Increased Magneto Resistive Head Temperature Stability
Original Publication Date: 1996-Mar-01
Included in the Prior Art Database: 2005-Mar-31
Publishing Venue
IBM
Related People
Eickelmann, H-J: AUTHOR [+4]
Abstract
This article describes a method to increase the temperature stability of a Magneto Resistive (MR) head on wafer level.
Increased Magneto Resistive Head Temperature Stability
This article
describes a method to increase the temperature
stability of a Magneto Resistive (MR) head on wafer level.
Normally, MR
head products are tested before implementation
using temperatures of about 200-220 degrees C and more for
approximately 24 hours to simulate that the heads still operate even
under elevated temperatures.
However, it
was shown that many of the heads fail the test at a
temperature level of 220 degrees C showing ABS delamination. This,
in turn, affects the head operation and leads to a non functional
file.
It could be
shown that delamination occurs due to the amount
of redeposition at the side of the permalloy 1 layer. Redeposition
is originated during MR head manufacture by several sputter-etch
processes. It is accumulated at the side
wall because of the
negative wall angle present. This
negative wall angle avoids a
redeposition cleaning of the various seedlayers during sputter-etch.
Redeposition at the sidewall of P1, which is mostly affected, is the
cause for delamination because of its large amount. During the
temperature cycle this redeposition oxidizes.
A channel to the
isolation stack is formed and this connection between the air bearing
surface, and the element stack leads to a physical change of the
stack and finally to delamination.
This
reliability problem can be solved by avoiding redeposition
accumulation at the sid...