Small track width MR sensors stabilized with NiMn

Small track width magnetoresistive sensors, stabilized with NiMn exchange tabs were fabricated. Two configurations were investigated: one with the NiMn on top and the other with the NiMn at the bottom. Both types of structures were found to be effectively stabilized by the antiferromagnetic NiMn. In order to obtain the desired properties of the NiMn/NiFe exchange couple, a long, high temperature anneal needs to be done. With the second configuration (NiMn at the bottom), the anneal is done before the deposition of the NiFe sensor. This configuration could be extended to spin-valves which are temperature sensitive, and since the anneal is done before the deposition of the NiFe, the sensor material is not subject to the high temperature anneal. The two configurations require different fabrication steps which are described in this paper. The stabilizing properties of NiMn are also compared with NiO