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

A method for forming a magnetoresistive (MR) sensor element comprising:

• providing a substrate;
• forming over the substrate a first magnetoresistive (MR) layer;
• forming contacting the first magnetoresistive (MR) layer a magnetically biased first magnetic bias layer, the magnetically biased first magnetic bias layer being biased in a first magnetic bias direction with a first magnetic bias field strength;
• forming separated from the first magnetoresistive (MR) layer by a spacer layer a second magnetoresistive (MR) layer;
• forming contacting the second magnetoresistive (MR) layer a magnetically un-biased second magnetic bias layer;
• biasing 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;
• and
• annealing 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:
• 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 magnetic bias field strength greater than the partially demagnetized first magnetic bias field strength;
• and
• 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.

A method for forming an anti-parallel magnetically biased dual stripe magnetoresistive (DSMR) sensor element comprising:

• providing a substrate;
• forming over the substrate a patterned first magnetoresistive (MR) layer;
• forming contacting a pair of opposite ends of the patterned first magnetoresistive (MR) layer a pair of magnetically biased patterned first longitudinal magnetic bias layers which defines a first trackwidth of the patterned first magnetoresistive (MR) layer, the pair of magnetically biased patterned first longitudinal magnetic bias layers being biased with a first magnetic bias field strength in a first longitudinal magnetic bias direction substantially parallel with an axis of the patterned first magnetoresistive (MR) layer which separates the pair of patterned first longitudinal magnetic bias layers;
• forming separated from the patterned first magnetoresistive (MR) layer by a non-magnetic spacer layer a patterned second magnetoresistive layer;
• forming contacting a pair of opposite ends of the patterned second magnetoresistive (MR) layer a pair of magnetically un-biased patterned second longitudinal magnetic bias layers which defines a second trackwidth of the patterned second magnetoresistive (MR) layer;
• biasing 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 pair of magnetically un-biased patterned second longitudinal magnetic bias layers to form a pair of magnetically biased patterned second longitudinal magnetic bias layers having a second magnetic bias field strength in a second magnetic bias direction anti-parallel to the first magnetic bias direction while simultaneously partially demagnetizing the pair of magnetically biased patterned first longitudinal magnetic bias layers to provide a pair of partially demagnetized magnetically biased patterned first longitudinal magnetic bias layers having a partially demagnetized first magnetic bias field strength less than the first magnetic bias field strength;
• and
• annealing thermally through use of a second thermal annealing method employing a second thermal annealing temperature and a second thermal annealing exposure time without a second magnetic bias field:
• the pair of partially demagnetized magnetically biased patterned first longitudinal magnetic bias layers to form a pair of remagnetized partially demagnetized patterned first longitudinal magnetic bias layers having a remagnetized partially demagnetized first magnetic bias field strength greater than the partially demagnetized first magnetic bias field strength;
• and
• the pair of magnetically biased patterned second longitudinal magnetic bias layers to form a pair of further magnetic biased patterned second longitudinal magnetic bias layers having a further magnetized second magnetic bias field strength greater than the second magnetic bias field strength.