SUBMICRON-TRACKWIDTH INDUCTIVE MR COMPOSITE HEAD

To explore possibility for ultra-high areal density recording, submicron-trackwidth inductive-write/MR-read composite heads are fabricated. The Focused Ion Beam etching technique is applied to fabricate a approximately 1-mu-m wide write-track completely aligned to the read-region of the MR sensor. The write head using multilayered Fe-based alloy pole pieces with a saturation magnetization of 2.0 T revealed sufficient writability and excellent frequency response. A shunt-biased MR sensor having narrow gap-length operated at a high current density over 3 x 10(7) A/cm2 is developed to reproduce a sufficient signal amplitude at high linear-density regions. Recording tests are carried out on a thin film media with a head-medium clearance of 0.05-mu-m. The output voltage per micron of trackwidth over 400-mu-V with symmetrical pulses, and a -6dB rolloff density of around 90 kFCI are measured. With the combination of the modified signal processing method and an advanced head positioning technique, an areal density of over 2 Gigabits per square inch is possible at a low bit error rate comparable to those in current products.