Patents by Inventor Jeffrey Childress

Jeffrey Childress 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: 20070171581
    Abstract: Formation of the magnetic sensor layers of a magnetic sensor are separated into at least two depositions to reduce the dimension of the sensor. The free layer portion of the sensor is deposited at a different process step than the pinned layer portion. The top of the free layer stack can be a tunnel barrier, the free layer, or part of the free layer. The free layer stack also may contain an in-stack bias layer. The longitudinal bias layer may be patterned in a separate processing step, which allows the stack containing the free layer to be effectively thinner and allow smaller track width dimensions.
    Type: Application
    Filed: January 20, 2006
    Publication date: July 26, 2007
    Inventors: Jeffrey Childress, Robert Fontana, Jeffrey Lille
  • Publication number: 20070138002
    Abstract: A method for manufacturing a magnetic layer with a magnetic anisotropy. The method includes an endpoint detection process for determining an end point to carefully control the final thickness of the magnetic layer. The method includes depositing a magnetic layer and then depositing a sacrificial layer over the magnetic layer. A low power angled ion milling is then performed until the magnetic layer has been reached. The angled ion milling can be performed at an angle relative to normal and without rotation in order to form an anisotropic surface texture that induces a magnetic anisotropy in the magnetic layer. An indicator layer may be included between the magnetic layer and the sacrificial layer in order to further improve endpoint detection.
    Type: Application
    Filed: December 22, 2006
    Publication date: June 21, 2007
    Inventors: Matthew Carey, Jeffrey Childress, Stefan Maat
  • Publication number: 20070137028
    Abstract: A method for manufacturing a magnetic layer with a magnetic anisotropy. The method includes an endpoint detection process for determining an end point to carefully control the final thickness of the magnetic layer. The method includes depositing a magnetic layer and then depositing a sacrificial layer over the magnetic layer. A low power angled ion milling is then performed until the magnetic layer has been reached. The angled ion milling can be performed at an angle relative to normal and without rotation in order to form an anisotropic surface texture that induces a magnetic anisotropy in the magnetic layer. An indicator layer may be included between the magnetic layer and the sacrificial layer in order to further improve endpoint detection.
    Type: Application
    Filed: December 22, 2006
    Publication date: June 21, 2007
    Inventors: Matthew Carey, Jeffrey Childress, Stefan Maat
  • Publication number: 20070139820
    Abstract: A magnetic write head for magnetic data recording. The magnetic write head has a write pole with a magnetic anisotropy induced by an angled, directional ion milling of a seed layer. The magnetic anisotropy is such that a magnetic easy axis of magnetization is oriented substantially parallel with the air bearing surface (ABS) of the write head. This orientation of the easy axis of magnetization increases the write speed and data rate of the write head by increasing the speed with which the magnetization of the write pole can switch from one direction to another writing.
    Type: Application
    Filed: December 22, 2006
    Publication date: June 21, 2007
    Inventors: Matthew Carey, Jeffrey Childress, Stefan Maat
  • Publication number: 20070139826
    Abstract: A magnetic shield for use in a magnetic head. The magnetic shield has a magnetic anisotropy associated with a magnetic easy axis of magnetization oriented substantially parallel with the air bearing surface. The magnetic anisotropy of the shield is induced by an anisotropic surface texture. This anisotropic surface texture can be formed in a surface of one or more magnetic layers of the shield, or can be formed in a surface of an under-layer on which the shield is deposited. The shield could also be constructed as a lamination of magnetic layers separated by non-magnetic layers, with the anisotropic surface texture being formed on one or more of the non-magnetic layers.
    Type: Application
    Filed: December 22, 2006
    Publication date: June 21, 2007
    Inventors: Matthew Carey, Jeffrey Childress, Stefan Maat
  • Publication number: 20070133251
    Abstract: A Magnetic Random Access Memory (MRAM) cell and array for storing data. The MRAM array includes a memory cell having a magnetic pinned layer, a magnetic free layer and a non-magnetic spacer or barrier layer sandwiched between the pinned and free layer. The pinned layer has magnetization that is pinned, and the free layer has a magnetization that is free to rotate but is stable in directions that are parallel or antiparallel with the magnetization of the pinned layer. The free layer has a magnetic anisotropy the maintains the stability of the free layer magnetization. The free layer anisotropy is induced by a surface roughness either in the surface of the free layer itself, or in the surface of the underling barrier/spacer layer. This anisotropic roughness is induced by an angled direct ion milling.
    Type: Application
    Filed: October 2, 2006
    Publication date: June 14, 2007
    Inventors: Matthew Carey, Jeffrey Childress, Stefan Maat
  • Publication number: 20070133132
    Abstract: A magnetoresistive sensor having a magnetic anisotropy induced in one or both of the free layer and/or pinned layer. The magnetic anisotropy is induced by a surface texture formed in the surface of the magnetic layer of either or both of the free layer or pinned layer. The surface texture is formed by a direct, angled ion mill performed on the surface of the magnetic layer while holding the wafer on a stationary chuck. By applying this ion milling technique, the magnetic anisotropy of the pinned layer can be formed in a first direction (eg. perpendicular to the ABS) while the magnetic anisotropy of the free layer can be formed perpendicular to that of the pinned layer (eg. parallel to the ABS).
    Type: Application
    Filed: December 14, 2005
    Publication date: June 14, 2007
    Inventors: Matthew Carey, Jeffrey Childress, Stefan Maat
  • Publication number: 20070109692
    Abstract: A magnetoresistive sensor having improved pinning field strength. The sensor includes a pinned layer structure pinned by exchange coupling with an antiferromagnetic (AFM) layer. The AFM layer is constructed upon an under layer having treated surface with an anisotropic roughness. The anisotropic roughness, produced by an angled ion etch, results in improved pinning strength. The underlayer may include a seed layer and a thin layer of crystalline material such as PtMn formed over the seed layer. The magnetic layer may include a first sub-layer of NiFeCr and a second sub-layer of NiFe formed there over. The present invention also includes a magnetoresistive sensor having a magnetic layer deposited on an underlayer (such as a non-magnetic spacer) having a surface treated with an anisotropic texture. An AFM layer is then deposited over the magnetic layer.
    Type: Application
    Filed: November 17, 2005
    Publication date: May 17, 2007
    Inventors: Matthew Carey, Jeffrey Childress, James Freitag, Stefan Maat, Mustafa Pinarbasi
  • Publication number: 20070109693
    Abstract: A magnetic head including a CPP GMR read sensor that includes a reference layer, a free magnetic layer and a spacer layer that is disposed between them, where the free magnetic layer and the reference magnetic layer are each comprised of Co2MnX where X is a material selected from the group consisting of Ge, Si, Al, Ga and Sn, and where the spacer layer is comprised of a material selected from the group consisting of Ni3Sn, Ni3Sb, Ni2LiGe, Ni2LiSi, Ni2CuSn, Ni2CuSb, Cu2NiSn, Cu2NiSb, Cu2LiGe and Ag2LiSn. Further embodiments include a dual spin valve sensor where the free magnetic layers and the reference layers are each comprised of Heusler alloys. A further illustrative embodiment includes a laminated magnetic layer structure where the magnetic layers are each comprised of a ferromagnetic Heusler alloy, and where the spacer layers are comprised of a nonmagnetic Heusler alloy.
    Type: Application
    Filed: November 16, 2005
    Publication date: May 17, 2007
    Inventors: Matthew Carey, Jeffrey Childress, Stefan Maat
  • Publication number: 20070097558
    Abstract: A current-perpendicular-to-the-plane spin-valve (CPP-SV) magnetoresistive sensor has an insulating layer with at least one aperture that confines the flow of sense current through the active region. The apertures are located closer to the sensing edge of the sensor than to the back edge of the sensor. The aperture (or apertures) are patterned by e-beam lithography, which enables the number, size and location of the apertures to be precisely controlled. The insulating layer may be located inside the electrically conductive nonmagnetic spacer layer, or outside of the magnetically active layers of the spin-valve. More than one insulating layer may be included in the stack to define conductive current paths where the apertures of the insulating layers overlap. The apertures are filled with electrically conductive material, typically the same material as that used for the spacer layer.
    Type: Application
    Filed: November 3, 2005
    Publication date: May 3, 2007
    Inventors: Matthew Carey, Jeffrey Childress, Stefan Maat, Neil Smith
  • Publication number: 20070047155
    Abstract: A current-perpendicular-to-the-plane spin-valve (CPP-SV) magnetoresistive sensor has an improved antiparallel (AP) pinned structure, i.e., a structure with first (AP1) and second (AP2) ferromagnetic layers separated by a nonmagnetic antiparallel coupling (APC) layer with the magnetization directions of AP1 and AP2 oriented substantially antiparallel. The AP2 ferromagnetic layer (the layer in contact with the SV spacer layer) is an alloy of a ferromagnetic material and one or more additive elements of Cu, Au and Ag. The additive elements reduce the magnetic moment of the AP2 layer, which enables its thickness to be increased so that its magnetic moment remains close to the magnetic moment of the AP1 ferromagnetic layer. The thicker AP2 layer allows for more bulk spin-dependent scattering of electrons which increases the magnetoresistance of the sensor.
    Type: Application
    Filed: August 30, 2005
    Publication date: March 1, 2007
    Inventors: Matthew Carey, Jeffrey Childress, Stefan Maat
  • Publication number: 20070047154
    Abstract: Current-perpendicular-to-planes (CPP) read sensors for magnetic heads having constrained current paths made of lithographically-defined conductive vias, and methods of making the same, are disclosed. In one illustrative example, a sensor stack structure which includes an electrically conductive spacer layer is formed over a first shield layer. An insulator layer is deposited over and adjacent the spacer layer, and a resist structure which exposes one or more portions of the insulator layer is formed over the insulator layer. With the resist structure in place, the exposed insulator layer portions are removed by etching to form one or more apertures through the insulator layer down to the spacer layer. Electrically conductive materials are subsequently deposited within the one or more apertures to form one or more lithographically-defined conductive vias of a current-constraining structure.
    Type: Application
    Filed: September 1, 2005
    Publication date: March 1, 2007
    Inventors: Jeffrey Childress, Jordan Katine
  • Publication number: 20070019338
    Abstract: A CPP GMR sensor structure having free and reference layers, where the magnetic orientations of the free and reference layers are non-orthogonal. In one embodiment, a ferromagnetic free layer film has a bias-point magnetization nominally oriented in plane of the film thereof, in a first direction at an angle ?fb with respect to a longitudinal axis being defined as the intersection of the plane of deposition of the free layer and the plane of the ABS. A ferromagnetic reference layer film has a bias-point magnetization nominally oriented in a plane of the film thereof, in a second direction at angle ?rb with respect to said longitudinal axis that is not orthogonal to the said first direction.
    Type: Application
    Filed: July 25, 2005
    Publication date: January 25, 2007
    Inventors: Jeffrey Childress, Neil Smith
  • Publication number: 20060221514
    Abstract: A magnetoresistive sensor having a hard magnetic pinning layer with an engineered magnetic anisotropy in a direction substantially perpendicular to the medium facing surface. The hard magnetic pinning layer may be constructed of CoPt, CoPtCr, or some other magnetic material and is deposited over an underlayer that has been ion beam etched. The ion beam etch has been performed at an angle with respect to normal in order to induce anisotropic roughness for example in form of oriented ripples or facets oriented along a direction parallel to the medium facing surface. The anisotropic roughness induces a strong uniaxial magnetic anisotropy substantially perpendicular to the medium facing surface in the hard magnetic pinning layer deposited there over.
    Type: Application
    Filed: March 31, 2005
    Publication date: October 5, 2006
    Inventors: Matthew Carey, Jeffrey Childress, Eric Fullerton, Stefan Maat
  • Publication number: 20060218774
    Abstract: A magnetoresistive sensor having a hard bias layer with an engineered magnetic anisotropy in a direction substantially parallel with the medium facing surface. The hard bias layer may be constructed of CoPt, CoPtCr or some other magnetic material and is deposited over an underlayer that has been ion beam etched. The ion beam etch has been performed at an angle with respect to normal in order to induce anisotropic roughness on its surface for example in form of oriented ripples or facets. The anisotropic roughness induces a uniaxial magnetic anisotropy substantially parallel to the medium facing surface in the hard magnetic bias layers deposited there over.
    Type: Application
    Filed: March 31, 2005
    Publication date: October 5, 2006
    Inventors: Matthew Carey, Jeffrey Childress, Eric Fullerton, Stefan Maat
  • Publication number: 20060222112
    Abstract: A magnetoresistive sensor having a hard bias layer with an engineered magnetic anisotropy in a direction substantially parallel with the medium facing surface. The hard bias layer may be constructed of CoPt, CoPtCr or some other magnetic material and is deposited over an underlayer that has been ion beam etched. The ion beam etch has been performed at an angle with respect to normal in order to induce anisotropic roughness on its surface for example in form of oriented ripples or facets. The anisotropic roughness induces a uniaxial magnetic anisotropy substantially parallel to the medium facing surface in the hard magnetic bias layers deposited there over.
    Type: Application
    Filed: March 31, 2005
    Publication date: October 5, 2006
    Inventors: Matthew Carey, Jeffrey Childress, Eric Fullerton, Stefan Maat
  • Publication number: 20060218775
    Abstract: A magnetoresistive sensor having a hard magnetic pinning layer with an engineered magnetic anisotropy in a direction substantially perpendicular to the medium facing surface. The hard magnetic pinning layer may be constructed of CoPt, CoPtCr, or some other magnetic material and is deposited over an underlayer that has been ion beam etched. The ion beam etch has been performed at an angle with respect to normal in order to induce anisotropic roughness for example in form of oriented ripples or facets oriented along a direction parallel to the medium facing surface. The anisotropic roughness induces a strong uniaxial magnetic anisotropy substantially perpendicular to the medium facing surface in the hard magnetic pinning layer deposited there over.
    Type: Application
    Filed: March 31, 2005
    Publication date: October 5, 2006
    Inventors: Matthew Carey, Jeffrey Childress, Eric Fullerton, Stefan Maat
  • Publication number: 20060221513
    Abstract: A magnetoresistive sensor having an in stack bias layer with an engineered magnetic anisotropy in a direction parallel with the medium facing surface. The in-stack bias layer may be constructed of CoPt, CoPtCr or some other magnetic material and is deposited over an underlayer that has been ion beam etched. The ion beam etch has been performed at an angle with respect to normal in order to form anisotropic roughness in form of oriented ripples or facets. The anisotropic roughness induces a uniaxial magnetic anisotropy substantially parallel to the medium facing surface in the hard magnetic in-stack bias layer deposited thereover.
    Type: Application
    Filed: March 31, 2005
    Publication date: October 5, 2006
    Inventors: Matthew Carey, Jeffrey Childress, Eric Fullerton, Stefan Maat
  • Publication number: 20060221515
    Abstract: A magnetoresistive sensor having a self biased free layer. The free layer is constructed upon an underlayer that has been treated by a surface texturing process that configures the underlayer with an anisotropic roughness that induces a magnetic anisotropy in the free layer. The treated layer underlying the free layer can be a spacer layer sandwiched between the free layer and pinned layer or can be a separate underlayer formed opposite the spacer layer. Alternatively, the texturing of an underlayer can be used to induce a magnetic anisotropy in a bias layer that is separated from the free layer by an orthogonal coupling layer. This self biasing of the free layer induced by texturing can also be used in conjunction with biasing from a hard-bias structure.
    Type: Application
    Filed: July 7, 2005
    Publication date: October 5, 2006
    Inventors: Matthew Carey, Jeffrey Childress, James Nix, Stefan Maat, Ian McFadyen
  • Publication number: 20060221509
    Abstract: A magnetoresistive sensor based on the spin accumulation effect has an in-stack biasing structure with a ferromagnetic biasing layer that is magnetically-coupled orthogonally with the sensor free ferromagnetic layer across a spacer layer. The sensor has an electrically conductive strip with a first tunnel barrier and a free ferromagnetic layer on the front or sensing end of the strip and second tunnel barrier and a fixed ferromagnetic layer on the back end of the strip. A magnetically-coupling spacer layer is formed on the free layer and the ferromagnetic biasing layer is formed on the spacer layer. The magnetically-coupling layer induces direct orthogonal magnetic coupling between the in-plane magnetization directions of the biasing layer and the free layer.
    Type: Application
    Filed: March 29, 2005
    Publication date: October 5, 2006
    Inventors: Matthew Carey, Jeffrey Childress, Stefan Maat