract: According to one embodiment, there is provided a thin magnetic film having a negative anisotropy of ?6×106 erg/cm3 or less and including, on at least a nonmagnetic substrate, at least one seed layer made of a metal or metal compound, a ruthenium underlayer for controlling the orientation of an immediately overlying layer, and a magnetic layer having negative anisotropy in the normal line direction perpendicular to a surface of the magnetic layer and mainly containing Co and Ir, wherein the additive element concentration of Ir in the magnetic layer is 10 (inclusive) to 45 (inclusive) at %.
    Type: Grant
    Filed: July 19, 2013
    Date of Patent: September 16, 2014
    Assignees: Kabushiki Kaisha Toshiba, Tohoku University, Showa Denko K.K.
    Inventors: Akihiko Takeo, Akira Kikitsu, Tomoyuki Maeda, Migaku Takahashi, Shin Saito, Ken Inoue, Gohei Kurokawa
  • Publication number: 20140247519
    Abstract: According to one embodiment, there is provided a magnetic recording medium which includes a base, a magnetic recording layer having convex-shaped magnetic layers, which is formed on the base, and a protective film formed on the magnetic recording layer. There are gaps in a region surrounded by the protective film, the surface of the base, and each side wall of each magnetic layer.
    Type: Application
    Filed: July 17, 2013
    Publication date: September 4, 2014
    Inventors: Kazutaka Takizawa, Akira Watanabe, Kaori Kimura, Tsuyoshi Onitsuka, Takeshi Iwasaki, Masahiro Takashita, Akihiko Takeo
  • Publication number: 20140248513
    Abstract: According to one embodiment, there is provided a method for producing a magnetic recording medium which includes forming a mask layer on a magnetic recording layer, applying metal fine particles on the mask layer, covering the metal fine particles with an overcoat layer, irradiating with energy beams through the overcoat layer so as to deactivate a protective coating of the metal fine particles, transferring a metal fine particle pattern from the mask layer to the magnetic recording layer, and removing the mask layer from the magnetic recording layer.
    Type: Application
    Filed: July 12, 2013
    Publication date: September 4, 2014
    Inventors: Kazutaka Takizawa, Akira Watanabe, Kaori Kimura, Tsuyoshi Onitsuka, Takeshi Iwasaki, Akihiko Takeo
  • Patent number: 8815336
    Abstract: According to one embodiment, there is provided a magnetic recording medium manufacturing method including forming a resist layer on a magnetic recording layer, patterning the resist layer, forming a magnetic pattern by performing ion implantation through the resist layer, partially modifying the surface of the magnetic recording layer, removing the resist, applying a self-organization material to the surface of the magnetic recording layer and forming a dotted mask pattern, and patterning the magnetic recording layer.
    Type: Grant
    Filed: October 23, 2012
    Date of Patent: August 26, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kaori Kimura, Masatoshi Sakurai, Kazuto Kashiwagi, Akihiko Takeo
  • Publication number: 20140153139
    Abstract: According to one embodiment, a method of manufacturing a magnetoresistive element includes a layered structure and a pair of electrodes, the layered structure including a cap layer, a magnetization pinned layer, a magnetization free layer, a spacer layer and a functional layer provided in the magnetization pinned layer, between the magnetization pinned layer and the spacer layer, between the spacer layer and the magnetization free layer, in the magnetization free layer, or between the magnetization free layer and the cap layer and including an oxide, the method including forming a film including a base material of the functional layer, performing an oxidation treatment on the film using a gas containing oxygen in a form of at least one selected from the group consisting of molecule, ion, plasma and radical, and performing a reduction treatment using a reducing gas on the film after the oxidation treatment.
    Type: Application
    Filed: February 10, 2014
    Publication date: June 5, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Akihiko TAKEO, Yoshihiko FUJI, Hiromi YUASA, Michiko HARA, Shuichi MURAKAMI, Hideaki FUKUZAWA
  • Publication number: 20140139952
    Abstract: According to one embodiment, there is provided a thin magnetic film having a negative anisotropy of ?6×106 erg/cm3 or less and including, on at least a nonmagnetic substrate, at least one seed layer made of a metal or metal compound, a ruthenium underlayer for controlling the orientation of an immediately overlying layer, and a magnetic layer having negative anisotropy in the normal line direction perpendicular to a surface of the magnetic layer and mainly containing Co and Ir, wherein the additive element concentration of Ir in the magnetic layer is 10 (inclusive) to 45 (inclusive) at %.
    Type: Application
    Filed: July 19, 2013
    Publication date: May 22, 2014
    Inventors: Akihiko Takeo, Akira Kikitsu, Tomoyuki Maeda, Migaku Takahashi, Shin Saito, Ken Inoue, Gohei Kurokawa