Fine pit pattern formation by EB-writing for a high density optical recording

Abstract

Possibility of fine pattern formation for an optical recording with a high recording density is researched using a conventional electro–optical system. Then, we checked whether conventional optics or near-field optics can read them out for high density recording. The conventional optics in a laser scanning optical microscope with a blue laser (a wavelength of 405 nm) and a high NA (numerical aperture) of 0.95 or 1.4 was used. The EB drawing technique provides patterns with a minimum size of 30 nm×100 nm. However, the advanced optics reads out fine pattern with a minimum size of 160 nm×320 nm using an NA of 0.95 and a wave length of 405 nm. We conclude that we have to develop multilevel memory technology and near-field optics to achieve 100 Gb/in 2.