Magnetoresistance sensor with reduced side reading, and its fabrication

#This invention relates to a thin-film magnetoresistance sensor and, more particularly, to such a sensor having reduced side reading and improved magnetic stability.

#A magnetoresistance (MR) sensor is used in a read/write head to read magnetic fields on a recording medium of a magnetic storage device. An example is the read/write head of a computer hard disk or a magnetic recording tape drive. The read/write head of the computer hard disk is positioned closely adjacent to the recording medium, separated from the recording medium by an air bearing that does not allow them to touch. A data bit is written onto an area, usually a track, of the recording medium using the writing portion of the read/write head by locally changing its magnetic state. That magnetic state is later sensed by the MR sensor to read the data bit.

#Two known types of MR sensors are a giant magnetoresistance (GMR) sensor and a tunnel magnetoresistance (TMR) sensor. In general, the sensors are multilayered thin-film devices that sense the magnetic state of the adjacent region of the recording medium. The general technical basis, construction, and operation of the GMR sensor are described, for example, in U.S. Pat. No. 5,436,778. The general technical basis, construction, and operation of the TMR sensor are described, for example, in U.S. Pat. No. 5,729,410. The disclosures of both patents are incorporated by reference in their entireties. These patents also describe the read/write heads and the magnetic storage systems.

#FIG. 1 is a schematic diagram of a magnetic disk data storage system;

#FIG. 2 is a schematic elevational view of the magnetoresistance sensor;

#FIG. 3 is a schematic elevational view of one form of the layered structure; and

#FIG. 1 shows a data storage system, here depicted as a magnetic disk drive system 20, with which the present approach may be used. The magnetic disk drive system 20 includes a rotatable magnetic storage disk 22 that is supported on a spindle 24 and rotated by a disk drive motor 26 under motor control 27 of a control unit 44. A magnetic storage medium 28 is deposited on a surface 30 of the magnetic storage disk 22.

#A slider 32 is positioned in facing relation to the magnetic storage disk 22. The slider 32 supports at least one read/write head 34 in facing relation to the magnetic storage medium 28 present on the facing surface of the magnetic storage disk 22. The slider 32 is mounted to an actuator arm 36 by a suspension 38. The actuator arm 36 and the slider 32 move radially inwardly and outwardly relative to the magnetic storage disk 22 so that the combined inward/outward motion of the slider 32 and the rotation of the magnetic storage disk 22 allow the read/write head 34 to be placed into facing relation to any region over the entire area of the magnetic storage medium 28. The actuator arm 36 is driven by an actuator 40 (depicted as a voice coil motor or VCM) under the radial position control 42 of the control unit 44.

#The suspension 38 generates a slight spring force which biases the slider 32 toward the surface 30 of the magnetic storage disk 22. During sensor operation the magnetic storage disk 22 turns, and an air bearing is created between the downwardly facing surface of the slider 32, termed the air bearing surface 46 or ABS, and the upwardly facing surface 30 of the magnetic storage disk 22. (Only the downwardly oriented slider is illustrated, but there may also or instead be an upwardly oriented slider facing the bottom side of the magnetic storage disk.) The air bearing counterbalances the slight spring force of the suspension 38 and supports the slider 32 a small distance above the surface 30 with a small, substantially constant separation.