A differential current-perpendicular-to-the-plane (CPP) giant magnetoresistive
(GMR) sensor is provided having nonmagnetic high conductivity leads to achieve
low lead resistance. The differential CPP GMR sensor comprises a first spin valve
(SV) sensor, a second SV sensor and a metal gap layer disposed between the first
and the second SV sensors. Because of the differential operation of the CPP GMR
sensor of this invention, there is no need for shield layers to screen the sensor
from stray magnetic fields. The shield layers are replaced with thick nonmagnetic
lead layers having high conductivity to reduce the lead resistance of the sensor.
Suitable materials for forming the leads include tungsten (W), gold (Au), rhodium
(Rh), copper (Cu) and tantalum (Ta) because of their conductivity properties and
because they are robust with respect to corrosion and smearing.
