Patent classifications
G11B5/3954
Bias Layer and Shield Biasing Design
A read head is longitudinally biased unidirectionally by laterally abutting soft magnetic layers or multilayers. The soft magnetic layers are themselves magnetically stabilized by layers of antiferromagnetic material that are exchange coupled to them. The same layers of antiferromagnetic materials can be used to stabilize a unidirectional anisotropy of an overhead shield by means of exchange coupling. By including the antiferromagnetic material layer within the patterned biasing structure itself, an additional layer of antiferromagnetic material that normally covers the entire sensor structure is eliminated. The elimination of an entire layer is also advantageous for reducing the inter-sensor spacing in a TDMR (two dimensional magnetic recording) configuration where two sensor are vertically stacked on top of each other.
Bias layer and shield biasing design
A read head is longitudinally biased unidirectionally by laterally abutting soft magnetic layers or multilayers. The soft magnetic layers are themselves magnetically stabilized by layers of antiferromagnetic material that are exchange coupled to them. The same layers of antiferromagnetic materials can be used to stabilize a unidirectional anisotropy of an overhead shield by means of exchange coupling. By including the antiferromagnetic material layer within the patterned biasing structure itself, an additional layer of antiferromagnetic material that normally covers the entire sensor structure is eliminated. The elimination of an entire layer is also advantageous for reducing the inter-sensor spacing in a TDMR (two dimensional magnetic recording) configuration where two sensor are vertically stacked on top of each other.
BIAS LAYER AND SHIELD BIASING DESIGN
A read head is longitudinally biased unidirectionally by laterally abutting soft magnetic layers or multilayers. The soft magnetic layers are themselves magnetically stabilized by layers of antiferromagnetic material that are exchange coupled to them. The same layers of antiferromagnetic materials can be used to stabilize a unidirectional anisotropy of an overhead shield by means of exchange coupling. By including the antiferromagnetic material layer within the patterned biasing structure itself, an additional layer of antiferromagnetic material that normally covers the entire sensor structure is eliminated. The elimination of an entire layer is also advantageous for reducing the inter-sensor spacing in a TDMR (two dimensional magnetic recording) configuration where two sensor are vertically stacked on top of each other.
Spin-Orbit Torque SOT Reader with Recessed Spin Hall Effect Layer
The present disclosure generally relates to a magnetic recording head comprising one or more spin-orbit torque (SOT) devices, the SOT devices each comprising a bismuth antimony (BiSb) layer. The magnetic recording head comprises a SOT device comprising a first shield extending to a media facing surface (MFS), a seed layer disposed over the first shield, the seed layer being disposed at the MFS, a free layer disposed on the seed layer, the free layer being disposed at the MFS, a bismuth antimony (BiSb) layer disposed over the free layer, the BiSb layer being recessed from the MFS, a second shield disposed over the BiSb layer, the second shield extending to the MFS, and a shield notch coupled to the second shield, the shield notch being disposed between the first shield and the second shield. The magnetic recording head may be a two-dimensional magnetic recording head comprising two SOT devices.
DFL TDMR Middle Shield Throat Height Control for Improved Stability
The present disclosure generally relates to a dual free layer two dimensional magnetic recording read head. The read head comprises a lower shield, a first sensor disposed over the first lower shield, a first rear hard bias (RHB) structure recessed from a media facing surface (MFS), a first upper shield disposed over the first sensor, a middle shield disposed over the first sensor at the MFS, a second sensor disposed over the middle shield, a second RHB structure recessed from the MFS, and an upper shield disposed over the second sensor. The middle shield has a U-like shape and a ratio of a width to a throat height of 6:1, where the throat height is less than or equal to about 2 m. The first and second RHB structures each individually has a stripe height about 3 times greater than a stripe height of the middle shield.
SENSOR STABILIZATION IN A MULTIPLE SENSOR MAGNETIC REPRODUCING DEVICE
A multi-sensor reader that includes a first sensor that has a sensing layer with a magnetization that changes according to an external magnetic field. The first sensor also includes first and second side biasing magnets having a magnetization substantially along a first direction. The first and second side biasing magnets align the magnetization of the sensing layer substantially along the first direction when the sensing layer is not substantially influenced by the external magnetic field. The multi-sensor reader further includes a second sensor that is stacked over the first sensor. The second sensor includes a reference layer that has a magnetization that is set substantially along a second direction. The first sensor further includes at least one sensor-stabilization feature that counteracts an influence of a magnetic field utilized to set the magnetization of the reference layer of the second sensor in the second direction on the magnetization of at least one of the first and second side biasing magnets in the first direction.
Rear Soft Bias Dual Free Layer Sensor With Patterned Decoupling Layer
Rather than disposing a cap layer on a rear soft bias (RSB) of a DFL read head prior to the patterning of the RSB and TMR sensor, disclosed is a decoupling layer disposed on the RSB and TMR sensor after they undergo patterning, with the decoupling layer undergoing its own subsequent patterning. The RSB and the TMR sensor can thus be patterned (defined) together without a RSB cap layer adversely affecting the patterning. As the decoupling layer undergoes its separate patterning, its cross-track width can be flexibly optimized to be greater than that of both the RSB and the TMR sensor. In some embodiments, the decoupling layer's extra width will help it completely decouple the RSB and TMR sensor from the top shield. The side shields will be partially decoupled from the top shield due to the extra width, but will still retain partial coupling to the top shield.
Produce thinner DTS and adjustable capacitance for TDMR heads
The present disclosure generally relates to a dual free layer two dimensional magnetic recording read head. The read head comprises a first lower shield, a first sensor disposed over the first lower shield, a first upper shield disposed over the first sensor, a read separation gap (RSG) disposed on the first upper shield, a second lower shield disposed on the RSG, a second sensor disposed over the second lower shield, and a second upper shield disposed over the second sensor. In one embodiment, the RSG comprises SiO.sub.2 and has a thickness of about 7 nm to about 14 nm. The SiO.sub.2 isolates the first sensor from the second sensor, and is a chemical mechanical processing (CMP) stop layer. In another embodiment, the RSG comprises a first sublayer comprising AlOx and a second sublayer comprising SiO.sub.2. The thicknesses of the first and second sublayers are based on an adjustable capacitance.
DFL Reader Signal Sidebump Imbalance Reduction
A dual free layer (DFL) read head or reader oftentimes has a sidebump in a signal amplitude vs. cross-track profile plot. The sidebump is a magnetic signal of the reader in response to the magnetic field of magnetic media with finite thickness. The sidebump magnitude is far below the main magnetic signal of the reader and is offset from the center of the track in the cross-track direction. When two sidebumps are present (one on each side of the center of the track), the sidebump should generally and ideally be symmetrically offset in the cross-track direction else there is a negative impact on reader performance. To obtain offset symmetry, a synthetic antiferromagnetic (SAF) shield may be used, magnetic moments of soft bias layers can be adjusted, and spacing between the free layers of the DFL read head and the layers of the soft bias can also be adjusted.
Spin-orbit torque SOT reader with recessed spin hall effect layer
The present disclosure generally relates to a magnetic recording head comprising one or more spin-orbit torque (SOT) devices, the SOT devices each comprising a bismuth antimony (BiSb) layer. The magnetic recording head comprises a SOT device comprising a first shield extending to a media facing surface (MFS), a seed layer disposed over the first shield, the seed layer being disposed at the MFS, a free layer disposed on the seed layer, the free layer being disposed at the MFS, a bismuth antimony (BiSb) layer disposed over the free layer, the BiSb layer being recessed from the MFS, a second shield disposed over the BiSb layer, the second shield extending to the MFS, and a shield notch coupled to the second shield, the shield notch being disposed between the first shield and the second shield. The magnetic recording head may be a two-dimensional magnetic recording head comprising two SOT devices.