Stabilizer for magnetoresistive head and method of manufacture
AssigneeTDK Corporation
InventorsRachid Sbiaa, Haruyuki Morita
Life of this patent
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Abstract
A reader of a current-perpendicular-to-plane magnetoresistive head includes a spin valve with sensor having a stabilizer adjacent thereto, to substantially avoid magnetization distribution at the edge of the sensor due to vortex effect. At least one free layer is spaced apart from at least one pinned layer by a spacer. Above the free layer, a capping layer is provided. The stabilizer includes a pinned ferromagnetic layer adjacent to the free layer, and an antiferromagnetic layer positioned thereon. It becomes easy to provide an effective biasing using a variety of materials having different magnetic moments and thickness. Also problems related to sensor edge for small size will be overcome. A method of manufacturing the reader is also provided.
Claims22
A device having a spin valve, comprising:
- a magnetic sensor including,
- a free layer having an adjustable magnetization direction in response to a magnetic field,
- a pinned layer having a fixed magnetization stabilized in accordance with a first antiferromagnetic (AFM) layer positioned on a surface of the pinned layer opposite a spacer sandwiched between the pinned layer and the free layer,
- a buffer sandwiched between the first AFM layer and a bottom shield that shields undesired flux at a lower surface of the magnetic sensor, and
- a capping layer sandwiched between the free layer and a top shield that shields undesired flux at an upper surface of the magnetic sensor;
- and
- a stabilizer positioned adjacent to the magnetic sensor and separated from the magnetic sensor by an insulator layer, the stabilizer comprising a pinned ferromagnetic stabilizer positioned on the insulator layer adjacent to the free layer and pinned by a second AFM layer sandwiched between the pinned ferromagnetic stabilizer and an upper insulator upon which the shield is positioned.
A method of fabricating a magnetic sensor, comprising the steps of:
- forming a free layer having an adjustable magnetization direction in response to an external field, a pinned layer having a fixed magnetization direction by exchange coupling with a first antiferromagnetic (AFM) layer positioned on a surface of the pinned layer opposite a spacer sandwiched between the pinned layer and the free layer, a buffer sandwiched between the AFM layer and a bottom shield that shields undesired flux at a first outer surface of the magnetic sensor, and a capping layer on the free layer;
- forming a mask on a first region on the capping layer;
- performing a first ion milling step to generate a sensor region and depositing a first insulator sublayer thereon;
- positioning a second mask to cover a second region smaller than the first region on the capping layer;
- performing a second ion milling step to generate a shape of the magnetic sensor by removing parts of the capping layer, the free layer and a first portion of the spacer that are outside of the second region;
- depositing a stabilizer having a second insulator sublayer, a pinned ferromagnetic stabilizer layer, a second AFM layer and an upper insulator, and then removing the second mask;
- and
- forming a top shield on the capping layer and the upper insulator.
Dependencies are inferred from the claim text.