Abstract: A microwave bandstop filter having a magnetic strip formed over dielectric material. The magnetic resonant frequency is controlled by an induced magnetic anisotropy in the magnetic strip of the microwave bandstop filter. The magnetic anisotropy field is induced by an anisotropic surface texture formed on the surface of the magnetic strip itself, or formed on an underlying layer. Alternatively, the anisotropic surface texture could be formed on both an underlying layer and on the magnetic strip itself. This induced magnetic anisotropy field allows the resonant frequency of the microwave filter to be controlled over a wide frequency range and make high frequency operation possible without reliance on the application of an externally applied magnetic field.

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.

Abstract: A magnetoresistive sensor having a magnetically stable free layer fabricated from a material having a positive magnetostriction such as a Co—Fe—B alloy. Although the free layer is fabricated from a material that has a positive magnetostriction, which would ordinarily make the free layer unstable, the magnetization of the free layer remains stable because of an induced magnetic anisotropy that has an easy axis of magnetization oriented parallel to the Air-bearing Surface (ABS). This magnetic anisotropy of the free layer is induced by an anisotropic texturing of the surface of the free layer. The resulting anisotropic surface texture is produced by an ion milling process that utilizes an ion beam directed at an acute angle relative to the normal to the surface of the wafer whereon the sensor is fabricated while the wafer is held on a stationary chuck.

Abstract: Current-perpendicular-to-plane (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 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.

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.

Abstract: A magnetoresistive sensor having a pinned layer that includes a first magnetic layer (AP1) a second magnetic layer (AP2) and an antiparallel coupling layer sandwiched between the AP1 and AP2 layers. The AP1 layer is adjacent to a layer of antiferromagnetic material (AFM layer) and is constructed so as to have a long spin diffusion length. The long spin diffusion length of the AP1 layer minimizes the negative GMR contribution of the AP1 layer, thereby increasing the overall GMR effect of the sensor.

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.

Abstract: A current perpendicular to plane dual giant magnetoresistive sensor (dual CPP GMR sensor) that prevents spin torque noise while having high dR/R performance. The sensor has a design that maximizes the GMR effect (dR/R) by providing a pinned layer structure that maximizes the positive GMR contribution of the AP2 layer (or magnetic layer closest to the spacer layer) while minimizing the negative GMR contribution of the AP1 layer. The pinned layer structure includes an AP1 layer that includes a thin CoFe layer that is exchange coupled with an IrMn or IrMnCr AFM layer and has two or more Co layers with a spin blocking layer sandwiched between them. The use of the Co layers and the spin blocking layer in the AP1 layer minimizes the negative contribution of the AP1 layer. The AP2 layer has a plurality of CoFe layers with nano-layers such as Cu sandwiched between the CoFe layers.

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.

Abstract: A current perpendicular to plane magnetoresistive sensor having improved resistance amplitude change and reduced spin torque noise. The sensor has an antiparallel coupled pinned layer structure with at least one of the layers of the pinned layer structure includes a high spin polarization material such as Co2FeGe. The sensor can also include an antiparallel coupled free layer.

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).

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.

Abstract: A TMR 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.

Abstract: A magnetic medium for perpendicular magnetic data recording. The magnetic medium has a magnetically soft under-layer and a magnetically harder top layer. The magnetic under-layer has a magnetic anisotropy that is oriented in a radial direction relative to the magnetic medium. The magnetic anisotropy is induced by an anisotropic texture on the surface of the magnetic underlayer.

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.

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.

Abstract: A magnetoresistive sensor having an in stack bias structure. The sensor includes a bias spacer that allows biasing of free layer magnetic moment in a direction orthogonal to the magnetic moment of the biasing layer.

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.

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.

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.