Formation of very fine pit and dot arrays using EB writing for ultrahigh density storage toward 1 Tb/in2

Fabrication of ultrahigh packed pit and dot arrays have been studied using conventional electron beam (EB) writing, and positive and negative EB resists, ZEP520 and calixarene, respectively. Using fine electron beam with high probe current and very thinner resists, we demonstrate that the negative resist has a potential to achieve an ultrahigh density storage with both bit pitch (BP) and track pitch (TP) of <30 nm and a dot diameter of <15 nm, although the positive resist has a limitation at a BP of 60nm and a TP of 40nm. This dot array opens a way toward >1 trillion bits per inch²(Tb/in²) storage technology.