Browse Prior Art Database

ABS Overcoat Protection Process

IP.com Disclosure Number: IPCOM000108891D
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 1 page(s) / 52K

Publishing Venue

IBM

Related People

Fontana, RE: AUTHOR [+2]

Abstract

Disclosed is a process for preventing erosion of elements in magnetic recording (MR) heads during the fabrication process. A protective overcoat is applied to the air bearing surface (ABS) prior to etching.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 74% of the total text.

ABS Overcoat Protection Process

      Disclosed is a process for preventing erosion of elements in
magnetic recording (MR) heads during the fabrication process.  A
protective overcoat is applied to the air bearing surface (ABS) prior
to etching.

      Reactive ion etching (RIE) is used to define the ABS rails.
However, after RIE a dramatic change is observed in the MR resistive
element.  This phenomenon has been attributed to erosion of the
magnesium iron (MnFe) layer used to stabilize Barkausen noise in MR
read head sensors.

      Resist delamination and cracking during RIE, and the resist
clean step after RIE create a highly acidic environment and
subsequent erosion of the MnFe.  One approach to this problem is to
produce a less corrosive MnFe layer by alloying it with passivating
materials like chromium.  While addition of such dopants improves
corrosion resistance, it also reduces the exchange field when coupled
to the MR layer.  Consequently, doping is not a viable solution.

      The proposed solution is to apply an overcoat of noncorrosive
material, such as sputtered alumina, to the ABS before RIE.  The rows
of sliders are then bonded to a carrier and a photoresist mask is
applied.  After the RIE process, the resist is removed and the rows
are debonded from the carrier.  These rows can then be parted into
individual sliders and tested with the protective overcoat still
present on the ABS.

      Overcoats with a thickness under one micr...