Patents by Inventor Hardayal Gill

Hardayal Gill 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: 20050068684
    Abstract: A dual/differential spin valve sensor of a magnetic head includes a first spin valve having an antiparallel (AP) “pinned” layer structure and a second spin valve having an AP “self-pinned” layer structure. The AP pinned layer structure has a magnetization direction which is fixed by an adjacent antiferromagnetic (AFM) layer, whereas the AP self-pinned layer structure has a magnetization direction which is fixed by magnetostriction as well as air bearing surface (ABS) stress. The magnetization direction of the AP pinned layer structure is fixed in a direction antiparallel to the magnetization direction of the AP self-pinned layer structure. The dual/differential spin valve sensor may be configured to have either a top AP pinned layer structure and a bottom AP self-pinned layer structure, or a top AP self-pinned layer structure and a bottom AP pinned layer structure.
    Type: Application
    Filed: September 30, 2003
    Publication date: March 31, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050064092
    Abstract: A method for making a tunnel valve head with a flux guide, a tunnel valve sensor having an isolated flux guide, and a magnetic storage system using a tunnel valve sensor having an isolated flux guide is disclosed. The tunnel valve senors is created by forming a tunnel valve at a first shield layer, the tunnel valve comprising a free layer distal to the first shield layer, depositing a first insulation layer over the first shield layer and around the tunnel valve, depositing a flux guide over the first insulation layer and coupling to the tunnel valve at the free layer, covering the flux guide with a second insulation layer and forming a second shield layer over the second insulation, wherein the flux guide and the free layer are physically isolated by the first and second insulation layers to prevent current shunts therefrom. The structure achieves physical connection between the flux guide and the free layer and insulates the flux guide from the shields.
    Type: Application
    Filed: October 29, 2004
    Publication date: March 24, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050057864
    Abstract: A method for fabricating a sensor having anti-parallel tab regions. The method includes forming a free layer, and forming a first layer of a carbon composition above the active area of the free layer. A layer of resist is formed above the first layer of carbon composition. A bias layer is formed above the tab areas of the free layer, the bias layer being operative to substantially pin magnetic moments of the tab areas of the free layer. Leads are formed above the bias layer. A second layer of carbon composition is formed above the tab areas of the free layer. Any material above a plane extending parallel to portions of the second layer of carbon composition above the tab areas are removed using chemical-mechanical polishing. Any remaining carbon composition is removed.
    Type: Application
    Filed: November 5, 2004
    Publication date: March 17, 2005
    Inventors: Marie-Claire Cyrille, Hardayal Gill, James Freitag
  • Publication number: 20050052792
    Abstract: A magnetic head having a free layer structure having at least three layers. First and second free layers have magnetic moments that are pinned antiparallel each other. A third free layer, closer to the second free layer than the first free layer, has a magnetic moment oriented parallel to the magnetic moment of the second free layer. Ends of the third free layer define track edges of the third free layer. The first and second free layers extend beyond the track edges in a direction parallel to the ABS.
    Type: Application
    Filed: September 9, 2003
    Publication date: March 10, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050030675
    Abstract: A magnetic head assembly includes a read head with a current perpendicular to the planes (CPP) sensor. The CPP sensor includes an AP pinned layer structure, a free layer and a spacer layer which is located between the free layer and the AP pinned layer structure. An in-stack longitudinal biasing structure for longitudinally biasing the free layer includes a pinned layer, an AFM pinning layer for pinning the pinned layer and a chromium spacer layer which is located between the pinned layer and the free layer. The free layer includes first and second free films with the first free film being iron and interfacing the spacer layer. The second free film may be nickel iron for imparting magnetic softness to the first free film. The pinned layer and a second AP pinned layer of the free layer structure may also be iron. The iron content of the layers in the sensor and the chromium spacer layer significantly increase the magnetoresistive coefficient dr/R of the CPP sensor.
    Type: Application
    Filed: August 31, 2004
    Publication date: February 10, 2005
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Gill
  • Publication number: 20050025999
    Abstract: The present disclosure describes magnetic tunnel junction (MTJ) devices and systems involving the use of diffusion components selected to alter the device properties. The diffusion components migrate from one layer of the MTJ structure to the tunneling barrier layer. Incorporation of the migrated components at the barrier layer adjusts the properties of the MTJ device.
    Type: Application
    Filed: July 29, 2003
    Publication date: February 3, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050024796
    Abstract: A giant magneto-resistive (GMR) sensor for a magnetic head for a hard disk drive is disclosed. The sensor includes: a free magnetic layer; a bias layer that provides a bias magnetic field to the free magnetic layer and a bias pinning layer that provides a stabilizing magnetic field to the bias layer and that has a width substantially longer than the width of the free magnetic layer. Embodiments of the invention may further include an anti-ferromagnetic layer having a width substantially longer than the width of the free layer, or both an anti-ferromagnetic layer and a pinned magnetic structure each having a width substantially longer than the width of the free layer.
    Type: Application
    Filed: July 30, 2003
    Publication date: February 3, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050024784
    Abstract: A method and apparatus for enhancing thermal stability, improving biasing and reducing damage from electrical surges in self-pinned abutted junction heads. The head includes a sandwiched hard bias layer having a first hard bias layer coupled to a free layer and a second, anti-parallel hard bias layer disposed away form the free layer to provide a net longitudinal bias on the free layer.
    Type: Application
    Filed: July 29, 2003
    Publication date: February 3, 2005
    Inventors: Hardayal Gill, Wen-Chien Hsiao, Jih-Shiuan Luo
  • Publication number: 20050024787
    Abstract: A magnetic head having a pinned area, a free area, and a nanoconstricted area encompassing portions of the pinned and free areas. A first layer of magnetic material extends along the pinned and free areas. An AP coupling layer extends along the pinned area. A third layer of magnetic material is positioned above the AP coupling layer, an active portion of the third layer extending along the pinned area but not along the free area. The first and third layers have magnetic moments that are self-pinned antiparallel to each other in the pinned area and a portion of the nanoconstricted area encompassing the pinned area.
    Type: Application
    Filed: July 30, 2003
    Publication date: February 3, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050024783
    Abstract: A method and apparatus for enhancing thermal stability, improving biasing and reducing damage from electrical surges in self-pinned abutted junction heads. The head includes a self-pinned layer, the self-pinned layer having a first end, a second end and central portion, a free layer disposed over the central portion of the self-pinned layer in a central region and a first and second hard bias layers formed over the first and second ends of the self-pinned layer respectively, the first and second hard bias layer abutting the free layer, the first and second end of the self-pinned layer extending under the hard bias layers at the first and second ends.
    Type: Application
    Filed: July 29, 2003
    Publication date: February 3, 2005
    Inventors: Hardayal Gill, Wen-Chien Hsiao, Jih-Shiuan Luo
  • Publication number: 20050024785
    Abstract: A method and apparatus for enhancing thermal stability, improving biasing and reducing damage from electrical surges in self-pinned abutted junction heads. The head includes a free layer having a first end and a second end defining a width selected to form a desired trackwidth and an extended self-pinned bias layer extending beyond the ends of the free layer, the self-pinned bias layer extending beyond the free layer increasing the volume of the extended self-pinned bias layer to provide greater thermal stability and stronger pinning of the free layer.
    Type: Application
    Filed: July 29, 2003
    Publication date: February 3, 2005
    Inventors: Hardayal Gill, Wen-Chien Hsiao, Jih-Shiuan Luo
  • Publication number: 20050024786
    Abstract: A method and apparatus for enhancing thermal stability, improving biasing and reducing damage from electrical surges in self-pinned abutted junction heads. A first self-pinned layer having a first magnetic orientation is provided, wherein the first self-pinned layer has a first end, a second end and central portion. A second self-pinned layer is formed over only the central portion of the first self-pinned layer and an interlayer is disposed between the first and second self-pinned layers. A free layer is formed in a central region over the second self-pinned layer. First and second hard bias layers are formed over the first and second ends of the first self-pinned layer respectively, the first and second hard bias layer abutting the free layer, the first and second end of the first self-pinned layer extending under the hard bias layers at the first and second ends.
    Type: Application
    Filed: July 29, 2003
    Publication date: February 3, 2005
    Inventors: Hardayal Gill, Wen-Chien Hsiao, Jih-Shiuan Luo
  • Publication number: 20050024794
    Abstract: A GMR sensor of a magnetic head for a hard disk drive including a free magnetic layer that is disposed between two hard bias layers that creates a bias magnetic field within the free magnetic layer. A bias reduction layer is disposed parallel to the free magnetic layer, and a spacer layer is disposed parallel to and between the free magnetic layer and the bias reduction layer. A negative magnetic coupling between the free magnetic layer and the bias reduction layer induces a bias reduction magnetic field in the free magnetic layer. The bias reduction field substantially counteracts the bias field in the central portion of the free magnetic layer, and the sensitivity of the free magnetic layer to small magnetic fields from the magnetic disk is significantly increased. A hard disk drive with decreased track width and increased areal density using this magnetic head is also disclosed.
    Type: Application
    Filed: July 30, 2003
    Publication date: February 3, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050018361
    Abstract: A Giant Magneto-Resistive (GMR) sensor (900) having Current Perpendicular to Plane (CPP) structure provides an extended first pinned layer (914) as compared to second pinned layer (912) and free layer (910). Increased magnetoresistance changes, increased pinning strength, increased thermal stability, and decreased susceptibility to Electro-Static Discharge (ESD) events is realized by maintaining equivalent current densities through free layer (910) and second pinned layer (912), while decreasing the relative current density through first pinned layer (914).
    Type: Application
    Filed: July 25, 2003
    Publication date: January 27, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050017314
    Abstract: A spin valve transistor includes an emitter, a collector, a base between the emitter and the collector, a spin valve which includes a free layer structure, a self-pinned antiparallel (AP) pinned layer structure and a nonmagnetic spacer layer between the free layer structure and the AP pinned layer structure wherein the base includes at least the free layer structure.
    Type: Application
    Filed: July 25, 2003
    Publication date: January 27, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050018360
    Abstract: The hard disk drive of the present invention includes a magnetic head wherein the read head portions have gap insulation layers between the magnetic shields. The gap insulation layers are made up of multilayered laminations of an oxide or nitride of a metal such as aluminum, silicon, chromium, and tantalum. A preferred embodiment of the present invention includes laminated G1 and G2 gap insulation layers having 5-10 laminations, and having a total thickness of approximately 50 ? to 500 ?.
    Type: Application
    Filed: December 9, 2003
    Publication date: January 27, 2005
    Inventors: Hardayal Gill, Douglas Werner
  • Publication number: 20050018365
    Abstract: A magnetic head having improved self-pinning. The head includes a sensor having an antiparallel (AP) pinned layer structure, where the AP pinned layer structure includes at least two pinned layers having magnetic moments that are self-pinned antiparallel to each other, the pinned layers being separated by an AP coupling layer. A pair of compression layers are positioned towards opposite track edges of the sensor. The compression layers provide compressive stress to the sensor.
    Type: Application
    Filed: July 25, 2003
    Publication date: January 27, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050018362
    Abstract: A Giant Magneto-Resistive (GMR) sensor (900) having Current Perpendicular to Plane (CPP) structure is formed providing an extended first pinned layer (914) as compared to second pinned layer (912) and free layer (910). Increased magnetoresistance changes, increased pinning strength, increased thermal stability, and decreased susceptibility to Electro-Static Discharge (ESD) events is realized by maintaining equivalent current densities through free layer (910) and second pinned layer (912), while decreasing the relative current density through first pinned layer (914).
    Type: Application
    Filed: July 25, 2003
    Publication date: January 27, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050018364
    Abstract: A magnetic head having a sensor with a free layer, the free layer having a magnetic moment. Hard bias layers are positioned towards opposite track edges of the sensor, the bias layers stabilizing the magnetic moment of the free layer. An antiparallel (AP) pinned layer structure is positioned toward each of the hard bias layers, each AP pinned layer structure having at least two pinned layers with magnetic moments that are self-pinned antiparallel to each other. Each AP pinned layer structure stabilizes a magnetic moment of the hard bias layer closest to it. An antiferromagnetic layer is positioned toward each of the AP pinned layer structures, each antiferromagnetic layer stabilizing a magnetic moment of pinned layer closest to it.
    Type: Application
    Filed: July 2, 2003
    Publication date: January 27, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050013062
    Abstract: A magnetic head having a sensor with a free layer, the free layer having a magnetic moment. Hard bias structures are positioned towards opposite ends of the sensor, the hard bias structures stabilizing the magnetic moment of the free layer. Each hard bias structure includes an antiparallel (AP) pinned layer structure and an antiferromagnetic layer positioned towards each of the AP pinned layer structures. Each AP pinned layer structure has a middle pinned layer aligned along a plane of the free layer of the sensor, and outer pinned layers positioned on opposite sides of the middle pinned layer. Each antiferromagnetic layer stabilizes a magnetic moment of the pinned layer closest thereto.
    Type: Application
    Filed: July 18, 2003
    Publication date: January 20, 2005
    Inventor: Hardayal Gill