Design and peak shift characterization of magnetoresistive head thin film media system

Abstract

The design, fabrication and peak shift characterization of a thin film head-thin film media system capable of recording at 19.4 Kbits/mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> (12.5 Mbits/in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) are described. The thin film media uses a magnetic layer of a sputter deposited alloy of Co having coercivity of 600 Oe. The thin film head is a single-turn-inductive write, barber-pole-biased magnetoresistive read head. This combination of read and write technologies reduces step coverage problems and simplifies the fabrication of the thin film head. A high resolution interval counter was used to measure the peak shift due to intersymbol interference and, hence, provide the information necessary for a focus-on-peak-shift design. The results of peak shift measurements for different gap length heads are reported. It has been found that the time interval between adjacent peaks varies with each write process, but once the transitions are recorded, the write process variations appear as a fixed peak shift for a given peak. This peak shift does not affect the error rate in the same statistical sense as random noise does.