Patents by Inventor Masatoshi Sakurai

Masatoshi Sakurai 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).

  • Method of manufacturing magnetic recording medium
    Patent number: 8029682
    Abstract: According to one embodiment, a method of manufacturing a magnetic recording medium includes forming a first hard mask, a second hard mask and a resist on a magnetic recording layer, imprinting a stamper to the resist to transfer patterns of protrusions and recesses to the resist, removing residues remaining in the recesses of the patterned resist, etching the second hard mask by using the patterned resist as a mask to transfer the patterns of protrusions and recesses to the second hard mask, etching the first hard mask by using the second hard mask as a mask to transfer the patterns of protrusions and recesses to the first hard mask, subjecting the magnetic recording layer exposed in the recesses to modifying treatment to change an etching rate, and deactivating the magnetic recording layer exposed in the recesses.
    Type: Grant
    Filed: February 12, 2010
    Date of Patent: October 4, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yousuke Isowaki, Kaori Kimura, Yoshiyuki Kamata, Masatoshi Sakurai
  • METHOD OF MANUFACTURING MAGNETIC RECORDING MEDIUM
    Publication number: 20110235212
    Abstract: According to one embodiment, a method of manufacturing a magnetic recording medium includes forming on a magnetic recording layer a first hard mask, a second hard mask, a third hard mask and a resist, imprinting the resist with a stamper, removing a residue left in the recesses of the patterned resist, etching the third hard mask by use of the patterned resist as a mask, etching the second hard mask by use of the third hard mask as a mask, etching the first hard mask by use of the second hard mask as a mask, forming a pattern of the magnetic recording layer with ion beam irradiation, and removing the first hard mask by use of a remover liquid with higher reactivity to the metal material of the first hard mask than to a constituent element of the magnetic recording layer.
    Type: Application
    Filed: January 14, 2011
    Publication date: September 29, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Masatoshi Sakurai, Kaori Kimura, Yousuke Isowaki, Akira Watanabe, Yoshiyuki Kamata
  • MAGNETIC RECORDING DEVICE, MAGNETIC RECORDING METHOD, AND MAGNETIC STORAGE MEDIUM
    Publication number: 20110222186
    Abstract: According to one embodiment, a magnetic recording device based on shingled-write recording method comprises a magnetic storage medium, a recording head, and an actuator. The magnetic storage medium comprises dot rows wherein a phase shift is between adjacent rows. The recording head covers a predetermined number of dot rows of the magnetic storage medium and comprises an edge at one of the dot rows. The actuator configured to move a recording head by an amount equivalent to a dot row after recording is performed on one of the dot rows by the recording head.
    Type: Application
    Filed: March 9, 2011
    Publication date: September 15, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Akihiro Itakura, Masatoshi Sakurai, Kazuhito Shimomura
  • Method of manufacturing magnetic recording medium and magnetic recording medium
    Patent number: 8017023
    Abstract: According to one embodiment, a method of manufacturing a magnetic recording medium includes forming a resist on a magnetic recording layer, imprinting a stamper to the resist to transfer patterns of protrusions and recesses, and partially etching the magnetic recording layer in areas not covered with patterns of the resist used as masks by ion beam etching using a mixed gas of He and N2 as well as modifying a remainder of the magnetic recording layer to leave behind a nonmagnetic layer having a reduced thickness.
    Type: Grant
    Filed: September 14, 2010
    Date of Patent: September 13, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiyuki Kamata, Kaori Kimura, Yousuke Isowaki, Masatoshi Sakurai
  • Method of manufacturing magnetic recording medium
    Patent number: 8012361
    Abstract: According to one embodiment, a method of manufacturing a magnetic recording medium includes forming a first hard mask, a second hard mask and a resist on a magnetic recording layer, imprinting a stamper to the resist to transfer patterns of protrusions and recesses to the resist, removing residues remaining in the recesses of the patterned resist, etching the second hard mask by using the patterned resist as a mask to transfer the patterns of protrusions and recesses to the second hard mask, etching the first hard mask by using the second hard mask as a mask to transfer the patterns of protrusions and recesses to the first hard mask, removing the second hard mask remaining on the protrusions of the first hard mask, and deactivating the magnetic recording layer exposed in the recesses by means of ion beam irradiation.
    Type: Grant
    Filed: February 12, 2010
    Date of Patent: September 6, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kaori Kimura, Yousuke Isowaki, Yoshiyuki Kamata, Masatoshi Sakurai
  • Method of manufacturing magnetic recording medium and magnetic recording medium
    Patent number: 8002997
    Abstract: According to one embodiment, a method of manufacturing a magnetic recording medium includes forming a resist on a magnetic recording layer, imprinting a stamper to the resist to transfer patterns of protrusions and recesses, and partially etching the magnetic recording layer in areas not covered with patterns of the resist used as masks by ion beam etching using a mixed gas of He and N2 as well as modifying a remainder of the magnetic recording layer to leave behind a nonmagnetic layer having a reduced thickness.
    Type: Grant
    Filed: August 20, 2009
    Date of Patent: August 23, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiyuki Kamata, Kaori Kimura, Yousuke Isowaki, Masatoshi Sakurai
  • Method of manufacturing magnetic recording medium
    Patent number: 7993536
    Abstract: According to one embodiment, a method of manufacturing a magnetic recording medium includes forming a first hard mask, a second hard mask and a resist film on a magnetic recording layer, imprinting a stamper on the resist film to transfer patterns of recesses and protrusions, removing residues remained in recess of the patterned resist film, etching the second hard mask using the patterned resist film as a mask to transfer patterns of recesses and protrusions, etching the first hard mask using the patterned second hard mask as a mask to transfer patterns of recesses and protrusions, and deactivating magnetism of the magnetic recording layer exposed in the recesses together with removing the second hard mask by ion-beam etching.
    Type: Grant
    Filed: December 11, 2009
    Date of Patent: August 9, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yousuke Isowaki, Kaori Kimura, Yoshiyuki Kamata, Masatoshi Sakurai
  • Magnetic recording medium with magnetic film pattern sidewalls having at least two faces of different slope angles and magnetic recording apparatus having the same
    Patent number: 7983004
    Abstract: According to one embodiment, there is provided a magnetic recording media including a substrate, and a magnetic recording layer including magnetic film patterns formed in a protruded form on the substrate, sidewalls of the magnetic film patterns having at least two faces of different slope angles.
    Type: Grant
    Filed: July 2, 2007
    Date of Patent: July 19, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Satoshi Shirotori, Masatoshi Sakurai, Yoshiyuki Kamata, Akira Kikitsu
  • Magnetic recording medium, method of fabricating the same, and magnetic recording apparatus
    Patent number: 7978434
    Abstract: A magnetic recording medium includes recording regions formed on a substrate, isolation regions formed between the recording regions so as to define the recording regions, and recording dots formed of a dot-like magnetic recording layer and arrayed in the recording regions, the recording dots including first recording dots arrayed in a line in each edge part of each recording region along the isolation region and second recording dots arrayed into a regular lattice in a central part of each recording region. A distance between a first recording dot and a second recording dot which are nearest neighboring is larger than a distance between second recording dots which are nearest neighboring.
    Type: Grant
    Filed: September 18, 2007
    Date of Patent: July 12, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kaori Kimura, Masatoshi Sakurai, Yoshiyuki Kamata
  • SUBSTRATE FOR MAGNETIC RECORDING MEDIUM, MAGNETIC RECORDING MEDIUM, AND MAGNETIC RECORDING AND REPRODUCING APPARATUS
    Publication number: 20110164337
    Abstract: In an example magnetic recording medium substrate, a plurality of recording tracks are formed on a substrate, each recording track being formed of a magnetic material. Non-recording sections are formed on the substrate, each non-recording section separating adjacent recording tracks. Each recording track includes a plurality of recording sections and connecting sections for connecting the recording sections adjacent thereto in a track longitudinal direction, and each connecting section has a cross-sectional area in a track width direction that is smaller than a cross-sectional area in a track width direction of adjacent recording sections.
    Type: Application
    Filed: March 14, 2011
    Publication date: July 7, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kaori KIMURA, Masatoshi SAKURAI, Akira KIKITSU, Yoshiyuki KAMATA, Satoshi SHIROTORI, Hiroyuki HIEDA
  • METHOD OF MANUFACTURING DISCRETE TRACK RECORDING MEDIUM AND DISCRETE TRACK RECORDING MEDIUM
    Publication number: 20110165438
    Abstract: According to one embodiment, a method of manufacturing a discrete track recording medium includes forming protruded magnetic patterns on a substrate, and repeating processes of depositing a nonmagnetic material so as to be filled in recesses between the magnetic patterns and etching back the nonmagnetic material two or more times with rotating the substrate in a plane thereof by an angle less than one revolution.
    Type: Application
    Filed: March 15, 2011
    Publication date: July 7, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yoshiyuki Kamata, Satoshi Shirotori, Kaori Kimura, Masatoshi Sakurai
  • Method of manufacturing magnetic recording medium
    Patent number: 7972523
    Abstract: According to one embodiment, a method of manufacturing a magnetic recording medium includes forming a magnetic recording layer, an oxidation inhibiting layer, a hard mask layer includes carbon on a substrate, coating the hard mask layer with a resist, transferring patterns of protrusions and recesses to the resist by imprinting to form resist patterns, sequentially performing etching of the hard mask layer using the resist patterns as masks, etching of the oxidation inhibiting layer, and etching and/or magnetism deactivation of the magnetic recording layer to form patterns of the magnetic recording layer, and sequentially performing stripping of the resist patterns, stripping of the hard mask layer and stripping of the oxidation inhibiting layer, in which ion beam etching is used for stripping the oxidation inhibiting layer.
    Type: Grant
    Filed: July 24, 2009
    Date of Patent: July 5, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kaori Kimura, Yousuke Isowaki, Yoshiyuki Kamata, Masatoshi Sakurai
  • Method of manufacturing magnetic recording medium
    Patent number: 7967993
    Abstract: According to one embodiment, a method of manufacturing a magnetic recording medium includes forming a hard mask and a resist on a magnetic recording layer, imprinting a stamper on the resist to transfer patterns of protrusions and recesses, removing resist residues left in the recesses of the patterned resist, etching the hard mask using the patterned resist as a mask to transfer the patterns of protrusions and recesses, stripping the resist, and performing ion beam etching to remove the remaining hard mask and to modify a surface of the magnetic recording layer uncovered with the remaining hard mask.
    Type: Grant
    Filed: July 23, 2009
    Date of Patent: June 28, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yousuke Isowaki, Kaori Kimura, Yoshiyuki Kamata, Masatoshi Sakurai
  • PERPENDICULAR MAGNETIC RECORDING MEDIUM, METHOD OF MANUFACTURING THE SAME, AND MAGNETIC READ/WRITE APPARATUS
    Publication number: 20110132754
    Abstract: According to one embodiment, patterns of protrusions and recesses includes a substrate including a conductive region on at least one major surface, and a projecting pattern layer formed on the conductive region on the major surface, and made of a microcrystalline material, a polycrystalline material, an amorphous material, or an oxide of the microcrystalline, polycrystalline, or amorphous material.
    Type: Application
    Filed: November 19, 2010
    Publication date: June 9, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Satoshi Shirotori, Yoshiyuki Kamata, Takuya Shimada, Masatoshi Sakurai
  • PERPENDICULAR MAGNETIC RECORDING MEDIUM, METHOD OF MANUFACTURING THE SAME, AND MAGNETIC READ/WRITE APPARATUS
    Publication number: 20110132752
    Abstract: According to one embodiment, an electroforming master comprises a patterns of protrusions and recesses formed on one major surface of an Si substrate having two major surfaces, corresponding to information for positioning of a read/write head (a preamble, address, and burst), recording tracks or recording bits. Impurity ions are doped in the surface of this patterns of protrusions and recesses. The impurity ion concentration distribution in the film thickness direction of the Si substrate has a peak in a portion from the patterns of protrusions and recesses surface to a depth of 40 nm in the film thickness direction. The impurity concentration of this peak is 1×1020 to 2×1021 ions/cm3.
    Type: Application
    Filed: December 6, 2010
    Publication date: June 9, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Satoshi SHIROTORI, Akira WATANABE, Yoshiyuki KAMATA, Masatoshi SAKURAI
  • Method of manufacturing stamper
    Patent number: 7938978
    Abstract: According to one embodiment, a method of manufacturing a stamper includes forming a first stamper from a master plate having lands and grooves through electroforming, forming a second stamper, a width of which is GW, from the first stamper through electroforming, forming a lamination film with a thickness of LLT on the second stamper, forming, on the lamination film, a second releasing layer, a transfer layer with a thickness of TLT and a third electroforming layer with a thickness of ELT, peeling off the transfer layer and the third electroforming layer from the second stamper to form a third stamper, and isotropically etching the transfer layer on the third stamper in an etching thickness of ET to reduce a width of lands of the third stamper, in which the following relations are satisfied: 10 nm?ELT and ET?TLT.
    Type: Grant
    Filed: January 21, 2010
    Date of Patent: May 10, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takuya Shimada, Shinobu Sugimura, Yoshiyuki Kamata, Masatoshi Sakurai
  • Substrate for magnetic recording medium, magnetic recording medium, and magnetic recording and reproducing apparatus
    Patent number: 7936537
    Abstract: It is possible to improve the recording and reproducing S/N ratio, the reproduction signal intensity, and the degree of high density recording. There are provided a plurality of recording tracks formed on a substrate, each recording track being formed of a magnetic material, and non-recording sections formed on the substrate, each non-recording section separating adjacent recording tracks, each recording track including a plurality of recording sections and connecting sections for connecting the recording sections adjacent thereto in a track longitudinal direction, and each connecting section having a cross-sectional area in a track width direction that is smaller than a cross-sectional area in a track width direction of adjacent recording sections.
    Type: Grant
    Filed: July 15, 2009
    Date of Patent: May 3, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kaori Kimura, Masatoshi Sakurai, Akira Kikitsu, Yoshiyuki Kamata, Satoshi Shirotori, Hiroyuki Hieda
  • Disk drive having a disk of discrete-track media type
    Patent number: 7933088
    Abstract: According to one embodiment, a disk drive has a DTM type disk. The DTM type disk has a servo area on one recording surface. In the servo area, a servo pattern is recorded. The servo pattern is composed of a projection-depression pattern and an N- and P-pole magnetic pattern. The N- and P-pole magnetic pattern is recorded in an address-data region that contains a cylinder code.
    Type: Grant
    Filed: December 18, 2008
    Date of Patent: April 26, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideo Sado, Masatoshi Sakurai, Yuji Sakai
  • Method of manufacturing discrete track recording medium and discrete track recording medium
    Patent number: 7927467
    Abstract: According to one embodiment, a method of manufacturing a discrete track recording medium includes forming protruded magnetic patterns on a substrate, and repeating processes of depositing a nonmagnetic material so as to be filled in recesses between the magnetic patterns and etching back the nonmagnetic material two or more times with rotating the substrate in a plane thereof by an angle less than one revolution.
    Type: Grant
    Filed: March 9, 2009
    Date of Patent: April 19, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiyuki Kamata, Satoshi Shirotori, Kaori Kimura, Masatoshi Sakurai
  • MAGNETIC RECORDING MEDIUM, METHOD OF FABRICATING THE SAME, AND MAGNETIC RECORDING APPARATUS
    Publication number: 20110085268
    Abstract: According to one embodiment, there is provided a magnetic recording medium having a data region in which a plurality of recording tracks, each including magnetic dots arrayed in a down-track direction with a pitch p, are formed in a cross-track direction, and a servo region including a preamble in which a plurality of lines of magnetic dots, which are arrayed in a cross-track direction with a pitch p, are formed at equal intervals in the down-track direction.
    Type: Application
    Filed: December 20, 2010
    Publication date: April 14, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masatoshi Sakurai, Kazuto Kashiwagi, Akira Kikitsu