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Thin-Film Disk Overcoat with Discrete Asperities

IP.com Disclosure Number: IPCOM000113732D
Original Publication Date: 1994-Sep-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Gregory, TA: AUTHOR [+5]

Abstract

Disclosed is a method for texturing or roughening the overcoat layer of a thin film disk. This process results in small discrete asperities. Asperity height, density, and shape are controllable over a wide range for thin-film disk applications. The asperities are formed by masking the disk overcoat with a dispersion of adherent particles, then plasma etching the overcoat, and finally stripping off the particles.

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Thin-Film Disk Overcoat with Discrete Asperities

      Disclosed is a method for texturing or roughening the overcoat
layer of a thin film disk.  This process results in small discrete
asperities.  Asperity height, density, and shape are controllable
over a wide range for thin-film disk applications.  The asperities
are formed by masking the disk overcoat with a dispersion of adherent
particles, then plasma etching the overcoat, and finally stripping
off the particles.

      Disk overcoats produced by thin-film vapor deposition processes
(PVD and CVD), in general, have very little intrinsic roughness.
Overcoats, such as sputtered carbon, typically are a planer layer
which covers the magnetic film on a disk.  To produce asperities in
the overcoat, areas of the overcoat film are protected by a mask and
the unprotected areas are thinned by Reactive Ion Etching (RIE) or
sputter etching.  The mask consists of a random dispersion of small
particles which have been applied to the disk.  The particles could
consist of organic or inorganic materials of the correct size.  These
could form by nucleating out of a solution applied to the overcoat
surface or by application of suspended particles in a volatile
solvent.  Application can be achieved by dipping, spin coating, or
spraying the solution or suspension.  Following application of the
mask, the disk is ion etched to produce the correct asperity heights.
The final step is to remove the mask particles by an appropri...