Ion projection printing for patterning of magnetic media

Abstract

A patterned storage media featuring independent single magnetic domain bit cells would allow one to further postpone the limitation of superparamagnetism. Ion irradiation allows the modification of the magnetic properties of Co/Pt multilayers and patterning of magnetic properties can be achieved by irradiation through contact stencil masks. Ion projection printing facilitates a resistless structuring which is attractive as a potential manufacturing process for future magnetic storage media. Complex patterns (e.g. in rotational symmetry) in the stencil mask can be transferred into the magnetic medium at a given demagnification factor (4-10 times) which reduces the requirements for the stencil mask process. Co/Pt multilayer media with perpendicular anisotropy grown on Si substrates as well as 1'' glass disks have been used. The feasibility of ion projection printing for full disk surface processing was investigated using the process development projector in Vienna. Concentric tracks including data patterns as well as head positioning servo informations was patterned onto a 1'' glass disk substrate as used in the IBM microdrive™.