Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Fabrication of Thin Film Magnetic Disks Without Orientation Ratio

IP.com Disclosure Number: IPCOM000102289D
Original Publication Date: 1990-Nov-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 2 page(s) / 78K

Publishing Venue

IBM

Related People

Edmonson, DA: AUTHOR [+4]

Abstract

Disclosed is a process for the fabrication of magnetic thin film storage disks with an orientation ratio of one and lower squareness in the circumferential direction than obtained by current fabrication techniques.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Fabrication of Thin Film Magnetic Disks Without Orientation Ratio

       Disclosed is a process for the fabrication of magnetic
thin film storage disks with an orientation ratio of one and lower
squareness in the circumferential direction than obtained by current
fabrication techniques.

      In the production of longitudinal magnetic thin film disks,
circumferential texturing of the NiP substrate is necessary for good
mechanical performance, but it can result in the formation of an
orientation ratio (OR) > 1 in the magnetic film.  (The OR is defined
as the ratio of remanent magnetization in the circumferential
direction to that in the radial direction.)  The formation of OR > 1
(which is also associated with a very high squareness in the
circumferential direction) was found, by the authors, to be due the
combination of <11.0> crystallographic preferred orientation in the
magnetic film and the texture (parallel circumferential scratches) of
the substrate [*].  The absence of either will result in OR = 1.  The
formation of OR > 1 in thin film disks can cause such undesirable
effects as non-uniformity of OR, very high coercive squareness in the
circumferential direction and high soft error rate. Thus it is
desirable to fabricate thin film disks with an OR = 1 to provide
lower squareness in the circumferential direction and constant OR
around the disk.

      The use of an appropriate sub-underlayer has been shown to
produce disks with OR = 1 and decreased coercive squareness in the
circumferential direction.  Si and S...