Method for fabricating a non-parallel magnetically biased multiple magnetoresistive (MR) layer magnetoresistive (MR) sensor element

摘要

Within a method for forming a magnetoresistive (MR) sensor element there is first provided a substrate. There is then formed over the substrate a first magnetoresistive (MR) layer having formed contacting the first magnetoresistive (MR) layer a magnetically biased first magnetic bias layer biased in a first magnetic bias direction with a first magnetic bias field strength. There is also formed separated from the first magnetoresistive (MR) layer by a spacer layer a second magnetoresistive (MR) layer having formed contacting the second magnetoresistive (MR) layer a magnetically un-biased second magnetic bias layer. There is then biased through use of a first thermal annealing method employing a first thermal annealing temperature, a first thermal annealing exposure time and a first extrinsic magnetic bias field the magnetically un-biased second magnetic bias layer to form a magnetically biased second magnetic bias layer having a second magnetic bias field strength in a second magnetic bias direction non-parallel to the first magnetic bias direction while simultaneously partially demagnetizing the magnetically biased first magnetic bias layer to provide a partially demagnetized magnetically biased first magnetic bias layer having a partially demagnetized first magnetic bias field strength less than the first magnetic bias field strength. Finally, there is then annealed thermally through use of a second thermal annealing employing a second thermal annealing temperature and a second thermal annealing exposure time without a second magnetic bias field: (1) the partially demagnetized magnetically biased first magnetic bias layer to form a remagnetized partially demagnetized first magnetic bias layer having a remagnetized partially demagnetized first netic bias field strength greater than the partially demagnetized first magnetic bias field strength; and (2) the magnetically biased second magnetic bias layer to form a further magnetically biased second magnetic bias layer having a further magnetized second magnetic bias field strength greater than the second magnetic bias field strength.