Patents Represented by Attorney Rambod Nader
  • Patent number: 7770282
    Abstract: A magnetic sensing device for use in a magnetic head includes a sensor stack structure having a sensing layer structure and an insulator structure formed adjacent the sensing layer structure. The insulator structure includes a plurality of oxidized metallic sublayers, a plurality of nitrided metallic sublayers, or a plurality of oxynitrided metallic sublayers. The insulator structure may be a capping layer structure of a giant magnetoresistance sensor or, alternatively, a tunnel barrier layer structure of a tunneling magnetoresistance sensor or a magnetic random access memory. Advantageously, each treated metallic sublayer is sufficiently uniformly treated so as to increase the magnetoresistive effect and improve soft magnetic properties of the magnetic sensing device.
    Type: Grant
    Filed: September 1, 2005
    Date of Patent: August 10, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Alexander M. Zeltser, Jinshan Li, Brian York
  • Patent number: 7623319
    Abstract: An electrically conductive etch stop layer is formed over a first electrically conductive layer. An electrically conductive diffusion barrier layer is then formed over the etch stop layer, followed by the formation of an insulator layer over the diffusion barrier layer. Utilizing an etching process with a patterned photoresist in place, insulator materials in a central region are removed to form a via which exposes electrically conductive materials in the central region. Finally, a second electrically conductive layer is formed within the via over the electrically conductive materials in the central region.
    Type: Grant
    Filed: November 30, 2004
    Date of Patent: November 24, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Mustafa Michael Pinarbasi, Howard Gordon Zolla
  • Patent number: 7440227
    Abstract: A magnetic head has a sensor which employs the “Hall effect”. In one illustrative example, the sensor includes a generally planar body made of a semiconductor heterostructure; first and second contacts comprising first and second drains, respectively, which are formed over a first end of the body and spaced equally apart from a centerline of the body; and a third contact comprising a source formed over a second end of the body which is opposite the first end of the body. The semiconductor heterostructure is comprised of a high mobility two-dimensional electron or hole gas close to an air bearing surface (ABS) of the magnetic head so as to be exposed to magnetic field lines substantially normal to it from magnetically recorded bits. Advantageously, the sensor does not require magnetic materials utilized in conventional sensors and therefore does not suffer from magnetic noise associated therewith.
    Type: Grant
    Filed: February 28, 2005
    Date of Patent: October 21, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Amitava Chattopadhyay, Stefan Maat, Ernesto E. Marinero, Bruce Alvin Gurney
  • Patent number: 7428129
    Abstract: A magnetic head with improved hard magnet properties includes a read sensor; a multi-layered seed layer structure in end regions adjacent the read sensor; and a multi-layered seed layer structure formed upon crystalline materials of the read sensor in the end regions. The multi-layered seed layer structure includes a first seed layer made of chromium-molybdenum (Cr—Mo); a second seed layer made of nickel-tantalum (Ni—Ta); and a third seed layer made of chromium-molybdenum (Cr—Mo). The hard bias layer is preferably cobalt-platinum-chromium (Co—Pt—Cr).
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: September 23, 2008
    Assignee: Hitachi Global Storage Technologies Amsterdam
    Inventor: Mustafa Michael Pinarbasi
  • Patent number: 7379321
    Abstract: Memory cell structures make use of the extraordinary Hall effect (EHE) for increased data storage capacity. A memory cell has a ferromagnetic structure which includes at least a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer in between the first and the second ferromagnetic layers. The first and the second ferromagnetic layers exhibit perpendicular magnetic anisotropy and have magnetic moments which are set in accordance with one of a plurality of magnetic orientation sets of the ferromagnetic structure, and the ferromagnetic structure exhibits one of a plurality of predetermined extraordinary Hall resistances RH in accordance with the magnetic orientation set. The extraordinary Hall resistance is exhibited between first and second ends of the ferromagnetic structure across a path which intersects a bias current path between third and fourth ends of the ferromagnetic structure.
    Type: Grant
    Filed: February 6, 2006
    Date of Patent: May 27, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Dafine Ravelosona, Bruce David Terris
  • Patent number: 7272883
    Abstract: In one illustrative example disclosed, a method for use in making a magnetic head involves forming a thermal-assist heater for the magnetic head; forming a plurality of coil layers of a write coil using a damascene process; and simultaneously forming an electrical connection to the thermal-assist heater in the same damascene process used to form the write coil. Advantageously, fabrication steps are reduced using a parallel process that provides for relatively small dimensions and reduces the possibility of electrical shorting. The method may be alternatively used to form an electrical connection to any other suitable electrical device for the magnetic head, such as an electrical lapping guide (ELG) or other component.
    Type: Grant
    Filed: August 29, 2003
    Date of Patent: September 25, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Quang Van Le, Jeffrey Scott Lille
  • Patent number: 7268965
    Abstract: A method and apparatus for estimating the flyheight of an airbearing slider in a storage device. The slider floats on an airbearing over a rotating storage disk. The storage disk includes a washboard-sequence having washboard-sections each comprising surface profile variations having a different pitch. The pitches are selected from within a range of values likely to excite an airbearing resonance of the slider as the storage disk rotates at a rated storage disk velocity. For each of the washboard-sections, a maximum amplitude of flyheight modulation of the slider resulting from the slider floating over that washboard-section is measured. A determination is made of which washboard-section caused the largest measured flyheight modulation. The washboard-section having a pitch that provides an excitation frequency (when the disk is rotated at the rated storage disk velocity) that is closest to the actual airbearing resonance frequency of the slider will produce the largest flyheight modulation.
    Type: Grant
    Filed: July 9, 2004
    Date of Patent: September 11, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Hammond Brannon, Hal Hjalmar Ottesen, Gordon James Smith
  • Patent number: 7085100
    Abstract: A magnetic head having improved overwrite capabilities and reduced fringing fields are described along with methods of making the same. The magnetic head has a first pole piece and a second pole piece. The first pole piece includes a first bottom pole piece layer, a pedestal portion formed over the first bottom pole piece layer, and a notched top pole portion formed over the pedestal portion. A gap layer separates the second pole piece from the notched top pole portion. The pedestal portion has a first saturation magnetization MS1 and the top pole portion has a second saturation magnetization MS2 that is greater than the first saturation magnetization MS1. The top pole portion has a substantially planar top surface over which a portion of the gap layer and the second pole piece are formed.
    Type: Grant
    Filed: March 19, 2002
    Date of Patent: August 1, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Tom King Harris, III, Wen-chien David Hsiao, Gautam Mohan Khera, David Kaimon Lee, Edward Hin Pong Lee, Hugo Alberto Emilio Santini, Samuel Wei-san Yuan
  • Patent number: 6952326
    Abstract: A magnetic head assembly includes first and second pole pieces and first and second coil layers wherein the second pole piece has a ferromagnetic pole tip which forms a portion of an air bearing surface and defines a track width of a write head. A write gap layer is located between the first pole piece and the pole tip. A dielectric first insulation layer interfaces first and second side surfaces of the pole tip and is located between the first and second coil layers. The second pole piece has a ferromagnetic second pole piece structure which is magnetically connected to each of the pole tip and the first pole piece and extends across the second coil layer. In a first embodiment the second pole piece structure is a single layer and in a second embodiment the second pole piece structure has front and back components with a flat laminated second pole piece yoke layer located therebetween.
    Type: Grant
    Filed: June 30, 2003
    Date of Patent: October 4, 2005
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Yimin Hsu, Hugo Alberto Emilio Santini, Neil Smith, Mason Lamar Williams
  • Patent number: 6785079
    Abstract: A method and apparatus for estimating the flyheight of an airbearing slider in a storage device. The slider floats on an airbearing over a rotating storage disk. The storage disk includes a washboard-sequence having washboard-sections each comprising surface profile variations having a different pitch. The pitches are selected from within a range of values likely to excite an airbearing resonance of the slider as the storage disk rotates at a rated storage disk velocity. For each of the washboard-sections, a maximum amplitude of flyheight modulation of the slider resulting from the slider floating over that washboard-section is measured. A determination is made of which washboard-section caused the largest measured flyheight modulation. The washboard-section having a pitch that provides an excitation frequency (when the disk is rotated at the rated storage disk velocity) that is closest to the actual airbearing resonance frequency of the slider will produce the largest flyheight modulation.
    Type: Grant
    Filed: March 16, 2001
    Date of Patent: August 31, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Hammond Brannon, Hal Hjalmar Ottesen, Gordon James Smith
  • Patent number: 6762899
    Abstract: A method and apparatus for estimating the flyheight of an airbearing slider in a storage device using variable spindle velocity. The slider floats on an airbearing over a rotating storage disk. The storage disk includes a washboard-sequence having washboard-sections each comprising surface profile variations having a different pitch. The pitches are selected from within a range of values likely to excite an airbearing resonance of the slider as the storage disk rotates at a plurality of discrete velocities. For each of the washboard-sections and at each of the velocities, a maximum amplitude of flyheight modulation of the slider resulting from the slider floating over that washboard-section is measured as the storage disk rotates at that velocity. A determination is made of the velocity/washboard-section combination that caused the largest measured flyheight modulation.
    Type: Grant
    Filed: March 16, 2001
    Date of Patent: July 13, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hal Hjalmar Ottesen, Gordon James Smith
  • Patent number: 6630265
    Abstract: An inexpensive composite electrolyte for use in electrochemical fuel cells includes (i) an inorganic cation exchange material, (i) a silica-based binder; and (ii) a polymer-based binder. The cation exchange material includes aluminosilicate clays. The composite electrolyte can be fabricated with a tape casting apparatus.
    Type: Grant
    Filed: August 13, 2002
    Date of Patent: October 7, 2003
    Assignee: Hoku Scientific, Inc.
    Inventors: Karl Milton Taft, III, Matthew Robert Kurano
  • Patent number: D530341
    Type: Grant
    Filed: April 1, 2005
    Date of Patent: October 17, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Yukinobu Maruyama, Keiichi Ochi, Masayuki Ohki, Tadaaki Tomikawa
  • Patent number: D543206
    Type: Grant
    Filed: April 1, 2005
    Date of Patent: May 22, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Yukinobu Maruyama, Keiichi Ochi, Masayuki Ohki, Tadaaki Tomikawa