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: 20050213258
    Abstract: A method and apparatus for providing a dual current-perpendicular-to-plane (CPP) GMR sensor with improved top pinning is disclosed. In the passive regions of the sensor, a tri-level biasing layer is formed proximate to the top self-pinned layer. The tri-level biasing layer includes a first metal oxide layer, a layer of alpha-Fe2O3 and a second metal oxide layer. The pinning of the top self-pinned layer is enhanced by the layer of alpha-Fe2O3. The layer of alpha-Fe2O3 pins the top portion of the pinned layer by providing higher coercivity (HC) to the pinned layer.
    Type: Application
    Filed: March 29, 2004
    Publication date: September 29, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050213265
    Abstract: A magnetoresistive (MR) read head is disclosed including an MR sensor having a free layer and a pinned layer. A multi-layer hard bias layer stabilizes the free layer of the MR sensor.
    Type: Application
    Filed: May 24, 2005
    Publication date: September 29, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050213263
    Abstract: A method and apparatus for providing a current-in-plane (CIP) GMR sensor with an improved in-stack bias layer with a thinner sensor stack is disclosed. Improved pinning of a free-layer in a CIP GMR sensor stack is provided using dual in-stack biasing layers. The sensor stack is made thin because an anti-ferromagnetic layer is not necessary to bias the free-layer.
    Type: Application
    Filed: March 29, 2004
    Publication date: September 29, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050201024
    Abstract: A magnetoresistive sensor having an in stack bias layer extending beyond the track width of the sensor for improved free layer stability and resistance against amplitude flipping.
    Type: Application
    Filed: March 15, 2004
    Publication date: September 15, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050195534
    Abstract: A magnetoresistive sensor having employing a synthetic free layer having a first magnetic layer that contributes strongly to the GMR effect and a second magnetic layer that does not contribute to GMR effect, but has a negative magnetostriction to compensate for a positive magnetostriction of the first ferromagnetic layer.
    Type: Application
    Filed: March 3, 2004
    Publication date: September 8, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050190508
    Abstract: A magnetic head having a free layer and an antiparallel (AP) pinned layer structure spaced apart from the free layer, the AP pinned layer structure including at least two AP-pinned layers having magnetic moments that are self-pinned antiparallel to each other, the AP-pinned layers being separated by an AP coupling layer. An easy axis of a first or both of the AP-pinned layers is oriented at an angle of at least 5° from the ABS along a plane of the first AP-pinned layer.
    Type: Application
    Filed: February 26, 2004
    Publication date: September 1, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050190509
    Abstract: A spin valve (SV) sensor of the self-pinned type includes one or more compressive stress modification layers for reducing the likelihood that the pinning field will flip its direction. The spin valve sensor includes a capping layer formed over a spin valve structure which includes a free layer, an antiparallel (AP) self-pinned layer structure, and a spacer layer in between the free layer and the AP self-pinned layer structure. A compressive stress modification layer is formed above or below the capping layer, adjacent the AP self-pinned layer structure, or both. Preferably, the compressive stress modification layer is made of ruthenium (Ru) or other suitable material.
    Type: Application
    Filed: February 27, 2004
    Publication date: September 1, 2005
    Inventors: Ciaran Fox, Hardayal Gill, Prakash Kasiraj, Wen-Yaung Lee, Mustafa Pinarbasi
  • Publication number: 20050180059
    Abstract: A magnetic head having a free layer, an antiparallel (AP) pinned layer structure spaced apart from the free layer, and a high coercivity structure. The high coercivity structure pins a magnetic orientation of the AP pinned layer structure. The high coercivity structure includes a layer of high coercivity material, and an amorphous layer positioned between the high coercivity material and the AP pinned layer structure.
    Type: Application
    Filed: February 18, 2004
    Publication date: August 18, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050180058
    Abstract: A magnetic head having a free layer, an antiparallel (AP) pinned layer structure spaced apart from the free layer, and a high coercivity structure positioned towards the AP pinned layer structure on an opposite side thereof relative to the free layer. The high coercivity structure pins a magnetic orientation of the AP pinned layer structure. The AP pinned layer structure includes at least two Fe-containing pinned layers having magnetic moments that are self-pinned antiparallel to each other, the pinned layers being separated by an AP coupling layer of Cr.
    Type: Application
    Filed: February 18, 2004
    Publication date: August 18, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050180060
    Abstract: A magnetoresistive sensor having improved free layer biasing and track width control.
    Type: Application
    Filed: February 17, 2004
    Publication date: August 18, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050174702
    Abstract: A thin dual magnetic tunnel junction head having a free layer and first and second antiparallel (AP) pinned layer structures positioned on opposite sides of the free layer, each of the AP pinned layer structures including at least two pinned layers having magnetic moments that are self-pinned antiparallel to each other, the pinned layers of each AP pinned layer structure being separated by an AP coupling layer. A first barrier layer is positioned between the first AP pinned layer structure and the free layer. A second barrier layer is positioned between the second AP pinned layer structure and the free layer. The head does not have any antiferromagnetic layers, and so is much thinner than dual magnetic tunnel junction sensors heretofore known. As such, dual magnetic tunnel junction heads can be fabricated at a thickness of less than about 500 ?.
    Type: Application
    Filed: February 11, 2004
    Publication date: August 11, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050174691
    Abstract: A magnetic head that uses a thick AP coupling layer in an AP-tab structure. The head includes a free layer having an active area and tab regions on opposite sides of the active area. An antiparallel (AP) coupling layer is formed above the free layer. In one embodiment, the AP coupling layer has a thickness of 15 ? or more. In another embodiment, the AP coupling layer is formed of Ir, and preferably has a thickness of 15 ? or more. A bias layer is formed above each of the tab portions of the free layer, magnetic moments of the tab regions of the free layer being pinned antiparallel to the magnetic moments of the bias layers.
    Type: Application
    Filed: February 11, 2004
    Publication date: August 11, 2005
    Inventors: Hardayal Gill, Stefan Maat
  • Publication number: 20050174703
    Abstract: A magnetic head has a read sensor including a free layer, a spacer layer and a number of self-pinned layers. These self-pinned layers include interleaved layers of ferromagnetic material and non-magnetic metal. The self-pinned layers are pinned through magnetostrictive anisotropy, and preferably have a net magnetic moment which is approximately zero.
    Type: Application
    Filed: February 11, 2004
    Publication date: August 11, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050157436
    Abstract: A magnetic head has a read sensor which includes at least one primary pinned layer, a barrier layer, and a free layer. An in-stack biasing structure having net magnetic moment near zero, notated as dM=0, is constructed above the free layer. This in-stack biasing structure acts to stabilize the free layer by exchange coupling.
    Type: Application
    Filed: January 20, 2004
    Publication date: July 21, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050141145
    Abstract: A spin valve sensor with an antiparallel coupled lead/sensor overlap region is provided comprising a ferromagnetic bias layer antiparallel coupled to a free layer in first and second passive regions where first and second lead layers overlap the spin valve sensor layers. The ferromagnetic material of the bias layer in a track width region defined by a space between the first and second lead layers is converted to a nonmagnetic oxide layer allowing the free layer in the track width region to rotate in response to signal fields from a magnetic disk.
    Type: Application
    Filed: February 24, 2005
    Publication date: June 30, 2005
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Gill
  • Publication number: 20050128653
    Abstract: A magnetic head includes a read sensor having a primary stack, a secondary stack and an exchange layer. The primary stack includes one or more primary pinned layers having a top surface, a barrier layer, a free layer, and a seed layer. The secondary stack includes one or more layers of antiferromagnetic (AFM) material, and a secondary pinned layer, which is pinned by said AFM material. The secondary pinned layer has a top surface which is substantially level with the top surface of the primary pinned layer. An exchange layer contacts the top surface of the secondary pinned layer and is pinned thereby, and also contacts the top surface of the primary pinned layer and acts to pin the primary pinned layers. The secondary stack is removed from the ABS, but is in proximity to the primary stack.
    Type: Application
    Filed: December 12, 2003
    Publication date: June 16, 2005
    Inventor: Hardayal Gill
  • Publication number: 20050128652
    Abstract: In one illustrative example, a spin valve (SV) sensor of the self-pinned type includes a free layer; an antiparallel (AP) self-pinned layer structure; and a non-magnetic electrically conductive spacer layer in between the free layer and the AP self-pinned layer structure. The AP self-pinned layer structure includes a first AP pinned layer having a first thickness; a second AP pinned layer having a second thickness; and an antiparallel coupling (APC) layer formed between the first and the second AP pinned layers. The first thickness is slightly greater than the second thickness. Configured as such, the AP pinned layer structure provides for a net magnetic moment that is in the same direction as a magnetic field produced by the sense current flow, which reduces the likelihood of amplitude flip in the SV sensor.
    Type: Application
    Filed: December 10, 2003
    Publication date: June 16, 2005
    Inventors: James Freitag, Hardayal Gill, Jih-Shiuan Luo, Mustafa Pinarbasi
  • Publication number: 20050088786
    Abstract: A method and apparatus for providing a spin valve transistor with differential detection is disclosed. The present invention provides a structure including spin valves that are (100)-oriented on a (100) substrate to take advantages of the high MR sensitivity of spin valve transistor read heads without the need for shields. This allows the distance between the free layers in the differential sensor to be minimized thereby allowing an increase in the areal density.
    Type: Application
    Filed: October 27, 2003
    Publication date: April 28, 2005
    Inventor: Hardayal Gill
  • 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: 20050068685
    Abstract: A method and apparatus for providing a ballistic magnetoresistive sensor in a current perpendicular-to-plane mode is disclosed. A nickel nano-contact is provided in a current perpendicular-to-plane sensor. The nano-contact switches its magnetization with the switching of the free layer to provide an increase in resistance that is used to detect magnetically recorded data.
    Type: Application
    Filed: September 30, 2003
    Publication date: March 31, 2005
    Inventor: Hardayal Gill