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An Improved Laminated Media for High Coercivity

IP.com Disclosure Number: IPCOM000108428D
Original Publication Date: 1992-May-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 1 page(s) / 44K

Publishing Venue

IBM

Related People

Ahlert, RH: AUTHOR [+3]

Abstract

Lamination of thin film Co-Alloy media has been shown to improve the signal-to-noise ratio by reducing the media noise significantly. However, lamination of the media can cause a decrease in the coercivity. The magnitude of the coercivity loss increases with increasing lamination. The usual sputtering conditions for lamination include low temperature deposition and grounded substrates during sputtering. These conditions lead to low surface mobility during deposition and are typical of sputter processes in passby sputter systems for disk production. In our process, we show that conditions that produce high surface mobility (high substrate temperature and substrate bias during deposition) produce a laminated media with high coercivity.

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An Improved Laminated Media for High Coercivity

      Lamination of thin film Co-Alloy media has been shown to
improve the signal-to-noise ratio by reducing the media noise
significantly.  However, lamination of the media can cause a decrease
in the coercivity.  The magnitude of the coercivity loss increases
with increasing lamination.  The usual sputtering conditions for
lamination include low temperature deposition and grounded substrates
during sputtering.  These conditions lead to low surface mobility
during deposition and are typical of sputter processes in passby
sputter systems for disk production.  In our process, we show that
conditions that produce high surface mobility (high substrate
temperature and substrate bias during deposition) produce a laminated
media with high coercivity. To demonstrate the new process we
fabricated a two-layer lamination media (Si substrate/150 A CoPtCr/50
A CrV/150 A CoPtCr) using both the control process (room temperature
deposition and grounded substrates) versus proposed processes using
high temperature and bias.  The coercivity of the control was 1325
Oe.  Increasing the deposition temperature to 150~C increased the
coercivity of the two-layer media to 1650 Oe (ground substrate).  The
coercivity of the two-layer media was further increased to 1800 Oe by
using the 150~C deposition temperature and adding a substrate bias of
150 Volts during sputtering.

      Experiments have shown that deposition temperature is an
ef...