Patents by Inventor Yoshiyuki Kamata

Yoshiyuki Kamata 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: 20130077191
    Abstract: A magnetic disk according to an embodiment includes: a plurality of data regions each including a plurality of tracks, each of the tracks being arranged to extend in a circumferential direction; a servo region provided between the data regions, the servo region extending in a radial direction, the servo region including: a plurality of guide patterns each extending in the radial direction; and at least one line of dots arranged by post patterns in the radial direction at least on a side of one of adjacent guide patterns, the post patterns being arranged in the radial direction between the adjacent guide patterns.
    Type: Application
    Filed: June 29, 2012
    Publication date: March 28, 2013
    Inventors: TAKESHI OKINO, NAOKO KIHARA, YOSHIYUKI KAMATA
  • Publication number: 20130075361
    Abstract: A pattern forming method according to an embodiment includes: forming a pattern film on a first substrate, the pattern film having a concave-convex pattern, the pattern film being made of a material containing a first to-be-imprinted agent; forming a material film on a second substrate, the material film containing a second to-be-imprinted agent having a higher etching rate than an etching rate of the first to-be-imprinted agent; transferring the concave-convex pattern of the pattern film onto the material film by applying pressure between the first substrate and the second substrate, with the pattern film being positioned to face the material film, and by curing the second to-be-imprinted agent; detaching the first substrate from the pattern film; and removing the material film by etching, to leave the pattern film on the second substrate.
    Type: Application
    Filed: June 20, 2012
    Publication date: March 28, 2013
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yoshiaki KAWAMONZEN, Yasuaki OOTERA, Akiko YUZAWA, Naoko KIHARA, Yoshiyuki KAMATA, Hiroyuki HIEDA, Norikatsu SASAO, Ryosuke YAMAMOTO, Takeshi OKINO, Tomoyuki MAEDA, Takuya SHIMADA
  • Publication number: 20130075358
    Abstract: A magnetic recording medium a magnetic recording medium includes a soft magnetic layer formed on a substrate, magnetic patterns made of a protruded ferromagnetic layer separated from each other on the soft magnetic layer, and a nonmagnetic layer formed between the magnetic patterns, a nitrogen concentration therein being higher on a surface side than on a substrate side.
    Type: Application
    Filed: November 15, 2012
    Publication date: March 28, 2013
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kaori KIMURA, Yoshiyuki KAMATA, Satoshi SHIROTORI, Tsuyoshi ONITSUKA
  • Publication number: 20130069272
    Abstract: In one embodiment, a method of manufacturing a mold includes: forming a first layer having an affinity to a second polymer on a substrate having an affinity to a first polymer; forming first and second openings in the first layer; filling a resist in the second openings and hardening the resist to obtain a hardened resist; and forming a second layer containing a block copolymer and causing it to self-assemble.
    Type: Application
    Filed: March 19, 2012
    Publication date: March 21, 2013
    Inventors: Yasuaki OOTERA, Yoshiyuki KAMATA, Naoko KIHARA, Yoshiaki KAWAMONZEN, Takeshi OKINO, Ryosuke YAMAMOTO, Tomoyuki MAEDA, Norikatsu SASAO, Akiko YUZAWA, Takuya SHIMADA, Hiroyuki Hieda
  • Patent number: 8372253
    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: Grant
    Filed: November 19, 2010
    Date of Patent: February 12, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Satoshi Shirotori, Yoshiyuki Kamata, Takuya Shimada, Masatoshi Sakurai
  • Patent number: 8349163
    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: Grant
    Filed: December 6, 2010
    Date of Patent: January 8, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Satoshi Shirotori, Akira Watanabe, Yoshiyuki Kamata, Masatoshi Sakurai
  • Publication number: 20130004724
    Abstract: In one embodiment, there is provided a master for producing a stamper. The master includes: a substrate made of a first material and comprising a first surface, wherein the first surface of the substrate is formed with a groove; a first layer made of a second material and formed in the groove, wherein the second material is different from the first material, and wherein a surface of the first layer is substantially flush with the first surface of substrate; and a projection portion formed on at least one of the first surface of the substrate and the surface of the first layer. The first material is silicon and the second material is selected from silicon oxide, aluminum oxide, titanium oxide, and glass.
    Type: Application
    Filed: September 13, 2012
    Publication date: January 3, 2013
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Saori Kashiwada, Yuichi Ohsawa, Junichi Ito, Chikayoshi Kamata, Yoshiyuki Kamata
  • Patent number: 8343362
    Abstract: According to one embodiment, when forming first, second, and third stampers by transferring three-dimensional patterns of a master, a height adjusting layer having a film thickness greater on the upper surface of a projection than on the bottom surface of a recess is formed between the second stamper and a second release layer, and the surface of the third stamper is etched with an acidic solution having a pH of less than 3.
    Type: Grant
    Filed: December 17, 2009
    Date of Patent: January 1, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takuya Shimada, Shinobu Sugimura, Yoshiyuki Kamata, Masatoshi Sakurai
  • Patent number: 8338007
    Abstract: A magnetic recording medium a magnetic recording medium includes a soft magnetic layer formed on a substrate, magnetic patterns made of a protruded ferromagnetic layer separated from each other on the soft magnetic layer, and a nonmagnetic layer formed between the magnetic patterns, a nitrogen concentration therein being higher on a surface side than on a substrate side.
    Type: Grant
    Filed: September 26, 2008
    Date of Patent: December 25, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kaori Kimura, Yoshiyuki Kamata, Satoshi Shirotori, Tsuyoshi Onitsuka
  • Patent number: 8333899
    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: Grant
    Filed: January 14, 2011
    Date of Patent: December 18, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masatoshi Sakurai, Kaori Kimura, Yousuke Isowaki, Akira Watanabe, Yoshiyuki Kamata
  • Patent number: 8318331
    Abstract: According to one embodiment, a magnetic recording medium includes a substrate, and a magnetic recording layer formed on the substrate and having patterns of protrusions and recesses corresponding to a servo area and a recording area, in which the magnetic recording layer located in each of the recesses in the recording area has a thickness smaller than two thirds of a thickness of the magnetic recording layer corresponding to each of the protrusions, the magnetic recording layer remaining in each of the recesses in the recording area has a thickness of 1 nm or more, and a difference in height on a surface of the magnetic recording medium is 7 nm or less.
    Type: Grant
    Filed: November 20, 2007
    Date of Patent: November 27, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masatoshi Sakurai, Yoshiyuki Kamata, Satoshi Shirotori
  • Patent number: 8308965
    Abstract: According to one embodiment, a stamper manufacturing method includes forming a conductive material concentration gradient layer including the projections pattern, and a composition ratio of a buffering agent to a conductive material in the conductive material concentration gradient layer reducing in a thickness direction from a master side.
    Type: Grant
    Filed: April 25, 2011
    Date of Patent: November 13, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masatoshi Sakurai, Satoshi Shirotori, Seiji Morita, Shinobu Sugimura, Takuya Shimada, Yoshiyuki Kamata
  • Patent number: 8298690
    Abstract: A magnetic recording medium includes a disk substrate, and recording cells arrayed on the disk substrate in a track direction, the recording cells includes a ferromagnetic pattern and a magnetic pattern formed on one of two sidewalls of the ferromagnetic pattern in the track direction and having a lower crystalline magnetic anisotropy constant Ku than that of the ferromagnetic pattern.
    Type: Grant
    Filed: November 20, 2008
    Date of Patent: October 30, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroyuki Hieda, Kazuto Kashiwagi, Akira Kikitsu, Yousuke Isowaki, Yoshiyuki Kamata
  • Patent number: 8300340
    Abstract: According to one embodiment, a servo area of a magnetic recording medium includes magnetic dots arrayed at a period L0. The magnetic dots include a plurality of magnetic dot regions divided in the cross track direction. A width Wm in the down track direction of the mth magnetic dot region from the innermost circumference and a number Nm of dot rows in the down track direction of the mth region meet a relationship represented by L0{Nm?3/2?0.3}?Wm?L0{Nm?3/2+0.3}??(1).
    Type: Grant
    Filed: March 2, 2011
    Date of Patent: October 30, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masatoshi Sakurai, Ryosuke Yamamoto, Naoko Kihara, Akiko Yuzawa, Yoshiyuki Kamata
  • Publication number: 20120251655
    Abstract: According to one embodiment, a stamper is described with a surface that comprises patterns of protrusions and recessed. The arithmetic average roughness Ra of the surface is 1 nanometer (nm) or more and 5 nm or less.
    Type: Application
    Filed: June 8, 2012
    Publication date: October 4, 2012
    Inventors: Shinobu Sugimura, Kaori Kimura, Takuya Shimada, Yoshiyuki Kamata, Masatoshi Sakurai
  • Patent number: 8257560
    Abstract: A patterned media has a substrate, and a magnetic recording layer on the substrate including protruded magnetic patterns and a nonmagnetic material filled in between the protruded magnetic patterns. In the patterned media, a depth Db and a depth Da, which are defined that Db is a depth from a surface of the magnetic patterns to a surface of the nonmagnetic material filled in a first central part between the magnetic patterns adjacent to each other in a cross-track direction or a down-track direction, and Da is a depth from a surface of the magnetic patterns to a surface of the nonmagnetic material filled in a second central part in a portion surrounded by the magnetic patterns, have a relationship that the depth Da is greater than the depth Db.
    Type: Grant
    Filed: August 2, 2010
    Date of Patent: September 4, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiyuki Kamata, Masatoshi Sakurai, Satoshi Shirotori, Kaori Kimura
  • Patent number: 8221637
    Abstract: According to one embodiment, a method for manufacturing a magnetic recording medium includes forming patterns having protrusions and recesses of a ferromagnetic material onto a recording track section and a servo section on a substrate, forming a flattening film, a top surface of which is higher than that of the protrusion of the ferromagnetic material, onto the ferromagnetic material, and performing ion beam etching onto the flattening film up to a top surface of the protrusion of the ferromagnetic material, and determining an end point of flattening etching on the basis of a change in the total number of incident particles by means of an ion counter installed so as to be at an angle ? with respect to a perpendicular direction to the substrate in accordance with a material of the flattening film.
    Type: Grant
    Filed: July 2, 2010
    Date of Patent: July 17, 2012
    Assignees: Kabushiki Kaisha Toshiba, Showa Denko K.K.
    Inventors: Yoshiyuki Kamata, Katsuyuki Naito, Akira Kikitsu, Masatoshi Sakurai, Masahiro Oka
  • Publication number: 20120177948
    Abstract: According to one embodiment, a method of manufacturing a patterned medium includes depositing a magnetic recording layer and applying an ultraviolet curable resin on both surfaces of a medium substrate, pressing a first resin stamper and a second resin stamper each including patterns of recesses and protrusions, corresponding to a patterned medium, against both surfaces of the medium substrate in such a manner that a direction from a center of the medium substrate toward a center of the first resin stamper is off-oriented from a direction from the center of the medium substrate toward a center of the second resin stamper to imprint the patterns of recesses and protrusions on the ultraviolet curable resin, and irradiating the ultraviolet curable resin with an ultraviolet ray through each of the first and second resin stampers to cure the ultraviolet curable resin.
    Type: Application
    Filed: March 19, 2012
    Publication date: July 12, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Akira Kikitsu, Yoshiyuki Kamata, Masatoshi Sakurai
  • Patent number: 8206602
    Abstract: According to one embodiment, there is provided a method of manufacturing a magnetic recording medium, including forming a first hard mask including carbon as a main component, a second hard mask including a main component other than carbon and a resist on a magnetic recording layer, contacting a stamper to the resist to transfer patterns of protrusions and recesses to the resist, removing residues in the recesses of the patterned resist, etching the second hard mask, etching the first hard mask, patterning the magnetic recording layer, and removing the first hard mask, the method further including, between etching the first hard mask and removing the first hard mask, removing the second hard mask remaining on the protrusions of the first hard mask, and removing a contaminating layer on a surface of the first hard mask by a mixed gas of oxygen-based gas and a fluorine compound.
    Type: Grant
    Filed: July 16, 2010
    Date of Patent: June 26, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kaori Kimura, Yousuke Isowaki, Yoshiyuki Kamata, Masatoshi Sakurai
  • Publication number: 20120118853
    Abstract: According to one embodiment, a method for manufacturing a master disk for discoid patterned medium having a plurality of sectors arranged in a circumferential direction, the plurality of sectors including a recording data portion and a servo data portion that includes a sector identification region having gaps formed in a linear pattern is provided. An imprint master disk having a linear pattern which is common to the sectors before the gaps are formed in the sector identification region and including at least one pattern of the sector is prepared, imprinting is repeated in the circumferential direction by using the imprint master disk to form patterns of a discoid patterned medium on a substrate, and a sector identification pattern is formed in each sector by forming gaps in the linear pattern of each sector identification region among the patterns formed on the substrate.
    Type: Application
    Filed: January 24, 2012
    Publication date: May 17, 2012
    Inventors: Munehiro OGASAWARA, Yoshiyuki KAMATA, Akira KIKITSU