Fabrication of 10-nm-Order Block Copolymer Self-Assembled Nanodots for High-Density Magnetic Recording

In this work, we investigated the fabrication of 10-nm-order block copolymer self-assembled nanodots using high-etching-selectivity polystyrene-poly(dimethylsiloxane) (PS-PDMS) block copolymers for high-density storage devices. We adopted PS-PDMS polymers with two different molecular weights of 13,500-4,000 and 11,700-2,900. With decreasing molecular weight, the nanodot size decreased from 12 to 10 nm, and the pitch correspondingly decreased from 22 to 20 nm. The PS-PDMS film thickness is the critical-factor to determine whether nanodot arrays can form on a large area or not. It was demonstrated that the thicknesses of 36 and 33nm were optimal for the PS-PDMS polymers of 13,500-4,000 and 11,700-2,900, respectively. The limitation in the selection of PS-PDMS to form a smaller size of self-assembled nanodots is also predicted. This work promises to open way toward 1.6 Tbit/in.(2) storage device with cheap cost production. (C) 2011 The Japan Society of Applied Physics