Patents by Inventor James Mac Freitag

James Mac Freitag 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).

  • Patent number: 7497008
    Abstract: An embodiment of the invention is a magnetic head with overlaid lead pads that contact the top surface of the sensor between the hardbias structures and do not contact the hardbias structures which are electrically insulated from direct contact with the sensor. The lead pad contact area on the top of the sensor is defined by sidewall deposition of a conductive material to form leads pads on a photoresist prior to formation of the remainder of the leads. The conductive material for the lead pads is deposited at a shallow angle to maximize the sidewall deposition on the photoresist, then ion-milled at a high angle to remove the conductive material from the field while leaving the sidewall material. An insulation layer is deposited on the lead material at a high angle, then milled at a shallow angle to remove insulation from the sidewall.
    Type: Grant
    Filed: August 24, 2005
    Date of Patent: March 3, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Tsung Yuan Chen, Frederick Hayes Dill, James Mac Freitag, Kuok San Ho, Wipul Pemsiri Jayasekara, Kim Y. Lee, Mustafa Michael Pinarbasi, Ching Hwa Tsang, Patrick Rush Webb
  • Patent number: 7466524
    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: Grant
    Filed: December 13, 2005
    Date of Patent: December 16, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Hardayal Singh Gill, Jih-Shiuan Luo, Mustafa Michael Pinarbasi
  • Patent number: 7440243
    Abstract: A read sensor of the current-perpendicular-to-the-planes (CPP) type includes a sensor stack structure formed in a central region between first and second shield layers which serve as leads for the read sensor; insulator layers formed in side regions adjacent the central region; seed layer structures formed over the insulator layers in the side regions; and hard bias layers formed over the seed layer structures in the side regions. The hard bias layers are made of a nitrogenated cobalt-based alloy, such as nitrogenated cobalt-platinum (CoPt). Suitable if not exemplary coercivity and squareness properties are exhibited using the nitrogenated cobalt-based alloy. The hard bias layers may be formed by performing an ion beam deposition of cobalt-based materials using a sputtering gas (e.g. xenon) and nitrogen as a reactive gas.
    Type: Grant
    Filed: April 9, 2007
    Date of Patent: October 21, 2008
    Assignee: Hitachi Global Storage Technologies
    Inventors: James Mac Freitag, Mustafa Michael Pinarbasi
  • Patent number: 7436629
    Abstract: A magnetic structure for use in a perpendicular magnetic write head that prevents magnetic domain formation and reduces magnetic remanence in the structure. The magnetic structure includes magnetic layers sandwiched between thin non-magnetic layers. Each of the magnetic layers includes a relatively thicker layer of CoFe sandwiched between relatively thinner layers of NiFe.
    Type: Grant
    Filed: October 23, 2007
    Date of Patent: October 14, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Hardayal Singh Gill, Yimin Hsu, Yinshi Liu
  • Patent number: 7433163
    Abstract: A seedlayer structure for a high coercivity hard bias layer is disclosed, having at least one bi-layer seedlayer, including a CrMo layer, and a W layer fabricated on the CrMo layer. A hard bias layer is fabricated on the bi-layer seedlayer. Preferably, the seedlayer structure includes two bi-layer seedlayers, which including a first CrMo layer, a first W layer fabricated on the first CrMo layer, a second CrMo layer fabricated on the first W layer, and a second W layer fabricated on the second CrMo layer. Also disclosed is a high coercivity hard bias stack structure, a magnetic read head for a disk drive having a high coercivity hard bias stack structure and a method for fabricating a coercivity hard bias layer for a magnetic read head.
    Type: Grant
    Filed: February 13, 2006
    Date of Patent: October 7, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Mohamad Towfik Krounbi, Mustafa Michael Pinarbasi
  • Patent number: 7420787
    Abstract: A magnetoresistive sensor having a pinned layer that extends beyond the stripe height defined by the free layer of the sensor. The extended pinned layer has a strong shape induced anisotropy that maintains pinning of the pinned layer moment. The extended portion of the pinned layer has sides beyond the stripe height that are perfectly aligned with the sides of the sensor within the stripe height. This perfect alignment is made possible by a manufacturing method that uses a mask structure for more than one manufacturing phase, eliminating the need for multiple mask alignments.
    Type: Grant
    Filed: August 15, 2005
    Date of Patent: September 2, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Kuok San Ho, Mustafa Michael Pinarbasi, Ching Hwa Tsang
  • Publication number: 20080151441
    Abstract: A magnetoresistive sensor having magnetically anisotropic bias layers for biasing the free layer of the sensor. The sensor includes a sensor stack with a pinned layer structure and a free layer structure and having first and second sides. Hard bias structures for biasing the magnetization of the free layer are formed at either side of the sensor stack, and each of the hard bias structure includes a hard magnetic layer that has a magnetic anisotropy to enhance the stability of the biasing. The hard bias structure can include a Cr under-layer having a surface that has been treated by a low power angled ion milling to form it with an anisotropic surface texture. A layer of Cr—Mo alloy is formed over the Cr under-layer and the hard magnetic material layer is formed over the Cr—Mo alloy layer. The anisotropic surface texture of the Cr layer induces an aligned crystalline structure in the hard magnetic layer that causes the hard magnetic layer to have a magnetic anisotropy.
    Type: Application
    Filed: December 22, 2006
    Publication date: June 26, 2008
    Inventors: James Mac Freitag, Mustafa Michael Pinarbasi, Wipul Pemsiri Jayasekara
  • Publication number: 20080137237
    Abstract: A magnetoresistive sensor having magnetically anisotropic bias layers for biasing the free layer of the sensor. The sensor includes a sensor stack with a pinned layer structure and a free layer structure and having first and second sides. Hard bias structures for biasing the magnetization of the free layer are formed at either side of the sensor stack, and each of the hard bias structure includes a hard magnetic layer that has a magnetic anisotropy to enhance the stability of the biasing. The hard bias layer is formed on a buffer layer and a seed layer, the seed layer being sandwiched between the buffer layer and the hard bias layer. The buffer layer has an anisotropic surface texture that promotes the magnetic anisotropy in the hard bias layer. The buffer layer can be CrMo or Ru or can be a bi-layer including a layer of CrMo with a layer of Ru over the CrMo. The seed layer can be constructed of a material having a BCC structure and is preferably constructed of CrMo.
    Type: Application
    Filed: December 12, 2006
    Publication date: June 12, 2008
    Inventors: James Mac Freitag, Mustafa Michael Pinarbasi
  • Publication number: 20080112090
    Abstract: A lead overlay design of a magnetic sensor is described with sensor and free layer dimensions such that the free layer is stabilized by the large demagnetization field due to the shape anisotropy. In one embodiment the giant magnetoresistive (GMR) effect under the leads is destroyed by removing the antiferromagnetic (AFM) and pinned layers above the free layer. The overlaid lead pads are deposited on the exposed spacer layer at the sides of the mask that defines the active region. In other embodiment a layer of electrically insulating material is deposited over the sensor to encapsulate it and thereby insulate it from contact with the hardbias structures. Various embodiments with self-aligned leads are also described. In a variation of the encapsulation embodiment, the insulating material is also deposited under the lead pads so the electrical current is channeled through the active region of the sensor and sidewall deposited lead pads.
    Type: Application
    Filed: November 9, 2006
    Publication date: May 15, 2008
    Inventors: James Mac Freitag, David Eugene Heim, Kuok San Ho, Wipul Pemsiri Jayasekara, Kim Y. Lee, Tsann Lin, Jyh-Shuey Lo, Mustafa Michael Pinarbasi, Ching Hwa Tsang
  • Patent number: 7369371
    Abstract: A magnetoresistive sensor having a pinned layer that extends beyond the stripe height defined by the free layer of the sensor. The extended pinned layer has a strong shape induced anisotropy that maintains pinning of the pinned layer moment. The extended portion of the pinned layer has sides beyond the stripe height that are perfectly aligned with the sides of the sensor within the stripe height. This perfect alignment is made possible by a manufacturing method that uses a mask structure for more than one manufacturing phase, eliminating the need for multiple mask alignments.
    Type: Grant
    Filed: August 15, 2005
    Date of Patent: May 6, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Kuok San Ho, Mustafa Michael Pinarbasi, Ching Hwa Tsang
  • Publication number: 20080094761
    Abstract: A magnetoresistive sensor having a shape enhanced pinning and a flux guide structure. The sensor includes a sensor stack with a pinned layer, spacer layer and pinned layer. First and second hard bias layers and lead layers extend from the sides of the sensor stack. The hard bias layers and leads have a stripe height that is smaller than the stripe height of the free layer, resulting in a free layer that extends beyond the back edge of the lead and hard bias layer. This portion of the free layer that extends beyond the back edge of the leads and hard bias layers provides a back flux guide. Similarly, the sensor may have a free layer that extends beyond the front edge of the lead and hard bias layers to provide a front flux guide. The pinned layer extends significantly beyond the back edge of the free layer, providing the pinned layer with a strong shape enhanced magnetic anisotropy.
    Type: Application
    Filed: October 24, 2006
    Publication date: April 24, 2008
    Inventors: James Mac Freitag, Kuok San Ho, Mustafa Michael Pinarbasi, Ching Hwa Tsang
  • Patent number: 7362547
    Abstract: A magnetic head having an improved PtMn layer formed by ion beam deposition, an antiparallel (AP) pinned layer structure formed above the PtMn layer, and a free layer formed above the AP pinned layer structure. The spin valve structure provides improved soft magnetic properties of the free layer as well as increases the dR/R of spin valve structures in which implemented.
    Type: Grant
    Filed: April 22, 2005
    Date of Patent: April 22, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Mustafa Michael Pinarbasi
  • Patent number: 7341876
    Abstract: A method for fabricating a sensor having anti-parallel tab regions. The method includes forming a free layer having tab areas on opposite sides of an active area, forming a first layer of a carbon composition above the active area of the free layer, the first layer of carbon being substantially absent from tab areas of the free area, forming spacer layers above the tab areas of the free layer, the spacer layers being operable to make magnetic moments of ferromagnetic layers on opposite sides thereof antiparallel, forming bias layers above the spacer layers, the bias layers being operative to substantially pin magnetic moments of the tab areas of the free layer, forming second layers of carbon composition above the tab areas of the free layer, and removing the layers of carbon composition and any portions of the layers overlying the layers of carbon composition.
    Type: Grant
    Filed: August 30, 2005
    Date of Patent: March 11, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Marie-Claire Cyrille, Hardayal Singh Gill, James Mac Freitag
  • Publication number: 20080055794
    Abstract: A magnetoresistive sensor having a pinned layer that extends beyond the free layer in the stripe height direction for improved shape enhanced pinning. The sensor includes hard bias layers and leads that extend in the stripe height direction beyond the stripe height of the free layer, providing increased conductive material for improved conduction of sense current to the sensor. The hard bias layers contact the sensor stack in the region between the ABS and the stripe height of the free layer, but are electrically insulated from the pinned layer in regions beyond the stripe height of the free layer by a layer of conformally deposited non-magnetic, electrically insulating material such as alumina.
    Type: Application
    Filed: August 30, 2006
    Publication date: March 6, 2008
    Inventors: James Mac Freitag, Mustafa Michael Pinarbasi
  • Publication number: 20080037183
    Abstract: A current perpendicular to plane (CPP) magnetoresistive sensor having a current path defined by first and second overlying insulation layers between which an electrically conductive lead makes content with a surface of the sensor stack. The current path being narrower than the width of the sensor stack allows the outer edges of the sensor stack to be moved outside of the active area of the sensor. This results in a sensor that is unaffected by damage at outer edges of the sensor layers. The sensor stack includes a free layer that is biased by direct exchange coupling with a layer of antiferromagnetic material (AFM layer). The strength of the exchange field can be controlled by adding Cr to the AFM material to ensure that the exchange field is sufficiently weak to avoid pinning the free layer.
    Type: Application
    Filed: August 10, 2006
    Publication date: February 14, 2008
    Inventors: James Mac Freitag, Kuok San Ho, Mustafa Michael Pinarbasi, Ching Hwa Tsang
  • Patent number: 7310209
    Abstract: A magnetoresistive sensor having hard bias layers constructed of CoPtCrB, which high coercivity when deposited over crystalline materials such as an AFM layer or other sensor material. The bias layer material exhibits high coercivity and high moment even when deposited over a crystalline structure such as that of an underlying sensor material by not assuming the crystalline structure of the underlying crystalline layer. The bias layer material is especially beneficial for use in a partial mill sensor design wherein a portion of the sensor layers extends beyond the active area of the sensor and the bias layer must be deposited on the extended portion of sensor material.
    Type: Grant
    Filed: September 29, 2004
    Date of Patent: December 18, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Mustafa Michael Pinarbasi
  • Patent number: 7280314
    Abstract: A magnetic write head for perpendicular magnetic recording having a laminated write pole with improved low saturation field.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: October 9, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hardayal Singh Gill, James Mac Freitag, Yimin Hsu, Yinshi Liu
  • Patent number: 7270854
    Abstract: A method for forming a magnetic head having an improved PtMn layer, including forming a PtMn layer by ion beam deposition, forming an antiparallel (AP) pinned layer structure above the PtMn layer, and forming a free layer above the AP pinned layer structure. The method provides a spin valve structure having improved soft magnetic properties of the free layer as well as increases the dR/R of spin valve structures in which implemented.
    Type: Grant
    Filed: November 19, 2003
    Date of Patent: September 18, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Mustafa Michael Pinarbasi
  • Patent number: 7268985
    Abstract: A magnetic head having an improved read head structure. The read head includes a free magnetic layer with hard bias elements disposed proximate its ends, where the hard bias elements include an improved hard bias magnetic grain structure. This is accomplished by fabricating the hard bias element as a bilayer structure having a first hard bias sublayer, a nonmagnetic midlayer and a second hard bias sublayer. The midlayer is preferably composed of a nonmagnetic material such as chromium, and the hard bias sublayers are composed of a magnetic material such as CoPtCr. Each sublayer is formed with its own magnetic grains, and because there are two sublayers, the hard bias element is fabricated with approximately twice the number of magnetic grains as the prior art single layer hard bias element.
    Type: Grant
    Filed: May 28, 2004
    Date of Patent: September 11, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: James Mac Freitag, James L. Nix, Mustafa Michael Pinarbasi
  • Patent number: 7230802
    Abstract: A method and apparatus for providing magnetostriction control in a free layer of a magnetic memory device is disclosed. The same target compositions for the free layers may be used, but the relative thickness values are modified to obtain a desired magnetostriction without a change in the magenetoristance ratio, ?R/R.
    Type: Grant
    Filed: November 12, 2003
    Date of Patent: June 12, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Mustafa Michael Pinarbasi