Fabrication and wafer testing of barber-pole and exchange-biased narrow-track MR sensors

We have designed, fabricated and tested 10μm × 15μm barber-pole biased unshielded MR sensors. Results show that strong domain activities, inherent in these small elements, produce noisy MR responses without any observable biasing effects. Furthermore, we found that these domains, caused by magnetostatic effects, can be suppressed by applying an adequate longitudinal bias field. These findings lead to the fabrication of MR sensors with longitudinal exchange-biasing and transverse barber-pole biasing. These sensors produce quiet and strongly biased MR responses.