A current perpendicular to plane (CPP) magnetoresistive sensor having a
current path defined by first and second overlying insulation layers
between which an electrically conductive lead makes content with a
surface of the sensor stack. The current path being narrower than the
width of the sensor stack allows the outer edges of the sensor stack to
be moved outside of the active area of the sensor. This results in a
sensor that is unaffected by damage at outer edges of the sensor layers.
The sensor stack includes a free layer that is biased by direct exchange
coupling with a layer of antiferromagnetic material (AFM layer). The
strength of the exchange field can be controlled by adding Cr to the AFM
material to ensure that the exchange field is sufficiently weak to avoid
pinning the free layer.