Electrical characteristics of a 500 Mb/in2 slanted contact MR head

Several approaches to achieving high area density in rigid disc magnetic recording with magnetoresistive heads are currently being pursued. The mainstream approach has been dictated by the introduction of two IBM products. These products use soft-adjacent layer (SAL) transverse biasing and either exchange coupling or permanent magnet longitudinal biasing. Rotated current biasing, characteristic of barberpole and slanted contact (SC) biasing, offers the advantages of processing simplicity but suffers from a relatively wide read sensitivity function (RSF). The 45° contact geometry produces a long tail on one side of the RSF which causes excessive adjacent track crosstalk. It is possible to produce readwidths as narrow as 2.5 μm by using the proper current direction and narrow contacts. This approach allows the practical implementation of 5000-6000 tpi devices and 500 Mb/in² technology. This paper describes the electrical characteristics of one such design and attempts to extrapolate the future performance of SC technology