5274results about "Manufacture of flux-sensitive heads" patented technology

A magnetoresistive element which records information by supplying spin-polarized electrons to a magnetic material, includes a first pinned layer which is made of a magnetic material and has a first magnetization directed in a direction perpendicular to a film surface, a free layer which is made of a magnetic material and has a second magnetization directed in the direction perpendicular to the film surface, the direction of the second magnetization reversing by the spin-polarized electrons, and a first nonmagnetic layer which is provided between the first pinned layer and the free layer. A saturation magnetization Ms of the free layer satisfies a relationship 0≧Ms<√{square root over ( )}{Jw/(6nAt)}. Jw is a write current density, t is a thickness of the free layer, A is a constant.

A RRAM memory cell is formed on a silicon substrate having a operative junction therein and a metal plug formed thereon, includes a first oxidation resistive layer; a first refractory metal layer; a CMR layer; a second refractory metal layer; and a second oxidation resistive layer. A method of fabricating a multi-layer electrode RRAM memory cell includes preparing a silicon substrate; forming a junction in the substrate taken from the group of junctions consisting of N+ junctions and P+ junctions; depositing a metal plug on the junction; depositing a first oxidation resistant layer on the metal plug; depositing a first refractory metal layer on the first oxidation resistant layer; depositing a CMR layer on the first refractory metal layer; depositing a second refractory metal layer on the CMR layer; depositing a second oxidation resistant layer on the second refractory metal layer; and completing the RRAM memory cell.

A magnetic head for perpendicular recording on double layer media with suppressed side writing and controlled write width is disclosed. The present invention reduces the problem of side writing and controls the write width of the writing element by providing a writing element with a trailing edge sized dimensionally larger than the leading edge, side shields, and specifically spaced writing gaps placed at various distances between the write element and the side shields, return poles, and the main pole.

The present invention provides a tunneling magneto-resistive read sensor structure that improves sensitivity and linear density of the sensor structure. The sensor includes first and second electrodes and a stack positioned between the electrodes. The stack includes first and second free layers with magnetization orientations that are biased relative to each other. A tunneling barrier (insulating layer) or non-magnetic metal spacer is positioned between the first and second free layers. A sense current is passed between the first and second free layers of the stack. The amount of current passing through the first and second free layer changes based upon the orientation of the first and second free layers relative to each other.

The preferred embodiment of the present invention provides a write head having an interlaced conductor coil winding and method of fabrication. The interlaced winding of the present invention may have alternating turns of a first and a second coil. In the preferred embodiment, the side walls of successive coil turns are separated by an ultra thin inorganic insulation which defines the distance between successive turns of the first and second coil. In one method of fabrication, a conductive seed layer is deposited on a generally planar insulative surface, a resist mask is formed on the seed layer, and a conductive material deposited on the exposed seed layer to form the turns of the first coil. The masked portions of the seed layer are removed, after resist mask removal, to electrically isolate the turns of the first coil. The inorganic insulation may be formed in a layer conformal with the first coil. The second coil is formed between the turns of the first coil. A seed layer and mask may be used to facilitate second coil deposition. Etching, or planarization, may be used to electrically isolate the turns of the second coil. A capping layer may be formed over any exposed conductor material to insulate the winding from an upper pole structure or other overlying structure. Embodiments of the present invention may have multiple layers of conductor winding having some conventional, or all interlaced coil structure.

A method and system for providing a magnetoresistive sensor is disclosed. The method and system include providing a first pinned layer, providing a free layer having a length, and providing a first spacer layer disposed between the first pinned layer and the free layer. The first spacer layer has a first interface with the first pinned layer. The method and system also include providing a second pinned layer and providing a second spacer layer disposed between the free layer and the second pinned layer. The second spacer layer has a second interface with the second pinned layer. A direction of a current passed through the magnetoresistive sensor is through the first interface, through the second interface, and along at least a portion of the length of the free layer.

A method and system for manufacturing a pole for a magnetic recording head. The method and system include providing an insulator and fabricating at least one hard mask on the insulator. The at least one hard mask has an aperture therein. The method and system also include removing a portion of the insulator to form a trench within the insulator. The trench is formed under the aperture. The method and system further include depositing at least one ferromagnetic material. The pole includes a portion of the ferromagnetic material within the trench.

A method and system provide a magnetic transducer including first and second shields, a read sensor, and magnetic bias structure(s) adjacent to the read sensor. The read sensor and magnetic bias structure(s) are between the shields. The second shield includes first and second ferromagnetic layers, a nonmagnetic spacer layer and a pinning layer. The nonmagnetic spacer layer is between the first and second ferromagnetic layers. The first ferromagnetic layer is between the read sensor and the nonmagnetic spacer layer. The pinning layer is adjacent to the second ferromagnetic layer. The first and second ferromagnetic layers are coupled antiparallel. The first ferromagnetic layer includes magnetic layers interleaved with trilayer(s). Each magnetic layer includes crystalline grains. The trilayer(s) include an amorphous nonmagnetic layer less than three Angstroms thick. Thus, the magnetic layers are ferromagnetically coupled but the crystalline grains in different magnetic layers are decoupled.

A magnetic disk including a substrate, a recording track section which is made of a magnetic member for recording and reproducing information magnetically and is provided on the substrate, and a guard band member which is provided between the recording track sections adjacent to each other so that they are substantially continued in a track direction and is harder than the magnetic member and is made of a non-magnetic material. Moreover, the magnetic member is not provided or magnetic members with a different thickness from the magnetic member forming the recording track section is provided on a lower area of the guard band member.

An enchance recording head design provides conduction and mechanical restraint control in order to minimize the pole tip protrusion and the head temperature resulting from the thermal heating of the magnetic recording head during operation. In one embodiment, the recording head includes a hybrid diffuser formed within an insulation layer, at a predetermined distance from the head write section. The hybrid diffuser is comprised of a thermal conduction layer with high thermal conductivity, such as gold or copper, and a mechanical restraint layer having near zero CTE, such as a 60-80% face-centered-cubic NiFe (Invar) material. The hybrid diffuser is recessed from the ABS to prevent the delamination of the hybrid diffuser due to the otherwise displacement incompatibility between the inner insulating layer and the hybrid diffuser at the ABS.

The present invention provides an improved top spin valve and method of fabrication. In the preferred embodiment of the top spin valve of the present invention, a seed layer is formed of non-magnetic material having the elements Ni and Cr. In the preferred embodiments, the seed layer material has an ion milling rate comparable to that of the free layer material. This allows free layer sidewalls to be formed with shorter tails, improving free layer-to-magnetic bias layer junction, thus improving free layer domain structure and track width. In one embodiment, the seed layer may have NiFeCr, with Cr from about 20% to 50%. In another embodiment, the seed layer may have NiCr, with about 40%. Some embodiments may have the seed layer formed on an optional Ta pre-seed layer. Such embodiments provide an improved fcc (111) texture particularly for NiFe and for NiFe/CoFe free layers grown on a seed layer improving spin valve performance, and especially in embodiments having very thin NiFe free layers, ultra thin NiFe free layers, and free layers without NiFe, such as a free layer of CoFe. Such a seed layer can improve AFM pinning layer texture to improve the exchange bias, thus providing better thermal stability. Such a seed layer also provides high resistivity and can improve the magnetostriction of adjacent NiFe free layer material or improve the soft properties of an adjacent CoFe free layer.

A method and system for providing a read magnetic transducer having an air-bearing surface (ABS) is described. The magnetic read transducer includes a first shield, a read sensor stack, an antiferromagnetic (AFM) tab, and a second shield. The read sensor stack includes a pinned layer, a spacer layer, and a free layer. The spacer layer is nonmagnetic and between the pinned layer and the free layer. A portion of the read sensor stack is at the ABS. The AFM tab is recessed from the ABS and adjacent to a portion of the pinned layer. The read sensor resides between the first shield and the second shield.

We describe the structure and method of forming a STT-MTJ MRAM cell that utilizes transfer of spin angular momentum as a mechanism for changing the magnetic moment direction of a free layer. The device includes an IrMn pinning layer, a SyAP pinned layer, a naturally oxidized, crystalline MgO tunneling barrier layer that is formed on an Ar-ion plasma smoothed surface of the pinned layer and, in one embodiment, a free layer that comprises an amorphous layer of Co₆₀Fe₂₀B₂₀. of approximately 20 angstroms thickness formed between two crystalline layers of Fe of 3 and 6 angstroms thickness respectively. The free layer is characterized by a low Gilbert damping factor and by very strong polarizing action on conduction electrons. The resulting cell has a low critical current, a high dR/R and a plurality of such cells will exhibit a low variation of both resistance and pinned layer magnetization angular dispersion.

The present invention provides spin valve with a magnetic compensation field which couples to the pinned layer and counteracts sensing current induced magnetic field. The spin valve sensor of the present invention may be formed having a structure comprising: a free layer, a first spacer layer, a pinned layer, a pinning layer, a second spacer layer, and a compensation layer. The compensation layer may be formed of ferromagnetic material with its magnetization set so that the compensation field oriented in a reinforcing relationship with the magnetization of the pinned layer. Current through the compensation layer and the spacer layer may add to the compensation field. The spacer layer may be formed of a nonmagnetic material of sufficient thickness to prevent interaction between the pinning layer and the compensation layer while providing a sufficiently small distance to allow sufficient magnetic coupling to the pinned layer. The present invention may be used to improve thermal stability and reduce Barkhausen noise while not impacting output symmetry.

An MTJ in an MRAM array or in a TMR read head is comprised of a capping layer with a lower inter-diffusion barrier layer, an intermediate oxygen gettering layer, and an upper metal layer that contacts a top conductor. The composite capping layer is especially useful with a moderate spin polarization free layer such as a NiFe layer with a Fe content of about 17.5 to 20 atomic %. The capping layer preferably has a Ru/Ta/Ru configuration in which the lower Ru layer is about 10 to 30 Angstroms thick and the Ta layer is about 30 Angstroms thick. As a result, a high dR/R of about 40% is achieved with low magnetostriction less than about 1.0 E-6 in an MTJ in an MRAM array. Best results are obtained with an AlOx tunnel barrier layer formed by an in-situ ROX process on an 8 to 10 Angstrom thick Al layer.

A method of forming a near field transducer (NFT) for energy assisted magnetic recording is disclosed. A structure comprising an NFT metal layer and a first hardmask layer over the NFT metal layer is provided A first patterned hardmask is formed from the first hardmask layer, the first patterned hardmask disposed over a disk section and a pin section of the NFT to be formed. An etch process is performed on the NFT metal layer via the first patterned hardmask, the etch process forming the NFT having the disk section and the pin section.

A method and system for providing a magnetic transducer having an air-bearing surface (ABS) is described. The magnetic read transducer includes a first shield, a magnetoresistive sensor, at least one soft magnetic side shield, and a second shield. The magnetoresistive sensor includes a sensor layer having at least one edge in the track width direction along the ABS. The at least one soft magnetic side shield is adjacent to the at least one edge of the sensor layer. The at least one soft magnetic side shield has a full film permeability of at least ten. The magnetoresistive sensor is between the first shield and the second shield and free of an in-stack hard bias layer.

A disk drive includes a disk having a recording surface, a head stack assembly that includes a body portion, an actuator arm cantilevered from the body portion and a head gimbal assembly supported at the actuator arm. The head gimbal assembly includes a suspension having a first end and a second end, the first end being attached to the actuator arm, a slider coupled to the second end of the suspension, the slider comprising a transducer for reading from and writing to the recording surface. A gimbal is coupled to the second end of the suspension and to the slider. An array of diodes is attached to the suspension to protect the transducer from electrostatic discharge or electrical overstress events.

A method and system for providing a magnetoresistive sensor and a read head that includes the magnetoresistive sensor is disclosed. The method and system include providing a pinned layer, a nonmagnetic spacer layer and a composite sensor layer. The pinned layer has a first magnetization that is pinned in a particular direction. The nonmagnetic spacer layer resides between the composite sensor layer and the pinned layer. The composite sensor layer includes a CoFe layer and a composite layer adjacent to the CoFe layer. The composite layer includes CoFe and at least one of Ta, Hf, Ti, Nb, Zr, Au, Ag, Cu, B, C, O₂, H₂ and N₂.

A method and system for providing a magnetic element is disclosed. The method and system include providing a ferromagnetic pinned layer, providing a free layer, and providing a spacer layer between the pinned layer and the free layer. The pinned layer and free layer are ferromagnetic and have a pinned layer magnetization and a free layer magnetization, respectively. The spacer layer is nonmagnetic. In one aspect, the free layer is configured to have an increased magnetic damping constant. In another aspect, the method and system also include providing a second pinned layer and a second spacer layer between the free layer and the second pinned layer. In this aspect, the first pinned layer and/or the second pinned layer are configured such that a forward torque and a reflected torque due to a current driven through the magnetic element in a current-perpendicular-to-plane configuration are substantially equal and opposite.

A magnetic memory fabricated on a semiconductor substrate is disclosed. The method and system include a plurality of magnetic tunneling junctions and a plurality of shields for magnetically shielding the plurality of magnetic tunneling junctions. Each of the plurality of magnetic tunneling junctions includes a first ferromagnetic layer, a second ferromagnetic layer and an insulating layer between the first ferromagnetic layer and the second ferromagnetic layer. At least a portion of the plurality of shields have a high moment and a high permeability and are conductive. The plurality of shields are electrically isolated from the plurality of magnetic tunneling junctions. The plurality of magnetic tunneling junctions are between the plurality of shields.