Ion projection direct structuring for patterning of magnetic media

Abstract

Ion projection facilitates a direct structuring, which Is an attractive potential manufacturing process for patterned storage media. An advantage to this method is that the media roughness remaines unchanged. The feasibility of ion projection direct structuring for processing full disk surfaces was investigated using a next generation lithography projector. Co-Pt multilayer films with strong perpendicular anisotropy were deposited on 1-in glass disks as used in the IBM microdrive and on Si substrates. Concentric tracks including data, as well as head positioning servo structures, were patterned in a single exposure step with 45 keV He+ at a 4 x demagnification. In a second experiment, sub-100-nm magnetic islands were produced using projection at 8.7 x demagnification and visualized by magnetic force microscopy

Methods for preparing patterned media for high-density recording

“…IPDS [26] facilitates a large-area pattering process. It is a non-contact process, which preserve the as-grown surface structures.…”

“…The ion energy at the mask is lower than the ion energy at the Co/Pt layer, and moreover the medium is at a significant distance from the masks. Circular tracks of 17 mm in diameter containing data and servo structures were structured [26].…”

Magnetic Tailoring of Domains in NiFe/Au/Co/Au Multilayers by He Ion Bombardment through Nanospheres

“…As a result of intermixing at the interfaces the perpendicular anisotropy decreases with increasing ion dose and for large fluence transforms to easy-plane anisotropy [4,6]. Magnetic patterning in nanoscale can be realized by focused ion beam [7], or by bombardment through stencil [8] or lithographic masks [4]. In this contribution we demonstrate that large area magnetic patterning in the nanoscale can be realized by 10 keV He ion bombardment of NiFe/Au/Co/Au multilayers through a single layer of polystyrene (latex) nanospheres arranged in a regular lattice.…”

Magnetic lithography for servowriting applications using flexible magnetic masks nanofabricated on plastic substrates

“…Since magnetic media disks may have imperfect flatness and particle contamination, using a flexible magnetic mask is key to compliant contact to the magnetic media. ML process with flexible magnetic mask works with any type of conventional magnetic media, in contrast to media with pre-embossed information (Tanaka et al 1994 ), or patterned media (Terris et al1999;Dietzel et al 2002), where each magnetic disk has to be modified by stamping or ion beam patterning. In addition, the ML process described here uses a flexible magnetic mask, in contrast to rigid silicon masters described in other studies (Saito et al 2002).…”