A method for fabricating a stitched CPP synthetic spin-valve sensor with
in-stack stabilization of its free layer. The method can also be applied
to the formation of a stitched tunneling magnetoresistive sensor. The
free layer is strongly stabilized by magnetostatic coupling through the
use of a longitudinal biasing formation that includes a ferromagnetic
layer, denoted LBL, within the pillar portion of the sensor and a
synthetic exchange coupled tri-layer within the stitched portion of the
sensor. The tri-layer consists of two ferromagnetic layers, FM1 and FM2
separated by a coupling layer and magnetized longitudinally in
antiparallel directions. A criterion for the magnetic thicknesses of the
layers: [t(LBL)+t(FM1)]/t(FM2)=70/90 angstroms of CoFe insures a strong
exchange coupling. The magnetization of the tri-layer is done in a low
field anneal that does not disturb the previous magnetization of the
ferromagnetic free layer.