The present invention provides an improved current perpendicular to the
plane thin film read head device and method of fabrication. With the
present invention, the lower lead is formed to inhibit accumulation of
redeposited lead material on CPP sensor element side walls during CPP
sensor formation. In the preferred embodiment, the upper portion of the
lower lead, which normally is etched during sensor element formation, is
formed of a low sputter yield material to reduce redeposition flux to the
sensor side walls. It is also preferred to form the upper portion of a
material that also has a low value for the ratio of its sputter yield at
the lead milling angle-to-its sputter yield at the side wall milling angle
to inhibit redeposition accumulation on the side wall. It is preferred to
clad conventional lead material with a low sputter yield ratio, low
resistivity material, to inhibit side wall redeposition accumulation while
also providing a low resistance lower lead. The underlying lead material
may be formed of conventional low resistance lead materials with a
cladding of a refractory metal, such as tantalum, titanium, tungsten,
molybdenum, zirconium, vanadium, niobium, their alloys, or the like. The
improved CPP read head of the present invention may be embodied in a data
storage and retrieval apparatus.
