63-nm-pitch pit pattern fabricated on polycarbonate surface by direct nanoprinting

Nanoscale pit patterns were fond on a polycarbonate substrate surface, whic h is commonly used for compact disks, by direct nanoprinting. Pit patterns with 100, 70, and 63nm pitches were imprinted on the disk surface using a S iC mold with a nanostructure projection pattern. These pitches correspond t o the the storage densities of 75, 150, and 185 Gbit/in(2). We evaluated th e mold-holding temperature and press-pressure dependence of the pit depth. We also evaluated the press-time dependence. With a relatively low press-pr essure of 1.3 kg/mm(2) at room temperature, a 100-nm-Ditch pit pattern with a pit depth of over 40 nm was fabricated using a mold with a projection he ight of 60 nm.