Read Rite Corporation

Western Digital (fremont), Inc.

Marcos Moises Lederman

Daniel A Nepela

Yiming Huai

David John Seagle

Kroum Stanimirov Stoev

Francis H Liu

Samuel Wonder Yuan

Matthew R Gibbons

Hua-Ching Tong

Derek Jan Kroes

James Han Wang

Mohamad Towfik Krounbi

Jing Zhang

Mark David Thomas

Ming Zhao

Durga P Ravipati

Yining Hu

Qing He

Loi Dac Pham

Bogdan M Simion

Aparna C Vadde

Kenneth Kung

Mathew Gibbons

A head including a write element for writing data to a magnetic media, and methods for its production are provided. A write element of the invention includes one or more of a recessed first pole, a heat sink layer, and a shortened yoke length. A method of the invention provides forming an anti-reflective layer before forming a mask layer. During photolithography the anti-reflective layer suppresses undesirable reflections off of features, such as vertical sidewalls, that otherwise limit how closely to such features portions of the mask layer can be formed.

Write element with recessed pole and heat sink layer for ultra-high density writing

A magnetic write head provides a significant write field and minimal adjacent track erasure, and lends itself to improved manufacturability. The write head includes a pedestal throat height that defines a bottom pole, P, and that is substantially recessed from the air bearing surface. The write head further includes a top pole, P, that defines a nose that is closer to the air bearing surface than the pedestal zero throat. This design achieves a relatively high ratio of the off-track to on-track field. As an example, a 1:4 ratio could be achieved to significantly mitigate the erasure problem of the adjacent tracks resulting from magnetic flux saturation.

Write head for improved manufacturability larger write field and reduced adjacent track erasure

A magnetic head for a disk drive is disclosed that has a first soft magnetic pole layer disposed in the head adjacent to a medium-facing surface and extending perpendicular to the medium-facing surface; a second soft magnetic pole layer disposed closer than the first pole layer to the trailing end, the second pole layer magnetically coupled to the first pole layer in a backgap region; a soft magnetic pedestal adjoining the second pole layer, disposed closer than the second pole layer to the medium-facing surface and extending less than the second pole layer extends from the medium-facing surface, the pedestal separated from the first pole layer by a nonferromagnetic gap, the pedestal having a thickness that is less than four hundred and fifty nanometers between the gap and the second pole layer. Longitudinal and perpendicular recording embodiments are disclosed, as well as solenoidal, single-layer and dual-layer reversed-current coil structures.

Magnetic head with thin trailing pedestal layer

Magnetoresistive (MR) sensors are disclosed that have leads with reduced resistance, improving the signal-to-noise ratio of the sensors. The leads have broad layers of highly conductive material for connection to MR structures, as opposed to thin wires of highly conductive material or broad layers of resistive material, lowering the resistance of the leads. The low-resistance leads can be formed without increasing the shield-to-shield spacing, providing highly sensitive and focused MR sensors.

Highly conductive lead adjoining MR stripe and extending beyond stripe height at junction

Magnetoresistive (MR) sensors have leads that overlap a MR structure and distribute current to the MR structure so that the current is not concentrated in small portions of the leads. An electrically resistive capping layer can be formed between the leads and the MR structure to distribute the current. The leads can include resistive layers and conductive layers, the resistive layers having a thickness-to-resistivity ratio that is greater than that of each of the conductive layers. The resistive layers may protect the conductive layers during MR structure etching, so that the leads have broad layers of electrically conductive material for connection to MR structures. The broad leads conduct heat better than the read gap material that they replace, further reducing the temperature at the connection between the leads and the MR structure.

Magnetoresistive sensor with overlapping leads having distributed current

A dual-stripe current-pinned spin valve magnetoresistive read sensor includes a first soft ferromagnetic (FM) layer separated from a second soft FM layer by a first spacer layer formed of conductive material. The first spacer layer is also configured to receive a first biasing current for generating a first magnetic field of sufficient strength to saturate the first soft FM layer. The read sensor further includes a third soft FM layer and a fourth soft FM layer separated by a second spacer layer formed of conductive material. The second spacer layer is configured to receive a second biasing current for generating a second magnetic field of sufficient strength to saturate the fourth soft FM layer. An insulation layer also is disposed between the second soft FM layer and the third FM layer. The first and second biasing currents thereby pin magnetizations of the first and fourth soft FM layers, while having a combined negligible effect on magnetizations of substantial portions of the second and third soft ferromagnetic layers.

Dual stripe spin valve sensor without antiferromagnetic pinning layer

A magnetoresistive read sensor fabricated on a substrate includes a ferromagnetic layer that is exchange coupled with an antiferromagnetic layer made of a defined composition of iridium manganese. A tantalum layer is used so that the exchange field and coercivity do not change with variations in annealing temperature. The antiferromagnetic layer is formed with a material composition of Ir Mn , wherein x is in the range of 15<x>23. In an embodiment of a spin valve structure, the tantalum layer is disposed over the substrate and the antiferromagnetic layer is in direct contact with a pinned ferromagnetic layer. In another embodiment, the IrMn layer is formed over a soft active layer. In a third embodiment using exchange pinning, spaced IrMn regions are formed over the active magnetoresistive layer to define the sensor track width.

Spin valve magnetoresistive sensor for high temperature environment using iridium manganese

A dual symmetric spin valve sensor consists of outer ferromagnetic pinned layers which are pinned by a current induced magnetic field. One of the outer pinned layers is magnetically coupled to an inner pinned layer which is pinned so that the magnetization of the other outer and the inner pinned layers are in the same direction. This provides the magnetization for the free layer disposed between the two layers to properly use the spin valve effect. The ferromagnetic layers are separated by conductor layers. The pin layers are synthetic antiferromagnetic layers consisting of the two layers tightly interlayer exchange coupled. The field induced by the sense current pins the pinned layers.

Dual, synthetic spin valve sensor using current pinning

The present invention provides an improved synthetic spin valve sensor having a high resistivity antiparallel coupling layer, typically formed of rhenium, between pinned layers. The spin valve sensor of the present invention may be formed having a layered structure as follows: pinning layer/first pinned layer/high resistivity antiparallel coupling layer/second pinned layer/metallic nonferromagnetic spacer layer/free layer. Capping and seed layers typically are also included. The high resistivity of the antiparallel coupling layer of the present invention reduces shunt current through that layer to improve the GMR effect of the spin valve while maintaining sufficient antiparallel coupling between the pinned layers. The antiparallel coupling layer of the present invention also provides improved thermal stability.

Synthetic spin-valve device having high resistivity anti parallel coupling layer

A magnetoresistive read sensor fabricated on a substrate includes a ferromagnetic layer that is exchange coupled with an antiferromagnetic layer made of a defined composition of iridium manganese. A tantalum layer is used so that the exchange field and coercivity do not change with variations in annealing temperature. The antiferromagnetic layer is formed with a material composition of Ir.sub.x Mn.sub.100-x, wherein x is in the range of 15&lt;.times.&gt;23. In an embodiment of a spin valve structure, the tantalum layer is disposed over the substrate and the antiferromagnetic layer is in direct contact with a pinned ferromagnetic layer. In another embodiment, the IrMn layer is formed over a soft active layer. In a third embodiment using exchange pinning, spaced IrMn regions are formed over the active magnetoresistive layer to define the sensor track width.

Magnetoresistive sensor for high temperature environment using iridium

A magnetoresistive sensor including a magnetoresistive (MR) sensing element, a nonmagnetic layer ('spacer') contacting the magnetoresistive sensing element; a first antiferromagnetic (AFM) layer contacting the nonmagnetic layer such that the nonmagnetic layer is sandwiched between the magnetoresistive sensing element and the antiferromagnetic layer; a ferromagnetic soft adjacent layer (SAL) contacting the antiferromagnetic layer such that the antiferromagnetic layer is sandwiched between the nonmagnetic layer and the soft adjacent layer; and a second antiferromagnetic layer contacting the SAL such that the SAL is sandwiched between the first and second antiferromagnetic layers. The two antiferromagnetic layers provide a stronger pinning effect. In one embodiment of the invention, the magnetoresistive sensing element is an anisotropic magnetoresistive (AMR) sensing element comprising a soft ferromagnetic layer. In another embodiment of the invention, the magnetoresistive sensing element is giant magnetoresistive (GMR) sensing element comprising a plurality of layers. The bias scheme can be non-symmetric, or may be symmetric around the magnetoresistive sensing element. An exchange biased bilayer (AFM/SAL) can have a multilayered structure such as AFM/SAL/AFM/SAL. . . . In this configuration, the SAL layer can be thin, so that a high exchange field with a high resistance can be obtained.

Magnetoresistive sensor with pinned SAL

A current-pinned spin valve sensor includes a soft ferromagnetic free layer having a first thickness, a soft ferromagnetic pinned layer having a second thickness less than the first thickness, a copper layer sandwiched between the free and the pinned layer, and a current source coupled to the free layer, pinned layer, and copper layer to provide a biasing current that generates a magnetic field of sufficient strength to saturate the pinned layer. Preferably, the free layer and pinned layer selected from a group of materials consisting of essentially Permalloy, Cobalt, Iron-Cobalt, and soft Cobalt-based ferromagnetic alloys. Also preferably the free layer has an Mrt of at least 0.3 memu/cm.sup.2 and the pinned layer has a Mrt of at most 0.28 memu/cm.sup.2, and such that the ratio of the Mrt of the free layer to the Mrt of the pinned layer is in the range of 2-10. The biasing current through the sensor is preferably at least 4 mA. The biasing current creates a magnetic field which creates the proper magnetization in the pinned layer without the need for an antiferromagnetic (AFM) layer in contact with the pinned layer.

Current-pinned spin valve sensor

A magnetoresistive (MR) read sensor fabricated on a substrate comprises an MR layer of magnetoresistive material, a soft adjacent layer (SAL) of soft magnetic material, and a manganese-based metallic antiferromagnetic (AFM) layer between the MR layer and the SAL layer. The AFM layer is in direct contact with the SAL layer and is separated from the MR layer by a non-magnetic spacer layer. A non-magnetic texturing layer is disposed between the SAL layer and the substrate. This structure exhibits a much larger pinning field than read sensors using oxide-based antiferromagnets.

Magnetoresistive sensor having a pinned soft magnetic layer

A magnetoresistive (MR) read transducer includes an MR sensor element having end regions and a center active region. The end regions are pinned both top and bottom by an exchange coupling antiferromagnetic material. This pinning action causes the end regions to act as permanent magnets having the same remanent magnetic moment M.sub.r as that of the center active region, thereby resulting in suppression of magnetic edge effects in the transducer. A magnetic soft bias layer adjacent to the magnetoresistive sensor element also has its ends pinned by exchange coupling antiferromagnetic material.

Magnetoresistive reas transducer with exchange biasing of

A magnetic sensing structure includes a spin valve sensor having a pinned magnetic layer and a free magnetic layer, the direction of magnetization of the free layer varying as a function of the magnetic field applied to the structure. A multilayered magnetic keeper structure is provided to cancel the magnetostatic field from the pinned layer to provide an ideal bias profile for the structure in the absence of an applied magnetic field. Longitudinal magnetic bias may be applied to the spin valve sensor through a contiguous junction magnetic structure adjacent to the keeper structure and spin valve sensor.

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San Francisco, CA, United States of America

Marcos Moises Lederman