AVS 46th International Symposium
    Magnetic Interfaces and Nanostructures Technical Group Tuesday Sessions
       Session MI+VM+AS-TuM

Paper MI+VM+AS-TuM2
Ion Beam Patterning of Magnetic Recording Media With a Stencil Mask

Tuesday, October 26, 1999, 8:40 am, Room 618/619

Session: Magnetic Recording: Media
Presenter: B.D. Terris, IBM Almaden Research Center
Authors: B.D. Terris, IBM Almaden Research Center
L. Folks, IBM Almaden Research Center
D. Weller, IBM Almaden Research Center
J.E.E. Baglin, IBM Almaden Research Center
A.J. Kellock, IBM Almaden Research Center
H. Rothuizen, IBM Zurich Research Lab
P. Vettiger, IBM Zurich Research Lab
Correspondent: Click to Email
In conventional scaling of magnetic recording media, the grain size is reduced as the bit density is increased, while the number of grains per bit is held approximately constant to maintain signal to noise levels. This scaling approach, however, will reach a fundamental limit when the grain sizes become so small that they are subject to reversal due to thermal excitation on time scales of less than the required data retention time. One approach to circumventing this thermal limit is to create magnetic bits that behave as single magnetic entities, e.g. either single domains or a collection of strongly coupled grains, rather than the hundreds of weakly coupled grains per bit found in conventional granular recording media. In one approach to patterned media, ion beam irradiation is used to locally alter the magnetic properties of thin Co/Pt multilayer films.@footnote 1@ With sufficient ion dose, the easy axis of magnetization is rotated from out-of-plane to in-plane. We have used this process in conjunction with a silicon stencil mask having 1 micrometer diameter holes to pattern regularly spaced micrometer-sized regions of magnetically altered material over areas of a square millimeter. The nature of these magnetic structures has been investigated by magnetic force microscopy. The technique is demonstrated with mask-sample spacing as large as 0.5 mm. In addition, smaller regions of magnetic contrast, down to 100 nm, were created by using two masks with partially overlapping micrometer holes. Unlike other patterning techniques, this approach is non-contact and does not require post-processing to clean the disk, both potential manufacturing advantages. @FootnoteText@ @footnote 1@ C. Chappert et al., Science 280,1919(1998).