A single-domain 26 nm-pitch pattern for the X-Y quantum dot media template

Guided self-assembly patterns for a template of the X-Y type quantum dot storage media were investigated. By adjusting the length of polystyrene-poly methyl methacrylate (PS-PMMA) block copolymer chains and relative volume fractions, the pitch of the phase-separated hexagonal-packing PMMA dots structure was 26 nm. This corresponds to the recording density of 1.1 tera bit per square inch. Phase diagram with respect to the polymer size and the fraction ratio is presented. Guide structures for aligning the self-ordering patterns were prepared using the nanoimprint process. Equilateral triangle guides were found to be suitable for the hexagonal-packed self-ordering structure. A single-domain hexagonal-packing structure was formed with each crystal axis parallel to the side of the triangle.