Headway Technologies, Incorporated

International Business Machines Corporation

Charles C Lin

Min Li

Kochan Ju

Cheng Tzong Horng

Simon H Liao

Jeiwei Chang

CPP magnetic read head designs have been improved by increasing the length of the AFM layer relative to that of both the free and spacer layers. The length of the pinned layer is also increased, but by a lesser amount, an abutting conductive layer being inserted to fill the remaining space over the AFM layer. The extended pinned layer increases the probability of spin interaction while the added conducting layer serves to divert sensor current away from the bottom magnetic shield which now is no longer needed for use as a lead.

CPP with elongated pinned layer

It is known that the magnetic shields, between which CPP GMR stacks are sandwiched, can be a source of AMR (anisotropic magneto-resistance) noise. This has been significantly reduced by coating both the magnetic shields with highly conductive layers. If the guidelines disclosed in the invention are followed, the read head can exhibit AMR noise reduced by about 14 to 20. Additionally, the total thickness of the read gap can be maintained to be as low as 300 to 400 Angstroms.

CPP read head for high density and shield noise suppression

A method for forming a top spin-valve SyAP GMR read sensor having a novel conductive lead overlay configuration and the sensor so formed. The lead overlay electrically contacts the sensor at a position within the SyAP pinned layer, thus simultaneously assuring improved electrical contact and destroying the GMR properties of the sensor at the junction to improve the definition of the sensor track width.

Magnetic assist read track-width definition for a lead overlay top spin-valve GMR head

As the recording density of magnetic disk drives approaches 100 Gbits/in , write track lengths of about 0.10 microns will be required. This cannot be accomplished using conventional photolithography. The present invention solves this problem by first forming on the bottom pole of the write head a cavity in a layer of photoresist, using conventional means. A seed layer of non-magnetic material is electrolessly laid down, following which a second layer of photoresist is deposited and patterned to form a second cavity that symmetrically surrounds the first one, thereby forming a mold around it. Ferromagnetic metal is then electro-deposited in this mold to form the top magnetic pole. Following the removal of all photoresist and a brief selective etch of the bottom pole, an extremely narrow write head is obtained.

Process to form narrow write track for magnetic recording

A transducer for servoing on data or separate servo information is fabricated with two adjacent magnetoresistive (MR) elements stagger connected such that each MR element senses one-half of the data magnetic transition track or separate coded servo tracks. Each MR element is magnetostatically biased by a soft magnetic film formed as a portion of its adjacent MR element material.

Magnetoresistive read head assembly for servo operation

A magnetoresistive sensing element used for sensing magnetic transitions includes relatively thick shields and substantially thinner shields between the thick shields and the MR element. The output pulse waveform resulting from the MR element sensing a magnetic transition is improved permitting a higher linear density. The thick shields can comprise the legs of an inductive write transducer with the thin shields and MR element interposed for the read function. Another read/write head embodiment can include a separate write tranducer with the thin shields and the MR element placed between one of the legs of a write transducer and a third magnetic shield formed from either a thick magnetic layer or a magnetic substrate.

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San Jose, CA, United States of America

Charles C Lin