Nanoimprint Mold for 2.5 Tbit/in.² Directed Self-Assembly Bit Patterned Media with Phase Servo Pattern

We demonstrate the mold fabrication and replication process for the production of 0.8 and 2.5 Tbit/in. 2 directed self-assembly bit patterned media (DSA-BPM). These devices are fabricated with 33 and 17 nm dot pitch patterns using the microphase segregation structure of polystyrene–poly(dimethylsiloxane) as an etching mask template. The self-assembled dot arrays are simultaneously ordered on both the circular tracks for the data area and the arbitrary marks for the servo area by DSA using groove guides. We fabricated the Si mold with dot pillars of 19.3 nm height for the 2.5 Tbit/in. 2 DSA-BPM from the poly(dimethylsiloxane) dot mask. We also demonstrated the nickel mold replication of the 0.8 Tbit/in. 2 DSA-BPM by electroforming from the Si mold.