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The Hitachi San Jose Research Center maintains
an advanced processing laboratory to develop thin
film processing techniques required to create
advanced read/write heads as well as special test
structures for basic research in magnetic recording
to extend areal density and internal data rate
of the thin film head. These processing activities
are conducted in a 5000 sq. ft. class 10 clean
room facility with capabilities for electroplating,
fine line photolithography, reactive ion etching,
ion milling, chemical-mechanical planarization,
thin film metal and insulator depositions, and
wet etching. In the past 10 years, this laboratory
has developed the processing concepts and fabricated
the head structures associated with IBM's MR and
GMR demonstrations up to the latest areal densities.
Using this facility the advanced processing group
was responsible for the fabrication of the industry's
first GMR spin valve read sensor and this design
was the basis for a head which shipped in a 1997
IBM disk drive.
Currently, advanced photolithographic processes
are being developed to create a narrow trackwidth
inductive head to support 100 Gbits/in2 . Additionally,
the electroplating of high magnetic moment materials
for the write head pole to provide adequate field
strength to write at this density in a key on
going process development. The investigation of
novel head structures beyond GMR is a key responsibility
at San Jose Research Center, and the fabrication
and evaluation of magnetic tunnel valve sensors
is one area of investigation. The process design
for fabrication of novel write head structures
with low inductances is an additional area. The
laboratory also supports research into advanced
materials by fabrication of test structures to
evaluate novel insulator compositions, to evaluate
new longitudinal bias schemes, and to evaluate
test structures for advanced head designs as required
by the recording physics group.
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