Nanoimprint process for 2.5Tb/in2 bit patterned media fabricated byself-assembling method

摘要

Bit patterned media (BPM) is a promising candidate for high-density magnetic recording media beyond 2.5 Tb/in~2. To realize such a high-density BPM, directed self-assembling (DSA) technology is a possible solution. On the other hand, from the viewpoint of low-cost production, nanoimprint lithography is a promising process for the mass-production of such a high-density BPM. We examine the replication of the BPM etching mask by UV nanoimprint process. At first, the BPM silicon master mold consisting of servo pattern with dot array is made by the DSA method using PS-PDMS. For the 30-nm pitch corresponding to the density of 2.5 Tb/in~2, the nickel stamper is replicated from the silicon master mold by electroplating. The etching mask is transcribed by the UV nanoimprint process with the transparent mold replicated from the nickel mother stamper. On the other hand, as for the DSA-BPM pattern of 17-nm pitch corresponding to the density of 2.5 Tb/in~2, we adopt an alternative process and confirm the replication possibility.