Nano-dot and -pit arrays with a pitch of 25 nm × 25 nm fabricated by EB drawing, RIE and nano-imprinting for 1 Tb/in2 storage

The possibility of forming very fine pits or dots with a pitch of less than 25 nm was researched using electron beam (EB) drawing, reactive ion etching (RIE), and nano-imprinting for the future lithographic production of patterned media. We were able to fabricate ultrahighly packed dot arrays with a dot diameter of less than 15 nm and a dot pitch of 25 nm × 25 nm in negative calixarene resist using EB drawing. We also formed Si dot arrays patterns by CF4-RIE. Furthermore, pit arrays were formed in polymer film through nano-imprinting by the photo-polymer method using a Si dot arrays pattern as the master mold. We demonstrated that the EB-drawn dot arrays resist pattern is very suitable for the fabrication of Si dot arrays and pit arrays with a pitch of 25 nm × 25 nm in this polymer, which corresponds to a storage density of about 1 Tb/in2 in patterned media. The Si dot and pit diameters were less than 10 nm.