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

A method of fabricating a top spin-valve giant magnetoresistive (GMR) read head with a novel conductive lead overlay configuration, comprising:

• providing a substrate and a dielectric layer formed thereupon;
• forming on the dielectric a first seed layer;
• forming on the seed layer a ferromagnetic free layer;
• forming on the ferromagnetic free layer a metallic, non-magnetic spacer layer;
• forming on the spacer layer a synthetic antiferromagnetic pinned layer (SyAP), said formation further comprising the steps of:
• forming a first ferromagnetic layer, AP1;
• forming on said first ferromagnetic layer a metallic, non-magnetic coupling layer;
• forming on the metallic, non-magnetic coupling layer a second ferromagnetic layer, AP2;
• forming on said SyAP layer an antiferromagnetic pinning layer;
• forming on the antiferromagnetic pinning layer a first capping layer, completing, thereby, a GMR top spin-valve SyAP sensor stack formation;
• etching away a portion of the sensor stack formation to form, laterally disposed on either side of said sensor stack formation, contiguous junction surfaces for the formation of a longitudinal magnetic bias layer;
• forming said magnetic bias layer contiguously with said junction surfaces;
• forming on said magnetic bias layer a second capping layer, which will also serve as a first ion-beam etching mask;
• forming symmetrically over a central portion of said sensor stack formation a single structure which will serve as both a second ion-beam etching mask and a lift-off stencil, the width of said structure corresponding approximately to a desired track-width of the read head;
• ion-beam etching a region between said first ion-beam etching mask and said second ion-beam etching mask, said etching process removing a thickness of said sensor stack formation extending vertically downward from the first capping layer to a position approximately between said AP2 layer and said metallic, non-magnetic spacer layer formed on said ferromagnetic free layer;
• forming, now using said second ion-beam etching mask as a lift-off stencil, a conducting lead layer overlaying said ion-beam etched region and said longitudinal magnetic bias layer;
• removing said second ion-beam etching mask and lift-off stencil.