Abstract: The present invention generally relates to a TMR reader and a method for its manufacture. The TMR reader discussed herein adds a shield layer to the sensor structure. The shield layer is deposited over the capping layer so that the shield layer and the capping layer collectively protect the free magnetic layer within the sensor structure from damage during further processing. Additionally, the hard bias layer is shaped such that the entire hard bias layer underlies the hard bias capping layer so that a top lead layer is not present. By eliminating the top lead layer and including a shield layer within the sensor structure, the read gap is reduced while still protecting the free magnetic layer during later processing.

Abstract: A current-perpendicular-to-plane (CPP) tunneling magnetoresistance (TMR) or giant magnetoresistance (GMR) read sensor with ferromagnetic amorphous buffer and polycrystalline seed layers is disclosed for reducing a read gap, in order to perform magnetic recording at higher linear densities. The ferromagnetic amorphous buffer and polycrystalline seed layers couples to a ferromagnetic lower shield, thus acting as part of the ferromagnetic lower shield and defining the upper surface of the ferromagnetic polycrystalline seed layer as the lower bound of the read gap. In addition, a CPP TMR or GMR read sensor with nonmagnetic and ferromagnetic cap layers is also disclosed for reducing the read gap, in order to perform magnetic recording at even higher linear densities. The ferromagnetic cap layer couples to a ferromagnetic upper shield, thus acting as part of the ferromagnetic upper shield and defining the lower surface of the ferromagnetic cap layer as the upper bound of the read gap.

Abstract: The invention provides a current-perpendicular-to-plane (CPP) tunneling magnetoresistance (TMR) or giant magnetoresistance (GMR) read sensor with multiple ferromagnetic sense layers. In one embodiment of the invention, a CPP TMR read sensor comprises a first sense layer formed by a ferromagnetic polycrystalline Co—Fe film, a second sense layer formed by a ferromagnetic interstitial-type amorphous Co—Fe—B film, a third sense layer formed by a ferromagnetic substitute-type amorphous Co—Fe—X film where X is Hf, Zr or Y, and a fourth sense layer formed by a ferromagnetic Ni—Fe film. The third sense layer acts as a diffusion barrier layer to suppress Ni diffusion, thus allowing the incorporation of the Ni—Fe fourth sense layer for improving ferromagnetic properties of the multiple sense layers. The multiple sense layers induce spin-dependent scattering, thus facilitating the CPP TMR read sensor to exhibit a strong TMR effect.

Abstract: A current-perpendicular-to-plane (CPP) tunneling magnetoresistance (TMR) or giant magnetoresistance (GMR) read sensor with ferromagnetic buffer and seed layers is proposed for high-resolution magnetic recording. The ferromagnetic buffer layer is preferably formed of an amorphous Co—X (where X is Hf, Y, Zr, etc.) film. It provides the CPP read sensor with microstructural discontinuity from a ferromagnetic lower shield, thus facilitating the CPP read sensor to grow freely with preferred crystalline textures, and with ferromagnetic continuity to the ferromagnetic lower shield, thus acting as a portion of the ferromagnetic lower shield. The ferromagnetic seed layer is preferably formed of a polycrystalline Ni—X (where X is Pt, Pd, Rh, Ru, etc.) film. It exhibits a face-centered-cubic (fcc) structure and does not exchange-couple with the antiferromagnetic pinning layer.

Abstract: A current-perpendicular-to-plane (CPP) tunneling magnetoresistance (TMR) or giant magnetoresistance (GMR) read sensor with ferromagnetic buffer, shielding and seed layers is proposed for high-resolution magnetic recording. The ferromagnetic buffer layer is preferably formed of an amorphous Co—X (where X is Hf, Y, Zr, etc.) film. It provides the CPP read sensor with microstructural discontinuity from a ferromagnetic lower shield, thus facilitating the CPP read sensor to grow freely with preferred crystalline textures, and with ferromagnetic continuity to the ferromagnetic lower shield, thus acting as a portion of the ferromagnetic lower shield. The ferromagnetic shielding layer is preferably formed of a polycrystalline Ni—Fe film. It exhibits magnetic properties exactly identical to those of the ferromagnetic lower shield, thus acting identically as the ferromagnetic lower shield, and a uniform columnar grain morphology, thus initiating a uniform large grain morphology in the CPP read sensor.

Abstract: A dual magnetic tunnel junction (MTJ) sensor is provided with a longitudinal bias stack sandwiched between a first MTJ stack and a second MTJ stack. The longitudinal bias stack comprises an antiferromagnetic (AFM) layer sandwiched between first and second ferromagnetic layers. The first and second MTJ stacks comprise antiparallel (AP)-pinned layers pinned by AFM layers made of an AFM material having a higher blocking temperature than the AFM material of the bias stack allowing the AP-pinned layers to be pinned in a transverse direction and the bias stack to be pinned in a longitudinal direction. The demagnetizing fields of the two AP-pinned layers cancel each other and the bias stack provides flux closures for the sense layers of the first and second MTJ stacks.

Abstract: A current-to-perpendicular-to-plane (CPP) read sensor with multiple reference layers and associated fabrication methods are disclosed. According to one embodiment of the invention, the multiple reference layers of a CPP tunneling magnetoresistance (TMR) read sensor includes a first reference layer formed by a ferromagnetic polycrystalline Co—Fe film, a second reference layer formed by a ferromagnetic substitute-type amorphous Co—Fe—X film where X is Hf, Zr or Y, and a third reference layer formed by a ferromagnetic interstitial-type amorphous Co—Fe—B film. The first reference layer facilitates the CPP TMR read sensor to exhibit high exchange and antiparallel-coupling fields. The second reference layer provides a thermally stable flat surface, thus facilitating the CPP TMR read sensor to exhibit a low ferromagnetic-coupling field. The multiple reference layers may induce spin-dependent scattering, thus facilitating the CPP TMR sensor to exhibit a high TMR coefficient.

Abstract: A fall-down alarm system includes a contact detection unit, a non-contact detection unit and a fall-down evaluation unit connecting respectively to the contact detection unit and non-contact detection unit. The contact detection unit and non-contact detection unit respectively detect an abnormal detected shape of an object and abnormal life symptoms of the object, and then the fall-down evaluation unit determines a fall-down condition and sends a trigger signal to request assistance. Through the contact detection unit and non-contact detection unit respectively detecting the shape and life symptoms of the object, the erroneous fall-down judgment can be reduced.

Abstract: A current-to-perpendicular-to-plane (CPP) read sensor with multiple reference layers and associated fabrication methods are disclosed. According to one embodiment of the invention, the multiple reference layers of a CPP tunneling magnetoresistance (TMR) read sensor includes a first reference layer formed by a ferromagnetic polycrystalline Co—Fe film, a second reference layer formed by a ferromagnetic substitute-type amorphous Co—Fe—X film where X is Hf, Zr or Y, and a third reference layer formed by a ferromagnetic interstitial-type amorphous Co—Fe—B film. The first reference layer facilitates the CPP TMR read sensor to exhibit high exchange and antiparallel-coupling fields. The second reference layer provides a thermally stable flat surface, thus facilitating the CPP TMR read sensor to exhibit a low ferromagnetic-coupling field. The multiple reference layers may induce spin-dependent scattering, thus facilitating the CPP TMR sensor to exhibit a high TMR coefficient.

Abstract: A current-to-perpendicular-to-plane (CPP) read sensor with multiple reference layers and associated fabrication methods are disclosed. According to one embodiment, the multiple reference layers of a CPP read sensor include a first reference layer (e.g., Co—Fe) formed by a ferromagnetic polycrystalline film, a second reference layer (e.g., Co—Fe—Hf) formed by a ferromagnetic amorphous film, a third reference layer (e.g., Co—Fe—B) formed by a ferromagnetic amorphous film, and a fourth reference layer (e.g., Co—Fe) formed by a ferromagnetic polycrystalline film. A plasma treatment is applied to the fourth reference layer for surface smoothening, and no replenishment is needed as long as the fourth reference layer is not completely removed after the plasma treatment. The fourth reference layer protects the surface of the third reference layer from spin polarization deterioration caused by the plasma treatment, thereby maintaining a strong TMR or GMR effect.

Abstract: A read head having an improved longitudinal bias stack for stabilizing the sense layer structure of a CPP read sensor is proposed. The longitudinal bias stack is separated by an insulation layer from the CPP read sensor in each of two side regions, and is sandwiched together with the insulation layer and the CPP read sensor between lower and upper ferromagnetic shields in the read head. In a preferred embodiment of the invention, the longitudinal bias stack mainly comprises an Fe—Pt longitudinal bias layer without any seed layers, and thus the thickness of the insulation layer alone defines a spacing between the Fe—Pt longitudinal bias layer and the CPP read sensor. Since the Fe—Pt longitudinal bias layer without any seed layers exhibits good in-plane hard-magnetic properties after annealing and the spacing is narrow, the stabilization scheme is effective.

Abstract: A current-perpendicular-to-plane (CPP) read sensor with Co—Fe buffer layers is proposed to improve pinning and magnetoresistance properties. The read sensor comprises first and second Co—Fe buffer layers in the lower and upper portions of a keeper layer structure, respectively, third and fourth Co—Fe buffer layers in the lower and upper portion of a reference layer structure, respectively, and a fifth Co—Fe buffer layer in the lower portion of a sense layer structure. The first buffer layer is adjacent to a pinning layer and has a specific composition to improve unidirectional-anisotropy pinning properties. The second and third buffer layers are adjacent to an antiparallel-coupling layer and have specific compositions to improve bidirectional-anisotropy pinning properties. The fourth and fifth buffer layers are adjacent to a barrier or spacer layer and have specific compositions to improve magnetoresistance properties.

Abstract: A tunneling magnetoresistance (TMR) read sensor with a Co—Fe—B lower sense layer and a Co—Hf upper sense layer is disclosed. In order for the dual sense layers to exhibit a negative saturation magnetostriction (?S), their Fe contents are either substantially reduced or even eliminated, instead of adding a conventional Ni—Fe film as an additional sense layer. By optimizing compositions and thicknesses of the dual sense layers, the dual sense layers indeed exhibit a negative ?S, while the TMR sensor exhibits a TMR coefficient (?RT/RJ) of greater than 80% at a junction resistance-area product (RJAJ) of less than 2 ?-?m2.

Abstract: A tunneling magnetoresistive (TMR) sensor with a free layer made of a Co—Fe—B alloy is disclosed. The Co—Fe—B free layer has an Fe content of not greater than 10 atomic percent, and a B content of not greater than 10 atomic percent. The free-layer structure can include a first free layer lying on a barrier layer and a second free layer lying on the first free layer. The first free layer is made of an alloy selected from Co—Fe, Co—B and Co—Fe—B alloys, while the second free layer is made of an alloy selected from Co—B and Co—Fe—B alloys.

Abstract: A current-perpendicular-to-plane (CPP) magnetoresistance sensor and a method for forming a current-perpendicular-to-plane (CPP) magnetoresistance sensor. The method includes providing a ferromagnetic shield layer and disposing one or more seed layers on the ferromagnetic shield layer. The method also includes disposing a pinning layer on the one or more seed layers, wherein the pinning layer excludes PtMn, and disposing a pinned layer on the pinning layer. The shield layer, each of the one or more seed layers, the pinning layer, and the pinned layer are comprised of compounds having face-centered-cubic structures.

Abstract: A magnetic structure in one embodiment includes a tunnel barrier layer; a free layer; and a buffer layer between the tunnel barrier layer and the free layer, wherein a cross sectional area of the tunnel barrier layer in a direction parallel to a plane of deposition thereof is greater than a cross sectional area of the free layer in a direction parallel to a plane of deposition thereof, wherein a cross sectional area of the buffer layer in a direction parallel to a plane of deposition thereof is greater than a cross sectional area of the free layer in the direction parallel to the plane of deposition thereof. Additional systems and methods are also presented.

Abstract: A current-perpendicular-to-plane (CPP) tunneling magnetoresistance (TMR) or giant magnetoresistance (GMR) read sensor with ferromagnetic amorphous buffer and polycrystalline seed layers is disclosed for reducing a read gap, in order to perform magnetic recording at higher linear densities. The ferromagnetic amorphous buffer and polycrystalline seed layers couples to a ferromagnetic lower shield, thus acting as part of the ferromagnetic lower shield and defining the upper surface of the ferromagnetic polycrystalline seed layer as the lower bound of the read gap. In addition, a CPP TMR or GMR read sensor with nonmagnetic and ferromagnetic cap layers is also disclosed for reducing the read gap, in order to perform magnetic recording at even higher linear densities. The ferromagnetic cap layer couples to a ferromagnetic upper shield, thus acting as part of the ferromagnetic upper shield and defining the lower surface of the ferromagnetic cap layer as the upper bound of the read gap.

Abstract: A magnetic head in one embodiment includes first and second ferromagnetic shield layers, first and second nonmagnetic read-gap layers positioned between the first and second ferromagnetic shield layers, a sensor used in a current-in-plane (CIP) mode, first and second longitudinal bias layers electrically coupled with the sensor, and first and second conducting layers electrically coupled with the first and second longitudinal bias layers, respectively.

Abstract: This invention provides a CPP TMR or GMR sensor with an amorphous ferromagnetic lower keeper layer and a crystalline ferromagnetic upper keeper layer. The amorphous ferromagnetic lower keeper layer strongly exchange-couples to an underlying antiferromagnetic pinning layer and planarizes its rough surface. The crystalline ferromagnetic upper keeper layer strongly antiparallel-couples to an adjacent ferromagnetic reference layer across a nonmagnetic spacer layer. The amorphous ferromagnetic lower keeper layer is preferably made of a Co—Fe—B alloy film with an Fe content high enough to ensure strong exchange-coupling to the underlying antiferromagnetic pinning layer, and with a B content high enough to ensure the formation of an amorphous phase for planarizing an otherwise rough surface due to the underlying antiferromagnetic pinning layer.

Abstract: A method for fabricating a magnetic head including a spin valve sensor having a sensor layer stack that includes a pinned magnetic layer, a spacer layer formed on the pinned magnetic layer, and a free magnetic layer formed on the spacer layer. In a preferred embodiment the spacer layer is comprised of CuOx. The method includes the plasma smoothing of the upper surface of the pinned magnetic layer prior to depositing the spacer layer, and a preferred plasma gas is a mixture of argon and oxygen.