A high temperature stable spin valve sensor head for high density applications

In this paper, we will report a read-only spin valve that has a trackwidth of 1.4 /spl mu/m, a read gap of 0.23 /spl mu/m, and with a stripe height of 0.75 /spl mu/m. It had a corrosion resistant exchange pinning layer, Co/sub 90/Fe/sub 10//FeMnRh, that provided an exchange bias of 225 Oe. It produces a very stable signal and a normalized amplitude of 1 mv//spl mu/m/(memu/cm/sup 2/). Furthermore its asymmetry is lower that 6%. The /spl Delta/R/R of the spin valve film was 5.2% with the following structure: Ta(5 nm)/NiFe(2 nm)/Co/sub 90/Fe/sub 10/(5 nm)/Cu(2.8 nm)/Co/sub 90/Fe/sub 10/(1.2 nm)/NiFe(2 nm)/FeMnRh(10 nm)/Ta(5 nm). The spin valve heads were soaked for 96 hours in a corrosion test chamber that was operated at a temperature of 85 C and a humidity of 85%. The sensor element, the exchange bias film, the hard magnetic longitudinal bias, and the conducting leads were free from corrosion after the corrosion test. Furthermore the spin valve read-only heads were electro-migration tested in an oven operated at 120/spl deg/C, and the heads survived with the operating current up to 9 ma.