Overlaid lead giant magnetoresistive head with side reading reduction

A magnetic head assembly having an air bearing surface (ABS), comprising:

• a write head including:
• ferromagnetic first and second pole piece layers that have a yoke portion located between a pole tip portion and a back gap portion;
• a nonmagnetic write gap layer located between the pole tip portions of the first and second pole piece layers;
• an insulation stack with at least one coil layer embedded therein located between the yoke portions of the first and second pole piece layers;
• and
• the first and second pole piece layers being connected at their back gap portions;
• a read head including:
• a spin valve sensor;
• nonmagnetic electrically nonconductive first and second read gap layers;
• the spin valve sensor being located between the first and second read gap layers;
• a ferromagnetic first shield layer;
• the first and second gap layers being located between the first shield layer and the first pole piece layer;
• and
• the spin valve sensor having a top surface, a bottom surface and first and second side surfaces which intersect the ABS;
• the spin valve sensor including:
• a ferromagnetic pinned layer structure that has a magnetic moment;
• a pinning layer exchange coupled to the pinned layer structure for pinning the magnetic moment of the pinned layer structure;
• a ferromagnetic free layer structure that has a magnetic moment that is free to rotate in response to a field signal;
• a nonmagnetic electrically conductive spacer layer located between the free layer structure and the pinned layer structure;
• a cap layer forming said top surface of the sensor;
• and
• each of the pinned layer structure, the pinning layer structure, the free layer structure, the spacer layer and the cap layer having first and second side surfaces which form said first and second side surfaces respectively of the sensor;
• first and second hard bias layers that interface said first and second side surfaces of the sensor;
• a top portion of the first side surface having a first notch and a top portion of the second side surface having a second notch;
• the first and second notches being sized to enable a reduction of a magnetoresistive coefficient of first and second side portions of the sensor beyond a track width of the sensor;
• said first and second notches being at least partially formed by first and second side surfaces of the cap layer being recessed from first and second side surfaces of a remainder of the spin valve sensor so as to expose first and second top surfaces of one of the free, spacer and pinned layers;
• and
• nonmagnetic electrically conductive first and second lead layers overlaying the first and second hard bias layers respectively, disposed in the first and second notches respectively, interfacing the first and second top surfaces respectively of one of said free, spacer and pinned layers and being spaced apart by a distance that defines a track width of the read head.

A magnetic disk drive including at least one magnetic head assembly that has an air bearing surface (ABS) and that includes a write head and a read head, comprising:

• a write head including:
• ferromagnetic first and second pole piece layers that have a yoke portion located between a pole tip portion and a back gap portion;
• a nonmagnetic write gap layer located between the pole tip portions of the first and second pole piece layers;
• an insulation stack with at least one coil layer embedded therein located between the yoke portions of the first and second pole piece layers;
• and
• the first and second pole piece layers being connected at their back gap portions;
• a read head including:
• a spin valve sensor;
• nonmagnetic electrically nonconductive first and second read gap layers;
• the spin valve sensor being located between the first and second read gap layers;
• a ferromagnetic first shield layer;
• the first and second read gap layers being located between the first shield layer and the first pole piece layer;
• and
• the spin valve sensor having a top surface, a bottom surface and first and second side surfaces which intersect the ABS;
• the spin valve sensor including:
• a ferromagnetic pinned layer structure that has a magnetic moment;
• a pinning layer exchange coupled to the pinned layer structure for pinning the magnetic moment of the pinned layer structure;
• a ferromagnetic free layer structure that has a magnetic moment that is free to rotate in response to a field signal;
• a nonmagnetic electrically conductive spacer layer located between the free layer structure and the pinned layer structure;
• a cap layer forming said top surface of the sensor;
• and
• each of the pinned layer structure, the pinning layer structure, the free layer structure, the spacer layer and the cap layer having first and second side surfaces which form said first and second side surfaces respectively of the sensor;
• first and second hard bias layers that interface said first and second side surfaces of the sensor;
• a top portion of the first side surface having a first notch and a top portion of the second side surface having a second notch;
• the first and second notches being sized to enable a reduction of a magnetoresistive coefficient of first and second side portions of the sensor beyond a track width of the sensor;
• said first and second notches being at least partially formed by first and second side surfaces of the cap layer being recessed from first and second side surfaces of a remainder of the spin valve sensor so as to expose first and second top surfaces of one of the free, spacer and pinned layers;
• nonmagnetic electrically conductive first and second lead layers overlaying the first and second hard bias layers respectively, disposed in the first and second notches respectively, interfacing the first and second top surfaces respectively of one of said free, spacer and pinned layers and being spaced apart by a distance that defines the track width of the read head;
• a housing;
• a magnetic disk rotatably supported in the housing;
• a support mounted in the housing for supporting the magnetic head assembly with said ABS facing the magnetic disk so that the magnetic head assembly is in a transducing relationship with the magnetic disk;
• a spindle motor for rotating the magnetic disk;
• an actuator positioning means connected to the support for moving the magnetic head assembly to multiple positions with respect to said magnetic disk;
• and
• a processor connected to the magnetic head assembly, to the spindle motor and to the actuator for exchanging signals with the magnetic head assembly, for controlling movement of the magnetic disk and for controlling the position of the magnetic head assembly.

A method of making a magnetic read head which has an air bearing surface (ABS), comprising:

• forming a spin valve sensor that has a top surface, a bottom surface and first and second side surfaces which intersect the ABS;
• making the spin valve sensor including the steps of:
• forming a ferromagnetic pinned layer structure that has a magnetic moment;
• forming a pinning layer exchange coupled to the pinned layer structure for pinning the magnetic moment of the pinned layer structure;
• forming a ferromagnetic free layer structure that has a magnetic moment that is free to rotate in response to a field signal;
• forming a nonmagnetic electrically conductive spacer layer between the free layer structure and the pinned layer structure;
• forming a cap layer which forms a top surface of the sensor;
• and
• forming each of the pinned layer structure, the pinning layer structure, the free layer structure, the spacer layer and the cap layer with first and second side surfaces which form said first and second side surfaces respectively of the sensor;
• forming first and second hard bias layers interfacing said first and second side surfaces of the sensor;
• forming a top portion of the first side surface with a first notch and a top portion of the second side surface with a second notch with the first and second notches being sized to enable a reduction of a magnetoresistive coefficient of first and second side portions of the sensor beyond a track width of the sensor;
• said first and second notches being at least partially formed by first and second side surfaces of the cap layer being recessed from first and second side surfaces of a remainder of the spin valve sensor so as to expose first and second top surfaces of one of the free, spacer and pinned layers;
• and
• forming nonmagnetic electrically conductive first and second lead layers overlaying the first and second hard bias layers respectively, disposed in the first and second notches respectively, interfacing the first and second top surfaces respectively of one of said free, spacer and pinned layers and spaced apart by a distance that defines a track width of the read head.

A method of making magnetic head assembly that has an air bearing surface (ABS), comprising the steps of:

• making a write head including the steps of:
• forming ferromagnetic first and second pole piece layers in pole tip, yoke and back gap regions wherein the yoke region is located between the pole tip and back gap regions;
• forming a nonmagnetic electrically nonconductive write gap layer between the first and second pole piece layers in the pole tip region;
• forming an insulation stack with at least one coil layer embedded therein between the first and second pole piece layers in the yoke region;
• and
• connecting the first and pole piece layers at said back gap region;
• making a read head including the steps of:
• forming nonmagnetic electrically nonconductive first and second read gap layers;
• forming a spin valve sensor between the first and second read gap layers;
• forming the first and second read gap layers between the first shield layer and the first pole piece layer;
• and
• forming the spin valve sensor with a top surface, a bottom surface and first and second side surfaces which intersect the ABS;
• making the spin valve sensor including the steps of:
• forming a ferromagnetic pinned layer structure that has a magnetic moment;
• forming a pinning layer exchange coupled to the pinned layer structure for pinning the magnetic moment of the pinned layer structure;
• forming a ferromagnetic free layer structure that has a magnetic moment that is free to rotate in response to a field signal;
• forming a nonmagnetic electrically conductive spacer layer between the free layer structure and the pinned layer structure;
• forming a cap layer which has a top surface of the sensor;
• and
• forming each of the pinned layer structure, the pinning layer structure, the free layer structure, the spacer layer and the cap layer having first and second side surfaces which, in turn, form said first and second side surfaces respectively of the sensor;
• forming first and second hard bias layers interfacing said first and second side surfaces of the sensor;
• forming a top portion of the first side surface with a first notch and a top portion of the second side surface with a second notch with the first and second notches being sized to enable a reduction of a magnetoresistive coefficient of first and second side portions of the sensor beyond a track width of the sensor;
• said first and second notches being at least partially formed by first and second side surfaces of the cap layer being recessed from first and second side surfaces of a remainder of the spin valve sensor so as to expose first and second top surfaces of one of the free, spacer and pinned layers;
• and
• forming nonmagnetic electrically conductive first and second lead layers overlaying the first and second hard bias layers respectively, disposed in the first and second notches respectively, interfacing the first and second top surfaces respectively of one of said free, spacer and pinned layers and spaced apart by a distance that defines the track width of the read head.