Shielded magnetoresistive head for high density recording

The fabrication process and the head material properties for shielded magnetoresistive heads with planarized lower shields using a tri-layered MR element are described in detail. Applying the etch-back process with low molecular weight polystyrene and CF₄/O₂ reactive ion etching, the residual step height for a lower shield is dramatically decreased to less than 5% of the initial step height. The tri-layered MR element consists of an MR layer, a magnetic separation layer (MSL), and a soft adjacent layer (SAL). 40-nm thick Ni ₈₁Fe₁₉ (wt.%) films were deposited by evaporation for use as an MR layer. Evaporated Ti MSL thickness was experimentally determined to be 20 nm. Amorphous Co₈₂Zr₆Mo₁₂ SAL films exhibited preferable magnetic properties as an SAL material. The fabricated shielded MR heads, using the tri-layered MR element with these NiFe, Ti, and CoZrMo films, provide superior capability to realize high recording density