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Process Application for the Production of Permalloy Structures in Thin Film Magnetic Heads

IP.com Disclosure Number: IPCOM000117843D
Original Publication Date: 1996-Jun-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 4 page(s) / 84K

Publishing Venue

IBM

Related People

Thiele, M: AUTHOR

Abstract

Thin film inductive and magnetoresistive heads require a tight control of written bit patterns in hard disk drives. This is translated into the so-called P2 track width, which is the lateral dimension of the second pole piece near the write gap.

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Process Application for the Production of Permalloy Structures in
Thin Film Magnetic Heads

      Thin film inductive and magnetoresistive heads require a tight
control of written bit patterns in hard disk drives.  This is
translated into the so-called P2 track width, which is the lateral
dimension of the second pole piece near the write gap.

      This second pole piece is currently plated on 1-3 layers of
copper coils which are embedded in hard baked photo resist layers.  A
positive photo resist is then spun onto a NiFe seed layer as a
plating base.  The resist cannot equalize the topology and forms
uneven thickness distribution over a single device.

      The crucial P2 track width has the highest resist thickness of
all parts of the P2 structure.  Precise control of the track width
after plating requires a very precise photolithography and
measurement technique.  The present process suffers from several
deficiencies.

      Therefore, it is proposed that, instead of using one single
step to create the upper pole structure, it should be done in two
phases, thereby performing the following process steps (Fig. 1):
  o  Produce the P1 structure as usual,
  o  Provide an insulation layer C1 to define zero TH which is the
      point where the P2 structure first touches the inductive gap
      (Fig. 2),
  o  Form the critical P2 structure which has little topology at this
      stage and full film frame plating,
  o  Etch sacrificial perma...