Magnetic recording properties onto nano-imprinted patterned media

Nanoimprint is a promising technique, which allows the replication of nano-objects on a large surface by a low cost and simple process. A Si mould was prepared on an 8 inch diameter wafer by high-resolution e-beam lithography. The reverse image of the pattern was obtained by imprinting a resist at a force of 15 kN. This image is subsequently transferred in Si by reactive ion etching (RIE). The magnetic layers have been deposited by magnetron sputtering after nano-imprint and RIE. Both Co/Pt multilayers and CoPtCrTa exhibit a high out-of-plane anisotropy and the magnetic dots as deposited are single domain and exchange decoupled. The recording performances on the pre-patterned structures have been studied with a quasi-static tester using a high-resolution (~1nm) piezoelectric positioning stage and commercial magnetoresistive (MR) write/read heads. The signal to noise ratio (SNR) has been calculated with respect to the BL.