Fabrication of Discrete Track Media by Cr Ion Implantation

Discrete track media were successfully fabricated by Cr ion implantation. The saturation magnetization of the CoCrPt-SiO₂ perpendicular recording layer was decreased down to 6% by implanting Cr ions with a dosage of 1 × 10¹⁷ ions/cm and an ion energy of 20 keV. A resist mask with a discrete track pattern was prepared by e-beam lithography and the pattern was transferred to the recording layer by Cr ion implantation. A clear magnetic contrast of the tracks was observed and the average surface roughness was maintained less than 1 nm. A clear servo signal was obtained by spin-stand measurement using a flying head. Feasibility of discrete track media fabrication by Cr ion implantation was confirmed.