SHIELDED MAGNETORESISTIVE HEAD FOR HIGH-DENSITY RECORDING

The fabrication process as well as the head material properties for shielded MR 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). 40nm thick Ni81Fe19(wt%) films were deposited by evaporation for use as an MR layer. Evaporated Ti MSL thickness was experimentally determined to be 20nm. 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. © 1990 IEEE