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: 20090073599Abstract: Embodiments of the present invention provide a perpendicular magnetic recording medium suitable for high density recording. According to one embodiment, a magnetic recording layer comprises four layers in which a first magnetic layer, a magnetic coupling layer, a second magnetic layer, and a third magnetic layer are formed above a substrate. The first magnetic layer and the second magnetic layer are perpendicular magnetization films containing an oxide, and ferromagnetically coupled with each other by way of the magnetic coupling layer, and they are, more preferably, a Co alloy layer containing an oxide. The third magnetic layer is ferromagnetically coupled with the second magnetic layer. The concentration of the oxide contained in the third magnetic layer is lower than the concentration of the oxide in the second recording layer, or the third magnetic layer does not contain the oxide.Type: ApplicationFiled: September 2, 2008Publication date: March 19, 2009Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hiroaki Nemoto, Ikuko Takekuma, Zhengang Zhang
-
Patent number: 7457064Abstract: Embodiments in accordance with the present invention provide a perpendicular magnetic recording medium which is easy to record, offers superior thermal stability of recording magnetization, and allows high-density recording. In one embodiment, a perpendicular magnetic layer with controlled magnetic properties is used as a magnetic storage layer of a perpendicular magnetic recording medium, the magnetic properties having been controlled such that an indicator ?hsw [%] of the dispersion of magnetization switching fields in the perpendicular magnetic layer and an indicator Dn [nm] of the intensity of exchange interactions, in film surface directions, in the perpendicular magnetic layer satisfy inequalities ?hsw/27+Dn/90<1, and Dn>20. The indicators can be measured using a magnetometer.Type: GrantFiled: March 6, 2007Date of Patent: November 25, 2008Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hiroaki Nemoto, Ikuko Takekuma, Yuzuru Hosoe
-
Publication number: 20070269734Abstract: 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: ApplicationFiled: January 14, 2005Publication date: November 22, 2007Inventors: Toru Kimura, Yukio Nishimura, Tomohiro Utaka, Hiroaki Nemoto, Atsushi Nakamura, Takashi Chiba, Hiroki Nakagawa
-
Publication number: 20070223142Abstract: According to embodiments of the present invention, a shielded pole writer and a perpendicular magnetic recording medium suitable thereto are combined to provide high medium SNR and excellent OW characteristic simultaneously. A perpendicular magnetic recording medium of a magnetic storage apparatus mounting a shielded pole writer, including a perpendicular magnetic recording medium having a recording layer of a three layered structure is used. A first recording layer has a granular structure consisting of grain boundaries containing an oxide and columnar grains comprising a CoCrPt alloy, in which a second recording layer and a third recording layer formed thereabove comprise Co as a main ingredient, contain Cr and do not contain an oxide, and the Cr concentration in the second recording layer is lower than the Cr concentration in the third recording layer.Type: ApplicationFiled: March 20, 2007Publication date: September 27, 2007Applicant: Hitachi Global Storage Technologies Netherlands B. V.Inventors: Ikuko Takekuma, Hiroyuki Nakagawa, Hiroaki Nemoto, Yoshiyuki Hirayama
-
Publication number: 20070217048Abstract: Embodiments in accordance with the present invention provide a perpendicular magnetic recording medium which is easy to record, offers superior thermal stability of recording magnetization, and allows high-density recording. In one embodiment, a perpendicular magnetic layer with controlled magnetic properties is used as a magnetic storage layer of a perpendicular magnetic recording medium, the magnetic properties having been controlled such that an indicator ?hsw [%] of the dispersion of magnetization switching fields in the perpendicular magnetic layer and an indicator Dn [nm] of the intensity of exchange interactions, in film surface directions, in the perpendicular magnetic layer satisfy inequalities ?hsw/27+Dn/90<1, and Dn>20. The indicators can be measured using a magnetometer.Type: ApplicationFiled: March 6, 2007Publication date: September 20, 2007Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hiroaki Nemoto, Ikuko Takekuma, Yuzuru Hosoe
-
Publication number: 20070188924Abstract: 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: ApplicationFiled: January 9, 2007Publication date: August 16, 2007Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Ichiro Tamai, Ikuko Takekuma, Hiroaki Nemoto, Yoshiyuki Hirayama
-
Publication number: 20070164261Abstract: 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: ApplicationFiled: May 19, 2005Publication date: July 19, 2007Inventors: Takashi Miyamatsu, Hiroaki Nemoto, Yong Wang
-
Publication number: 20070026260Abstract: A double-layer perpendicular magnetic recording medium suitable for high density recording is obtained. In one embodiment, a granular recording medium is formed on a undercoating layer, in which a first metal composed of Pt, Pd, or an alloy thereof and a second metal composed of Cr or V are included and their composition is 15%<B/(A+B)<30% when the atomic fraction of the first metal is assumed to be A and the atomic fraction of the second metal is assumed to be B.Type: ApplicationFiled: July 26, 2006Publication date: February 1, 2007Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hiroaki Nemoto, Yuzuru Hosoe
-
Patent number: 7140094Abstract: Magnetic heads capable of recording and reading with high sensitivity and resolution are provided by minimizing the outflow of magnetic fluxes from a flux guide to magnetic shields while using a flux guide structure for an MR element. In the magnetic head, magnetic shields exposed on a surface opposite a magnetic recording medium (air bearing surface) and a flux guide exposed between the magnetic heads via a non-magnetic layer are provided, and magnetic fluxes are guided by the flux guide to a magnetoresistive (MR) element formed in a position not exposed on the air bearing surface. The height of the magnetic shields in direction perpendicular to the air bearing surface is less than the distance from the air bearing surface to the MR element.Type: GrantFiled: October 7, 2003Date of Patent: November 28, 2006Assignee: Hitachi, Ltd.Inventor: Hiroaki Nemoto
-
Publication number: 20060134467Abstract: 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: ApplicationFiled: February 15, 2006Publication date: June 22, 2006Inventors: Yoshiyuki Hirayama, Ichiro Tamai, Takayuki Ichihara, Hiroyuki Nakagawa, Hiroaki Nemoto, Mineaki Kodama, Ikuko Takekuma
-
Patent number: 7033686Abstract: 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: November 6, 2003Date of Patent: April 25, 2006Assignee: Hitachi Global Storage Technologies Japan, Ltd.Inventors: Yoshiyuki Hirayama, Ichiro Tamai, Takayuki Ichihara, Hiroyuki Nakagawa, Hiroaki Nemoto, Mineaki Kodama, Ikuko Takekuma
-
Publication number: 20050227121Abstract: 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: ApplicationFiled: June 9, 2005Publication date: October 13, 2005Inventors: Yoshiyuki Hirayama, Hiroyuki Nakagawa, Hiroaki Nemoto, Ichiro Tamai, Ikuko Takekuma
-
Patent number: 6916557Abstract: 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: February 25, 2003Date of Patent: July 12, 2005Assignee: Hitachi Global Storage Technologies Japan, Ltd.Inventors: Yoshiyuki Hirayama, Hiroyuki Nakagawa, Hiroaki Nemoto, Ichiro Tamai, Ikuko Takekuma
-
Publication number: 20050142378Abstract: Embodiments of the invention provide a granular medium structure and a significant increase of the Ku value of a magnetic material at the same time using a non-metal material, thereby obtaining a magnetic recording medium capable of high density recording. In one embodiment, a magnetic metal grain in a granular magnetic film made of magnetic metal grains and a non-magnetic material is obtained by laminating a ferromagnetic exchange metallic element that contains mainly Co or Fe and a Pt element alternately and the lamination period is set between about 0.35 nm and 0.9 nm, preferably between about 0.4 nm and 0.55 nm.Type: ApplicationFiled: December 14, 2004Publication date: June 30, 2005Applicant: Hitachi Global Storage Technologies Netherlands, B.V.Inventors: Hiroaki Nemoto, Yuzuru Hosoe, Yoshiyuki Hirayama, Mineaki Kodama
-
Patent number: 6890663Abstract: A process for forming an inorganic material layer pattern on a substrate. The process includes the steps of transferring an inorganic powder dispersed paste layer supported on a support film to the surface of the substrate to form the inorganic powder dispersed paste layer on the substrate; forming a resist film on the inorganic powder dispersed paste layer transferred to the surface of the substrate; exposing the resist film to light through a mask to form a latent image of a resist pattern; developing the exposed resist film to form the resist pattern; etching exposed portions of the inorganic powder dispersed paste layer to form an inorganic powder dispersed paste layer pattern corresponding to the resist pattern; and baking the pattern to form an inorganic material layer pattern.Type: GrantFiled: October 23, 2002Date of Patent: May 10, 2005Assignee: JSR CorporationInventors: Hideaki Masuko, Tadahiko Udagawa, Hiroaki Nemoto, Nobuo Bessho
-
Publication number: 20050042367Abstract: A perpendicular magnetic recording medium, which has a low level of recording noise and sufficiently large perpendicular magnetic anisotropy energy relative to demagnetizing field energy, includes a substrate and a multi-layered magnetic film. The multi-layered magnetic film is composed of ferromagnetic metal layers of Co alloy containing at least Cr and non-magnetic metal layers of Pd alloy, each one layer of which are laminated alternately on top of one layer of the other. The ferromagnetic metal layers and the non-magnetic metal layers have a thickness of d1 and d2, respectively, with the ratio of d1/d2 being in the range of 1.5 to 4.0. This specific layer structure reduces the magnetic exchange interaction between magnetic particles in the multi-layered magnetic film. Therefore, the perpendicular magnetic recording medium is stable against thermal disturbance and has a low level of recording noise.Type: ApplicationFiled: September 30, 2004Publication date: February 24, 2005Inventors: Hiroaki Nemoto, Hiroyuki Nakagawa, Yuzuru Hosoe
-
Patent number: 6815083Abstract: A perpendicular magnetic recording medium, which has a low level of recording noise and sufficiently large perpendicular magnetic anisotropy energy relative to demagnetizing field energy, includes a substrate and a multi-layered magnetic film. The multi-layered magnetic film is composed of ferromagnetic metal layers of Co alloy containing at least Cr and non-magnetic metal layers of Pd alloy, each one layer of which are laminated alternately on top of one layer of the other. The ferromagnetic metal layers and the non-magnetic metal layers have a thickness of d1 and d2, respectively, with the ratio of d1/d2 being in the range of 1.5 to 4.0. This specific layer structure reduces the magnetic exchange interaction between magnetic particles in the multi-layered magnetic film. Therefore, the perpendicular magnetic recording medium is stable against thermal disturbance and has a low level of recording noise.Type: GrantFiled: August 14, 2002Date of Patent: November 9, 2004Assignee: Hitachi, Ltd.Inventors: Hiroaki Nemoto, Hiroyuki Nakagawa, Yuzuru Hosoe
-
Patent number: 6809908Abstract: A light induction type thin film magnetic recording head according to the present invention includes a lower magnetic core (2) formed on a substrate, an upper magnetic core (6) whose front end part is connected to the lower magnetic core through a magnetic gap film and whose rear end part is directly connected to the lower magnetic core with a back contact part (11) formed of a magnetic substance, and an insulating layer (3) formed between the upper magnetic core and the lower magnetic core, characterized in that an optically transparent waveguide part (5) whose width is smaller than the width of the upper magnetic core and whose thickness is thinner than the thickness of the upper magnetic core is buried in the upper magnetic core, and a coil (8) which generates magnetic flux in a magnetic circuit composed of the upper magnetic core, lower magnetic core, magnetic gap, and back contact part is arranged around the back contact part.Type: GrantFiled: May 20, 2002Date of Patent: October 26, 2004Assignee: Hitachi, Ltd.Inventors: Kenchi Ito, Hideki Saga, Hiroaki Nemoto, Tomohiro Okada
-
Publication number: 20040191571Abstract: 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: ApplicationFiled: November 6, 2003Publication date: September 30, 2004Inventors: Yoshiyuki Hirayama, Ichiro Tamai, Takayuki Ichihara, Hiroyuki Nakagawa, Hiroaki Nemoto, Mineaki Kodama, Ikuko Takekuma
-
Patent number: 6778471Abstract: In an optical recording and magnetic-head reproducing system, the reproduced output is prevented from starting to decrease, upon the length of record bits getting shorter, in the range of the bit length larger than reproducing resolution of a magnetic reproducing head. When data are recorded magneto-optically on a magnetic recording medium, the radius of curvature of arcs constituting the boundary of recorded magnetic domains is made as large as possible so that the shape of the recorded spot may be substantially rectangular. As a result, it becomes possible to improve the efficiency of magnetic reproduction, and high-output as well as high-SN-ratio reproduction at high linear recording density can be achieved.Type: GrantFiled: June 27, 2000Date of Patent: August 17, 2004Assignee: Hitachi, Ltd.Inventors: Kazuetsu Yoshida, Hiroaki Nemoto, Hideki Saga