Magnetic Lithography Using Flexible Magnetic Masks: Applications to Servowriting

Abstract

Magnetic lithography (qualitatively analogous to optical lithography) is a process that transfers information from a patterned magnetic mask (analog of optical photomask) to magnetic media (analog of photoresist). The mask consists of patterned soft magnetic material (FeNiCo, FeCo) deposited on a thin flexible substrate. A flexible magnetic mask is considered a key element for achieving intimate contact between mask and the media. When uniformly magnetized media is brought into contact with the flexible magnetic mask, an externally applied magnetic field selectively changes the magnetic orientation in the areas not contacted by the soft magnetic material. Samples of submicron patterned FeCo and FeNiCo flexible magnetic masks have been fabricated and magnetic transition patterns successfully transferred to hard disk CrCo-based magnetic media. The authors report on the magnetics of the pattern transfer, fabrication of magnetic masks on flexible plastic substrates, magnetic force microscopy images of the magnetic transition patterns, and disk spinstand tests.