Patents by Inventor Hiroaki Nemoto
Hiroaki Nemoto 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: 20120225325Abstract: Surface flatness of magnetic recording medium to which a magnetic recording layer made of L10 FePt magnetic alloy thin film, with distance between a magnetic head and a magnetic recording medium sufficiently reduced. The magnetic recording layer includes: magnetic layers containing a magnetic alloy including Fe and Pt as principal materials; and one non-magnetic material selected from carbon, oxide and nitride. The first magnetic layer disposed closer to a substrate has a granular structure in which magnetic alloy grains including FePt alloy as the principal material are separated from grain boundaries including the non-magnetic material as the principal material. The second magnetic layer disposed closer to the surface than the first magnetic layer is fabricated so as to have a homogeneous structure in which an FePt alloy and the non-magnetic material are mixed in a state finer than diameters of the FePt magnetic alloy grains in the first magnetic layer.Type: ApplicationFiled: February 13, 2012Publication date: September 6, 2012Inventors: HIROAKI NEMOTO, Ikuko TAKEKUMA, Kimio NAKAMURA, Junichi SAYAMA
-
Publication number: 20120214021Abstract: There is provided a magnetic recording medium including an MgO underlayer that can be formed by a mass production process and has a thickness of 3 nm or less as well as including a magnetic recording layer made of an L10-type FePt ordered alloy having excellent magnetic properties. A conductive compound having a crystal structure belonging to a cubic system is used as a material of an underlayer provided at the bottom of the MgO underlayer. The thickness of the MgO layer is 1 nm or more and 3 nm or less.Type: ApplicationFiled: February 2, 2012Publication date: August 23, 2012Inventors: Junichi Sayama, Ikuko Takekuma, Hiroaki Nemoto
-
Patent number: 8247165Abstract: An immersion upper layer film composition is provided which exhibits sufficient transparency for the exposure wavelength 248 nm(KrF) and 193 nm(ArF), can form a protective film on the photoresist film without being intermixed with the photoresist film, is not eluted into water used during immersion exposure to maintain a stable film, and can be easily dissolved in an alkaline developer. The composition applied to coat on the photoresist film when using an immersion exposure device which is irradiated through water provided between a lens and the photoresist film, the composition comprises a resin forming a water-stable film during irradiation and being dissolved in a subsequent developer, and a solvent containing a monovalent alcohol having 6 or less carbon atoms, and the resin contains a resin component having an alcoholic hydroxyl group on the side chain containing a fluoroalkyl group on at least the carbon atom of ?-position.Type: GrantFiled: January 14, 2005Date of Patent: August 21, 2012Assignee: JSR CorporationInventors: Toru Kimura, Yukio Nishimura, Tomohiro Utaka, Hiroaki Nemoto, Atsushi Nakamura, Takashi Chiba, Hiroki Nakagawa
-
Patent number: 8169728Abstract: To avoid the occurrence of a recording error by suppressing the influence that a magneto-static interaction acting between the pattern dots exerts on a recording process and expand a margin for recording synchronization timing lag or tracking misregistration on the pattern dot. Each pattern dot has a structure in which a plurality of parts having different magnetization reversal fields are bonded with exchange interaction in the in-plane direction of a medium, substrate. The positional relationship between the parts having different magnetization reversal fields is substantially coincident between the adjacent pattern dots, which are arranged to have a gradient of magnetization reversal field in a track direction or track transverse direction. Further, the recording is performed by adapting a gradient of recording magnetic field to the gradient of magnetization reversal field. Other methods and systems are described as well.Type: GrantFiled: December 3, 2009Date of Patent: May 1, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hiroaki Nemoto, Hiroyuki Suzuki, Masae Suzuki, legal representative, Miki Hara, Yoshio Suzuki
-
Publication number: 20120052330Abstract: A perpendicular magnetic recording medium having sufficient perpendicular uniaxial magnetic anisotropy energy and a crystal grain size for realizing an areal recording density of one terabit or more per one square centimeter, and excellent in mass productivity, and a manufacturing method of the same are provided. On a substrate, a substrate-temperature control layer, an underlayer and a magnetic recording layer are sequentially formed. The magnetic recording layer is formed by repeating a magnetic layer stacking step N times (N?2), which includes a first step of heating the substrate in a heat process chamber, and a second step of depositing, in a deposition process chamber, the magnetic recording layer constituted of an alloy mainly composed of FePt to which at least one kind of non-magnetic material selected from a group constituted of C and an Si oxide is added.Type: ApplicationFiled: August 22, 2011Publication date: March 1, 2012Applicant: HITACHI, LTD.Inventors: Ikuko TAKEKUMA, Kimio NAKAMURA, Junichi SAYAMA, Hiroaki NEMOTO
-
Patent number: 8089829Abstract: A thermally assisted magnetic recording medium includes a substrate and at least two, i.e., first and second magnetic recording layers. These layers are hard magnetic layers and contain magnetic grains and a non-magnetic substance magnetically segregating the magnetic grains at grain boundaries. The first magnetic recording layer has a magnetic anisotropy energy Ku1, a grain volume v1, and energy for maintaining its recording magnetization Ku1v1; the second magnetic recording layer has a magnetic anisotropy energy Ku2, a grain volume v2, and energy for maintaining its recording magnetization Ku2v2; and the ratio Ku1v1/kBT of Ku1v1 to a thermal fluctuation energy kBT, where kB represents a Boltzmann constant and T represents an absolute temperature, and the ratio Ku2v2/kBT of Ku2v2 to kBT satisfy the following conditions: Ku1v1/kBT is larger than Ku2v2/kBT at room temperature, but is smaller than Ku2v2/kBT at temperatures around the Curie temperature of the first magnetic recording layer.Type: GrantFiled: October 29, 2009Date of Patent: January 3, 2012Assignee: Hitachi, Ltd.Inventors: Fumiko Akagi, Masukazu Igarashi, Hiroaki Nemoto, Takayuki Ichihara
-
Patent number: 8059497Abstract: In an information recording/reproducing method performing a thermo-magnetic recording, a tracking offset value of a recording light spot and/or a tracking offset value of a magnetic flux detecting element is changed in accordance with a radial position at which a tracking is performed at the present time, to make a direction of a magnetic wall of a recording magnetic domain in accord with a longitudinal direction of the magnetic flux detecting element. Alternatively, a shape of a heated area is changed to be in accord with the direction of the magnetic flux detecting means at respective radial position, to make the direction of the magnetic wall of the recording magnetic domain in accord with the longitudinal direction of the magnetic flux detecting element.Type: GrantFiled: February 23, 2010Date of Patent: November 15, 2011Assignee: Hitachi, Ltd.Inventors: Hiroaki Nemoto, Hideki Saga, Hirofumi Sukeda
-
Publication number: 20110122525Abstract: According to one embodiment, a magnetic recording medium includes a magnetic recording layer formed above a substrate, comprising: a first magnetic layer formed from a [Co/Pt]n multilayered film, wherein the first magnetic layer has a face-centered cubic (fcc) (111) crystal structure, the (111) direction being perpendicular to a film surface thereof, and a second magnetic layer comprising a CoCrPt or CoCrPt alloy film formed above the first magnetic layer, wherein the second magnetic layer has a hexagonal close packed (hcp) (00.1) crystal structure, the (00.1) direction being perpendicular to a film surface thereof. According to another embodiment, a system includes a magnetic recording medium as described above, a magnetic head for reading from and/or writing to the magnetic recording medium, a magnetic head slider for supporting the magnetic head, and a control unit coupled to the magnetic head for controlling operation of the magnetic head.Type: ApplicationFiled: November 2, 2010Publication date: May 26, 2011Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hiroaki Nemoto, Kiwamu Tanahashi, Hiroyuki Nakagawa
-
Publication number: 20110020669Abstract: A magnetic recording medium having excellent stability of recorded magnetic signals and capable of recording magnetic signals by a thermally assisted magnetic recording system in which a magnetic recording layer of the magnetic recording medium contains ferromagnetic crystal grains of a Co—Ni—Pt alloy with a Pt content of 44 at % or more and 55 at % or less and with an atom content ratio: Ni/(Co+Ni) of 0.64 or more and 0.8 or less. The magnetic recording medium has extremely excellent stability of recorded magnetic signals since the Co—Ni—Pt alloy constituting the magnetic recording layer has an extremely high anisotropy field at a normal temperature. Further, the magnetic recording medium can perform signal recording based on the thermally assisted magnetic recording system since the Co—Ni—Pt alloy constituting the magnetic recording layer has a Curie point within an appropriate temperature range.Type: ApplicationFiled: July 21, 2010Publication date: January 27, 2011Inventors: Junichi SAYAMA, Hiroaki Nemoto, Hiroshi Ide, Hiroyasu Kataoka, Nobuyukl Takahashi, Takehito Shimatsu, Osamu Kitakami, Satoshi Okamoto, Hajime Aoi
-
Publication number: 20100188769Abstract: In an information recording/reproducing method performing a thermo-magnetic recording, a tracking offset value of a recording light spot and/or a tracking offset value of a magnetic flux detecting element is changed in accordance with a radial position at which a tracking is performed at the present time, to make a direction of a magnetic wall of a recording magnetic domain in accord with a longitudinal direction of the magnetic flux detecting element. Alternatively, a shape of a heated area is changed to be in accord with the direction of the magnetic flux detecting means at respective radial position, to make the direction of the magnetic wall of the recording magnetic domain in accord with the longitudinal direction of the magnetic flux detecting element.Type: ApplicationFiled: February 23, 2010Publication date: July 29, 2010Applicant: HITACHI, LTD.Inventors: Hiroaki Nemoto, Hideki Saga, Hirofumi Sukeda
-
Publication number: 20100165500Abstract: In order to provide a thermal energy assisted medium capable of improving anti-sliding reliability over long periods of time in low flying head conditions, while also maintaining a high SNR, a unique medium is proposed. A soft magnetic layer is formed on a substrate, a soft magnetic layer is formed thereon via a non-magnetic intermediate layer, and an intermediate layer, a crystal oriented control intermediate layer, an artificial lattice intermediate layer having an artificial lattice film in which a first layer comprising Co and a second layer comprising Pt and Pd are laminated repeatedly to form a recording layer, and a cap layer and an lubricating layer are formed. The concentration of Pd comprising the second layer is from about 20 atomic % to about 40 atomic %. Other mediums and systems are also described.Type: ApplicationFiled: December 3, 2009Publication date: July 1, 2010Inventors: Hiroyuki Suzuki, Masae Suzuki, Hiroaki Nemoto, Hiroyuki Nakagawa, Takayuki Ichihara
-
Publication number: 20100142084Abstract: To avoid the occurrence of a recording error by suppressing the influence that a magneto-static interaction acting between the pattern dots exerts on a recording process and expand a margin for recording synchronization timing lag or tracking misregistration on the pattern dot. Each pattern dot has a structure in which a plurality of parts having different magnetization reversal fields are bonded with exchange interaction in the in-plane direction of a medium, substrate. The positional relationship between the parts having different magnetization reversal Fields is substantially coincident between the adjacent pattern dots, which are arranged to have a gradient of magnetization reversal field in a track direction or track transverse direction. Further, the recording is performed by adapting a gradient of recording magnetic field to the gradient of magnetization reversal field. Other methods and systems are described as well.Type: ApplicationFiled: December 3, 2009Publication date: June 10, 2010Inventors: Hiroaki Nemoto, Hiroyuki Suzuki, Masae Suzuki, Miki Hara, Yoshio Suzuki
-
Publication number: 20100110576Abstract: A thermally assisted magnetic recording medium includes a substrate and at least two, i.e., first and second magnetic recording layers. These layers are hard magnetic layers and contain magnetic grains and a non-magnetic substance magnetically segregating the magnetic grains at grain boundaries. The first magnetic recording layer has a magnetic anisotropy energy Ku1, a grain volume v1, and energy for maintaining its recording magnetization Ku1v1; the second magnetic recording layer has a magnetic anisotropy energy Ku2, a grain volume v2, and energy for maintaining its recording magnetization Ku2v2; and the ratio Ku1v1/kBT of Ku1v1 to a thermal fluctuation energy kBT, where kB represents a Boltzmann constant and T represents an absolute temperature, and the ratio Ku2v2/kBT of Ku2v2 to kBT satisfy the following conditions: Ku1v1/kBT is larger than Ku2v2/kBT at room temperature, but is smaller than Ku2v2/kBT at temperatures around the Curie temperature of the first magnetic recording layer.Type: ApplicationFiled: October 29, 2009Publication date: May 6, 2010Inventors: Fumiko AKAGI, Masukazu IGARASHI, Hiroaki NEMOTO, Takayuki ICHIHARA
-
Patent number: 7701667Abstract: Embodiments in accordance with the present invention provide a perpendicular recording medium with low noise and high recording density by reducing the effects from noise generated from the vicinity of the interface with the intermediate layer of the recording layer, in a perpendicular recording medium utilizing a granular recording layer containing oxygen or oxide additive in a cobalt-chromium alloy formed on an intermediate layer with a ruthenium or ruthenium alloy layer. A first recording layer and a second recording layer are formed in order on an intermediate layer of ruthenium or ruthenium alloy. The first recording layer and the second recording layer are comprised of cobalt as the main material in a granular structure containing chromium and oxygen. The saturation magnetization of the first recording layer is lower than the saturation magnetization of the second recording layer.Type: GrantFiled: January 9, 2007Date of Patent: April 20, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Ichiro Tamai, Ikuko Takekuma, Hiroaki Nemoto, Yoshiyuki Hirayama
-
Patent number: 7688685Abstract: In an information recording/reproducing method performing a thermo-magnetic recording, a tracking offset value of a recording light spot and/or a tracking offset value of a magnetic flux detecting element is changed in accordance with a radial position at which a tracking is performed at the present time, to make a direction of a magnetic wall of a recording magnetic domain in accord with a longitudinal direction of the magnetic flux detecting element. Alternatively, a shape of a heated area is changed to be in accord with the direction of the magnetic flux detecting means at respective radial position, to make the direction of the magnetic wall of the recording magnetic domain in accord with the longitudinal direction of the magnetic flux detecting element.Type: GrantFiled: March 1, 2000Date of Patent: March 30, 2010Assignee: Hitachi, Ltd.Inventors: Hiroaki Nemoto, Hideki Saga, Hirofumi Sukeda
-
Patent number: 7625646Abstract: Disclosed are a perpendicular magnetic recording medium with lower medium noise, insusceptible to thermal fluctuation and high recording resolution and a method of manufacturing it. As the step of forming a metal layer at the time of forming a recording layer on a non-magnetic substrate via a plurality of underlayers and the step of forming an oxide layer with an average thickness of 0.2 nm or less are repeated, the crystal grains are magnetically isolated without disturbing the orientation of the crystal grain of the recording layer of the perpendicular magnetic recording medium or without degrading the magnetic characteristic of the crystal grain of the recording layer.Type: GrantFiled: February 15, 2006Date of Patent: December 1, 2009Assignee: Hitachi Global Storage Technologies Japan, Ltd.Inventors: Yoshiyuki Hirayama, Ichiro Tamai, Takayuki Ichihara, Hiroyuki Nakagawa, Hiroaki Nemoto, Mineaki Kodama, Ikuko Takekuma
-
Patent number: 7580111Abstract: An immersion exposure liquid which exhibits a high refractive index, prevents elution and dissolution of a photoresist film or its upper layer film component, and reduces defects during formation of a resist pattern when used in an immersion exposure method, and an immersion exposure method using the immersion exposure liquid. The immersion exposure liquid is used for an immersion exposure device or an immersion exposure method in which a substrate is exposed through a liquid provided between a lens of a projection optical system and the substrate, the immersion exposure liquid being liquid in an operating temperature range of the immersion exposure device and including an alicyclic hydrocarbon compound or a cyclic hydrocarbon compound containing a silicon atom in the ring structure.Type: GrantFiled: May 19, 2005Date of Patent: August 25, 2009Assignee: JSR CorporationInventors: Takashi Miyamatsu, Hiroaki Nemoto, Yong Wang
-
Publication number: 20090195924Abstract: Embodiments of the present invention help allow accurate control of the magnetization reversal in a magnetic recording layer in small reversal units, whereby high-density recording can be achieved. According to one embodiment, by forming an intermediate layer having a granular structure similar to that of the magnetic recording layer below the magnetic recording layer, a continuous crystal grain boundary is formed at the interface between the magnetic recording layer and the intermediate layer, thereby preventing incomplete formation of the crystal grain boundary found in the initial growth layer of the magnetic recording layer. The intermediate layer comprises a non-magnetic alloy comprising Co and Cr as its main components and an oxide such as Al, Cr, Hf. Mg, Nb, Si, Ta, Ti and Zr. Further, the average content of the oxygen element in the intermediate layer is in the range from 6 at % to 20 at %.Type: ApplicationFiled: October 21, 2008Publication date: August 6, 2009Inventors: Hiroaki Nemoto, Ikuko Takekuma, Ichiro Tamai, Yoshiyuki Hirayama
-
Publication number: 20090116137Abstract: Embodiments of the present invention provide a perpendicular magnetic recoding medium capable of decreasing exchange coupling between crystal grains while suppressing increase in the crystal grain size of the magnetic recording layer. According to one embodiment, a perpendicular magnetic recoding medium is formed by stacking a seed layer, an intermediate layer, a magnetic recording layer, and a protecting layer all above a substrate. The magnetic recording layer has a granular structure constituted of a plurality of columnar grains comprising a CoCrPt alloy and a grain boundary containing an oxide.Type: ApplicationFiled: October 21, 2008Publication date: May 7, 2009Inventors: Ikuko Takekuma, Hiroaki Nemoto, Hiroyuki Nakagawa
-
Patent number: 7510789Abstract: A perpendicular magnetic recording medium includes an intermediate film formed of a plurality of layers between a soft magnetic film and a perpendicular magnetization film. The intermediate film includes at least two layers, i.e., an oxygen-containing layer, or a nonmetallic element-containing layer containing nitrogen, silicon or carbon, and a metallic layer formed on a surface side of the oxygen-containing layer or the nonmetallic element-containing layer. The metallic layer includes a plurality of isolated island-shaped structures. Crystal grains of the perpendicular magnetization film are formed so as to correspond to the isolated island-shaped structures. As a result, a high recording density is obtained.Type: GrantFiled: June 9, 2005Date of Patent: March 31, 2009Assignee: Hitachi Global Storage Technologies Japan, Ltd.Inventors: Yoshiyuki Hirayama, Hiroyuki Nakagawa, Hiroaki Nemoto, Ichiro Tamai, Ikuko Takekuma