AVS 47th International Symposium
    Magnetic Interfaces and Nanostructures Friday Sessions
       Session MI-FrM

Invited Paper MI-FrM1
Focused Ion Beam Patterning of Magnetic Films

Friday, October 6, 2000, 8:20 am, Room 206

Session: Magnetic Recording: Media and Heads
Presenter: B.D. Terris, IBM Almaden Research Center
Authors: B.D. Terris, IBM Almaden Research Center
C.T. Rettner, IBM Almaden Research Center
M.E. Best, IBM Almaden Research Center
Correspondent: Click to Email
In the future it may be necessary to pattern magnetic recording media to achieve data densities beyond 100 Gb/sq. in. The required patterning should have minimal cost and leave a surface suitable for flying a recording head. One promising approach to achieving such patterning is to use ion beams to directly modify the magnetic properties of thin films. It has been shown previously that Co/Pt multilayers can be modified magnetically by exposure to a uniform beam of ions (eg. He+, N+), where the easy magnetization axis of the film is rotated from out-of-plane in the as grown film to in-plane in the irradiated film. Local areas of in-plane magnetization can thus be produced by exposing the film through masks.@footnote 1-3@ We have now demonstrated that such films can be also be patterned using a focused ion beam (FIB) of Ga+ ions without the use of a mask. In addition to patterning the multilayer Co/Pt films by easy axis rotation, films of granular CoPtCr have been patterned by removal of the magnetic film by Ga+ milling. The remanent magnetization state of square islands ranging from 80 nm to 230 nm in size was studied by MFM and the smallest islands appear to be single domain. Remanent hysteresis loops generated from MFM data show that the coercivity of the CoPtCr films is unchanged by the FIB patterning, in contrast to the FIB patterning of Co/Pt multilayers where the coercivity decreases with increasing ion dose and decreasing island size. @FootnoteText@ @footnote 1@C. Chappert et al., Science 280, 1919 (1998) @footnote 2@B. D. Terris et al., Appl. Phys. Lett.75, 403 (1999) @footnote 3@T. Devolder et al., Appl. Phys. Lett. 74, 3383 (1999)