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Self Aligned, Very Narrow Trackwidth Inductive Thin Film Heads for Very High Track Density

IP.com Disclosure Number: IPCOM000109244D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 3 page(s) / 146K

Publishing Venue

IBM

Related People

Chen, MM: AUTHOR [+4]

Abstract

The devices disclosed are self-aligned, inductive thin film heads with a track width below two microns, enabling a very high track density. Also described is a new process for fabricating such heads which is also compatible with designs such as the merged magnetic recording head. Finally, a method is proposed for reducing the total photoresist thickness necessary to produce these heads.

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Self Aligned, Very Narrow Trackwidth Inductive Thin Film Heads for Very High Track Density

       The devices disclosed are self-aligned, inductive thin
film heads with a track width below two microns, enabling a very high
track density.  Also described is a new process for fabricating such
heads which is also compatible with designs such as the merged
magnetic recording head.  Finally, a method is proposed for reducing
the total photoresist thickness necessary to produce these heads.

      The drive towards higher recording areal density has created
the need for recording heads with high linear resolution and high
track density.  To achieve high track density, a write head must
possess two characteristics: a physical track width under two microns
and minimal side writing effects.  Current fabrication methods have
failed to produce heads meeting such rigid requirements.

      Several approaches have been used in the fabrication of
inductive heads. The conventional frame plating approach patterns the
P1 and P2 pole tips separately.  Alignment requirements result in a
structure where P1 is wider than P2.  This restriction limits the
extendibility of the process for widths below two microns.

      Another method of fabrication is the ion pole trimming process.
This approach patterns the pole tips and gap simultaneously using ion
milling.  A thick resistive layer on the order of 20 microns forms
the milling mask.

      While this method has been used successfully to create track
widths as narrow as 4 microns, its applicability for head widths
under two microns is doubtful.  Furthermore, this process cannot be
used to build device structures such as the merged magnetic recording
(MR) head, where the P1 layer functions as both a first pole for the
write head and a second shield for the read head.

      The proposed fabrication process permits construction of
inductive write heads below two microns, is compatible with
structures such as merged MR heads, and uses a photoresist of only
one third to one half the thickness of those used in ion trimming.
FABRICATION OF INDUCTIVE HEADS

      The process for constructing an inductive read/write head is
similar to the standard frame plating approach.  The P1, head gap,
insulation layers, and coil are fabricated using the conventional
approach. The P1 track width can be several microns larger than P2
since P1 will be trimmed at the P2 level.  The process sequence at
the P2 level follows.
      1)  A thick resist process serves as a plating frame.  The
photoresist must be applied at least one micron thicker than the
thickness of the P2 permalloy plating desired over the yoke.
      2)  A trim mask is next formed by one of two methods. The first
method entails plating P2 with a standard permalloy or high 4piMs
material thick enough to function as a trim mask.
    ...