Exchange tab readback transducer using reactive ion etching to define the trackwidth

Abstract

IrMn was used to stabilize the free layer in exchange tab type magnetic recording readback heads. These heads were fabricated using either reactive ion etching (RIE) or argon ion beam etching (IBE) to define the trackwidth. The two processes were used to eliminate the coupling between the exchange tab material (IrMn) and the free layer (NiFe), which creates a sensitive, nonhysteretic, linear, stable free layer. Wafer level test structures were measured during the head build process and results for the RIE and IBE processes are compared. Transmission electron micrographs were taken. Undercutting of the electrodes can be seen on the RIE processed heads. Spin-stand data for the read heads were compared and the RIE processed heads had a larger low frequency amplitude and sensitivity. Micro-track profiles and tack scans were also taken using the RIE processed heads. The increased process latitude that the RIE process has over the IBE process leads to, on average, overall better performing heads.